/*
 *  spreadspace avr utils
 *
 *
 *  Copyright (C) 2012 Christian Pointner <equinox@spreadspace.org>
 *
 *  This file is part of spreadspace avr utils.
 *
 *  spreadspace avr utils is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  any later version.
 *
 *  spreadspace avr utils 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.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with spreadspace avr utils. If not, see <http://www.gnu.org/licenses/>.
 */


#include <avr/io.h>
#include <avr/wdt.h>
#include <avr/interrupt.h>
#include <avr/power.h>

#include "util.h"
#include "led.h"

/*
             LUFA Library
     Copyright (C) Dean Camera, 2012.

  dean [at] fourwalledcubicle [dot] com
           www.lufa-lib.org
*/
#include <LUFA/Drivers/Peripheral/SPI.h>
#include <LUFA/Drivers/Misc/RingBuffer.h>
#include <LUFA/Drivers/USB/USB.h>
#include "lufa-descriptor-usbserial.h"

    /* Global I/O Buffers: */
static RingBuffer_t SPItoUSB_Buffer;
static uint8_t      SPItoUSB_Buffer_Data[16];

/** LUFA CDC Class driver interface configuration and state information. This structure is
 *  passed to all CDC Class driver functions, so that multiple instances of the same class
 *  within a device can be differentiated from one another.
 */
USB_ClassInfo_CDC_Device_t VirtualSerial_CDC_Interface =
  {
    .Config =
      {
        .ControlInterfaceNumber         = 0,

        .DataINEndpointNumber           = CDC_TX_EPNUM,
        .DataINEndpointSize             = CDC_TXRX_EPSIZE,
        .DataINEndpointDoubleBank       = false,

        .DataOUTEndpointNumber          = CDC_RX_EPNUM,
        .DataOUTEndpointSize            = CDC_TXRX_EPSIZE,
        .DataOUTEndpointDoubleBank      = false,

        .NotificationEndpointNumber     = CDC_NOTIFICATION_EPNUM,
        .NotificationEndpointSize       = CDC_NOTIFICATION_EPSIZE,
        .NotificationEndpointDoubleBank = false,
      },
  };

void EVENT_USB_Device_ConfigurationChanged(void)
{
  CDC_Device_ConfigureEndpoints(&VirtualSerial_CDC_Interface);
}

void EVENT_USB_Device_ControlRequest(void)
{
  CDC_Device_ProcessControlRequest(&VirtualSerial_CDC_Interface);
}
/* end LUFA CDC-ACM specific definitions*/


    /* Hardware Defines: */
#define SPI_CS_DDR DDRB
#define SPI_CS_PORT PORTB
#define CS   0
#define PWRDWN_DDR DDRB
#define PWRDWN_PORT PORTB
#define PWRDWN   7
#define INT_DDR DDRD
#define INT_PORT PORTD
#define INT_PIN PIND
#define INT  0

volatile unsigned char cnt = 0;

void SetupHardware(void)
{
  MCUSR &= ~(1 << WDRF);
  wdt_disable();

  cpu_init();
  led_init();
  USB_Init();

  TCCR0B = (1 << CS02);

  SPI_Init(SPI_SPEED_FCPU_DIV_8  | SPI_MODE_MASTER | SPI_ORDER_MSB_FIRST | 
           SPI_SCK_LEAD_RISING | SPI_SAMPLE_LEADING);
  SPI_CS_DDR |= (1<<CS);
  SPI_CS_PORT |= (1<<CS);

  PWRDWN_DDR |= (1<<PWRDWN);
  PWRDWN_PORT |= (1<<PWRDWN);

  INT_DDR &= ~(1<<INT);
  INT_PORT |= (1<<INT);
}

void IDM_SendCmd(uint8_t cmd)
{
  led_on();
  SPI_CS_PORT &= ~(1<<CS);
  SPI_SendByte(cmd);
  SPI_CS_PORT |= (1<<CS);
  led_off();
}

unsigned char tmp_cnt = 0;

void IDM_ReadData(void)
{
  /* uint8_t int_state = (INT_PIN & (1<<INT)); */
  /* while(!int_state) {  */
  /*   RingBuffer_Insert(&SPItoUSB_Buffer, tmp_cnt); */
  /*   /\* tmp_cnt = tmp_cnt >= 255 ? 32 : tmp_cnt+1; *\/ */
  /*   tmp_cnt++; */
  /*   if(RingBuffer_IsFull(&SPItoUSB_Buffer)) */
  /*     break; */
  /*   int_state = (INT_PIN & (1<<INT)); */
  /* } */

  led_on();
  SPI_CS_PORT &= ~(1<<CS);
  _delay_us(100);

  SPI_SendByte('r');
  _delay_us(30);
  uint8_t int_state = (INT_PIN & (1<<INT));
  while(!int_state) {
    uint8_t ReceivedByte = SPI_TransferByte(0);
    /* if(ReceivedByte == tmp_cnt) */
    /*   RingBuffer_Insert(&SPItoUSB_Buffer, '.'); */
    /* else */
    /*   RingBuffer_Insert(&SPItoUSB_Buffer, 'e'); */
    RingBuffer_Insert(&SPItoUSB_Buffer, ReceivedByte);
    tmp_cnt++;

    /* if(RingBuffer_IsFull(&SPItoUSB_Buffer)) */
    if(RingBuffer_GetFreeCount(&SPItoUSB_Buffer) == 1)
      break;
    _delay_us(70);
    int_state = (INT_PIN & (1<<INT));
  }
  
  RingBuffer_Insert(&SPItoUSB_Buffer, 128);
  
  _delay_us(30);
  SPI_CS_PORT |= (1<<CS);
  _delay_us(50);
  led_off();
}

int main(void)
{
  SetupHardware();
  RingBuffer_InitBuffer(&SPItoUSB_Buffer, SPItoUSB_Buffer_Data, sizeof(SPItoUSB_Buffer_Data));
  sei();

  for (;;) {
    int16_t BytesReceived = CDC_Device_BytesReceived(&VirtualSerial_CDC_Interface);
    while(BytesReceived > 0) {
      int16_t ReceivedByte = CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
      if (ReceivedByte >= 0) {
        switch(ReceivedByte) {
        case 'p': PWRDWN_PORT &= ~(1<<PWRDWN); break;
        case 'P': PWRDWN_PORT |= (1<<PWRDWN); break;
        case 'r': break;
        default: IDM_SendCmd(ReceivedByte); break;
        }
      }
      BytesReceived--;
    }

    if(!(INT_PIN & (1<<INT)))
      IDM_ReadData();

    uint16_t BufferCount = RingBuffer_GetCount(&SPItoUSB_Buffer);
    if ((TIFR0 & (1 << TOV0)) || (BufferCount > (uint8_t)(sizeof(SPItoUSB_Buffer_Data) * .75))) {
      TIFR0 |= (1 << TOV0);
      while (BufferCount--) {
        if(CDC_Device_SendByte(&VirtualSerial_CDC_Interface,
                               RingBuffer_Peek(&SPItoUSB_Buffer)) != ENDPOINT_READYWAIT_NoError)
          break;

        RingBuffer_Remove(&SPItoUSB_Buffer);
      }
    }

    CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
    USB_USBTask();
  }
}