/*
  William Rice, USA
  Based on Arduino Reaction Timer using an RGB LCD 16x2 Character Display
  Derek Molloy, DCU, Ireland.
*/

#include <TM1637Display.h> // Include the TM1637Display library for controlling LED displays

// Define pin assignments for the three LED displays
int CLK1 = 8;  // Clock pin for the first display
int DIO1 = 9;  // Data pin for the first display
int CLK2 = 10; // Clock pin for the second display
int DIO2 = 11; // Data pin for the second display
int CLK3 = 12; // Clock pin for the third display
int DIO3 = 13; // Data pin for the third display
int resetPin = A1; // Pin connected to reset function
int count = 0; // Variable to store count

// Define pin assignments for LEDs, buttons, and program selection
int ledPin1 = A3; // Pin for the first red stop LED
int ledPin2 = A2; // Pin for the second red stop LED
int sel1 = 2;     // Pin for selecting program 1
int sel2 = 3;     // Pin for selecting program 2
int sel3 = 4;     // Pin for selecting program 3
int start = 5;    // Pin for starting program
int buttonPin1 = 6; // Pin for reaction timer button1
int buttonPin2 = 7; // Pin for reaction timer button2

// Initialize display objects for the three LED displays
TM1637Display display1 = TM1637Display(CLK1, DIO1); // First LED display object
TM1637Display display2 = TM1637Display(CLK3, DIO3); // Second LED display object
TM1637Display display3 = TM1637Display(CLK2, DIO2); // Third LED display object

// Define states for the program
enum State {prepareState, waitState, timingState}; // Enumeration for different states
State currentState = prepareState; // Initial state is prepareState

// Setup function - called only once
void setup() {
  // Set display brightness
  display1.setBrightness(5);
  display2.setBrightness(5);
  display3.setBrightness(5);

  // Set reset pin high
  digitalWrite(resetPin, HIGH); // Set the reset pin to HIGH initially
  pinMode(resetPin, OUTPUT); // Set the reset pin as an output
  
  // Set pin modes
  pinMode(ledPin1, OUTPUT); // Set ledPin1 as an output
  pinMode(ledPin2, OUTPUT); // Set ledPin2 as an output
  pinMode(buttonPin1, INPUT); // Set buttonPin1 as an input
  pinMode(buttonPin2, INPUT); // Set buttonPin2 as an input
  pinMode(sel1, INPUT); // Set sel1 as an input
  pinMode(sel2, INPUT); // Set sel2 as an input
  pinMode(sel3, INPUT); // Set sel3 as an input
  pinMode(start, INPUT); // Set start as an input

  // Seed random number generator
  randomSeed(analogRead(0)); // Seed the random number generator with an analog reading
}

// Loop function - runs continuously
void loop() {
  count = millis(); // Get current time in milliseconds
  count++; // Increment count

  // Check if sel2 is true
  if (digitalRead(sel2) == true) { // Check if select pin 2 is HIGH
    switch (currentState) { // Check the current state
      case prepareState: // If in prepare state
        digitalWrite(ledPin1, LOW); // Turn off LED 1
        digitalWrite(ledPin2, LOW); // Turn off LED 2
        long randomDelayTime = random(1000, 5000); // Generate random delay between 1 to 5 seconds
        while ((digitalRead(buttonPin1) == true) || (digitalRead(buttonPin2) == true)) {} // Wait until both buttons are released
        currentState = waitState; // Change state to wait state
        display1.clear(); // Clear display 1
        display2.clear(); // Clear display 2
        display3.clear(); // Clear display 3
        display2.showNumberDecEx(randomDelayTime, false, 2, 4); // Show random delay time on display 2
        break;
      
      case waitState: // If in wait state
        delay(randomDelayTime); // Wait for the random delay time
        digitalWrite(ledPin1, HIGH); // Turn on LED 1
        digitalWrite(ledPin2, HIGH); // Turn on LED 2
        currentState = timingState; // Change state to timing state
        long timerStartMillis = millis(); // Record the start time
        break;
      
      case timingState: // If in timing state
        if (digitalRead(buttonPin1) == true) { // Check if button 1 is pressed
          long timerEndMillis = millis(); // Record the end time
          digitalWrite(ledPin1, LOW); // Turn off LED 1
          long difference = timerEndMillis - timerStartMillis; // Calculate the difference in time
          display1.clear(); // Clear display 1
          display1.showNumberDecEx(difference, false, 2, 4); // Show reaction time on display 1
          delay(5000); // Delay for 5 seconds
          currentState = prepareState; // Change state to prepare state
          break;
        }
        else if (digitalRead(buttonPin2) == true) { // Check if button 2 is pressed
          long timerEndMillis = millis(); // Record the end time
          digitalWrite(ledPin2, LOW); // Turn off LED 2
          long difference = timerEndMillis - timerStartMillis; // Calculate the difference in time
          display1.clear(); // Clear display 1
          display3.showNumberDecEx(difference, false, 2, 4); // Show reaction time on display 3
          delay(5000); // Delay for 5 seconds
          currentState = prepareState; // Change state to prepare state
          break;
        }

        long countt = count - randomDelayTime; // Calculate the difference between count and random delay time
        if (countt >= 5000) { // If countt is greater than or equal to 5000
          digitalWrite(resetPin, LOW); // Reset timer
        }
    }
  }
}