#include <limits.h>
#include <stdint.h>

#include "keyboard.h"
#include "action.h"
#include "encoder.h"
#include "util.h"
#include "action_layer.h"

/** \brief Default Layer State
 */
layer_state_t default_layer_state = 0;

/** \brief Default Layer State Set At user Level
 *
 * Run user code on default layer state change
 */
__attribute__((weak)) layer_state_t default_layer_state_set_user(layer_state_t state) {
    return state;
}

/** \brief Default Layer State Set At Keyboard Level
 *
 *  Run keyboard code on default layer state change
 */
__attribute__((weak)) layer_state_t default_layer_state_set_kb(layer_state_t state) {
    return default_layer_state_set_user(state);
}

/** \brief Default Layer State Set
 *
 * Static function to set the default layer state, prints debug info and clears keys
 */
static void default_layer_state_set(layer_state_t state) {
    state = default_layer_state_set_kb(state);
    ac_dprintf("default_layer_state: ");
    default_layer_debug();
    ac_dprintf(" to ");
    default_layer_state = state;
    default_layer_debug();
    ac_dprintf("\n");
#if defined(STRICT_LAYER_RELEASE)
    clear_keyboard_but_mods(); // To avoid stuck keys
#elif defined(SEMI_STRICT_LAYER_RELEASE)
    clear_keyboard_but_mods_and_keys(); // Don't reset held keys
#endif
}

/** \brief Default Layer Print
 *
 * Print out the hex value of the 32-bit default layer state, as well as the value of the highest bit.
 */
void default_layer_debug(void) {
    ac_dprintf("%08hX(%u)", default_layer_state, get_highest_layer(default_layer_state));
}

/** \brief Default Layer Set
 *
 * Sets the default layer state.
 */
void default_layer_set(layer_state_t state) {
    default_layer_state_set(state);
}

#ifndef NO_ACTION_LAYER
/** \brief Default Layer Or
 *
 * Turns on the default layer based on matching bits between specified layer and existing layer state
 */
void default_layer_or(layer_state_t state) {
    default_layer_state_set(default_layer_state | state);
}
/** \brief Default Layer And
 *
 * Turns on default layer based on matching enabled bits between specified layer and existing layer state
 */
void default_layer_and(layer_state_t state) {
    default_layer_state_set(default_layer_state & state);
}
/** \brief Default Layer Xor
 *
 * Turns on default layer based on non-matching bits between specified layer and existing layer state
 */
void default_layer_xor(layer_state_t state) {
    default_layer_state_set(default_layer_state ^ state);
}
#endif

#ifndef NO_ACTION_LAYER
/** \brief Keymap Layer State
 */
layer_state_t layer_state = 0;

/** \brief Layer state set user
 *
 * Runs user code on layer state change
 */
__attribute__((weak)) layer_state_t layer_state_set_user(layer_state_t state) {
    return state;
}

/** \brief Layer state set keyboard
 *
 * Runs keyboard code on layer state change
 */
__attribute__((weak)) layer_state_t layer_state_set_kb(layer_state_t state) {
    return layer_state_set_user(state);
}

/** \brief Layer state set
 *
 * Sets the layer to match the specified state (a bitmask)
 */
void layer_state_set(layer_state_t state) {
    state = layer_state_set_kb(state);
    ac_dprintf("layer_state: ");
    layer_debug();
    ac_dprintf(" to ");
    layer_state = state;
    layer_debug();
    ac_dprintf("\n");
#    if defined(STRICT_LAYER_RELEASE)
    clear_keyboard_but_mods(); // To avoid stuck keys
#    elif defined(SEMI_STRICT_LAYER_RELEASE)
    clear_keyboard_but_mods_and_keys(); // Don't reset held keys
#    endif
}

/** \brief Layer clear
 *
 * Turn off all layers
 */
void layer_clear(void) {
    layer_state_set(0);
}

/** \brief Layer state is
 *
 * Return whether the given state is on (it might still be shadowed by a higher state, though)
 */
bool layer_state_is(uint8_t layer) {
    return layer_state_cmp(layer_state, layer);
}

/** \brief Layer state compare
 *
 * Used for comparing layers {mostly used for unit testing}
 */
bool layer_state_cmp(layer_state_t cmp_layer_state, uint8_t layer) {
    if (!cmp_layer_state) {
        return layer == 0;
    }
    return (cmp_layer_state & ((layer_state_t)1 << layer)) != 0;
}

/** \brief Layer move
 *
 * Turns on the given layer and turn off all other layers
 */
void layer_move(uint8_t layer) {
    layer_state_set((layer_state_t)1 << layer);
}

/** \brief Layer on
 *
 * Turns on given layer
 */
void layer_on(uint8_t layer) {
    layer_state_set(layer_state | ((layer_state_t)1 << layer));
}

/** \brief Layer off
 *
 * Turns off given layer
 */
void layer_off(uint8_t layer) {
    layer_state_set(layer_state & ~((layer_state_t)1 << layer));
}

/** \brief Layer invert
 *
 * Toggle the given layer (set it if it's unset, or unset it if it's set)
 */
void layer_invert(uint8_t layer) {
    layer_state_set(layer_state ^ ((layer_state_t)1 << layer));
}

/** \brief Layer or
 *
 * Turns on layers based on matching bits between specified layer and existing layer state
 */
void layer_or(layer_state_t state) {
    layer_state_set(layer_state | state);
}
/** \brief Layer and
 *
 * Turns on layers based on matching enabled bits between specified layer and existing layer state
 */
void layer_and(layer_state_t state) {
    layer_state_set(layer_state & state);
}
/** \brief Layer xor
 *
 * Turns on layers based on non-matching bits between specified layer and existing layer state
 */
void layer_xor(layer_state_t state) {
    layer_state_set(layer_state ^ state);
}

/** \brief Layer debug printing
 *
 * Print out the hex value of the 32-bit layer state, as well as the value of the highest bit.
 */
void layer_debug(void) {
    ac_dprintf("%08hX(%u)", layer_state, get_highest_layer(layer_state));
}
#endif

#if !defined(NO_ACTION_LAYER) && !defined(STRICT_LAYER_RELEASE)
/** \brief source layer cache
 */

uint8_t source_layers_cache[((MATRIX_ROWS * MATRIX_COLS) + (CHAR_BIT)-1) / (CHAR_BIT)][MAX_LAYER_BITS] = {{0}};
#    ifdef ENCODER_MAP_ENABLE
uint8_t encoder_source_layers_cache[(NUM_ENCODERS + (CHAR_BIT)-1) / (CHAR_BIT)][MAX_LAYER_BITS] = {{0}};
#    endif // ENCODER_MAP_ENABLE

/** \brief update source layers cache impl
 *
 * Updates the supplied cache when changing layers
 */
void update_source_layers_cache_impl(uint8_t layer, uint16_t entry_number, uint8_t cache[][MAX_LAYER_BITS]) {
    const uint16_t storage_idx = entry_number / (CHAR_BIT);
    const uint8_t  storage_bit = entry_number % (CHAR_BIT);
    for (uint8_t bit_number = 0; bit_number < MAX_LAYER_BITS; bit_number++) {
        cache[storage_idx][bit_number] ^= (-((layer & (1U << bit_number)) != 0) ^ cache[storage_idx][bit_number]) & (1U << storage_bit);
    }
}

/** \brief read source layers cache
 *
 * reads the cached keys stored when the layer was changed
 */
uint8_t read_source_layers_cache_impl(uint16_t entry_number, uint8_t cache[][MAX_LAYER_BITS]) {
    const uint16_t storage_idx = entry_number / (CHAR_BIT);
    const uint8_t  storage_bit = entry_number % (CHAR_BIT);
    uint8_t        layer       = 0;

    for (uint8_t bit_number = 0; bit_number < MAX_LAYER_BITS; bit_number++) {
        layer |= ((cache[storage_idx][bit_number] & (1U << storage_bit)) != 0) << bit_number;
    }

    return layer;
}

/** \brief update encoder source layers cache
 *
 * Updates the cached encoders when changing layers
 */
void update_source_layers_cache(keypos_t key, uint8_t layer) {
    if (key.row < MATRIX_ROWS && key.col < MATRIX_COLS) {
        const uint16_t entry_number = (uint16_t)(key.row * MATRIX_COLS) + key.col;
        update_source_layers_cache_impl(layer, entry_number, source_layers_cache);
    }
#    ifdef ENCODER_MAP_ENABLE
    else if (key.row == KEYLOC_ENCODER_CW || key.row == KEYLOC_ENCODER_CCW) {
        const uint16_t entry_number = key.col;
        update_source_layers_cache_impl(layer, entry_number, encoder_source_layers_cache);
    }
#    endif // ENCODER_MAP_ENABLE
}

/** \brief read source layers cache
 *
 * reads the cached keys stored when the layer was changed
 */
uint8_t read_source_layers_cache(keypos_t key) {
    if (key.row < MATRIX_ROWS && key.col < MATRIX_COLS) {
        const uint16_t entry_number = (uint16_t)(key.row * MATRIX_COLS) + key.col;
        return read_source_layers_cache_impl(entry_number, source_layers_cache);
    }
#    ifdef ENCODER_MAP_ENABLE
    else if (key.row == KEYLOC_ENCODER_CW || key.row == KEYLOC_ENCODER_CCW) {
        const uint16_t entry_number = key.col;
        return read_source_layers_cache_impl(entry_number, encoder_source_layers_cache);
    }
#    endif // ENCODER_MAP_ENABLE
    return 0;
}
#endif

/** \brief Store or get action (FIXME: Needs better summary)
 *
 * Make sure the action triggered when the key is released is the same
 * one as the one triggered on press. It's important for the mod keys
 * when the layer is switched after the down event but before the up
 * event as they may get stuck otherwise.
 */
action_t store_or_get_action(bool pressed, keypos_t key) {
#if !defined(NO_ACTION_LAYER) && !defined(STRICT_LAYER_RELEASE)
    if (disable_action_cache) {
        return layer_switch_get_action(key);
    }

    uint8_t layer;

    if (pressed) {
        layer = layer_switch_get_layer(key);
        update_source_layers_cache(key, layer);
    } else {
        layer = read_source_layers_cache(key);
    }
    return action_for_key(layer, key);
#else
    return layer_switch_get_action(key);
#endif
}

/** \brief Layer switch get layer
 *
 * Gets the layer based on key info
 */
uint8_t layer_switch_get_layer(keypos_t key) {
#ifndef NO_ACTION_LAYER
    action_t action;
    action.code = ACTION_TRANSPARENT;

    layer_state_t layers = layer_state | default_layer_state;
    /* check top layer first */
    for (int8_t i = MAX_LAYER - 1; i >= 0; i--) {
        if (layers & ((layer_state_t)1 << i)) {
            action = action_for_key(i, key);
            if (action.code != ACTION_TRANSPARENT) {
                return i;
            }
        }
    }
    /* fall back to layer 0 */
    return 0;
#else
    return get_highest_layer(default_layer_state);
#endif
}

/** \brief Layer switch get layer
 *
 * Gets action code based on key position
 */
action_t layer_switch_get_action(keypos_t key) {
    return action_for_key(layer_switch_get_layer(key), key);
}

#ifndef NO_ACTION_LAYER
layer_state_t update_tri_layer_state(layer_state_t state, uint8_t layer1, uint8_t layer2, uint8_t layer3) {
    layer_state_t mask12 = ((layer_state_t)1 << layer1) | ((layer_state_t)1 << layer2);
    layer_state_t mask3  = (layer_state_t)1 << layer3;
    return (state & mask12) == mask12 ? (state | mask3) : (state & ~mask3);
}

void update_tri_layer(uint8_t layer1, uint8_t layer2, uint8_t layer3) {
    layer_state_set(update_tri_layer_state(layer_state, layer1, layer2, layer3));
}
#endif
