#pragma once

// Python headers must be included before any system headers, since
// they define _POSIX_C_SOURCE
#include <Python.h>

#include <algorithm>
#include <array>
#include <cstdint>  // <cstdint> requires c++11 support
#include <functional>
#include <iostream>
#include <map>
#include <numeric>
#include <stdexcept>
#include <vector>

#ifndef WITHOUT_NUMPY
#define NPY_NO_DEPRECATED_API NPY_1_7_API_VERSION
#include <numpy/arrayobject.h>

#ifdef WITH_OPENCV
#include <opencv2/opencv.hpp>
#endif  // WITH_OPENCV

/*
 * A bunch of constants were removed in OpenCV 4 in favour of enum classes, so
 * define the ones we need here.
 */
#if CV_MAJOR_VERSION > 3
#define CV_BGR2RGB cv::COLOR_BGR2RGB
#define CV_BGRA2RGBA cv::COLOR_BGRA2RGBA
#endif
#endif  // WITHOUT_NUMPY

#if PY_MAJOR_VERSION >= 3
#define PyString_FromString PyUnicode_FromString
#define PyInt_FromLong PyLong_FromLong
#define PyString_FromString PyUnicode_FromString
#endif

namespace matplotlibcpp {
namespace detail {

static std::string s_backend;

struct _interpreter {
  PyObject* s_python_function_arrow;
  PyObject* s_python_function_show;
  PyObject* s_python_function_close;
  PyObject* s_python_function_draw;
  PyObject* s_python_function_pause;
  PyObject* s_python_function_save;
  PyObject* s_python_function_figure;
  PyObject* s_python_function_fignum_exists;
  PyObject* s_python_function_plot;
  PyObject* s_python_function_quiver;
  PyObject* s_python_function_contour;
  PyObject* s_python_function_semilogx;
  PyObject* s_python_function_semilogy;
  PyObject* s_python_function_loglog;
  PyObject* s_python_function_fill;
  PyObject* s_python_function_fill_between;
  PyObject* s_python_function_hist;
  PyObject* s_python_function_imshow;
  PyObject* s_python_function_scatter;
  PyObject* s_python_function_boxplot;
  PyObject* s_python_function_subplot;
  PyObject* s_python_function_subplot2grid;
  PyObject* s_python_function_legend;
  PyObject* s_python_function_xlim;
  PyObject* s_python_function_ion;
  PyObject* s_python_function_ginput;
  PyObject* s_python_function_ylim;
  PyObject* s_python_function_title;
  PyObject* s_python_function_axis;
  PyObject* s_python_function_axvline;
  PyObject* s_python_function_axvspan;
  PyObject* s_python_function_xlabel;
  PyObject* s_python_function_ylabel;
  PyObject* s_python_function_gca;
  PyObject* s_python_function_xticks;
  PyObject* s_python_function_yticks;
  PyObject* s_python_function_margins;
  PyObject* s_python_function_tick_params;
  PyObject* s_python_function_grid;
  PyObject* s_python_function_cla;
  PyObject* s_python_function_clf;
  PyObject* s_python_function_errorbar;
  PyObject* s_python_function_annotate;
  PyObject* s_python_function_tight_layout;
  PyObject* s_python_colormap;
  PyObject* s_python_empty_tuple;
  PyObject* s_python_function_stem;
  PyObject* s_python_function_xkcd;
  PyObject* s_python_function_text;
  PyObject* s_python_function_suptitle;
  PyObject* s_python_function_bar;
  PyObject* s_python_function_barh;
  PyObject* s_python_function_colorbar;
  PyObject* s_python_function_subplots_adjust;

  /* For now, _interpreter is implemented as a singleton since its currently not
     possible to have multiple independent embedded python interpreters without
     patching the python source code or starting a separate process for each.
     [1] Furthermore, many python objects expect that they are destructed in the
     same thread as they were constructed. [2] So for advanced usage, a `kill()`
     function is provided so that library users can manually ensure that the
     interpreter is constructed and destroyed within the same thread.

       1:
     http://bytes.com/topic/python/answers/793370-multiple-independent-python-interpreters-c-c-program
       2: https://github.com/lava/matplotlib-cpp/pull/202#issue-436220256
     */

  static _interpreter& get() { return interkeeper(false); }

  static _interpreter& kill() { return interkeeper(true); }

  // Stores the actual singleton object referenced by `get()` and `kill()`.
  static _interpreter& interkeeper(bool should_kill) {
    static _interpreter ctx;
    if (should_kill) ctx.~_interpreter();
    return ctx;
  }

  PyObject* safe_import(PyObject* module, std::string fname) {
    PyObject* fn = PyObject_GetAttrString(module, fname.c_str());

    if (!fn)
      throw std::runtime_error(
          std::string("Couldn't find required function: ") + fname);

    if (!PyFunction_Check(fn))
      throw std::runtime_error(
          fname + std::string(" is unexpectedly not a PyFunction."));

    return fn;
  }

 private:
#ifndef WITHOUT_NUMPY
#if PY_MAJOR_VERSION >= 3

  void* import_numpy() {
    import_array();  // initialize C-API
    return NULL;
  }

#else

  void import_numpy() {
    import_array();  // initialize C-API
  }

#endif
#endif

  _interpreter() {
    // optional but recommended
#if PY_MAJOR_VERSION >= 3
    wchar_t name[] = L"plotting";
#else
    char name[] = "plotting";
#endif
    Py_SetProgramName(name);
    Py_Initialize();

    wchar_t const* dummy_args[] = {
        L"Python",
        NULL};  // const is needed because literals must not be modified
    wchar_t const** argv = dummy_args;
    int argc = sizeof(dummy_args) / sizeof(dummy_args[0]) - 1;
    PySys_SetArgv(argc, const_cast<wchar_t**>(argv));

#ifndef WITHOUT_NUMPY
    import_numpy();  // initialize numpy C-API
#endif

    PyObject* matplotlibname = PyString_FromString("matplotlib");
    PyObject* pyplotname = PyString_FromString("matplotlib.pyplot");
    PyObject* cmname = PyString_FromString("matplotlib.cm");
    PyObject* pylabname = PyString_FromString("pylab");
    if (!pyplotname || !pylabname || !matplotlibname || !cmname) {
      throw std::runtime_error("couldnt create string");
    }

    PyObject* matplotlib = PyImport_Import(matplotlibname);
    Py_DECREF(matplotlibname);
    if (!matplotlib) {
      PyErr_Print();
      throw std::runtime_error("Error loading module matplotlib!");
    }

    // matplotlib.use() must be called *before* pylab, matplotlib.pyplot,
    // or matplotlib.backends is imported for the first time
    if (!s_backend.empty()) {
      PyObject_CallMethod(matplotlib, const_cast<char*>("use"),
                          const_cast<char*>("s"), s_backend.c_str());
    }

    PyObject* pymod = PyImport_Import(pyplotname);
    Py_DECREF(pyplotname);
    if (!pymod) {
      throw std::runtime_error("Error loading module matplotlib.pyplot!");
    }

    s_python_colormap = PyImport_Import(cmname);
    Py_DECREF(cmname);
    if (!s_python_colormap) {
      throw std::runtime_error("Error loading module matplotlib.cm!");
    }

    PyObject* pylabmod = PyImport_Import(pylabname);
    Py_DECREF(pylabname);
    if (!pylabmod) {
      throw std::runtime_error("Error loading module pylab!");
    }

    s_python_function_arrow = safe_import(pymod, "arrow");
    s_python_function_show = safe_import(pymod, "show");
    s_python_function_close = safe_import(pymod, "close");
    s_python_function_draw = safe_import(pymod, "draw");
    s_python_function_pause = safe_import(pymod, "pause");
    s_python_function_figure = safe_import(pymod, "figure");
    s_python_function_fignum_exists = safe_import(pymod, "fignum_exists");
    s_python_function_plot = safe_import(pymod, "plot");
    s_python_function_quiver = safe_import(pymod, "quiver");
    s_python_function_contour = safe_import(pymod, "contour");
    s_python_function_semilogx = safe_import(pymod, "semilogx");
    s_python_function_semilogy = safe_import(pymod, "semilogy");
    s_python_function_loglog = safe_import(pymod, "loglog");
    s_python_function_fill = safe_import(pymod, "fill");
    s_python_function_fill_between = safe_import(pymod, "fill_between");
    s_python_function_hist = safe_import(pymod, "hist");
    s_python_function_scatter = safe_import(pymod, "scatter");
    s_python_function_boxplot = safe_import(pymod, "boxplot");
    s_python_function_subplot = safe_import(pymod, "subplot");
    s_python_function_subplot2grid = safe_import(pymod, "subplot2grid");
    s_python_function_legend = safe_import(pymod, "legend");
    s_python_function_ylim = safe_import(pymod, "ylim");
    s_python_function_title = safe_import(pymod, "title");
    s_python_function_axis = safe_import(pymod, "axis");
    s_python_function_axvline = safe_import(pymod, "axvline");
    s_python_function_axvspan = safe_import(pymod, "axvspan");
    s_python_function_xlabel = safe_import(pymod, "xlabel");
    s_python_function_ylabel = safe_import(pymod, "ylabel");
    s_python_function_gca = safe_import(pymod, "gca");
    s_python_function_xticks = safe_import(pymod, "xticks");
    s_python_function_yticks = safe_import(pymod, "yticks");
    s_python_function_margins = safe_import(pymod, "margins");
    s_python_function_tick_params = safe_import(pymod, "tick_params");
    s_python_function_grid = safe_import(pymod, "grid");
    s_python_function_xlim = safe_import(pymod, "xlim");
    s_python_function_ion = safe_import(pymod, "ion");
    s_python_function_ginput = safe_import(pymod, "ginput");
    s_python_function_save = safe_import(pylabmod, "savefig");
    s_python_function_annotate = safe_import(pymod, "annotate");
    s_python_function_cla = safe_import(pymod, "cla");
    s_python_function_clf = safe_import(pymod, "clf");
    s_python_function_errorbar = safe_import(pymod, "errorbar");
    s_python_function_tight_layout = safe_import(pymod, "tight_layout");
    s_python_function_stem = safe_import(pymod, "stem");
    s_python_function_xkcd = safe_import(pymod, "xkcd");
    s_python_function_text = safe_import(pymod, "text");
    s_python_function_suptitle = safe_import(pymod, "suptitle");
    s_python_function_bar = safe_import(pymod, "bar");
    s_python_function_barh = safe_import(pymod, "barh");
    s_python_function_colorbar = PyObject_GetAttrString(pymod, "colorbar");
    s_python_function_subplots_adjust = safe_import(pymod, "subplots_adjust");
#ifndef WITHOUT_NUMPY
    s_python_function_imshow = safe_import(pymod, "imshow");
#endif
    s_python_empty_tuple = PyTuple_New(0);
  }

  ~_interpreter() { Py_Finalize(); }
};

}  // end namespace detail

/// Select the backend
///
/// **NOTE:** This must be called before the first plot command to have
/// any effect.
///
/// Mainly useful to select the non-interactive 'Agg' backend when running
/// matplotlibcpp in headless mode, for example on a machine with no display.
///
/// See also:
/// https://matplotlib.org/2.0.2/api/matplotlib_configuration_api.html#matplotlib.use
inline void backend(const std::string& name) { detail::s_backend = name; }

inline bool annotate(std::string annotation, double x, double y) {
  detail::_interpreter::get();

  PyObject* xy = PyTuple_New(2);
  PyObject* str = PyString_FromString(annotation.c_str());

  PyTuple_SetItem(xy, 0, PyFloat_FromDouble(x));
  PyTuple_SetItem(xy, 1, PyFloat_FromDouble(y));

  PyObject* kwargs = PyDict_New();
  PyDict_SetItemString(kwargs, "xy", xy);

  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, str);

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_annotate, args, kwargs);

  Py_DECREF(args);
  Py_DECREF(kwargs);

  if (res) Py_DECREF(res);

  return res;
}

namespace detail {

#ifndef WITHOUT_NUMPY
// Type selector for numpy array conversion
template <typename T>
struct select_npy_type {
  const static NPY_TYPES type = NPY_NOTYPE;
};  // Default
template <>
struct select_npy_type<double> {
  const static NPY_TYPES type = NPY_DOUBLE;
};
template <>
struct select_npy_type<float> {
  const static NPY_TYPES type = NPY_FLOAT;
};
template <>
struct select_npy_type<bool> {
  const static NPY_TYPES type = NPY_BOOL;
};
template <>
struct select_npy_type<int8_t> {
  const static NPY_TYPES type = NPY_INT8;
};
template <>
struct select_npy_type<int16_t> {
  const static NPY_TYPES type = NPY_SHORT;
};
template <>
struct select_npy_type<int32_t> {
  const static NPY_TYPES type = NPY_INT;
};
template <>
struct select_npy_type<int64_t> {
  const static NPY_TYPES type = NPY_INT64;
};
template <>
struct select_npy_type<uint8_t> {
  const static NPY_TYPES type = NPY_UINT8;
};
template <>
struct select_npy_type<uint16_t> {
  const static NPY_TYPES type = NPY_USHORT;
};
template <>
struct select_npy_type<uint32_t> {
  const static NPY_TYPES type = NPY_ULONG;
};
template <>
struct select_npy_type<uint64_t> {
  const static NPY_TYPES type = NPY_UINT64;
};

// Sanity checks; comment them out or change the numpy type below if you're
// compiling on a platform where they don't apply static_assert(sizeof(long
// long) == 8); template <> struct select_npy_type<long long> { const static
// NPY_TYPES type = NPY_INT64; }; static_assert(sizeof(unsigned long long) ==
// 8); template <> struct select_npy_type<unsigned long long> { const static
// NPY_TYPES type = NPY_UINT64; };
// TODO: add int, long, etc.

template <typename Numeric>
PyObject* get_array(const std::vector<Numeric>& v) {
  npy_intp vsize = v.size();
  NPY_TYPES type = select_npy_type<Numeric>::type;
  if (type == NPY_NOTYPE) {
    size_t memsize = v.size() * sizeof(double);
    double* dp = static_cast<double*>(::malloc(memsize));
    for (size_t i = 0; i < v.size(); ++i) dp[i] = v[i];
    PyObject* varray = PyArray_SimpleNewFromData(1, &vsize, NPY_DOUBLE, dp);
    PyArray_UpdateFlags(reinterpret_cast<PyArrayObject*>(varray),
                        NPY_ARRAY_OWNDATA);
    return varray;
  }

  PyObject* varray =
      PyArray_SimpleNewFromData(1, &vsize, type, (void*)(v.data()));
  return varray;
}

template <typename Numeric>
PyObject* get_2darray(const std::vector<::std::vector<Numeric>>& v) {
  if (v.size() < 1) throw std::runtime_error("get_2d_array v too small");

  npy_intp vsize[2] = {static_cast<npy_intp>(v.size()),
                       static_cast<npy_intp>(v[0].size())};

  PyArrayObject* varray =
      (PyArrayObject*)PyArray_SimpleNew(2, vsize, NPY_DOUBLE);

  double* vd_begin = static_cast<double*>(PyArray_DATA(varray));

  for (const ::std::vector<Numeric>& v_row : v) {
    if (v_row.size() != static_cast<size_t>(vsize[1]))
      throw std::runtime_error("Missmatched array size");
    std::copy(v_row.begin(), v_row.end(), vd_begin);
    vd_begin += vsize[1];
  }

  return reinterpret_cast<PyObject*>(varray);
}

#else  // fallback if we don't have numpy: copy every element of the given
       // vector

template <typename Numeric>
PyObject* get_array(const std::vector<Numeric>& v) {
  PyObject* list = PyList_New(v.size());
  for (size_t i = 0; i < v.size(); ++i) {
    PyList_SetItem(list, i, PyFloat_FromDouble(v.at(i)));
  }
  return list;
}

#endif  // WITHOUT_NUMPY

// sometimes, for labels and such, we need string arrays
inline PyObject* get_array(const std::vector<std::string>& strings) {
  PyObject* list = PyList_New(strings.size());
  for (std::size_t i = 0; i < strings.size(); ++i) {
    PyList_SetItem(list, i, PyString_FromString(strings[i].c_str()));
  }
  return list;
}

// not all matplotlib need 2d arrays, some prefer lists of lists
template <typename Numeric>
PyObject* get_listlist(const std::vector<std::vector<Numeric>>& ll) {
  PyObject* listlist = PyList_New(ll.size());
  for (std::size_t i = 0; i < ll.size(); ++i) {
    PyList_SetItem(listlist, i, get_array(ll[i]));
  }
  return listlist;
}

}  // namespace detail

/// Plot a line through the given x and y data points..
///
/// See: https://matplotlib.org/3.2.1/api/_as_gen/matplotlib.pyplot.plot.html
template <typename Numeric>
bool plot(const std::vector<Numeric>& x, const std::vector<Numeric>& y,
          const std::map<std::string, std::string>& keywords) {
  assert(x.size() == y.size());

  detail::_interpreter::get();

  // using numpy arrays
  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  // construct positional args
  PyObject* args = PyTuple_New(2);
  PyTuple_SetItem(args, 0, xarray);
  PyTuple_SetItem(args, 1, yarray);

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyString_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_plot, args, kwargs);

  Py_DECREF(args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);

  return res;
}

// TODO - it should be possible to make this work by implementing
// a non-numpy alternative for `detail::get_2darray()`.
#ifndef WITHOUT_NUMPY
template <typename Numeric>
void plot_surface(const std::vector<::std::vector<Numeric>>& x,
                  const std::vector<::std::vector<Numeric>>& y,
                  const std::vector<::std::vector<Numeric>>& z,
                  const std::map<std::string, std::string>& keywords =
                      std::map<std::string, std::string>()) {
  detail::_interpreter::get();

  // We lazily load the modules here the first time this function is called
  // because I'm not sure that we can assume "matplotlib installed" implies
  // "mpl_toolkits installed" on all platforms, and we don't want to require
  // it for people who don't need 3d plots.
  static PyObject *mpl_toolkitsmod = nullptr, *axis3dmod = nullptr;
  if (!mpl_toolkitsmod) {
    detail::_interpreter::get();

    PyObject* mpl_toolkits = PyString_FromString("mpl_toolkits");
    PyObject* axis3d = PyString_FromString("mpl_toolkits.mplot3d");
    if (!mpl_toolkits || !axis3d) {
      throw std::runtime_error("couldnt create string");
    }

    mpl_toolkitsmod = PyImport_Import(mpl_toolkits);
    Py_DECREF(mpl_toolkits);
    if (!mpl_toolkitsmod) {
      throw std::runtime_error("Error loading module mpl_toolkits!");
    }

    axis3dmod = PyImport_Import(axis3d);
    Py_DECREF(axis3d);
    if (!axis3dmod) {
      throw std::runtime_error("Error loading module mpl_toolkits.mplot3d!");
    }
  }

  assert(x.size() == y.size());
  assert(y.size() == z.size());

  // using numpy arrays
  PyObject* xarray = detail::get_2darray(x);
  PyObject* yarray = detail::get_2darray(y);
  PyObject* zarray = detail::get_2darray(z);

  // construct positional args
  PyObject* args = PyTuple_New(3);
  PyTuple_SetItem(args, 0, xarray);
  PyTuple_SetItem(args, 1, yarray);
  PyTuple_SetItem(args, 2, zarray);

  // Build up the kw args.
  PyObject* kwargs = PyDict_New();
  PyDict_SetItemString(kwargs, "rstride", PyInt_FromLong(1));
  PyDict_SetItemString(kwargs, "cstride", PyInt_FromLong(1));

  PyObject* python_colormap_coolwarm = PyObject_GetAttrString(
      detail::_interpreter::get().s_python_colormap, "coolwarm");

  PyDict_SetItemString(kwargs, "cmap", python_colormap_coolwarm);

  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyString_FromString(it->second.c_str()));
  }

  PyObject* fig =
      PyObject_CallObject(detail::_interpreter::get().s_python_function_figure,
                          detail::_interpreter::get().s_python_empty_tuple);
  if (!fig) throw std::runtime_error("Call to figure() failed.");

  PyObject* gca_kwargs = PyDict_New();
  PyDict_SetItemString(gca_kwargs, "projection", PyString_FromString("3d"));

  PyObject* gca = PyObject_GetAttrString(fig, "gca");
  if (!gca) throw std::runtime_error("No gca");
  Py_INCREF(gca);
  PyObject* axis = PyObject_Call(
      gca, detail::_interpreter::get().s_python_empty_tuple, gca_kwargs);

  if (!axis) throw std::runtime_error("No axis");
  Py_INCREF(axis);

  Py_DECREF(gca);
  Py_DECREF(gca_kwargs);

  PyObject* plot_surface = PyObject_GetAttrString(axis, "plot_surface");
  if (!plot_surface) throw std::runtime_error("No surface");
  Py_INCREF(plot_surface);
  PyObject* res = PyObject_Call(plot_surface, args, kwargs);
  if (!res) throw std::runtime_error("failed surface");
  Py_DECREF(plot_surface);

  Py_DECREF(axis);
  Py_DECREF(args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);
}
#endif  // WITHOUT_NUMPY

template <typename Numeric>
void plot3(const std::vector<Numeric>& x, const std::vector<Numeric>& y,
           const std::vector<Numeric>& z,
           const std::map<std::string, std::string>& keywords =
               std::map<std::string, std::string>()) {
  detail::_interpreter::get();

  // Same as with plot_surface: We lazily load the modules here the first time
  // this function is called because I'm not sure that we can assume "matplotlib
  // installed" implies "mpl_toolkits installed" on all platforms, and we don't
  // want to require it for people who don't need 3d plots.
  static PyObject *mpl_toolkitsmod = nullptr, *axis3dmod = nullptr;
  if (!mpl_toolkitsmod) {
    detail::_interpreter::get();

    PyObject* mpl_toolkits = PyString_FromString("mpl_toolkits");
    PyObject* axis3d = PyString_FromString("mpl_toolkits.mplot3d");
    if (!mpl_toolkits || !axis3d) {
      throw std::runtime_error("couldnt create string");
    }

    mpl_toolkitsmod = PyImport_Import(mpl_toolkits);
    Py_DECREF(mpl_toolkits);
    if (!mpl_toolkitsmod) {
      throw std::runtime_error("Error loading module mpl_toolkits!");
    }

    axis3dmod = PyImport_Import(axis3d);
    Py_DECREF(axis3d);
    if (!axis3dmod) {
      throw std::runtime_error("Error loading module mpl_toolkits.mplot3d!");
    }
  }

  assert(x.size() == y.size());
  assert(y.size() == z.size());

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);
  PyObject* zarray = detail::get_array(z);

  // construct positional args
  PyObject* args = PyTuple_New(3);
  PyTuple_SetItem(args, 0, xarray);
  PyTuple_SetItem(args, 1, yarray);
  PyTuple_SetItem(args, 2, zarray);

  // Build up the kw args.
  PyObject* kwargs = PyDict_New();

  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyString_FromString(it->second.c_str()));
  }

  PyObject* fig =
      PyObject_CallObject(detail::_interpreter::get().s_python_function_figure,
                          detail::_interpreter::get().s_python_empty_tuple);
  if (!fig) throw std::runtime_error("Call to figure() failed.");

  PyObject* gca_kwargs = PyDict_New();
  PyDict_SetItemString(gca_kwargs, "projection", PyString_FromString("3d"));

  PyObject* gca = PyObject_GetAttrString(fig, "gca");
  if (!gca) throw std::runtime_error("No gca");
  Py_INCREF(gca);
  PyObject* axis = PyObject_Call(
      gca, detail::_interpreter::get().s_python_empty_tuple, gca_kwargs);

  if (!axis) throw std::runtime_error("No axis");
  Py_INCREF(axis);

  Py_DECREF(gca);
  Py_DECREF(gca_kwargs);

  PyObject* plot3 = PyObject_GetAttrString(axis, "plot");
  if (!plot3) throw std::runtime_error("No 3D line plot");
  Py_INCREF(plot3);
  PyObject* res = PyObject_Call(plot3, args, kwargs);
  if (!res) throw std::runtime_error("Failed 3D line plot");
  Py_DECREF(plot3);

  Py_DECREF(axis);
  Py_DECREF(args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);
}

template <typename Numeric>
bool stem(const std::vector<Numeric>& x, const std::vector<Numeric>& y,
          const std::map<std::string, std::string>& keywords) {
  assert(x.size() == y.size());

  detail::_interpreter::get();

  // using numpy arrays
  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  // construct positional args
  PyObject* args = PyTuple_New(2);
  PyTuple_SetItem(args, 0, xarray);
  PyTuple_SetItem(args, 1, yarray);

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyString_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_stem, args, kwargs);

  Py_DECREF(args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool fill(const std::vector<Numeric>& x, const std::vector<Numeric>& y,
          const std::map<std::string, std::string>& keywords) {
  assert(x.size() == y.size());

  detail::_interpreter::get();

  // using numpy arrays
  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  // construct positional args
  PyObject* args = PyTuple_New(2);
  PyTuple_SetItem(args, 0, xarray);
  PyTuple_SetItem(args, 1, yarray);

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (auto it = keywords.begin(); it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_fill, args, kwargs);

  Py_DECREF(args);
  Py_DECREF(kwargs);

  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool fill_between(const std::vector<Numeric>& x, const std::vector<Numeric>& y1,
                  const std::vector<Numeric>& y2,
                  const std::map<std::string, std::string>& keywords) {
  assert(x.size() == y1.size());
  assert(x.size() == y2.size());

  detail::_interpreter::get();

  // using numpy arrays
  PyObject* xarray = detail::get_array(x);
  PyObject* y1array = detail::get_array(y1);
  PyObject* y2array = detail::get_array(y2);

  // construct positional args
  PyObject* args = PyTuple_New(3);
  PyTuple_SetItem(args, 0, xarray);
  PyTuple_SetItem(args, 1, y1array);
  PyTuple_SetItem(args, 2, y2array);

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_fill_between, args, kwargs);

  Py_DECREF(args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool arrow(Numeric x, Numeric y, Numeric end_x, Numeric end_y,
           const std::string& fc = "r", const std::string ec = "k",
           Numeric head_length = 0.25, Numeric head_width = 0.1625) {
  PyObject* obj_x = PyFloat_FromDouble(x);
  PyObject* obj_y = PyFloat_FromDouble(y);
  PyObject* obj_end_x = PyFloat_FromDouble(end_x);
  PyObject* obj_end_y = PyFloat_FromDouble(end_y);

  PyObject* kwargs = PyDict_New();
  PyDict_SetItemString(kwargs, "fc", PyString_FromString(fc.c_str()));
  PyDict_SetItemString(kwargs, "ec", PyString_FromString(ec.c_str()));
  PyDict_SetItemString(kwargs, "head_width", PyFloat_FromDouble(head_width));
  PyDict_SetItemString(kwargs, "head_length", PyFloat_FromDouble(head_length));

  PyObject* plot_args = PyTuple_New(4);
  PyTuple_SetItem(plot_args, 0, obj_x);
  PyTuple_SetItem(plot_args, 1, obj_y);
  PyTuple_SetItem(plot_args, 2, obj_end_x);
  PyTuple_SetItem(plot_args, 3, obj_end_y);

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_arrow, plot_args, kwargs);

  Py_DECREF(plot_args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool hist(const std::vector<Numeric>& y, long bins = 10,
          std::string color = "b", double alpha = 1.0,
          bool cumulative = false) {
  detail::_interpreter::get();

  PyObject* yarray = detail::get_array(y);

  PyObject* kwargs = PyDict_New();
  PyDict_SetItemString(kwargs, "bins", PyLong_FromLong(bins));
  PyDict_SetItemString(kwargs, "color", PyString_FromString(color.c_str()));
  PyDict_SetItemString(kwargs, "alpha", PyFloat_FromDouble(alpha));
  PyDict_SetItemString(kwargs, "cumulative", cumulative ? Py_True : Py_False);

  PyObject* plot_args = PyTuple_New(1);

  PyTuple_SetItem(plot_args, 0, yarray);

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_hist, plot_args, kwargs);

  Py_DECREF(plot_args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);

  return res;
}

#ifndef WITHOUT_NUMPY
namespace detail {

inline void imshow(void* ptr, const NPY_TYPES type, const int rows,
                   const int columns, const int colors,
                   const std::map<std::string, std::string>& keywords,
                   PyObject** out) {
  assert(type == NPY_UINT8 || type == NPY_FLOAT);
  assert(colors == 1 || colors == 3 || colors == 4);

  detail::_interpreter::get();

  // construct args
  npy_intp dims[3] = {rows, columns, colors};
  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(
      args, 0, PyArray_SimpleNewFromData(colors == 1 ? 2 : 3, dims, type, ptr));

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_imshow, args, kwargs);
  Py_DECREF(args);
  Py_DECREF(kwargs);
  if (!res) throw std::runtime_error("Call to imshow() failed");
  if (out)
    *out = res;
  else
    Py_DECREF(res);
}

}  // namespace detail

inline void imshow(const unsigned char* ptr, const int rows, const int columns,
                   const int colors,
                   const std::map<std::string, std::string>& keywords = {},
                   PyObject** out = nullptr) {
  detail::imshow((void*)ptr, NPY_UINT8, rows, columns, colors, keywords, out);
}

inline void imshow(const float* ptr, const int rows, const int columns,
                   const int colors,
                   const std::map<std::string, std::string>& keywords = {},
                   PyObject** out = nullptr) {
  detail::imshow((void*)ptr, NPY_FLOAT, rows, columns, colors, keywords, out);
}

#ifdef WITH_OPENCV
void imshow(const cv::Mat& image,
            const std::map<std::string, std::string>& keywords = {}) {
  // Convert underlying type of matrix, if needed
  cv::Mat image2;
  NPY_TYPES npy_type = NPY_UINT8;
  switch (image.type() & CV_MAT_DEPTH_MASK) {
    case CV_8U:
      image2 = image;
      break;
    case CV_32F:
      image2 = image;
      npy_type = NPY_FLOAT;
      break;
    default:
      image.convertTo(image2, CV_MAKETYPE(CV_8U, image.channels()));
  }

  // If color image, convert from BGR to RGB
  switch (image2.channels()) {
    case 3:
      cv::cvtColor(image2, image2, CV_BGR2RGB);
      break;
    case 4:
      cv::cvtColor(image2, image2, CV_BGRA2RGBA);
  }

  detail::imshow(image2.data, npy_type, image2.rows, image2.cols,
                 image2.channels(), keywords);
}
#endif  // WITH_OPENCV
#endif  // WITHOUT_NUMPY

template <typename NumericX, typename NumericY>
bool scatter(const std::vector<NumericX>& x, const std::vector<NumericY>& y,
             const double s = 1.0,  // The marker size in points**2
             const std::map<std::string, std::string>& keywords = {}) {
  detail::_interpreter::get();

  assert(x.size() == y.size());

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  PyObject* kwargs = PyDict_New();
  PyDict_SetItemString(kwargs, "s", PyLong_FromLong(s));
  for (const auto& it : keywords) {
    PyDict_SetItemString(kwargs, it.first.c_str(),
                         PyString_FromString(it.second.c_str()));
  }

  PyObject* plot_args = PyTuple_New(2);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_scatter, plot_args, kwargs);

  Py_DECREF(plot_args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool boxplot(const std::vector<std::vector<Numeric>>& data,
             const std::vector<std::string>& labels = {},
             const std::map<std::string, std::string>& keywords = {}) {
  detail::_interpreter::get();

  PyObject* listlist = detail::get_listlist(data);
  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, listlist);

  PyObject* kwargs = PyDict_New();

  // kwargs needs the labels, if there are (the correct number of) labels
  if (!labels.empty() && labels.size() == data.size()) {
    PyDict_SetItemString(kwargs, "labels", detail::get_array(labels));
  }

  // take care of the remaining keywords
  for (const auto& it : keywords) {
    PyDict_SetItemString(kwargs, it.first.c_str(),
                         PyString_FromString(it.second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_boxplot, args, kwargs);

  Py_DECREF(args);
  Py_DECREF(kwargs);

  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool boxplot(const std::vector<Numeric>& data,
             const std::map<std::string, std::string>& keywords = {}) {
  detail::_interpreter::get();

  PyObject* vector = detail::get_array(data);
  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, vector);

  PyObject* kwargs = PyDict_New();
  for (const auto& it : keywords) {
    PyDict_SetItemString(kwargs, it.first.c_str(),
                         PyString_FromString(it.second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_boxplot, args, kwargs);

  Py_DECREF(args);
  Py_DECREF(kwargs);

  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool bar(const std::vector<Numeric>& x, const std::vector<Numeric>& y,
         std::string ec = "black", std::string ls = "-", double lw = 1.0,
         const std::map<std::string, std::string>& keywords = {}) {
  detail::_interpreter::get();

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  PyObject* kwargs = PyDict_New();

  PyDict_SetItemString(kwargs, "ec", PyString_FromString(ec.c_str()));
  PyDict_SetItemString(kwargs, "ls", PyString_FromString(ls.c_str()));
  PyDict_SetItemString(kwargs, "lw", PyFloat_FromDouble(lw));

  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* plot_args = PyTuple_New(2);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_bar, plot_args, kwargs);

  Py_DECREF(plot_args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool bar(const std::vector<Numeric>& y, std::string ec = "black",
         std::string ls = "-", double lw = 1.0,
         const std::map<std::string, std::string>& keywords = {}) {
  using T = typename std::remove_reference<decltype(y)>::type::value_type;

  detail::_interpreter::get();

  std::vector<T> x;
  for (std::size_t i = 0; i < y.size(); i++) {
    x.push_back(i);
  }

  return bar(x, y, ec, ls, lw, keywords);
}

template <typename Numeric>
bool barh(const std::vector<Numeric>& x, const std::vector<Numeric>& y,
          std::string ec = "black", std::string ls = "-", double lw = 1.0,
          const std::map<std::string, std::string>& keywords = {}) {
  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  PyObject* kwargs = PyDict_New();

  PyDict_SetItemString(kwargs, "ec", PyString_FromString(ec.c_str()));
  PyDict_SetItemString(kwargs, "ls", PyString_FromString(ls.c_str()));
  PyDict_SetItemString(kwargs, "lw", PyFloat_FromDouble(lw));

  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* plot_args = PyTuple_New(2);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_barh, plot_args, kwargs);

  Py_DECREF(plot_args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);

  return res;
}

inline bool subplots_adjust(
    const std::map<std::string, double>& keywords = {}) {
  detail::_interpreter::get();

  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, double>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyFloat_FromDouble(it->second));
  }

  PyObject* plot_args = PyTuple_New(0);

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_subplots_adjust, plot_args,
      kwargs);

  Py_DECREF(plot_args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool named_hist(std::string label, const std::vector<Numeric>& y,
                long bins = 10, std::string color = "b", double alpha = 1.0) {
  detail::_interpreter::get();

  PyObject* yarray = detail::get_array(y);

  PyObject* kwargs = PyDict_New();
  PyDict_SetItemString(kwargs, "label", PyString_FromString(label.c_str()));
  PyDict_SetItemString(kwargs, "bins", PyLong_FromLong(bins));
  PyDict_SetItemString(kwargs, "color", PyString_FromString(color.c_str()));
  PyDict_SetItemString(kwargs, "alpha", PyFloat_FromDouble(alpha));

  PyObject* plot_args = PyTuple_New(1);
  PyTuple_SetItem(plot_args, 0, yarray);

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_hist, plot_args, kwargs);

  Py_DECREF(plot_args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);

  return res;
}

template <typename NumericX, typename NumericY>
bool plot(const std::vector<NumericX>& x, const std::vector<NumericY>& y,
          const std::string& s = "") {
  assert(x.size() == y.size());

  detail::_interpreter::get();

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  PyObject* pystring = PyString_FromString(s.c_str());

  PyObject* plot_args = PyTuple_New(3);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);
  PyTuple_SetItem(plot_args, 2, pystring);

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_plot, plot_args);

  Py_DECREF(plot_args);
  if (res) Py_DECREF(res);

  return res;
}

template <typename NumericX, typename NumericY, typename NumericZ>
bool contour(const std::vector<NumericX>& x, const std::vector<NumericY>& y,
             const std::vector<NumericZ>& z,
             const std::map<std::string, std::string>& keywords = {}) {
  assert(x.size() == y.size() && x.size() == z.size());

  PyObject* xarray = get_array(x);
  PyObject* yarray = get_array(y);
  PyObject* zarray = get_array(z);

  PyObject* plot_args = PyTuple_New(3);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);
  PyTuple_SetItem(plot_args, 2, zarray);

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_contour, plot_args, kwargs);

  Py_DECREF(kwargs);
  Py_DECREF(plot_args);
  if (res) Py_DECREF(res);

  return res;
}

template <typename NumericX, typename NumericY, typename NumericU,
          typename NumericW>
bool quiver(const std::vector<NumericX>& x, const std::vector<NumericY>& y,
            const std::vector<NumericU>& u, const std::vector<NumericW>& w,
            const std::map<std::string, std::string>& keywords = {}) {
  assert(x.size() == y.size() && x.size() == u.size() && u.size() == w.size());

  detail::_interpreter::get();

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);
  PyObject* uarray = detail::get_array(u);
  PyObject* warray = detail::get_array(w);

  PyObject* plot_args = PyTuple_New(4);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);
  PyTuple_SetItem(plot_args, 2, uarray);
  PyTuple_SetItem(plot_args, 3, warray);

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_quiver, plot_args, kwargs);

  Py_DECREF(kwargs);
  Py_DECREF(plot_args);
  if (res) Py_DECREF(res);

  return res;
}

template <typename NumericX, typename NumericY>
bool stem(const std::vector<NumericX>& x, const std::vector<NumericY>& y,
          const std::string& s = "") {
  assert(x.size() == y.size());

  detail::_interpreter::get();

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  PyObject* pystring = PyString_FromString(s.c_str());

  PyObject* plot_args = PyTuple_New(3);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);
  PyTuple_SetItem(plot_args, 2, pystring);

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_stem, plot_args);

  Py_DECREF(plot_args);
  if (res) Py_DECREF(res);

  return res;
}

template <typename NumericX, typename NumericY>
bool semilogx(const std::vector<NumericX>& x, const std::vector<NumericY>& y,
              const std::string& s = "") {
  assert(x.size() == y.size());

  detail::_interpreter::get();

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  PyObject* pystring = PyString_FromString(s.c_str());

  PyObject* plot_args = PyTuple_New(3);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);
  PyTuple_SetItem(plot_args, 2, pystring);

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_semilogx, plot_args);

  Py_DECREF(plot_args);
  if (res) Py_DECREF(res);

  return res;
}

template <typename NumericX, typename NumericY>
bool semilogy(const std::vector<NumericX>& x, const std::vector<NumericY>& y,
              const std::string& s = "") {
  assert(x.size() == y.size());

  detail::_interpreter::get();

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  PyObject* pystring = PyString_FromString(s.c_str());

  PyObject* plot_args = PyTuple_New(3);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);
  PyTuple_SetItem(plot_args, 2, pystring);

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_semilogy, plot_args);

  Py_DECREF(plot_args);
  if (res) Py_DECREF(res);

  return res;
}

template <typename NumericX, typename NumericY>
bool loglog(const std::vector<NumericX>& x, const std::vector<NumericY>& y,
            const std::string& s = "") {
  assert(x.size() == y.size());

  detail::_interpreter::get();

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  PyObject* pystring = PyString_FromString(s.c_str());

  PyObject* plot_args = PyTuple_New(3);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);
  PyTuple_SetItem(plot_args, 2, pystring);

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_loglog, plot_args);

  Py_DECREF(plot_args);
  if (res) Py_DECREF(res);

  return res;
}

template <typename NumericX, typename NumericY>
bool errorbar(const std::vector<NumericX>& x, const std::vector<NumericY>& y,
              const std::vector<NumericX>& yerr,
              const std::map<std::string, std::string>& keywords = {}) {
  assert(x.size() == y.size());

  detail::_interpreter::get();

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);
  PyObject* yerrarray = detail::get_array(yerr);

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyString_FromString(it->second.c_str()));
  }

  PyDict_SetItemString(kwargs, "yerr", yerrarray);

  PyObject* plot_args = PyTuple_New(2);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);

  PyObject* res =
      PyObject_Call(detail::_interpreter::get().s_python_function_errorbar,
                    plot_args, kwargs);

  Py_DECREF(kwargs);
  Py_DECREF(plot_args);

  if (res)
    Py_DECREF(res);
  else
    throw std::runtime_error("Call to errorbar() failed.");

  return res;
}

template <typename Numeric>
bool named_plot(const std::string& name, const std::vector<Numeric>& y,
                const std::string& format = "") {
  detail::_interpreter::get();

  PyObject* kwargs = PyDict_New();
  PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));

  PyObject* yarray = detail::get_array(y);

  PyObject* pystring = PyString_FromString(format.c_str());

  PyObject* plot_args = PyTuple_New(2);

  PyTuple_SetItem(plot_args, 0, yarray);
  PyTuple_SetItem(plot_args, 1, pystring);

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_plot, plot_args, kwargs);

  Py_DECREF(kwargs);
  Py_DECREF(plot_args);
  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool named_plot(const std::string& name, const std::vector<Numeric>& x,
                const std::vector<Numeric>& y, const std::string& format = "") {
  detail::_interpreter::get();

  PyObject* kwargs = PyDict_New();
  PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  PyObject* pystring = PyString_FromString(format.c_str());

  PyObject* plot_args = PyTuple_New(3);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);
  PyTuple_SetItem(plot_args, 2, pystring);

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_plot, plot_args, kwargs);

  Py_DECREF(kwargs);
  Py_DECREF(plot_args);
  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool named_semilogx(const std::string& name, const std::vector<Numeric>& x,
                    const std::vector<Numeric>& y,
                    const std::string& format = "") {
  detail::_interpreter::get();

  PyObject* kwargs = PyDict_New();
  PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  PyObject* pystring = PyString_FromString(format.c_str());

  PyObject* plot_args = PyTuple_New(3);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);
  PyTuple_SetItem(plot_args, 2, pystring);

  PyObject* res =
      PyObject_Call(detail::_interpreter::get().s_python_function_semilogx,
                    plot_args, kwargs);

  Py_DECREF(kwargs);
  Py_DECREF(plot_args);
  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool named_semilogy(const std::string& name, const std::vector<Numeric>& x,
                    const std::vector<Numeric>& y,
                    const std::string& format = "") {
  detail::_interpreter::get();

  PyObject* kwargs = PyDict_New();
  PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  PyObject* pystring = PyString_FromString(format.c_str());

  PyObject* plot_args = PyTuple_New(3);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);
  PyTuple_SetItem(plot_args, 2, pystring);

  PyObject* res =
      PyObject_Call(detail::_interpreter::get().s_python_function_semilogy,
                    plot_args, kwargs);

  Py_DECREF(kwargs);
  Py_DECREF(plot_args);
  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool named_loglog(const std::string& name, const std::vector<Numeric>& x,
                  const std::vector<Numeric>& y,
                  const std::string& format = "") {
  detail::_interpreter::get();

  PyObject* kwargs = PyDict_New();
  PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));

  PyObject* xarray = detail::get_array(x);
  PyObject* yarray = detail::get_array(y);

  PyObject* pystring = PyString_FromString(format.c_str());

  PyObject* plot_args = PyTuple_New(3);
  PyTuple_SetItem(plot_args, 0, xarray);
  PyTuple_SetItem(plot_args, 1, yarray);
  PyTuple_SetItem(plot_args, 2, pystring);
  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_loglog, plot_args, kwargs);

  Py_DECREF(kwargs);
  Py_DECREF(plot_args);
  if (res) Py_DECREF(res);

  return res;
}

template <typename Numeric>
bool plot(const std::vector<Numeric>& y, const std::string& format = "") {
  std::vector<Numeric> x(y.size());
  for (size_t i = 0; i < x.size(); ++i) x.at(i) = i;
  return plot(x, y, format);
}

template <typename Numeric>
bool plot(const std::vector<Numeric>& y,
          const std::map<std::string, std::string>& keywords) {
  std::vector<Numeric> x(y.size());
  for (size_t i = 0; i < x.size(); ++i) x.at(i) = i;
  return plot(x, y, keywords);
}

template <typename Numeric>
bool stem(const std::vector<Numeric>& y, const std::string& format = "") {
  std::vector<Numeric> x(y.size());
  for (size_t i = 0; i < x.size(); ++i) x.at(i) = i;
  return stem(x, y, format);
}

template <typename Numeric>
void text(Numeric x, Numeric y, const std::string& s = "") {
  detail::_interpreter::get();

  PyObject* args = PyTuple_New(3);
  PyTuple_SetItem(args, 0, PyFloat_FromDouble(x));
  PyTuple_SetItem(args, 1, PyFloat_FromDouble(y));
  PyTuple_SetItem(args, 2, PyString_FromString(s.c_str()));

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_text, args);
  if (!res) throw std::runtime_error("Call to text() failed.");

  Py_DECREF(args);
  Py_DECREF(res);
}

inline void colorbar(PyObject* mappable = NULL,
                     const std::map<std::string, float>& keywords = {}) {
  if (mappable == NULL)
    throw std::runtime_error(
        "Must call colorbar with PyObject* returned from an image, contour, "
        "surface, etc.");

  detail::_interpreter::get();

  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, mappable);

  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, float>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyFloat_FromDouble(it->second));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_colorbar, args, kwargs);
  if (!res) throw std::runtime_error("Call to colorbar() failed.");

  Py_DECREF(args);
  Py_DECREF(kwargs);
  Py_DECREF(res);
}

inline long figure(long number = -1) {
  detail::_interpreter::get();

  PyObject* res;
  if (number == -1)
    res = PyObject_CallObject(
        detail::_interpreter::get().s_python_function_figure,
        detail::_interpreter::get().s_python_empty_tuple);
  else {
    assert(number > 0);

    // Make sure interpreter is initialised
    detail::_interpreter::get();

    PyObject* args = PyTuple_New(1);
    PyTuple_SetItem(args, 0, PyLong_FromLong(number));
    res = PyObject_CallObject(
        detail::_interpreter::get().s_python_function_figure, args);
    Py_DECREF(args);
  }

  if (!res) throw std::runtime_error("Call to figure() failed.");

  PyObject* num = PyObject_GetAttrString(res, "number");
  if (!num)
    throw std::runtime_error("Could not get number attribute of figure object");
  const long figureNumber = PyLong_AsLong(num);

  Py_DECREF(num);
  Py_DECREF(res);

  return figureNumber;
}

inline bool fignum_exists(long number) {
  detail::_interpreter::get();

  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, PyLong_FromLong(number));
  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_fignum_exists, args);
  if (!res) throw std::runtime_error("Call to fignum_exists() failed.");

  bool ret = PyObject_IsTrue(res);
  Py_DECREF(res);
  Py_DECREF(args);

  return ret;
}

inline void figure_size(size_t w, size_t h) {
  detail::_interpreter::get();

  const size_t dpi = 100;
  PyObject* size = PyTuple_New(2);
  PyTuple_SetItem(size, 0, PyFloat_FromDouble((double)w / dpi));
  PyTuple_SetItem(size, 1, PyFloat_FromDouble((double)h / dpi));

  PyObject* kwargs = PyDict_New();
  PyDict_SetItemString(kwargs, "figsize", size);
  PyDict_SetItemString(kwargs, "dpi", PyLong_FromSize_t(dpi));

  PyObject* res =
      PyObject_Call(detail::_interpreter::get().s_python_function_figure,
                    detail::_interpreter::get().s_python_empty_tuple, kwargs);

  Py_DECREF(kwargs);

  if (!res) throw std::runtime_error("Call to figure_size() failed.");
  Py_DECREF(res);
}

inline void legend() {
  detail::_interpreter::get();

  PyObject* res =
      PyObject_CallObject(detail::_interpreter::get().s_python_function_legend,
                          detail::_interpreter::get().s_python_empty_tuple);
  if (!res) throw std::runtime_error("Call to legend() failed.");

  Py_DECREF(res);
}

inline void legend(const std::map<std::string, std::string>& keywords) {
  detail::_interpreter::get();

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyString_FromString(it->second.c_str()));
  }

  PyObject* res =
      PyObject_Call(detail::_interpreter::get().s_python_function_legend,
                    detail::_interpreter::get().s_python_empty_tuple, kwargs);
  if (!res) throw std::runtime_error("Call to legend() failed.");

  Py_DECREF(kwargs);
  Py_DECREF(res);
}

template <typename Numeric>
void ylim(Numeric left, Numeric right) {
  detail::_interpreter::get();

  PyObject* list = PyList_New(2);
  PyList_SetItem(list, 0, PyFloat_FromDouble(left));
  PyList_SetItem(list, 1, PyFloat_FromDouble(right));

  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, list);

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_ylim, args);
  if (!res) throw std::runtime_error("Call to ylim() failed.");

  Py_DECREF(args);
  Py_DECREF(res);
}

template <typename Numeric>
void xlim(Numeric left, Numeric right) {
  detail::_interpreter::get();

  PyObject* list = PyList_New(2);
  PyList_SetItem(list, 0, PyFloat_FromDouble(left));
  PyList_SetItem(list, 1, PyFloat_FromDouble(right));

  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, list);

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_xlim, args);
  if (!res) throw std::runtime_error("Call to xlim() failed.");

  Py_DECREF(args);
  Py_DECREF(res);
}

inline double* xlim() {
  detail::_interpreter::get();

  PyObject* args = PyTuple_New(0);
  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_xlim, args);
  PyObject* left = PyTuple_GetItem(res, 0);
  PyObject* right = PyTuple_GetItem(res, 1);

  double* arr = new double[2];
  arr[0] = PyFloat_AsDouble(left);
  arr[1] = PyFloat_AsDouble(right);

  if (!res) throw std::runtime_error("Call to xlim() failed.");

  Py_DECREF(res);
  return arr;
}

inline double* ylim() {
  detail::_interpreter::get();

  PyObject* args = PyTuple_New(0);
  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_ylim, args);
  PyObject* left = PyTuple_GetItem(res, 0);
  PyObject* right = PyTuple_GetItem(res, 1);

  double* arr = new double[2];
  arr[0] = PyFloat_AsDouble(left);
  arr[1] = PyFloat_AsDouble(right);

  if (!res) throw std::runtime_error("Call to ylim() failed.");

  Py_DECREF(res);
  return arr;
}

template <typename Numeric>
inline void xticks(const std::vector<Numeric>& ticks,
                   const std::vector<std::string>& labels = {},
                   const std::map<std::string, std::string>& keywords = {}) {
  assert(labels.size() == 0 || ticks.size() == labels.size());

  detail::_interpreter::get();

  // using numpy array
  PyObject* ticksarray = detail::get_array(ticks);

  PyObject* args;
  if (labels.size() == 0) {
    // construct positional args
    args = PyTuple_New(1);
    PyTuple_SetItem(args, 0, ticksarray);
  } else {
    // make tuple of tick labels
    PyObject* labelstuple = PyTuple_New(labels.size());
    for (size_t i = 0; i < labels.size(); i++)
      PyTuple_SetItem(labelstuple, i, PyUnicode_FromString(labels[i].c_str()));

    // construct positional args
    args = PyTuple_New(2);
    PyTuple_SetItem(args, 0, ticksarray);
    PyTuple_SetItem(args, 1, labelstuple);
  }

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyString_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_xticks, args, kwargs);

  Py_DECREF(args);
  Py_DECREF(kwargs);
  if (!res) throw std::runtime_error("Call to xticks() failed");

  Py_DECREF(res);
}

template <typename Numeric>
inline void xticks(const std::vector<Numeric>& ticks,
                   const std::map<std::string, std::string>& keywords) {
  xticks(ticks, {}, keywords);
}

template <typename Numeric>
inline void yticks(const std::vector<Numeric>& ticks,
                   const std::vector<std::string>& labels = {},
                   const std::map<std::string, std::string>& keywords = {}) {
  assert(labels.size() == 0 || ticks.size() == labels.size());

  detail::_interpreter::get();

  // using numpy array
  PyObject* ticksarray = detail::get_array(ticks);

  PyObject* args;
  if (labels.size() == 0) {
    // construct positional args
    args = PyTuple_New(1);
    PyTuple_SetItem(args, 0, ticksarray);
  } else {
    // make tuple of tick labels
    PyObject* labelstuple = PyTuple_New(labels.size());
    for (size_t i = 0; i < labels.size(); i++)
      PyTuple_SetItem(labelstuple, i, PyUnicode_FromString(labels[i].c_str()));

    // construct positional args
    args = PyTuple_New(2);
    PyTuple_SetItem(args, 0, ticksarray);
    PyTuple_SetItem(args, 1, labelstuple);
  }

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyString_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_yticks, args, kwargs);

  Py_DECREF(args);
  Py_DECREF(kwargs);
  if (!res) throw std::runtime_error("Call to yticks() failed");

  Py_DECREF(res);
}

template <typename Numeric>
inline void yticks(const std::vector<Numeric>& ticks,
                   const std::map<std::string, std::string>& keywords) {
  yticks(ticks, {}, keywords);
}

template <typename Numeric>
inline void margins(Numeric margin) {
  // construct positional args
  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, PyFloat_FromDouble(margin));

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_margins, args);
  if (!res) throw std::runtime_error("Call to margins() failed.");

  Py_DECREF(args);
  Py_DECREF(res);
}

template <typename Numeric>
inline void margins(Numeric margin_x, Numeric margin_y) {
  // construct positional args
  PyObject* args = PyTuple_New(2);
  PyTuple_SetItem(args, 0, PyFloat_FromDouble(margin_x));
  PyTuple_SetItem(args, 1, PyFloat_FromDouble(margin_y));

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_margins, args);
  if (!res) throw std::runtime_error("Call to margins() failed.");

  Py_DECREF(args);
  Py_DECREF(res);
}

inline void tick_params(const std::map<std::string, std::string>& keywords,
                        const std::string axis = "both") {
  detail::_interpreter::get();

  // construct positional args
  PyObject* args;
  args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, PyString_FromString(axis.c_str()));

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyString_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_tick_params, args, kwargs);

  Py_DECREF(args);
  Py_DECREF(kwargs);
  if (!res) throw std::runtime_error("Call to tick_params() failed");

  Py_DECREF(res);
}

inline void subplot(long nrows, long ncols, long plot_number) {
  detail::_interpreter::get();

  // construct positional args
  PyObject* args = PyTuple_New(3);
  PyTuple_SetItem(args, 0, PyLong_FromDouble(nrows));
  PyTuple_SetItem(args, 1, PyLong_FromDouble(ncols));
  PyTuple_SetItem(args, 2, PyLong_FromDouble(plot_number));

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_subplot, args);
  if (!res) throw std::runtime_error("Call to subplot() failed.");

  Py_DECREF(args);
  Py_DECREF(res);
}

inline void subplot2grid(long nrows, long ncols, long rowid = 0, long colid = 0,
                         long rowspan = 1, long colspan = 1) {
  detail::_interpreter::get();

  PyObject* shape = PyTuple_New(2);
  PyTuple_SetItem(shape, 0, PyLong_FromLong(nrows));
  PyTuple_SetItem(shape, 1, PyLong_FromLong(ncols));

  PyObject* loc = PyTuple_New(2);
  PyTuple_SetItem(loc, 0, PyLong_FromLong(rowid));
  PyTuple_SetItem(loc, 1, PyLong_FromLong(colid));

  PyObject* args = PyTuple_New(4);
  PyTuple_SetItem(args, 0, shape);
  PyTuple_SetItem(args, 1, loc);
  PyTuple_SetItem(args, 2, PyLong_FromLong(rowspan));
  PyTuple_SetItem(args, 3, PyLong_FromLong(colspan));

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_subplot2grid, args);
  if (!res) throw std::runtime_error("Call to subplot2grid() failed.");

  Py_DECREF(shape);
  Py_DECREF(loc);
  Py_DECREF(args);
  Py_DECREF(res);
}

inline void title(const std::string& titlestr,
                  const std::map<std::string, std::string>& keywords = {}) {
  detail::_interpreter::get();

  PyObject* pytitlestr = PyString_FromString(titlestr.c_str());
  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, pytitlestr);

  PyObject* kwargs = PyDict_New();
  for (auto it = keywords.begin(); it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_title, args, kwargs);
  if (!res) throw std::runtime_error("Call to title() failed.");

  Py_DECREF(args);
  Py_DECREF(kwargs);
  Py_DECREF(res);
}

inline void suptitle(const std::string& suptitlestr,
                     const std::map<std::string, std::string>& keywords = {}) {
  detail::_interpreter::get();

  PyObject* pysuptitlestr = PyString_FromString(suptitlestr.c_str());
  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, pysuptitlestr);

  PyObject* kwargs = PyDict_New();
  for (auto it = keywords.begin(); it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_suptitle, args, kwargs);
  if (!res) throw std::runtime_error("Call to suptitle() failed.");

  Py_DECREF(args);
  Py_DECREF(kwargs);
  Py_DECREF(res);
}

inline void axis(const std::string& axisstr) {
  detail::_interpreter::get();

  PyObject* str = PyString_FromString(axisstr.c_str());
  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, str);

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_axis, args);
  if (!res) throw std::runtime_error("Call to title() failed.");

  Py_DECREF(args);
  Py_DECREF(res);
}

inline void axvline(double x, double ymin = 0., double ymax = 1.,
                    const std::map<std::string, std::string>& keywords =
                        std::map<std::string, std::string>()) {
  detail::_interpreter::get();

  // construct positional args
  PyObject* args = PyTuple_New(3);
  PyTuple_SetItem(args, 0, PyFloat_FromDouble(x));
  PyTuple_SetItem(args, 1, PyFloat_FromDouble(ymin));
  PyTuple_SetItem(args, 2, PyFloat_FromDouble(ymax));

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyString_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_axvline, args, kwargs);

  Py_DECREF(args);
  Py_DECREF(kwargs);

  if (res) Py_DECREF(res);
}

inline void axvspan(double xmin, double xmax, double ymin = 0.,
                    double ymax = 1.,
                    const std::map<std::string, std::string>& keywords =
                        std::map<std::string, std::string>()) {
  // construct positional args
  PyObject* args = PyTuple_New(4);
  PyTuple_SetItem(args, 0, PyFloat_FromDouble(xmin));
  PyTuple_SetItem(args, 1, PyFloat_FromDouble(xmax));
  PyTuple_SetItem(args, 2, PyFloat_FromDouble(ymin));
  PyTuple_SetItem(args, 3, PyFloat_FromDouble(ymax));

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    if (it->first == "linewidth" || it->first == "alpha")
      PyDict_SetItemString(kwargs, it->first.c_str(),
                           PyFloat_FromDouble(std::stod(it->second)));
    else
      PyDict_SetItemString(kwargs, it->first.c_str(),
                           PyString_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_axvspan, args, kwargs);
  Py_DECREF(args);
  Py_DECREF(kwargs);

  if (res) Py_DECREF(res);
}

inline void xlabel(const std::string& str,
                   const std::map<std::string, std::string>& keywords = {}) {
  detail::_interpreter::get();

  PyObject* pystr = PyString_FromString(str.c_str());
  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, pystr);

  PyObject* kwargs = PyDict_New();
  for (auto it = keywords.begin(); it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_xlabel, args, kwargs);
  if (!res) throw std::runtime_error("Call to xlabel() failed.");

  Py_DECREF(args);
  Py_DECREF(kwargs);
  Py_DECREF(res);
}

inline void ylabel(const std::string& str,
                   const std::map<std::string, std::string>& keywords = {}) {
  detail::_interpreter::get();

  PyObject* pystr = PyString_FromString(str.c_str());
  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, pystr);

  PyObject* kwargs = PyDict_New();
  for (auto it = keywords.begin(); it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_ylabel, args, kwargs);
  if (!res) throw std::runtime_error("Call to ylabel() failed.");

  Py_DECREF(args);
  Py_DECREF(kwargs);
  Py_DECREF(res);
}

inline void set_zlabel(
    const std::string& str,
    const std::map<std::string, std::string>& keywords = {}) {
  detail::_interpreter::get();

  // Same as with plot_surface: We lazily load the modules here the first time
  // this function is called because I'm not sure that we can assume "matplotlib
  // installed" implies "mpl_toolkits installed" on all platforms, and we don't
  // want to require it for people who don't need 3d plots.
  static PyObject *mpl_toolkitsmod = nullptr, *axis3dmod = nullptr;
  if (!mpl_toolkitsmod) {
    PyObject* mpl_toolkits = PyString_FromString("mpl_toolkits");
    PyObject* axis3d = PyString_FromString("mpl_toolkits.mplot3d");
    if (!mpl_toolkits || !axis3d) {
      throw std::runtime_error("couldnt create string");
    }

    mpl_toolkitsmod = PyImport_Import(mpl_toolkits);
    Py_DECREF(mpl_toolkits);
    if (!mpl_toolkitsmod) {
      throw std::runtime_error("Error loading module mpl_toolkits!");
    }

    axis3dmod = PyImport_Import(axis3d);
    Py_DECREF(axis3d);
    if (!axis3dmod) {
      throw std::runtime_error("Error loading module mpl_toolkits.mplot3d!");
    }
  }

  PyObject* pystr = PyString_FromString(str.c_str());
  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, pystr);

  PyObject* kwargs = PyDict_New();
  for (auto it = keywords.begin(); it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* ax =
      PyObject_CallObject(detail::_interpreter::get().s_python_function_gca,
                          detail::_interpreter::get().s_python_empty_tuple);
  if (!ax) throw std::runtime_error("Call to gca() failed.");
  Py_INCREF(ax);

  PyObject* zlabel = PyObject_GetAttrString(ax, "set_zlabel");
  if (!zlabel) throw std::runtime_error("Attribute set_zlabel not found.");
  Py_INCREF(zlabel);

  PyObject* res = PyObject_Call(zlabel, args, kwargs);
  if (!res) throw std::runtime_error("Call to set_zlabel() failed.");
  Py_DECREF(zlabel);

  Py_DECREF(ax);
  Py_DECREF(args);
  Py_DECREF(kwargs);
  if (res) Py_DECREF(res);
}

inline void grid(bool flag) {
  detail::_interpreter::get();

  PyObject* pyflag = flag ? Py_True : Py_False;
  Py_INCREF(pyflag);

  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, pyflag);

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_grid, args);
  if (!res) throw std::runtime_error("Call to grid() failed.");

  Py_DECREF(args);
  Py_DECREF(res);
}

inline void show(const bool block = true) {
  detail::_interpreter::get();

  PyObject* res;
  if (block) {
    res =
        PyObject_CallObject(detail::_interpreter::get().s_python_function_show,
                            detail::_interpreter::get().s_python_empty_tuple);
  } else {
    PyObject* kwargs = PyDict_New();
    PyDict_SetItemString(kwargs, "block", Py_False);
    res =
        PyObject_Call(detail::_interpreter::get().s_python_function_show,
                      detail::_interpreter::get().s_python_empty_tuple, kwargs);
    Py_DECREF(kwargs);
  }

  if (!res) throw std::runtime_error("Call to show() failed.");

  Py_DECREF(res);
}

inline void close() {
  detail::_interpreter::get();

  PyObject* res =
      PyObject_CallObject(detail::_interpreter::get().s_python_function_close,
                          detail::_interpreter::get().s_python_empty_tuple);

  if (!res) throw std::runtime_error("Call to close() failed.");

  Py_DECREF(res);
}

inline void xkcd() {
  detail::_interpreter::get();

  PyObject* res;
  PyObject* kwargs = PyDict_New();

  res = PyObject_Call(detail::_interpreter::get().s_python_function_xkcd,
                      detail::_interpreter::get().s_python_empty_tuple, kwargs);

  Py_DECREF(kwargs);

  if (!res) throw std::runtime_error("Call to show() failed.");

  Py_DECREF(res);
}

inline void draw() {
  detail::_interpreter::get();

  PyObject* res =
      PyObject_CallObject(detail::_interpreter::get().s_python_function_draw,
                          detail::_interpreter::get().s_python_empty_tuple);

  if (!res) throw std::runtime_error("Call to draw() failed.");

  Py_DECREF(res);
}

template <typename Numeric>
inline void pause(Numeric interval) {
  detail::_interpreter::get();

  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, PyFloat_FromDouble(interval));

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_pause, args);
  if (!res) throw std::runtime_error("Call to pause() failed.");

  Py_DECREF(args);
  Py_DECREF(res);
}

inline void save(const std::string& filename) {
  detail::_interpreter::get();

  PyObject* pyfilename = PyString_FromString(filename.c_str());

  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, pyfilename);

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_save, args);
  if (!res) throw std::runtime_error("Call to save() failed.");

  Py_DECREF(args);
  Py_DECREF(res);
}

inline void clf() {
  detail::_interpreter::get();

  PyObject* res =
      PyObject_CallObject(detail::_interpreter::get().s_python_function_clf,
                          detail::_interpreter::get().s_python_empty_tuple);

  if (!res) throw std::runtime_error("Call to clf() failed.");

  Py_DECREF(res);
}

inline void cla() {
  detail::_interpreter::get();

  PyObject* res =
      PyObject_CallObject(detail::_interpreter::get().s_python_function_cla,
                          detail::_interpreter::get().s_python_empty_tuple);

  if (!res) throw std::runtime_error("Call to cla() failed.");

  Py_DECREF(res);
}

inline void ion() {
  detail::_interpreter::get();

  PyObject* res =
      PyObject_CallObject(detail::_interpreter::get().s_python_function_ion,
                          detail::_interpreter::get().s_python_empty_tuple);

  if (!res) throw std::runtime_error("Call to ion() failed.");

  Py_DECREF(res);
}

inline std::vector<std::array<double, 2>> ginput(
    const int numClicks = 1,
    const std::map<std::string, std::string>& keywords = {}) {
  detail::_interpreter::get();

  PyObject* args = PyTuple_New(1);
  PyTuple_SetItem(args, 0, PyLong_FromLong(numClicks));

  // construct keyword args
  PyObject* kwargs = PyDict_New();
  for (std::map<std::string, std::string>::const_iterator it = keywords.begin();
       it != keywords.end(); ++it) {
    PyDict_SetItemString(kwargs, it->first.c_str(),
                         PyUnicode_FromString(it->second.c_str()));
  }

  PyObject* res = PyObject_Call(
      detail::_interpreter::get().s_python_function_ginput, args, kwargs);

  Py_DECREF(kwargs);
  Py_DECREF(args);
  if (!res) throw std::runtime_error("Call to ginput() failed.");

  const size_t len = PyList_Size(res);
  std::vector<std::array<double, 2>> out;
  out.reserve(len);
  for (size_t i = 0; i < len; i++) {
    PyObject* current = PyList_GetItem(res, i);
    std::array<double, 2> position;
    position[0] = PyFloat_AsDouble(PyTuple_GetItem(current, 0));
    position[1] = PyFloat_AsDouble(PyTuple_GetItem(current, 1));
    out.push_back(position);
  }
  Py_DECREF(res);

  return out;
}

// Actually, is there any reason not to call this automatically for every plot?
inline void tight_layout() {
  detail::_interpreter::get();

  PyObject* res = PyObject_CallObject(
      detail::_interpreter::get().s_python_function_tight_layout,
      detail::_interpreter::get().s_python_empty_tuple);

  if (!res) throw std::runtime_error("Call to tight_layout() failed.");

  Py_DECREF(res);
}

// Support for variadic plot() and initializer lists:

namespace detail {

template <typename T>
using is_function = typename std::is_function<
    std::remove_pointer<std::remove_reference<T>>>::type;

template <bool obj, typename T>
struct is_callable_impl;

template <typename T>
struct is_callable_impl<false, T> {
  typedef is_function<T> type;
};  // a non-object is callable iff it is a function

template <typename T>
struct is_callable_impl<true, T> {
  struct Fallback {
    void operator()();
  };
  struct Derived : T, Fallback {};

  template <typename U, U>
  struct Check;

  template <typename U>
  static std::true_type test(
      ...);  // use a variadic function to make sure (1) it accepts everything
             // and (2) its always the worst match

  template <typename U>
  static std::false_type test(Check<void (Fallback::*)(), &U::operator()>*);

 public:
  typedef decltype(test<Derived>(nullptr)) type;
  typedef decltype(&Fallback::operator()) dtype;
  static constexpr bool value = type::value;
};  // an object is callable iff it defines operator()

template <typename T>
struct is_callable {
  // dispatch to is_callable_impl<true, T> or is_callable_impl<false, T>
  // depending on whether T is of class type or not
  typedef typename is_callable_impl<std::is_class<T>::value, T>::type type;
};

template <typename IsYDataCallable>
struct plot_impl {};

template <>
struct plot_impl<std::false_type> {
  template <typename IterableX, typename IterableY>
  bool operator()(const IterableX& x, const IterableY& y,
                  const std::string& format) {
    detail::_interpreter::get();

    // 2-phase lookup for distance, begin, end
    using std::begin;
    using std::distance;
    using std::end;

    auto xs = distance(begin(x), end(x));
    auto ys = distance(begin(y), end(y));
    assert(xs == ys && "x and y data must have the same number of elements!");

    PyObject* xlist = PyList_New(xs);
    PyObject* ylist = PyList_New(ys);
    PyObject* pystring = PyString_FromString(format.c_str());

    auto itx = begin(x), ity = begin(y);
    for (size_t i = 0; i < xs; ++i) {
      PyList_SetItem(xlist, i, PyFloat_FromDouble(*itx++));
      PyList_SetItem(ylist, i, PyFloat_FromDouble(*ity++));
    }

    PyObject* plot_args = PyTuple_New(3);
    PyTuple_SetItem(plot_args, 0, xlist);
    PyTuple_SetItem(plot_args, 1, ylist);
    PyTuple_SetItem(plot_args, 2, pystring);

    PyObject* res = PyObject_CallObject(
        detail::_interpreter::get().s_python_function_plot, plot_args);

    Py_DECREF(plot_args);
    if (res) Py_DECREF(res);

    return res;
  }
};

template <>
struct plot_impl<std::true_type> {
  template <typename Iterable, typename Callable>
  bool operator()(const Iterable& ticks, const Callable& f,
                  const std::string& format) {
    if (begin(ticks) == end(ticks)) return true;

    // We could use additional meta-programming to deduce the correct element
    // type of y, but all values have to be convertible to double anyways
    std::vector<double> y;
    for (auto x : ticks) y.push_back(f(x));
    return plot_impl<std::false_type>()(ticks, y, format);
  }
};

}  // end namespace detail

// recursion stop for the above
template <typename... Args>
bool plot() {
  return true;
}

template <typename A, typename B, typename... Args>
bool plot(const A& a, const B& b, const std::string& format, Args... args) {
  return detail::plot_impl<typename detail::is_callable<B>::type>()(a, b,
                                                                    format) &&
         plot(args...);
}

/*
 * This group of plot() functions is needed to support initializer lists, i.e.
 * calling plot( {1,2,3,4} )
 */
inline bool plot(const std::vector<double>& x, const std::vector<double>& y,
                 const std::string& format = "") {
  return plot<double, double>(x, y, format);
}

inline bool plot(const std::vector<double>& y, const std::string& format = "") {
  return plot<double>(y, format);
}

inline bool plot(const std::vector<double>& x, const std::vector<double>& y,
                 const std::map<std::string, std::string>& keywords) {
  return plot<double>(x, y, keywords);
}

/*
 * This class allows dynamic plots, ie changing the plotted data without
 * clearing and re-plotting
 */
class Plot {
 public:
  // default initialization with plot label, some data and format
  template <typename Numeric>
  Plot(const std::string& name, const std::vector<Numeric>& x,
       const std::vector<Numeric>& y, const std::string& format = "") {
    detail::_interpreter::get();

    assert(x.size() == y.size());

    PyObject* kwargs = PyDict_New();
    if (name != "")
      PyDict_SetItemString(kwargs, "label", PyString_FromString(name.c_str()));

    PyObject* xarray = detail::get_array(x);
    PyObject* yarray = detail::get_array(y);

    PyObject* pystring = PyString_FromString(format.c_str());

    PyObject* plot_args = PyTuple_New(3);
    PyTuple_SetItem(plot_args, 0, xarray);
    PyTuple_SetItem(plot_args, 1, yarray);
    PyTuple_SetItem(plot_args, 2, pystring);

    PyObject* res = PyObject_Call(
        detail::_interpreter::get().s_python_function_plot, plot_args, kwargs);

    Py_DECREF(kwargs);
    Py_DECREF(plot_args);

    if (res) {
      line = PyList_GetItem(res, 0);

      if (line)
        set_data_fct = PyObject_GetAttrString(line, "set_data");
      else
        Py_DECREF(line);
      Py_DECREF(res);
    }
  }

  // shorter initialization with name or format only
  // basically calls line, = plot([], [])
  Plot(const std::string& name = "", const std::string& format = "")
      : Plot(name, std::vector<double>(), std::vector<double>(), format) {}

  template <typename Numeric>
  bool update(const std::vector<Numeric>& x, const std::vector<Numeric>& y) {
    assert(x.size() == y.size());
    if (set_data_fct) {
      PyObject* xarray = detail::get_array(x);
      PyObject* yarray = detail::get_array(y);

      PyObject* plot_args = PyTuple_New(2);
      PyTuple_SetItem(plot_args, 0, xarray);
      PyTuple_SetItem(plot_args, 1, yarray);

      PyObject* res = PyObject_CallObject(set_data_fct, plot_args);
      if (res) Py_DECREF(res);
      return res;
    }
    return false;
  }

  // clears the plot but keep it available
  bool clear() { return update(std::vector<double>(), std::vector<double>()); }

  // definitely remove this line
  void remove() {
    if (line) {
      auto remove_fct = PyObject_GetAttrString(line, "remove");
      PyObject* args = PyTuple_New(0);
      PyObject* res = PyObject_CallObject(remove_fct, args);
      if (res) Py_DECREF(res);
    }
    decref();
  }

  ~Plot() { decref(); }

 private:
  void decref() {
    if (line) Py_DECREF(line);
    if (set_data_fct) Py_DECREF(set_data_fct);
  }

  PyObject* line = nullptr;
  PyObject* set_data_fct = nullptr;
};

}  // end namespace matplotlibcpp
