/**
 * @file      bluetooth_driver.c
 * @version   V1.0.0    
 * @date      2014-11-10
 * @brief     bluetooth driver for Tananis.    
 * @author    - Adela 
 *            - Robert Zhang <armner@gmail.com>
 *            - 
 */

#include "board_taranis.h"
#include "string.h"
#include "../../fifo.h"

Fifo<64> btTxFifo;
Fifo<64> btRxFifo;

void bluetoothInit(uint32_t baudrate)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  USART_InitTypeDef USART_InitStructure;

  USART_DeInit(BT_USART);

  RCC_AHB1PeriphClockCmd(BT_RCC_AHB1Periph, ENABLE);
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART6, ENABLE);

  GPIO_InitStructure.GPIO_Pin = BT_GPIO_PIN_BRTS;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
  GPIO_Init(BT_GPIO_BRTS, &GPIO_InitStructure);
  GPIO_SetBits(BT_GPIO_BRTS, BT_GPIO_PIN_BRTS);

  GPIO_InitStructure.GPIO_Pin = BT_GPIO_PIN_EN;
  GPIO_Init(BT_GPIO_EN, &GPIO_InitStructure);

  GPIO_InitStructure.GPIO_Pin = BT_GPIO_PIN_BCTS;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
  GPIO_Init(BT_GPIO_BCTS, &GPIO_InitStructure);
	
  GPIO_InitStructure.GPIO_Pin = BT_GPIO_PIN_TX|BT_GPIO_PIN_RX;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
  GPIO_Init(BT_GPIO_TXRX, &GPIO_InitStructure);

  GPIO_PinAFConfig(BT_GPIO_TXRX, BT_GPIO_PinSource_TX, BT_GPIO_AF);
  GPIO_PinAFConfig(BT_GPIO_TXRX, BT_GPIO_PinSource_RX, BT_GPIO_AF);

  USART_InitStructure.USART_BaudRate = baudrate;
  USART_InitStructure.USART_Parity = USART_Parity_No;
  USART_InitStructure.USART_StopBits = USART_StopBits_1;
  USART_InitStructure.USART_WordLength = USART_WordLength_8b;
  USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
  USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
  USART_Init(BT_USART, &USART_InitStructure);

  USART_Cmd(BT_USART, ENABLE);
  USART_ITConfig(BT_USART, USART_IT_RXNE, ENABLE);

  NVIC_InitTypeDef NVIC_InitStructure;
  NVIC_InitStructure.NVIC_IRQChannel = BT_USART_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 8;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);

  GPIO_ResetBits(BT_GPIO_EN, BT_GPIO_PIN_EN); // open bluetooth
}

enum BluetoothState
{
  BLUETOOTH_INIT,
  BLUETOOTH_WAIT_TTM,
  BLUETOOTH_WAIT_BAUDRATE_CHANGE,
  BLUETOOTH_OK,
};

enum BluetoothWriteState
{
  BLUETOOTH_WRITE_IDLE,
  BLUETOOTH_WRITE_INIT,
  BLUETOOTH_WRITING,
  BLUETOOTH_WRITE_DONE
};

volatile uint8_t bluetoothState = BLUETOOTH_INIT;
volatile uint8_t bluetoothWriteState = BLUETOOTH_WRITE_IDLE;

extern "C" void USART6_IRQHandler(void)
{
  if (USART_GetITStatus(BT_USART, USART_IT_RXNE) != RESET) {
    USART_ClearITPendingBit(BT_USART, USART_IT_RXNE);
    uint8_t byte = USART_ReceiveData(BT_USART);
    btRxFifo.push(byte);
  }

  if (USART_GetITStatus(BT_USART, USART_IT_TXE) != RESET) {
    uint8_t byte;
    bool result = btTxFifo.pop(byte);
    if (result) {
      USART_SendData(BT_USART, byte);
    }
    else {
      USART_ITConfig(BT_USART, USART_IT_TXE, DISABLE);
      bluetoothWriteState = BLUETOOTH_WRITE_DONE;
    }
  }
}

void bluetoothWrite(const void * buffer, int len)
{
  uint8_t * data = (uint8_t *)buffer;
  for (int i=0; i<len; ++i) {
    btTxFifo.push(data[i]);
  }
}

void bluetoothWriteString(const char * str)
{
  while (*str != 0) {
    btTxFifo.push(*str++);
  }
}

void bluetoothWriteWakeup(void)
{
  if (bluetoothWriteState == BLUETOOTH_WRITE_IDLE) {
    if (!btTxFifo.empty()) {
      bluetoothWriteState = BLUETOOTH_WRITE_INIT;
      GPIO_ResetBits(BT_GPIO_BRTS, BT_GPIO_PIN_BRTS);
    }
  }
  else if (bluetoothWriteState == BLUETOOTH_WRITE_INIT) {
    bluetoothWriteState = BLUETOOTH_WRITING;
    USART_ITConfig(BT_USART, USART_IT_TXE, ENABLE);
  }
  else if (bluetoothWriteState == BLUETOOTH_WRITE_DONE) {
    bluetoothWriteState = BLUETOOTH_WRITE_IDLE;
    GPIO_SetBits(BT_GPIO_BRTS, BT_GPIO_PIN_BRTS);
  }
}

void bluetoothWakeup(void)
{
  if (bluetoothState != BLUETOOTH_OK) {
    static tmr10ms_t waitEnd = 0;

    if (bluetoothState == BLUETOOTH_INIT) {
      const char btMessage[] = "TTM:REN-Taranis";
      bluetoothWriteString(btMessage);
      bluetoothState = BLUETOOTH_WAIT_TTM;
      waitEnd = get_tmr10ms() + 25/*250*s*/;
    }
    else if (bluetoothState == BLUETOOTH_WAIT_TTM) {
      if (get_tmr10ms() > waitEnd) {
        char ttm[] = "TTM:REN";
        int index = 0;
        uint8_t c;
        bool found = false;
        while (btRxFifo.pop(c)) {
          if (c == ttm[index]) {
            index++;
            if (index == sizeof(ttm)-1) {
              found = true;
              break;
            }
          }
          else {
            index = 0;
          }
        }
        if (found) {
          bluetoothState = BLUETOOTH_OK;
        }
        else {
          bluetoothInit(9600);
          const char btMessage[] = "TTM:BPS-115200";
          bluetoothWriteString(btMessage);
          bluetoothState = BLUETOOTH_WAIT_BAUDRATE_CHANGE;
          waitEnd = get_tmr10ms() + 250;
        }
      }
    }
    else if (bluetoothState == BLUETOOTH_WAIT_BAUDRATE_CHANGE) {
      if (get_tmr10ms() > waitEnd) {
        bluetoothInit(115200);
        bluetoothState = BLUETOOTH_OK;
      }
    }
  }

  bluetoothWriteWakeup();
}

uint8_t bluetoothReady()
{
  return (bluetoothState == BLUETOOTH_OK);
}

int bluetoothRead(void * buffer, int len)
{
  int result = 0;
  uint8_t * data = (uint8_t *)buffer;
  while (result < len) {
    uint8_t byte;
    if (!btRxFifo.pop(byte)) {
      break;
    }
    data[result++] = byte;
  }
  return result;
}

void bluetoothDone()
{
  GPIO_SetBits(BT_GPIO_EN, BT_GPIO_PIN_EN); // close bluetooth
}