#include "toshiba_ir.h"
#include <stdint.h>
#include <stdio.h>
#include "esp_log.h"
#include "rxTimer.h"
#include <string.h>
#include "config.h"

uint8_t xorBytes(const uint8_t * const start, const uint16_t length);

/**
 * @Analys of Toshiba IR Rx:
 *  0  1  2  3  4  5  6  7  8
 * F2 0D 03 FC 01 D0 A3 00 72       30 Grader
 * F2 0D 03 FC 01 90 A3 00 32       26 Grader
 * F2 0D 03 FC 01 40 A3 00 E2       21 Grader
 * F2 0D 03 FC 01 30 A3 00 92       20 Grader
 * F2 0D 03 FC 01 20 A3 00 82       19 Grader
 * F2 0D 03 FC 01 10 A3 00 B2       18
 * F2 0D 03 FC 01 00 A3 00 A2       17
 * 
 * F2 0D 03 FC 01 D0 03 00 D2       Auto Fan  0000  0 (0 is Auto, 2-6 is the speed, 6 is Max)
 * F2 0D 03 FC 01 D0 43 00 92       1         0100  2
 *                                  2         0110  3
 * F2 0D 03 FC 01 D0 83 00 52       3         1000  4
 *                                  4         1010  5
 * F2 0D 03 FC 01 D0 C3 00 12       5         1100  6
 * 
 * F2 0D 03 FC 01 60 83 00 E2       ON        1000 0011 (3 is ON, 7 is OFF)
 * F2 0D 03 FC 01 60 87 00 E6       OFF       1000 0111
 * 
 */



uint8_t data[kToshibaNumberOfBytes];            // Temp data during rx
uint8_t dataTransfer[kToshibaNumberOfBytes];    // Send as pointer to receiver

enum
{
    UNKNOWN,
    STARTER,
    T0,
    T1,
    DONE
};

static uint8_t rx_state = UNKNOWN;

static uint32_t rx_numBits;


void Toshiba_ir_ResetDecoder()
{
    //ESP_LOGI("T", "Reset decoder");
    rx_numBits = 0;
    rx_state = UNKNOWN;
    memset(data,0,kToshibaNumberOfBytes);
}

static void addBit(uint8_t value)
{
    if( value == 1 ) {

        const uint8_t byteNo = rx_numBits / 8;
        const uint8_t shiftBits = rx_numBits % 8;

        //ESP_LOGI("BIT RX:","%u  %u", byteNo, shiftBits);

        data[byteNo] |= 1u << (7-shiftBits);
    }

    rx_numBits++;
}

#define START_PULSE_MIN (kToshibaAcHdrMark-200)
#define START_PULSE_MAX (kToshibaAcHdrMark+200)

#define T0_PULSE_MIN (kToshibaAcBitMark-100)
#define T0_PULSE_MAX (kToshibaAcBitMark+100)

#define SHORT_PULSE_MIN (kToshibaAcZeroSpace-100)
#define SHORT_PULSE_MAX (kToshibaAcZeroSpace+100)

#define LONG_PULSE_MIN (kToshibaAcOneSpace-100)
#define LONG_PULSE_MAX (kToshibaAcOneSpace+100)


static int32_t rx_decode(uint32_t width)
{
    switch (rx_state) {
        case UNKNOWN: // Start of frame A
            if ( START_PULSE_MIN <= width && width <= START_PULSE_MAX )
            {
                rx_state = STARTER;
                //ESP_LOGI("T", "->STARTER");
            }
            else
            {
                return -1; // error, reset
            }
            break;
        
        case STARTER: // Start of frame B
            if ( START_PULSE_MIN <= width && width <= START_PULSE_MAX )
            {
                rx_state = T0;
                //ESP_LOGI("T", "STARTER");
            }
            else
            {
                return -1; // error, reset
            }
            break;


        case T0: // First half of pulse : HIGH around 230us

            if(rx_numBits == kToshibaNumberOfBits)
            { // end of frame
                //ESP_LOGI("T", "END OF FRAME");
                rx_state = DONE;
                return 1;
            }
            else if( T0_PULSE_MIN <= width && width <= T0_PULSE_MAX )
            {
                rx_state = T1;
                //ESP_LOGI("T", "T0");
            }
            else
            {
                return -1; // error, reset
            }
            break;

        case T1:
            if( SHORT_PULSE_MIN <= width && width <= SHORT_PULSE_MAX )
            {
                addBit(0);
                //ESP_LOGI("T", "Short %u",rx_numBits);
            }
            else if( LONG_PULSE_MIN <= width && width <= LONG_PULSE_MAX )
            {
                addBit(1);
                //ESP_LOGI("T", "Long %u", rx_numBits);
            }
            else
            {
                return -1; // error, reset
            }
            rx_state = T0;
            break;
    }
    return 0;
}



uint8_t* nextPulseToshiba_ir(uint32_t width)
{
    uint8_t* retVal = NULL;

    if (width > 0)
    {
        if (rx_state != DONE)
        {
            switch (rx_decode(width))
            {
            case -1:
                Toshiba_ir_ResetDecoder();
                break;
            case 1:
                rx_state = DONE;
                // Check checksum
                if( xorBytes(data,8) == data[8] ) {
                    memcpy(dataTransfer,data,kToshibaNumberOfBytes);
                    Toshiba_ir_ResetDecoder();
                    retVal = dataTransfer;
                }
                else {
                    ESP_LOGE("TOSHIBA", "WRONG CHKSUM");
                    Toshiba_ir_ResetDecoder();
                }
                break;
            }
        }
    }
    
    return retVal;
}

/// Calculate a rolling XOR of all the bytes of an array.
/// @param[in] start A ptr to the start of the byte array to calculate over.
/// @param[in] length How many bytes to use in the calculation.
/// @return The 8-bit calculated result of all the bytes and init value.
/// Copied from: https://github.com/crankyoldgit/IRremoteESP8266/blob/master/src/IRutils.cpp
uint8_t xorBytes(const uint8_t * const start, const uint16_t length) {
  uint8_t checksum = 0;
  const uint8_t *ptr;
  for (ptr = start; ptr - start < length; ptr++) checksum ^= *ptr;
  return checksum;
}