#include "tca8418.h"
#include "i2c.h"
#include "pins.h"
#include <stdint.h>
#include <string.h>

KeyboardState_t keyboardState;

void tca8418_init(void) {
  i2c_write_reg(KEYBOARD_I2C_ADDRESS, TCA8418_REG_KP_GPIO1, 0x7F);
  i2c_write_reg(KEYBOARD_I2C_ADDRESS, TCA8418_REG_KP_GPIO2, 0xFF);
  i2c_write_reg(KEYBOARD_I2C_ADDRESS, TCA8418_REG_KP_GPIO3, 0x00);

  i2c_write_reg(KEYBOARD_I2C_ADDRESS, TCA8418_REG_CFG,
                TCA8418_CFG_INT_ENABLE | TCA8418_CFG_OVERFLOW_MODE);

  i2c_write_reg(KEYBOARD_I2C_ADDRESS, TCA8418_REG_UNLOCK1, 0x00);
  i2c_write_reg(KEYBOARD_I2C_ADDRESS, TCA8418_REG_UNLOCK2, 0x00);
  i2c_write_reg(KEYBOARD_I2C_ADDRESS, TCA8418_REG_KP_LCK_TIMER, 0x00);

  i2c_write_reg(KEYBOARD_I2C_ADDRESS, TCA8418_REG_INT_STAT, 0xFF);
  memset(&keyboardState, 0, sizeof(keyboardState));
}

int tca8418_read(uint8_t *key, uint8_t *pressed) {
  uint8_t count;

  // read event counter
  i2c_read_reg(KEYBOARD_I2C_ADDRESS, TCA8418_REG_KEY_LCK_EC, &count);

  count &= 0x0F;

  // no pending events
  if (!count)
    return 0;

  uint8_t ev;

  // reading this register POPS one FIFO event
  i2c_read_reg(KEYBOARD_I2C_ADDRESS, TCA8418_REG_KEY_EVENT_A, &ev);

  // bit7:
  // 0 = press
  // 1 = release
  *pressed = ((ev & 0x80) != 0);

  // lower 7 bits = key code
  *key = ev & 0x7F;

  // sanity check
  if (*key >= KEYBOARD_KEYS_COUNT)
    return 0;

  // clear ONLY key event interrupt
  i2c_write_reg(KEYBOARD_I2C_ADDRESS, TCA8418_REG_INT_STAT,
                TCA8418_INT_KEY_EVENT);

  // update key state table
  keyboardState.pressedKeys[*key] = *pressed;

  // update modifier state
  switch (*key) {

  case KEYBOARD_MOD_FN:
    keyboardState.fnPressed = *pressed;
    break;

  case KEYBOARD_MOD_ALT:
    keyboardState.altPressed = *pressed;
    break;

  case KEYBOARD_MOD_CTRL:
    keyboardState.ctrlPressed = *pressed;
    break;

  case KEYBOARD_MOD_OPT:
    keyboardState.optPressed = *pressed;
    break;

  case KEYBOARD_MOD_SHIFT:
    keyboardState.shiftPressed = *pressed;
    break;

  default:
    break;
  }

  return 1;
}

char getKeyboardChar(const uint8_t code) {
  if (keyboardState.shiftPressed) {
    return keymap_shift[code];
  } else {
    return keymap_normal[code];
  }
}

const char *getKeyboardKeyName(const uint8_t code) {
  if (keyboardState.shiftPressed) {
    return keymap_shift_name[code];
  } else {
    return keymap_normal_name[code];
  }
}