#include <Wire.h>
#include "Adafruit_MCP23017.h"

Adafruit_MCP23017 mcp;

int debug = 13;                 //Led de debugage

/* Definition des octets de la charte midi */
#define midi_start 0xFA         
#define midi_stop 0xFC
#define midi_clock 0xF8
#define midi_continue 0xFB


byte data;                      // Bit 
boolean play_flag = false;
boolean CHOIX = false;
boolean flag = false;
boolean changeFlag = false;
int tickNumber = 0;
float BPM = 0;
float BPM2 = 0;
unsigned int bpmSansFP;
unsigned int bpmSansFP1;
float time2;

byte wireTime;
byte wireTime1;
byte wireTime2;
byte wireTimeFP;
unsigned char wireTimeBuf[2];
unsigned long time = 0;
//unsigned char wireTime[6];

void setup()
{
  digitalWrite(debug, OUTPUT);
  pinMode(2, INPUT_PULLUP);
  Wire.begin(8);                // Bus i2c adressé a la 8
  Wire.onRequest(requestEvent);
  Serial.begin(31250);
  mcp.begin();
  mcp.pinMode(0, OUTPUT);
  mcp.pinMode(1, OUTPUT);
  mcp.pinMode(2, OUTPUT);
  mcp.pinMode(3, OUTPUT);
  mcp.pinMode(4, OUTPUT);
  mcp.pinMode(5, OUTPUT);
  mcp.pinMode(6, OUTPUT);
  mcp.pinMode(7, OUTPUT);
  mcp.pinMode(8, OUTPUT);
  mcp.pinMode(9, OUTPUT);
  mcp.pinMode(10, OUTPUT);
  mcp.pinMode(11, OUTPUT);
  mcp.pinMode(12, OUTPUT);
  mcp.pinMode(13, OUTPUT);
  mcp.pinMode(14, OUTPUT);
  mcp.pinMode(15, OUTPUT);
}

void loop()
{
  if (CHOIX != (digitalRead(2)))
  {
    CHOIX = digitalRead(2);
    play_flag = false;
    allLow();
  }
  int donneesALire = Serial.available();
  donneesALire = (donneesALire / 4);
  while (donneesALire == 1)
  {
    data = Serial.read();
    if (data == midi_start)
    {
      tickNumber = 0;
      play_flag = true;
      allLow();
    }
    else if (data == midi_continue)
    {
      play_flag = true;
    }
    else if (data == midi_stop)
    {
      play_flag = false;
    }
    else if ((data == midi_clock) && (play_flag = true))
    {
      tickNumber++;
      if (tickNumber == 1)
      {
        time = micros();
        mcp.digitalWrite(0, LOW);
        mcp.digitalWrite(7, HIGH);
        mcp.digitalWrite(15, LOW);
        mcp.digitalWrite(8, HIGH);
      }
      if (tickNumber == 2)
      {}
      if (tickNumber == 3)
      {}
      if (tickNumber == 4)
      {
        mcp.digitalWrite(7, LOW);
        mcp.digitalWrite(6, HIGH);
        mcp.digitalWrite(8, LOW);
        mcp.digitalWrite(9, HIGH);
      }
      if (tickNumber == 5)
      {}
      if (tickNumber == 6)
      {}
      if (tickNumber == 7)
      {
        mcp.digitalWrite(6, LOW);
        mcp.digitalWrite(5, HIGH);
        mcp.digitalWrite(9, LOW);
        mcp.digitalWrite(10, HIGH);
      }
      if (tickNumber == 8)
      {}
      if (tickNumber == 9)
      {}
      if (tickNumber == 10)
      {
        mcp.digitalWrite(5, LOW);
        mcp.digitalWrite(4, HIGH);
        mcp.digitalWrite(10, LOW);
        mcp.digitalWrite(11, HIGH);
      }
      if (tickNumber == 11)
      {}
      if (tickNumber == 12)
      {}
      if (tickNumber == 13)
      {
        mcp.digitalWrite(4, LOW);
        mcp.digitalWrite(3, HIGH);
        mcp.digitalWrite(11, LOW);
        mcp.digitalWrite(12, HIGH);
      }
      if (tickNumber == 14)
      {}
      if (tickNumber == 15)
      {}
      if (tickNumber == 16)
      {
        mcp.digitalWrite(3, LOW);
        mcp.digitalWrite(2, HIGH);
        mcp.digitalWrite(12, LOW);
        mcp.digitalWrite(13, HIGH);
      }
      if (tickNumber == 17)
      {}
      if (tickNumber == 18)
      {}
      if (tickNumber == 19)
      {
        mcp.digitalWrite(2, LOW);
        mcp.digitalWrite(1, HIGH);
        mcp.digitalWrite(13, LOW);
        mcp.digitalWrite(14, HIGH);
      }
      if (tickNumber == 20)
      {}
      if (tickNumber == 21)
      {}
      if (tickNumber == 22)
      {
        mcp.digitalWrite(1, LOW);
        mcp.digitalWrite(0, HIGH);
        mcp.digitalWrite(14, LOW);
        mcp.digitalWrite(15, HIGH);
      }
      if (tickNumber == 23)
      {}
      if (tickNumber == 24) // Lorsque 24 tick ont été recus (norme MIDI)
      {
        time = micros() - time;
        time2 = time; // On regarde le temps écoulé depuis le premier tick et l'inscrit dans la variable
        time = 0;
        time = micros();
        BPM = (time2 / 1000);
        BPM2 = (1 / (BPM / 1000)) * 57.52;
        bpmSansFP = (BPM2 * 100);

        wireTime = BPM2;    // Transtypage grace au passage du float a l'octet
        wireTimeFP = (bpmSansFP - (wireTime * 100));    // Transtypage avec une technique différente

        wireTimeBuf[0] = wireTime;
        wireTimeBuf[1] = wireTimeFP;

        tickNumber = 0;
      }
    }
  }
}

void requestEvent()
{
  Wire.write(wireTimeBuf, 2);
}
void allLow()
{
  mcp.digitalWrite(0, LOW);
  mcp.digitalWrite(1, LOW);
  mcp.digitalWrite(2, LOW);
  mcp.digitalWrite(3, LOW);
  mcp.digitalWrite(4, LOW);
  mcp.digitalWrite(5, LOW);
  mcp.digitalWrite(6, LOW);
  mcp.digitalWrite(7, LOW);
  mcp.digitalWrite(8, LOW);
  mcp.digitalWrite(9, LOW);
  mcp.digitalWrite(10, LOW);
  mcp.digitalWrite(11, LOW);
  mcp.digitalWrite(12, LOW);
  mcp.digitalWrite(13, LOW);
  mcp.digitalWrite(14, LOW);
  mcp.digitalWrite(15, LOW);

}