/*
 * This file is part of Espruino, a JavaScript interpreter for Microcontrollers
 *
 * Copyright (C) 2013 Gordon Williams <gw@pur3.co.uk>
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * ----------------------------------------------------------------------------
 * Utilities - reimplementation of jshardware bits in minimal flash
 * ----------------------------------------------------------------------------
 */
#include "platform_config.h"
#ifdef USB
 #include "usb_device.h"
 #include "usbd_cdc_hid.h"
#endif

#include "jshardware.h"

#define BUFFERMASK 8191
char rxBuffer[BUFFERMASK+1];
int rxHead=0, rxTail=0;
char txBuffer[BUFFERMASK+1];
int txHead=0, txTail=0;

static ALWAYS_INLINE uint16_t stmPin(Pin ipin) {
  JsvPinInfoPin pin = pinInfo[ipin].pin;
  return (uint16_t)(1 << (pin-JSH_PIN0));
}

static ALWAYS_INLINE GPIO_TypeDef *stmPort(Pin pin) {
  JsvPinInfoPort port = pinInfo[pin].port;
  return (GPIO_TypeDef *)((char*)GPIOA + (port-JSH_PORTA)*0x0400);
}

bool jshPinGetValue(Pin pin) {
  return GPIO_ReadInputDataBit(stmPort(pin), stmPin(pin)) != 0;
}

void jshPinOutput(Pin pin, bool value) {
  GPIO_InitTypeDef GPIO_InitStructure;
  GPIO_InitStructure.GPIO_Pin = stmPin(pin);
#ifdef STM32API2
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
#else
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
#endif
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(stmPort(pin), &GPIO_InitStructure);

#ifdef STM32API2
    if (value)
      GPIO_SetBits(stmPort(pin), stmPin(pin));
    else
      GPIO_ResetBits(stmPort(pin), stmPin(pin));
#else
    if (value)
      stmPort(pin)->BSRR = stmPin(pin);
    else
      stmPort(pin)->BRR = stmPin(pin);
#endif
}

#ifdef STM32F4

void WWDG_IRQHandler() {
  // why do we need this on the F401?
}

#endif




void SysTick_Handler(void) {
}

bool jshIsUSBSERIALConnected() {
  return true;
}

int jshGetCharToTransmit(IOEventFlags device) {
  if (txHead == txTail) return -1;
  char d = txBuffer[txTail];
  txTail = (txTail+1) & BUFFERMASK;
  return d;
}

void jshPushIOCharEvent(IOEventFlags channel, char charData) {
  rxBuffer[rxHead] = charData;
  rxHead = (rxHead+1) & BUFFERMASK;
  //if (rxHead == rxTail) weHaveOverFlowed();
}

bool jshHasEventSpaceForChars(int n) {
  return true;
}

int jshGetEventsUsed() {
  return 0;
}


void jshDelayMicroseconds(int c) {
  while (c--) {
    int i;
    for (i=0;i<80;i++);
  }
}

int _getc() {
  if (rxHead == rxTail) return -1;
  unsigned char d = (unsigned char)rxBuffer[rxTail];
  rxTail = (rxTail+1) & BUFFERMASK;
  return d;
}

unsigned char _getc_blocking() {
  int c = _getc();
  while (c<0) c=_getc();
  return c;
}

void _putc(char charData) {
  txBuffer[txHead] = charData;
  txHead = (txHead+1) & BUFFERMASK;
}

bool isButtonPressed() {
  return jshPinGetValue(BTN1_PININDEX) == BTN1_ONSTATE;
}

bool jumpToEspruinoBinary() {
  unsigned int *ResetHandler = (unsigned int *)(0x08000000 + ESPRUINO_BINARY_ADDRESS + 4);
  if (ResetHandler==0 || ResetHandler==0xFFFFFFFF)
    return false;
  void (*startPtr)() = *ResetHandler;
  startPtr();
  return true; // should never get here
}

void initHardware() {
#if defined(STM32F3)
 RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);
 RCC_AHBPeriphClockCmd( RCC_AHBPeriph_GPIOA |
                        RCC_AHBPeriph_GPIOB |
                        RCC_AHBPeriph_GPIOC |
                        RCC_AHBPeriph_GPIOD |
                        RCC_AHBPeriph_GPIOE |
                        RCC_AHBPeriph_GPIOF, ENABLE);
#elif defined(STM32F2) || defined(STM32F4)
 RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);
 RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA |
                        RCC_AHB1Periph_GPIOB |
                        RCC_AHB1Periph_GPIOC |
                        RCC_AHB1Periph_GPIOD |
                        RCC_AHB1Periph_GPIOE |
                        RCC_AHB1Periph_GPIOF |
                        RCC_AHB1Periph_GPIOG |
                        RCC_AHB1Periph_GPIOH, ENABLE);
#else
 RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);
 RCC_APB2PeriphClockCmd(
       RCC_APB2Periph_ADC1 |
       RCC_APB2Periph_GPIOA |
       RCC_APB2Periph_GPIOB |
       RCC_APB2Periph_GPIOC |
       RCC_APB2Periph_GPIOD |
       RCC_APB2Periph_GPIOE |
       RCC_APB2Periph_GPIOF |
       RCC_APB2Periph_GPIOG |
       RCC_APB2Periph_AFIO, ENABLE);
#endif

#ifdef BTN1_PININDEX
 GPIO_InitTypeDef GPIO_InitStructure;
#ifdef STM32API2
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
 GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
#else
 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
#endif

 #if defined(BTN1_PINSTATE) 
  #if BTN1_PINSTATE==JSHPINSTATE_GPIO_IN_PULLDOWN
 GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN; 
  #else
   #error Unknown pin state for BTN1
  #endif
 #endif
#endif
 GPIO_InitStructure.GPIO_Pin = stmPin(BTN1_PININDEX);
 GPIO_Init(stmPort(BTN1_PININDEX), &GPIO_InitStructure);

 jshPinOutput(LED1_PININDEX, 1);

  // if button is not set, jump to the address of the binary
  if (!isButtonPressed()) {
    jumpToEspruinoBinary();
    // we could return here - binary might be very obviously corrupted
  }

  // PREEMPTION
  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_4);

  RCC_PCLK1Config(RCC_HCLK_Div2); // PCLK1 must be >13 Mhz for USB to work (see STM32F103 C/D/E errata)
  RCC_PCLK2Config(RCC_HCLK_Div4);

#ifdef ESPRUINOBOARD
#ifndef DEBUG
  // reclaim A13 and A14 for the LEDs
  GPIO_PinRemapConfig(GPIO_Remap_SWJ_Disable, ENABLE); // Disable JTAG/SWD so pins are available
#endif
#endif


  /* System Clock */
  SysTick_CLKSourceConfig(SysTick_CLKSource_HCLK_Div8);
  SysTick_Config(SYSTICK_RANGE-1); // 24 bit
  NVIC_SetPriority(SysTick_IRQn, 0); // Super high priority

  MX_USB_DEVICE_Init();
}