/*********
  Rui Santos
  Complete project details at https://RandomNerdTutorials.com/raspberry-pi-pico-i2c-scanner-arduino/
  
  Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files.
  The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
*********/
#include <Wire.h>
#include <U8g2lib.h>

#define OLED_RST -1
#define OLED_SCL 5
#define OLED_SDA 4

U8G2_SH1107_128X128_F_HW_I2C u8g2(U8G2_R0, OLED_SCL, OLED_SDA);
 
#define STOP 0
#define PLAY 1
#define FF 2
#define REW 3

const char * stateStr[] = {"STOP" ,"PLAY", "FF", "REW"};
const int nsectors = 6;
int pulses = 0;
int turns = 0;
int sector = 0;
int state = STOP;
double tapeSpeed = 15.0;
double tapeTime = 12.8;
double tapeTimeLeft = 17.2;
double outsideDiam = 4.2;

const byte playPin = 11;
const byte ffPin = 12;
const byte rewPin = 13;
const byte stopPin = 14;


// calculate time from tape length and speed and display it on the OLED
// currently with the standard arduino, it is not fast wenouh to do this display 
// for every loop iteration, so on;y do this while stopped 
void displayTimes() {
  //Serial.print("8-");Serial.print(turns);Serial.print("/");Serial.println(sector);
   // update global time
  int mins = int(tapeTime / 60.0);
  double secs = tapeTime - 60.0 * mins;
  //Serial.print("4-");Serial.print(mins);Serial.print(":");Serial.println(secs);
  u8g2.drawFrame(0, 64, 128,64);
  u8g2.setCursor(6, 88);
  u8g2.setFont(u8g2_font_t0_16_tr);
  u8g2.print(F("Time:"));
  u8g2.setFont(u8g2_font_t0_18_tr);
  u8g2.setCursor(64, 88);
  u8g2.print(tapeTime);
  u8g2.setFont(u8g2_font_t0_12_tr );
  int minsLeft = int(tapeTimeLeft / 60.0);
  double secsLeft = tapeTimeLeft - 60.0 * minsLeft;
  u8g2.setCursor(10, 112);
  u8g2.print(String("Time Left:") + String(minsLeft) + String(":") + String(secsLeft, 1));

  u8g2.setCursor(10, 124);
  u8g2.print(F("Diameter: "));
  u8g2.print(outsideDiam, 1);
}

void displayState() {
  u8g2.setFont(u8g2_font_t0_12_tr); 
  u8g2.setCursor(6, 18);
  u8g2.print(stateStr[state]);
  u8g2.setFont(u8g2_font_inb27_mr);
  u8g2.setCursor(10, 52);
  u8g2.print(String(turns) + "/" + String(sector));
 }

void doDisplay(int n) {
    u8g2.clearBuffer();
    displayState();
    if (n == 2) {
      //updateGlobals(turns, sector);
      u8g2.drawFrame(0, 0, 128, 64);
      displayTimes();
    }
    u8g2.sendBuffer();
}



// arduino's initialization function
void setup() {
  Serial1.begin(115200);//enable serial monitor
  delay(1000);
  Serial1.println("STARTED");

  u8g2.begin(); 
 
  delay(1000);         // wait for initializing

  doDisplay(2);

  pinMode(playPin, INPUT);
  pinMode(ffPin, INPUT);
  pinMode(rewPin, INPUT);
  pinMode(stopPin,  INPUT);
  Serial1.println("SET UP");
 
}

int lastState = PLAY;

void setState() {
  ulong t = millis();
  int play = digitalRead(playPin);
  int ff= digitalRead(ffPin);
  int rew = digitalRead(rewPin);
  int stop= digitalRead(stopPin);
  //Serial1.print(String(play) + " " + String(ff) + " " + String(rew) + " " + String(stop) + " ");
  if (stop == HIGH) {
    // one of play/ff/rew is now low
    if (play == LOW) {
      state = PLAY;
    } else if (ff == LOW){
      state = FF;
    } else if (rew == LOW){
      state = REW;
    } else {
      state = STOP;
    }
    if (state != lastState) {
      Serial1.print(millis() - t);Serial1.print(":");Serial1.println(stateStr[state]);
      lastState = state;
    }
  } else {
    if (lastState != STOP) {
      Serial1.println("STOPPED");
      lastState = state;
    }
  }
}
 

void loop() {

  setState();
  
  pulses += 1;
  turns = pulses / nsectors;
  sector = pulses % nsectors + 1;

  doDisplay(2);
  delay(100);
}