/*
Copyright © 2023 Alibaba Group Holding Ltd.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package framework

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strings"

	v1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	kscheme "k8s.io/client-go/kubernetes/scheme"
	"k8s.io/client-go/rest"
	"k8s.io/client-go/tools/portforward"
	"k8s.io/client-go/tools/remotecommand"
	"k8s.io/client-go/transport/spdy"
)

func (f *Framework) PrintPodLogs(ctx context.Context, ns, p string) error {
	pod, err := f.KubeClient.CoreV1().Pods(ns).Get(ctx, p, metav1.GetOptions{})
	if err != nil {
		return fmt.Errorf("failed to print logs of pod '%v': failed to get pod: %w", p, err)
	}

	for _, c := range pod.Spec.Containers {
		req := f.KubeClient.CoreV1().Pods(ns).GetLogs(p, &v1.PodLogOptions{Container: c.Name})
		resp, err := req.DoRaw(ctx)
		if err != nil {
			return fmt.Errorf("failed to retrieve logs of pod '%v': %w", p, err)
		}

		fmt.Printf("=== Logs of %v/%v/%v:", ns, p, c.Name)
		fmt.Println(string(resp))
	}

	return nil
}

// GetPodRestartCount returns a map of container names and their restart counts for
// a given pod.
func (f *Framework) GetPodRestartCount(ctx context.Context, ns, podName string) (map[string]int32, error) {
	pod, err := f.KubeClient.CoreV1().Pods(ns).Get(ctx, podName, metav1.GetOptions{})
	if err != nil {
		return nil, fmt.Errorf("failed to retrieve pod to get restart count: %w", err)
	}

	restarts := map[string]int32{}

	for _, status := range pod.Status.ContainerStatuses {
		restarts[status.Name] = status.RestartCount
	}

	return restarts, nil
}

// ExecOptions passed to ExecWithOptions
type ExecOptions struct {
	Command       []string
	Namespace     string
	PodName       string
	ContainerName string
	Stdin         io.Reader
	CaptureStdout bool
	CaptureStderr bool
	// If false, whitespace in std{err,out} will be removed.
	PreserveWhitespace bool
}

// ExecWithOptions executes a command in the specified container, returning
// stdout, stderr and error. `options` allowed for additional parameters to be
// passed. Inspired by
// https://github.com/kubernetes/kubernetes/blob/dde6e8e7465468c32642659cb708a5cc922add64/test/e2e/framework/exec_util.go#L36-L51
func (f *Framework) ExecWithOptions(ctx context.Context, options ExecOptions) (string, string, error) {
	const tty = false

	req := f.KubeClient.CoreV1().RESTClient().Post().
		Resource("pods").
		Name(options.PodName).
		Namespace(options.Namespace).
		SubResource("exec").
		Param("container", options.ContainerName)
	req.VersionedParams(&v1.PodExecOptions{
		Container: options.ContainerName,
		Command:   options.Command,
		Stdin:     options.Stdin != nil,
		Stdout:    options.CaptureStdout,
		Stderr:    options.CaptureStderr,
		TTY:       tty,
	}, kscheme.ParameterCodec)

	var stdout, stderr bytes.Buffer
	err := execute(ctx, "POST", req.URL(), f.RestConfig, options.Stdin, &stdout, &stderr, tty)

	if options.PreserveWhitespace {
		return stdout.String(), stderr.String(), err
	}
	return strings.TrimSpace(stdout.String()), strings.TrimSpace(stderr.String()), err
}

func execute(ctx context.Context, method string, url *url.URL, config *rest.Config, stdin io.Reader, stdout, stderr io.Writer, tty bool) error {
	exec, err := remotecommand.NewSPDYExecutor(config, method, url)
	if err != nil {
		return err
	}

	return exec.Stream(remotecommand.StreamOptions{
		Stdin:  stdin,
		Stdout: stdout,
		Stderr: stderr,
		Tty:    tty,
	})
}

func StartPortForward(ctx context.Context, config *rest.Config, scheme string, name string, ns string, port string) (func(), error) {
	roundTripper, upgrader, err := spdy.RoundTripperFor(config)
	if err != nil {
		return nil, err
	}

	path := fmt.Sprintf("/api/v1/namespaces/%s/pods/%s/portforward", ns, name)
	hostIP := strings.TrimLeft(config.Host, "htps:/")
	serverURL := url.URL{Scheme: scheme, Path: path, Host: hostIP}
	dialer := spdy.NewDialer(upgrader, &http.Client{Transport: roundTripper}, http.MethodPost, &serverURL)

	stopChan, readyChan := make(chan struct{}, 1), make(chan struct{}, 1)
	out, errOut := new(bytes.Buffer), new(bytes.Buffer)
	forwarder, err := portforward.New(dialer, []string{port}, stopChan, readyChan, out, errOut)
	if err != nil {
		return nil, err
	}

	forwardErr := make(chan error, 1)
	go func() {
		if err := forwarder.ForwardPorts(); err != nil {
			forwardErr <- err
		}
		close(forwardErr)
	}()

	select {
	case <-readyChan:
		return func() { close(stopChan) }, nil
	case <-ctx.Done():
		var err error
		select {
		case err = <-forwardErr:
		default:
		}
		return nil, fmt.Errorf("%v: %v", ctx.Err(), err)
	}
}
