/* Copyright 2017 Fred Sundvik
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "report.h"
#include "host.h"
#include "keycode_config.h"
#include "debug.h"
#include "util.h"
#include <string.h>
#ifdef BLUETOOTH_ENABLE
#include "transport.h"
#endif

#ifdef RING_BUFFERED_6KRO_REPORT_ENABLE
#    define RO_ADD(a, b) ((a + b) % KEYBOARD_REPORT_KEYS)
#    define RO_SUB(a, b) ((a - b + KEYBOARD_REPORT_KEYS) % KEYBOARD_REPORT_KEYS)
#    define RO_INC(a) RO_ADD(a, 1)
#    define RO_DEC(a) RO_SUB(a, 1)
static int8_t cb_head  = 0;
static int8_t cb_tail  = 0;
static int8_t cb_count = 0;
#endif

/** \brief has_anykey
 *
 * FIXME: Needs doc
 */
uint8_t has_anykey(report_keyboard_t* keyboard_report) {
    uint8_t  cnt = 0;
    uint8_t* p   = keyboard_report->keys;
    uint8_t  lp  = sizeof(keyboard_report->keys);
#ifdef NKRO_ENABLE
#ifdef  BLUETOOTH_ENABLE
    if ((((get_transport() == TRANSPORT_USB) && keyboard_protocol) ||
          ((get_transport() == TRANSPORT_BLUETOOTH) && bluetooth_report_protocol)) 
          && keymap_config.nkro) {
#else
    if (keyboard_protocol && keymap_config.nkro) {
#endif

        p  = keyboard_report->nkro.bits;
        lp = sizeof(keyboard_report->nkro.bits);
    }
#endif
    while (lp--) {
        if (*p++) cnt++;
    }
    return cnt;
}

/** \brief get_first_key
 *
 * FIXME: Needs doc
 */
uint8_t get_first_key(report_keyboard_t* keyboard_report) {
#ifdef NKRO_ENABLE
#ifdef  BLUETOOTH_ENABLE
    if ((((get_transport() == TRANSPORT_USB) && keyboard_protocol) ||
          ((get_transport() == TRANSPORT_BLUETOOTH) && bluetooth_report_protocol)) 
          && keymap_config.nkro) {
#else
    if (keyboard_protocol && keymap_config.nkro) {
#endif
        uint8_t i = 0;
        for (; i < KEYBOARD_REPORT_BITS && !keyboard_report->nkro.bits[i]; i++)
            ;
        return i << 3 | biton(keyboard_report->nkro.bits[i]);
    }
#endif
#ifdef RING_BUFFERED_6KRO_REPORT_ENABLE
    uint8_t i = cb_head;
    do {
        if (keyboard_report->keys[i] != 0) {
            break;
        }
        i = RO_INC(i);
    } while (i != cb_tail);
    return keyboard_report->keys[i];
#else
    return keyboard_report->keys[0];
#endif
}

/** \brief Checks if a key is pressed in the report
 *
 * Returns true if the keyboard_report reports that the key is pressed, otherwise false
 * Note: The function doesn't support modifers currently, and it returns false for KC_NO
 */
bool is_key_pressed(report_keyboard_t* keyboard_report, uint8_t key) {
    if (key == KC_NO) {
        return false;
    }
#ifdef NKRO_ENABLE
#ifdef  BLUETOOTH_ENABLE
    if ((((get_transport() == TRANSPORT_USB) && keyboard_protocol) ||
          ((get_transport() == TRANSPORT_BLUETOOTH) && bluetooth_report_protocol)) 
          && keymap_config.nkro) {
#else
    if (keyboard_protocol && keymap_config.nkro) {
#endif
        if ((key >> 3) < KEYBOARD_REPORT_BITS) {
            return keyboard_report->nkro.bits[key >> 3] & 1 << (key & 7);
        } else {
            return false;
        }
    }
#endif
    for (int i = 0; i < KEYBOARD_REPORT_KEYS; i++) {
        if (keyboard_report->keys[i] == key) {
            return true;
        }
    }
    return false;
}

/** \brief add key byte
 *
 * FIXME: Needs doc
 */
void add_key_byte(report_keyboard_t* keyboard_report, uint8_t code) {
#ifdef RING_BUFFERED_6KRO_REPORT_ENABLE
    int8_t i     = cb_head;
    int8_t empty = -1;
    if (cb_count) {
        do {
            if (keyboard_report->keys[i] == code) {
                return;
            }
            if (empty == -1 && keyboard_report->keys[i] == 0) {
                empty = i;
            }
            i = RO_INC(i);
        } while (i != cb_tail);
        if (i == cb_tail) {
            if (cb_tail == cb_head) {
                // buffer is full
                if (empty == -1) {
                    // pop head when has no empty space
                    cb_head = RO_INC(cb_head);
                    cb_count--;
                } else {
                    // left shift when has empty space
                    uint8_t offset = 1;
                    i              = RO_INC(empty);
                    do {
                        if (keyboard_report->keys[i] != 0) {
                            keyboard_report->keys[empty] = keyboard_report->keys[i];
                            keyboard_report->keys[i]     = 0;
                            empty                        = RO_INC(empty);
                        } else {
                            offset++;
                        }
                        i = RO_INC(i);
                    } while (i != cb_tail);
                    cb_tail = RO_SUB(cb_tail, offset);
                }
            }
        }
    }
    // add to tail
    keyboard_report->keys[cb_tail] = code;
    cb_tail                        = RO_INC(cb_tail);
    cb_count++;
#else
    int8_t i     = 0;
    int8_t empty = -1;
    for (; i < KEYBOARD_REPORT_KEYS; i++) {
        if (keyboard_report->keys[i] == code) {
            break;
        }
        if (empty == -1 && keyboard_report->keys[i] == 0) {
            empty = i;
        }
    }
    if (i == KEYBOARD_REPORT_KEYS) {
        if (empty != -1) {
            keyboard_report->keys[empty] = code;
        }
    }
#endif
}

/** \brief del key byte
 *
 * FIXME: Needs doc
 */
void del_key_byte(report_keyboard_t* keyboard_report, uint8_t code) {
#ifdef RING_BUFFERED_6KRO_REPORT_ENABLE
    uint8_t i = cb_head;
    if (cb_count) {
        do {
            if (keyboard_report->keys[i] == code) {
                keyboard_report->keys[i] = 0;
                cb_count--;
                if (cb_count == 0) {
                    // reset head and tail
                    cb_tail = cb_head = 0;
                }
                if (i == RO_DEC(cb_tail)) {
                    // left shift when next to tail
                    do {
                        cb_tail = RO_DEC(cb_tail);
                        if (keyboard_report->keys[RO_DEC(cb_tail)] != 0) {
                            break;
                        }
                    } while (cb_tail != cb_head);
                }
                break;
            }
            i = RO_INC(i);
        } while (i != cb_tail);
    }
#else
    for (uint8_t i = 0; i < KEYBOARD_REPORT_KEYS; i++) {
        if (keyboard_report->keys[i] == code) {
            keyboard_report->keys[i] = 0;
        }
    }
#endif
}

#ifdef NKRO_ENABLE
/** \brief add key bit
 *
 * FIXME: Needs doc
 */
void add_key_bit(report_keyboard_t* keyboard_report, uint8_t code) {
    if ((code >> 3) < KEYBOARD_REPORT_BITS) {
        keyboard_report->nkro.bits[code >> 3] |= 1 << (code & 7);
    } else {
        dprintf("add_key_bit: can't add: %02X\n", code);
    }
}

/** \brief del key bit
 *
 * FIXME: Needs doc
 */
void del_key_bit(report_keyboard_t* keyboard_report, uint8_t code) {
    if ((code >> 3) < KEYBOARD_REPORT_BITS) {
        keyboard_report->nkro.bits[code >> 3] &= ~(1 << (code & 7));
    } else {
        dprintf("del_key_bit: can't del: %02X\n", code);
    }
}
#endif

/** \brief add key to report
 *
 * FIXME: Needs doc
 */
void add_key_to_report(report_keyboard_t* keyboard_report, uint8_t key) {
#ifdef NKRO_ENABLE
#ifdef  BLUETOOTH_ENABLE
    if ((((get_transport() == TRANSPORT_USB) && keyboard_protocol) ||
          ((get_transport() == TRANSPORT_BLUETOOTH) && bluetooth_report_protocol)) 
          && keymap_config.nkro) {
#else
    if (keyboard_protocol && keymap_config.nkro) {
#endif
        add_key_bit(keyboard_report, key);
        return;
    }
#endif
    add_key_byte(keyboard_report, key);
}

/** \brief del key from report
 *
 * FIXME: Needs doc
 */
void del_key_from_report(report_keyboard_t* keyboard_report, uint8_t key) {
#ifdef NKRO_ENABLE
#ifdef  BLUETOOTH_ENABLE
    if ((((get_transport() == TRANSPORT_USB) && keyboard_protocol) ||
          ((get_transport() == TRANSPORT_BLUETOOTH) && bluetooth_report_protocol)) 
          && keymap_config.nkro) {
#else
    if (keyboard_protocol && keymap_config.nkro) {
#endif
        del_key_bit(keyboard_report, key);
        return;
    }
#endif
    del_key_byte(keyboard_report, key);
}

/** \brief clear key from report
 *
 * FIXME: Needs doc
 */
void clear_keys_from_report(report_keyboard_t* keyboard_report) {
    // not clear mods
#ifdef NKRO_ENABLE
#ifdef  BLUETOOTH_ENABLE
    if ((((get_transport() == TRANSPORT_USB) && keyboard_protocol) ||
          ((get_transport() == TRANSPORT_BLUETOOTH) && bluetooth_report_protocol)) 
          && keymap_config.nkro) {
#else
    if (keyboard_protocol && keymap_config.nkro) {
#endif
        memset(keyboard_report->nkro.bits, 0, sizeof(keyboard_report->nkro.bits));
        return;
    }
#endif
    memset(keyboard_report->keys, 0, sizeof(keyboard_report->keys));
}

#ifdef MOUSE_ENABLE
/**
 * @brief Compares 2 mouse reports for difference and returns result
 *
 * @param[in] new_report report_mouse_t
 * @param[in] old_report report_mouse_t
 * @return bool result
 */
__attribute__((weak)) bool has_mouse_report_changed(report_mouse_t* new_report, report_mouse_t* old_report) {
    return memcmp(new_report, old_report, sizeof(report_mouse_t));
}
#endif
