/*
 * 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"
#include "frsky_device_firmware_update.h"

#define PRIM_REQ_POWERUP    0
#define PRIM_REQ_VERSION    1
#define PRIM_CMD_DOWNLOAD   3
#define PRIM_DATA_WORD      4
#define PRIM_DATA_EOF       5

#define PRIM_ACK_POWERUP    0x80
#define PRIM_ACK_VERSION    0x81
#define PRIM_REQ_DATA_ADDR  0x82
#define PRIM_END_DOWNLOAD   0x83
#define PRIM_DATA_CRC_ERR   0x84

void DeviceFirmwareUpdate::processFrame(const uint8_t * frame)
{
  if (frame[0] == 0x5E && frame[1] == 0x50) {
    switch (frame[2]) {
      case PRIM_ACK_POWERUP :
        if (state == SPORT_POWERUP_REQ) {
          state = SPORT_POWERUP_ACK;
        }
        break;

      case PRIM_ACK_VERSION:
        if (state == SPORT_VERSION_REQ) {
          state = SPORT_VERSION_ACK;
          // here we could display the version
        }
        break;

      case PRIM_REQ_DATA_ADDR:
        if (state == SPORT_DATA_TRANSFER) {
          address = *((uint32_t *)(&frame[3]));
          state = SPORT_DATA_REQ;
        }
        break;

      case PRIM_END_DOWNLOAD :
        state = SPORT_COMPLETE ;
        break;

      case PRIM_DATA_CRC_ERR :
        state = SPORT_FAIL ;
        break;
    }
  }
}

void DeviceFirmwareUpdate::startup()
{
  switch(module) {
    case INTERNAL_MODULE:
#if defined(INTMODULE_USART)
      intmoduleSerialStart(57600, true);
      break;
#endif

    default:
      telemetryInit(PROTOCOL_TELEMETRY_FRSKY_SPORT);
      break;
  }

  if (module == INTERNAL_MODULE)
    INTERNAL_MODULE_ON();
  else if (module == EXTERNAL_MODULE)
    EXTERNAL_MODULE_ON();
  else
    SPORT_UPDATE_POWER_ON();
}

const uint8_t * DeviceFirmwareUpdate::readFullDuplexFrame(ModuleFifo & fifo, uint32_t timeout)
{
  uint8_t len = 0;
  bool bytestuff = false;
  while (len < 10) {
    uint32_t elapsed = 0;
    uint8_t byte;
    while (!fifo.pop(byte)) {
      RTOS_WAIT_MS(1);
      if (elapsed++ >= timeout) {
        return nullptr;
      }
    }
    if (byte == 0x7D) {
      bytestuff = true;
      continue;
    }
    if (bytestuff) {
      frame[len] = 0x20 ^ byte;
      bytestuff = false;
    }
    else {
      frame[len] = byte;
    }
    if (len > 0 || byte == 0x7E) {
      ++len;
    }
  }
  return &frame[1];
}

const uint8_t * DeviceFirmwareUpdate::readHalfDuplexFrame(uint32_t timeout)
{
  for (int i=timeout; i>=0; i--) {
    uint8_t byte ;
    while (telemetryGetByte(&byte)) {
      if (pushFrskyTelemetryData(byte)) {
        return telemetryRxBuffer;
      }
    }
    RTOS_WAIT_MS(1);
  }
  return nullptr;
}

const uint8_t * DeviceFirmwareUpdate::readFrame(uint32_t timeout)
{
  switch(module) {
    case INTERNAL_MODULE:
#if defined(INTMODULE_USART)
      return readFullDuplexFrame(intmoduleFifo, timeout);
#endif

    default:
      return readHalfDuplexFrame(timeout);
  }
}

bool DeviceFirmwareUpdate::waitState(State newState, uint32_t timeout)
{
#if defined(SIMU)
  UNUSED(state);
  UNUSED(timeout);
  return true;
#else
  watchdogSuspend(timeout / 10);

  const uint8_t * frame = readFrame(timeout);
  if (!frame) {
    return false;
  }

  processFrame(frame);
  return state == newState;
#endif
}

void DeviceFirmwareUpdate::startFrame(uint8_t command)
{
  frame[0] = 0x50;
  frame[1] = command;
  memset(&frame[2], 0, 6);
}

// TODO merge this function
void DeviceFirmwareUpdate::sendFrame()
{
  uint8_t * ptr = outputTelemetryBuffer;
  *ptr++ = 0x7E;
  *ptr++ = 0xFF;
  frame[7] = crc16(frame, 7);
  for (int i=0; i<8; i++) {
    if (frame[i] == 0x7E || frame[i] == 0x7D) {
      *ptr++ = 0x7D;
      *ptr++ = 0x20 ^ frame[i];
    }
    else {
      *ptr++ = frame[i];
    }
  }

  switch(module) {
    case INTERNAL_MODULE:
#if defined(INTMODULE_USART)
      return intmoduleSendBuffer(outputTelemetryBuffer, ptr-outputTelemetryBuffer);
#endif

    default:
      return sportSendBuffer(outputTelemetryBuffer, ptr-outputTelemetryBuffer);
  }
}

const char * DeviceFirmwareUpdate::sendPowerOn()
{
  state = SPORT_POWERUP_REQ;
  waitState(SPORT_IDLE, 50); // Wait 50ms and clear the fifo
  for (int i=0; i<10; i++) {
    // max 10 attempts
    startFrame(PRIM_REQ_POWERUP);
    sendFrame();
    if (waitState(SPORT_POWERUP_ACK, 100))
      return nullptr;
  }

  if (telemetryProtocol != PROTOCOL_TELEMETRY_FRSKY_SPORT) {
    return TR("Not responding", "Not S.Port 1");
  }

  if (!IS_FRSKY_SPORT_PROTOCOL()) {
    return TR("Not responding", "Not S.Port 2");
  }
#if defined(PCBX7)
  if (IS_PCBREV_40()) {
    return TR("Bottom pin no resp", "Bottom pin not responding");
  }
  else {
    return TR("Module pin no resp", "Module pin not responding");
  }
#else
  return TR("Not responding", "Module not responding");
#endif
}

const char * DeviceFirmwareUpdate::sendReqVersion()
{
  waitState(SPORT_IDLE, 20); // Clear the fifo
  state = SPORT_VERSION_REQ;
  for (int i=0; i<10; i++) {
    // max 10 attempts
    startFrame(PRIM_REQ_VERSION) ;
    sendFrame();
    if (waitState(SPORT_VERSION_ACK, 100))
      return nullptr;
  }
  return "Version request failed";
}

const char * DeviceFirmwareUpdate::uploadFile(const char *filename)
{
  FIL file;
  uint32_t buffer[1024 / sizeof(uint32_t)];
  UINT count;

  if (f_open(&file, filename, FA_READ) != FR_OK) {
    return "Error opening file";
  }

  waitState(SPORT_IDLE, 200); // Clear the fifo
  state = SPORT_DATA_TRANSFER;
  startFrame(PRIM_CMD_DOWNLOAD);
  sendFrame();

  while (1) {
    if (f_read(&file, buffer, 1024, &count) != FR_OK) {
      f_close(&file);
      return "Error reading file";
    }

    count >>= 2;

    for (uint32_t i=0; i<count; i++) {
      if (!waitState(SPORT_DATA_REQ, 2000)) {
        return "Module refused data";
      }
      startFrame(PRIM_DATA_WORD);
      uint32_t offset = (address & 1023) >> 2; // 32 bit word offset into buffer
      *((uint32_t *)(frame + 2)) = buffer[offset];
      frame[6] = address & 0x000000FF;
      state = SPORT_DATA_TRANSFER,
      sendFrame();
      if (i == 0) {
        drawProgressBar(STR_WRITING, file.fptr, file.obj.objsize);
      }
    }

    if (count < 256) {
      f_close(&file);
      return nullptr;
    }
  }
}

const char * DeviceFirmwareUpdate::endTransfer()
{
  if (!waitState(SPORT_DATA_REQ, 2000))
    return "Module refused data";
  startFrame(PRIM_DATA_EOF);
  sendFrame();
  if (!waitState(SPORT_COMPLETE, 2000)) {
    return "Module rejected firmware";
  }
  return nullptr;
}

void DeviceFirmwareUpdate::flashFile(const char * filename)
{
  pausePulses();

  uint8_t intPwr = IS_INTERNAL_MODULE_ON();
  uint8_t extPwr = IS_EXTERNAL_MODULE_ON();

  INTERNAL_MODULE_OFF();
  EXTERNAL_MODULE_OFF();
  SPORT_UPDATE_POWER_OFF();

  /* wait 2s off */
  watchdogSuspend(2000);
  RTOS_WAIT_MS(2000);

  startup();

  const char * result = sendPowerOn();
  if (!result) result = sendReqVersion();
  if (!result) result = uploadFile(filename);
  if (!result) result = endTransfer();

  AUDIO_PLAY(AU_SPECIAL_SOUND_BEEP1 );
  BACKLIGHT_ENABLE();

  if (result) {
    POPUP_WARNING(STR_FIRMWARE_UPDATE_ERROR);
    SET_WARNING_INFO(result, strlen(result), 0);
  }
  else {
    POPUP_INFORMATION(STR_FIRMWARE_UPDATE_SUCCESS);
  }

  INTERNAL_MODULE_OFF();
  EXTERNAL_MODULE_OFF();
  SPORT_UPDATE_POWER_OFF();

  waitState(SPORT_IDLE, 500); // Clear the fifo

  /* wait 2s off */
  watchdogSuspend(2000);
  RTOS_WAIT_MS(2000);

  if (intPwr)
    INTERNAL_MODULE_ON();
  if (extPwr)
    EXTERNAL_MODULE_ON();

  state = SPORT_IDLE;

  resumePulses();
}