#include <WiFi.h> // WiFi header file
#include <PubSubClient.h> // MQTT publish and subscribe header file
#include <Wire.h> // I2C header file
#include <LiquidCrystal_I2C.h> // I2C lcd header file
#include <Arduino.h> 

// === Robert Gardner ====
// Final Project Component, Option 1

// WiFi and MQTT Settings
const char* ssid = "Wokwi-GUEST"; // Replace with your WiFi SSID
const char* password = ""; // Replace with your WiFi password
const char* mqttServer = "test.mosquitto.org"; // MQTT broker
int port = 1883;

// MQTT Client Variables
String macAddressString;
char macAddress[50];
char clientId[50];
WiFiClient espClient;
PubSubClient client(espClient);

// LCD Setup
LiquidCrystal_I2C lcd(0x27, 16, 2);

// LED and Button Pins
const int redLightNorthSouth = 14;
const int yellowLightNorthSouth = 12;
const int greenLightNorthSouth = 13;
const int redLightEastWest = 25;
const int yellowLightEastWest = 26;
const int greenLightEastWest = 27;
const int crossWalkButton = 19;
const int emergencyBlueLED = 16;
const int buzzerPin = 32;

// Timing Constants
const int walkTime = 10000; // 10 seconds
const int yellowTime = 2000; // 2 seconds
const int redTime = 3000; // 3 seconds

// State Variables
int crossWalkButtonState = 1; // 0: button pressed, 1: button not pressed
int loopCount = 0; 
int secondsLeft = 0;
int iotControl = 0; // 0: normal mode, 1: emergency mode

// Function Prototypes
void wifiConnect();
void mqttReconnect();
void callback(char* topic, byte* message, unsigned int length);
void handleNormalTraffic();
void handlePedestrianSignal();

void setup() {
  Serial.begin(115200);
  randomSeed(analogRead(0));
  delay(10);
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);
  wifiConnect();
  
  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
  Serial.println(WiFi.macAddress());
  macAddressString = WiFi.macAddress();
  macAddressString.replace(":", "_");
  strcpy(macAddress, macAddressString.c_str()); // Copy to char array
  Serial.println(macAddressString);

  // MQTT Setup
  client.setServer(mqttServer, port);
  client.setCallback(callback);

  // Initialize Pins
  pinMode(crossWalkButton, INPUT_PULLUP);
  attachInterrupt(crossWalkButton, buttonPressed, FALLING);
  pinMode(redLightNorthSouth, OUTPUT);
  pinMode(yellowLightNorthSouth, OUTPUT);
  pinMode(greenLightNorthSouth, OUTPUT);
  pinMode(redLightEastWest, OUTPUT);
  pinMode(yellowLightEastWest, OUTPUT);
  pinMode(greenLightEastWest, OUTPUT);
  pinMode(emergencyBlueLED, OUTPUT);
  pinMode(buzzerPin, OUTPUT);

  // LCD Setup
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("=== CEIS-114 ===");
}

void wifiConnect() {
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
}

void mqttReconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    long r = random(1000);
    sprintf(clientId, "clientId-%ld", r);
    if (client.connect(clientId)) {
      Serial.print(clientId);
      Serial.println(" connected");
      client.subscribe("LED");
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      delay(5000);
    }
  }
}

void callback(char* topic, byte* message, unsigned int length) {
  String stMessage;
  for (int i = 0; i < length; i++) {
    stMessage += (char)message[i];
  }
  if (String(topic) == "LED") {
    if (stMessage == "ON") {
      iotControl = 1;
    } else if (stMessage == "OFF") {
      iotControl = 0;
    }
  }
}

void handleNormalTraffic() {
  // Red - Green - Yellow cycle for North-South and East-West
  // (Red for NS, Green for EW)
  digitalWrite(redLightNorthSouth, HIGH);
  digitalWrite(yellowLightNorthSouth, LOW);
  digitalWrite(greenLightNorthSouth, LOW);
  digitalWrite(redLightEastWest, LOW);
  digitalWrite(yellowLightEastWest, LOW);
  digitalWrite(greenLightEastWest, HIGH); 
  delay(redTime);

  // (Yellow for EW)
  digitalWrite(redLightNorthSouth, HIGH);
  digitalWrite(yellowLightNorthSouth, LOW);
  digitalWrite(greenLightNorthSouth, LOW);
  digitalWrite(redLightEastWest, LOW);
  digitalWrite(yellowLightEastWest, HIGH); 
  digitalWrite(greenLightEastWest, LOW); 
  delay(yellowTime);

  // (Red for EW, Green for NS)
  digitalWrite(redLightNorthSouth, LOW);
  digitalWrite(yellowLightNorthSouth, LOW);
  digitalWrite(greenLightNorthSouth, HIGH); 
  digitalWrite(redLightEastWest, HIGH);
  digitalWrite(yellowLightEastWest, LOW);
  digitalWrite(greenLightEastWest, LOW); 
  delay(redTime);

  // (Yellow for NS)
  digitalWrite(redLightNorthSouth, LOW);
  digitalWrite(yellowLightNorthSouth, HIGH); 
  digitalWrite(greenLightNorthSouth, LOW); 
  digitalWrite(redLightEastWest, HIGH);
  digitalWrite(yellowLightEastWest, LOW);
  digitalWrite(greenLightEastWest, LOW); 
  delay(yellowTime);

  // (Red for NS, Green for EW)
  digitalWrite(redLightNorthSouth, HIGH);
  digitalWrite(yellowLightNorthSouth, LOW);
  digitalWrite(greenLightNorthSouth, LOW); 
  digitalWrite(redLightEastWest, LOW);
  digitalWrite(yellowLightEastWest, LOW);
  digitalWrite(greenLightEastWest, HIGH); 
  delay(redTime);
}

void handlePedestrianSignal() {
  // Pedestrian Signal Logic
  // Turn off all LEDs
  digitalWrite(yellowLightNorthSouth, LOW);
  digitalWrite(greenLightNorthSouth, LOW);
  digitalWrite(yellowLightEastWest, LOW);
  digitalWrite(greenLightEastWest, LOW);

  // Turn on red LEDs for both sides
  digitalWrite(redLightNorthSouth, HIGH);
  digitalWrite(redLightEastWest, HIGH);

  // "Walk" countdown
  for (int i = 10; i >= 0; i--) {
    Serial.print(" == Walk == ");
    Serial.println(i);
    lcd.setCursor(0, 1);
    lcd.print("  == Walk ==  ");
    lcd.setCursor(14, 1);
    lcd.print(i);
    digitalWrite(buzzerPin, HIGH);
    delay(500);
    digitalWrite(buzzerPin, LOW);
    delay(500);
  }

  // Turn off Red LEDs
  digitalWrite(redLightNorthSouth, LOW);
  digitalWrite(redLightEastWest, LOW);

  // Yellow LED for both sides
  digitalWrite(yellowLightNorthSouth, HIGH);
  digitalWrite(yellowLightEastWest, HIGH);
  delay(yellowTime);

  // Turn off Yellow LEDs
  digitalWrite(yellowLightNorthSouth, LOW);
  digitalWrite(yellowLightEastWest, LOW);
}

void loop() {
  if (!client.connected()) {
    mqttReconnect();
  }

  client.loop();

  if (iotControl == 0) {
    // Normal Traffic Light Mode
    lcd.setCursor(0, 1);
    lcd.print(" = Do Not Walk! =");
    Serial.println(" == Do Not Walk == ");
    digitalWrite(emergencyBlueLED, LOW); 

    if (crossWalkButtonState == 0) { 
      handlePedestrianSignal(); 
      crossWalkButtonState = 1; // Reset button state
    } else {
      handleNormalTraffic(); 
    }
  } else {
    // Emergency Mode
    lcd.setCursor(0, 1);
    lcd.println("= Emergency! =");
    Serial.println("= Emergency! =");
    digitalWrite(yellowLightNorthSouth, LOW);
    digitalWrite(greenLightNorthSouth, LOW);
    digitalWrite(yellowLightEastWest, LOW);
    digitalWrite(greenLightEastWest, LOW);
    digitalWrite(redLightNorthSouth, HIGH);
    digitalWrite(redLightEastWest, HIGH);
    digitalWrite(emergencyBlueLED, HIGH);
    digitalWrite(buzzerPin, HIGH);
    delay(500);
    digitalWrite(emergencyBlueLED, LOW);
    digitalWrite(buzzerPin, LOW);
    delay(500);
  }
}

void buttonPressed() {
  static unsigned long lastInterruptTime = 0;
  unsigned long interruptTime = millis();

  if (interruptTime - lastInterruptTime > 20) {
    crossWalkButtonState = 0;
  }
  lastInterruptTime = interruptTime;
}