/*
 * Copyright (C) OpenTX
 *
 * Based on code named
 *   th9x - http://code.google.com/p/th9x
 *   er9x - http://code.google.com/p/er9x
 *   gruvin9x - http://code.google.com/p/gruvin9x
 *
 * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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.
 */

#include "opentx.h"

#define KEY_LONG_DELAY              32  // long key press minimum duration (x10ms), must be less than KEY_REPEAT_DELAY
#define KEY_REPEAT_DELAY            40  // press longer than this enables repeat (but does not fire it yet)
#define KEY_REPEAT_TRIGGER          48  // repeat trigger, used in combination with m_state to produce decreasing times between repeat events
#define KEY_REPEAT_PAUSE_DELAY      64

#ifdef SIMU
  #define FILTERBITS                1   // defines how many bits are used for debounce
#else
  #define FILTERBITS                4   // defines how many bits are used for debounce
#endif

#define KSTATE_OFF                  0
#define KSTATE_RPTDELAY             95
#define KSTATE_START                97
#define KSTATE_PAUSE                98
#define KSTATE_KILLED               99


event_t s_evt;
struct t_inactivity inactivity = {0};
Key keys[NUM_KEYS];

event_t getEvent(bool trim)
{
  event_t evt = s_evt;
  int8_t k = EVT_KEY_MASK(s_evt) - TRM_BASE;
  bool trim_evt = (k>=0 && k<TRM_LAST-TRM_BASE+1);

  if (trim == trim_evt) {
    s_evt = 0;
    return evt;
  }
  else {
    return 0;
  }
}

void Key::input(bool val)
{
  // store new value in the bits that hold the key state history (used for debounce)
  uint8_t t_vals = m_vals ;
  t_vals <<= 1 ;
  if (val) t_vals |= 1;
  m_vals = t_vals ;

  m_cnt++;

  if (m_state && m_vals == 0) {
    // key is released
    if (m_state != KSTATE_KILLED) {
      // TRACE("key %d BREAK", key());
      putEvent(EVT_KEY_BREAK(key()));
    }
    m_state = KSTATE_OFF;
    m_cnt = 0;
    return;
  }

  switch (m_state) {
    case KSTATE_OFF:
      if (m_vals == ((1<<FILTERBITS)-1)) {
        m_state = KSTATE_START;
        m_cnt = 0;
      }
      break;
    case KSTATE_START:
      // TRACE("key %d FIRST", key());
      putEvent(EVT_KEY_FIRST(key()));
      inactivity.counter = 0;
      m_state = KSTATE_RPTDELAY;
      m_cnt = 0;
      break;

    case KSTATE_RPTDELAY: // gruvin: delay state before first key repeat
      if (m_cnt == KEY_LONG_DELAY) {
        // generate long key press
        // TRACE("key %d LONG", key());
        putEvent(EVT_KEY_LONG(key()));
      }
      if (m_cnt == KEY_REPEAT_DELAY) {
        m_state = 16;
        m_cnt = 0;
      }
      break;

    case 16:
    case 8:
    case 4:
    case 2:
      if (m_cnt >= KEY_REPEAT_TRIGGER) { //3 6 12 24 48 pulses in every 480ms
        m_state >>= 1;
        m_cnt = 0;
      }
      // no break
    case 1:
      if ((m_cnt & (m_state-1)) == 0) {
        // this produces repeat events that at first repeat slowly and then increase in speed
        // TRACE("key %d REPEAT", key());
        if (!IS_SHIFT_KEY(key()))
          putEvent(EVT_KEY_REPT(key()));
      }
      break;

    case KSTATE_PAUSE: //pause repeat events
      if (m_cnt >= KEY_REPEAT_PAUSE_DELAY) {
        m_state = 8;
        m_cnt = 0;
      }
      break;

    case KSTATE_KILLED: //killed
      break;
  }
}

void Key::pauseEvents()
{
  m_state = KSTATE_PAUSE;
  m_cnt = 0;
}

void Key::killEvents()
{
  // TRACE("key %d killed", key());
  m_state = KSTATE_KILLED;
}


uint8_t Key::key() const
{
  return (this - keys);
}

// Introduce a slight delay in the key repeat sequence
void pauseEvents(event_t event)
{
  event = EVT_KEY_MASK(event);
  if (event < (int)DIM(keys)) keys[event].pauseEvents();
}

// Disables any further event generation (BREAK and REPEAT) for this key, until the key is released
void killEvents(event_t event)
{
#if defined(ROTARY_ENCODERS)
  if (event == EVT_ROTARY_LONG) {
    killEvents(BTN_REa + g_eeGeneral.reNavigation - 1);
    return;
  }
#endif

  event = EVT_KEY_MASK(event);
  if (event < (int)DIM(keys)) {
    keys[event].killEvents();
  }
}

bool clearKeyEvents()
{
#if defined(PCBSKY9X)
  RTOS_WAIT_MS(200); // 200ms
#endif

  // loop until all keys are up
#if !defined(BOOT)
  tmr10ms_t start = get_tmr10ms();
#endif

  while (keyDown()) {

#if defined(SIMU)
    SIMU_SLEEP_NORET(1/*ms*/);
#else
    wdt_reset();
#endif

#if !defined(BOOT)
    if ((get_tmr10ms() - start) >= 300) {  // wait no more than 3 seconds
      //timeout expired, at least one key stuck
      return false;
    }
#endif
  }

  memclear(keys, sizeof(keys));
  putEvent(0);
  return true;
}