/*
 * SmartDrain Chennai - FIXED LED Control Version
 * LEDs now work exactly as described
 */

// Pin definitions (matching your diagram.json)
#define TRIG_PIN     26   // Ultrasonic TRIG
#define ECHO_PIN     25   // Ultrasonic ECHO
#define RELAY_PIN    27   // Motor/pump relay
#define GAS_PIN      36   // Gas sensor (VP pin)
#define BUTTON_PIN   34   // Tamper button

// LEDs
#define LED_GREEN    18   // Normal (led3)
#define LED_YELLOW1  19   // Warning 1 (led4) 
#define LED_YELLOW2  21   // Warning 2 (led2)
#define LED_BLUE     2    // Gas/Status LED (status_led)

// Water level thresholds (distance in cm)
#define DISTANCE_NORMAL     100   // >100cm = Normal
#define DISTANCE_WARNING1   50    // 50-100cm = Warning 1
#define DISTANCE_WARNING2   20    // 20-50cm = Warning 2
#define DISTANCE_CRITICAL   10    // <10cm = Critical

// Gas thresholds (raw analog values)
#define GAS_NORMAL          800   // Normal gas level
#define GAS_WARNING         1500  // Warning gas level
#define GAS_CRITICAL        2500  // Critical gas level

// Global variables
float distance;
int gasRaw;
int gasPPM;
bool tamperDetected;
String waterStatus;
String gasStatus;
String overallAlert;

unsigned long lastReading = 0;

void setup() {
  Serial.begin(115200);
  delay(2000);
  
  Serial.println("\n");
  Serial.println("🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊");
  Serial.println("                 SMARTDRAIN CHENNAI MONITORING SYSTEM              ");
  Serial.println("                  Urban Flood Prevention - FIXED LED VERSION       ");
  Serial.println("🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊");
  
  // Initialize pins
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(RELAY_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(LED_YELLOW1, OUTPUT);
  pinMode(LED_YELLOW2, OUTPUT);
  pinMode(LED_BLUE, OUTPUT);
  
  // Turn off all outputs initially
  digitalWrite(RELAY_PIN, LOW);
  digitalWrite(LED_GREEN, LOW);
  digitalWrite(LED_YELLOW1, LOW);
  digitalWrite(LED_YELLOW2, LOW);
  digitalWrite(LED_BLUE, LOW);
  
  // System initialization
  Serial.println("🔧 INITIALIZING SYSTEM COMPONENTS...");
  testAllComponents();
  
  Serial.println("📏 WATER LEVEL THRESHOLDS:");
  Serial.println("   🟢 NORMAL:    > " + String(DISTANCE_NORMAL) + " cm (Low Water)");
  Serial.println("   🟡 WARNING 1: " + String(DISTANCE_WARNING1) + "-" + String(DISTANCE_NORMAL) + " cm (Medium Water)");
  Serial.println("   🟠 WARNING 2: " + String(DISTANCE_WARNING2) + "-" + String(DISTANCE_WARNING1) + " cm (High Water)");
  Serial.println("   🔴 CRITICAL:  < " + String(DISTANCE_CRITICAL) + " cm (Flood Level!)");
  
  Serial.println("\n🧪 GAS DETECTION THRESHOLDS:");
  Serial.println("   🟢 NORMAL:    < " + String(GAS_NORMAL) + " (Safe Air)");
  Serial.println("   🟡 WARNING:   " + String(GAS_NORMAL) + "-" + String(GAS_WARNING) + " (Elevated)");
  Serial.println("   🔴 CRITICAL:  > " + String(GAS_CRITICAL) + " (Dangerous!)");
  
  Serial.println("\n✅ SMARTDRAIN SYSTEM READY!");
  Serial.println("📊 Starting continuous monitoring...");
  Serial.println("════════════════════════════════════════════════════════════════════════");
}

void loop() {
  // Read sensors every 3 seconds
  if (millis() - lastReading >= 3000) {
    readAllSensors();
    processAlertsFixed();  // Using fixed version
    displayDetailedStatus();
    lastReading = millis();
  }
  
  delay(100);
}

void testAllComponents() {
  Serial.println("   🔦 Testing LED indicators...");
  
  Serial.println("      🟢 Green LED (Normal Status)");
  digitalWrite(LED_GREEN, HIGH); delay(800); digitalWrite(LED_GREEN, LOW);
  
  Serial.println("      🟡 Yellow LED 1 (Warning Level 1)");
  digitalWrite(LED_YELLOW1, HIGH); delay(800); digitalWrite(LED_YELLOW1, LOW);
  
  Serial.println("      🟠 Yellow LED 2 (Warning Level 2)");
  digitalWrite(LED_YELLOW2, HIGH); delay(800); digitalWrite(LED_YELLOW2, LOW);
  
  Serial.println("      🔵 Blue LED (Gas Detection Status)");
  digitalWrite(LED_BLUE, HIGH); delay(800); digitalWrite(LED_BLUE, LOW);
  
  // Test sensors
  Serial.println("   📡 Testing sensor readings...");
  for(int i = 0; i < 3; i++) {
    float testDistance = readDistanceSensor();
    int testGas = analogRead(GAS_PIN);
    Serial.println("      Test " + String(i+1) + ": Distance=" + String(testDistance, 1) + "cm, Gas=" + String(testGas));
    delay(500);
  }
  
  Serial.println("   ✅ All components tested successfully!");
  Serial.println("");
}

void readAllSensors() {
  // Read ultrasonic distance sensor
  distance = readDistanceSensor();
  
  // Read gas sensor
  gasRaw = analogRead(GAS_PIN);
  gasPPM = map(gasRaw, 0, 4095, 50, 1000); // Convert to estimated PPM
  
  // Add realistic gas variation for demo
  if (random(100) < 10) { // 10% chance of gas spike
    gasRaw += random(500, 1500);
    gasPPM = map(gasRaw, 0, 4095, 50, 1000);
  }
  
  // Read tamper detection
  tamperDetected = (digitalRead(BUTTON_PIN) == LOW);
  
  // Determine status levels
  determineWaterStatus();
  determineGasStatus();
  determineOverallAlert();
}

float readDistanceSensor() {
  // Send ultrasonic pulse
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);
  
  // Read echo
  float duration = pulseIn(ECHO_PIN, HIGH, 30000); // 30ms timeout
  
  if (duration == 0) {
    Serial.println("⚠️ SENSOR ERROR: Ultrasonic timeout");
    return -1; // Error value
  }
  
  // Convert to distance
  float dist = duration * 0.034 / 2;
  
  // Add realistic variation (±2cm)
  dist += random(-20, 21) / 10.0;
  
  return constrain(dist, 0, 400);
}

void determineWaterStatus() {
  if (distance < 0) {
    waterStatus = "SENSOR_ERROR";
  } else if (distance > DISTANCE_NORMAL) {
    waterStatus = "NORMAL";
  } else if (distance > DISTANCE_WARNING1) {
    waterStatus = "WARNING_1";
  } else if (distance > DISTANCE_WARNING2) {
    waterStatus = "WARNING_2";  
  } else {
    waterStatus = "CRITICAL_FLOOD";
  }
}

void determineGasStatus() {
  if (gasRaw < GAS_NORMAL) {
    gasStatus = "SAFE";
  } else if (gasRaw < GAS_WARNING) {
    gasStatus = "ELEVATED";
  } else if (gasRaw < GAS_CRITICAL) {
    gasStatus = "WARNING";
  } else {
    gasStatus = "DANGEROUS";
  }
}

void determineOverallAlert() {
  if (waterStatus == "CRITICAL_FLOOD" || gasStatus == "DANGEROUS" || tamperDetected) {
    overallAlert = "🚨 CRITICAL EMERGENCY";
  } else if (waterStatus == "WARNING_2" || gasStatus == "WARNING") {
    overallAlert = "⚠️ HIGH ALERT";
  } else if (waterStatus == "WARNING_1" || gasStatus == "ELEVATED") {
    overallAlert = "⚠️ LOW ALERT";
  } else if (waterStatus == "SENSOR_ERROR") {
    overallAlert = "🔧 SYSTEM ERROR";
  } else {
    overallAlert = "✅ ALL NORMAL";
  }
}

// FIXED LED CONTROL FUNCTION
void processAlertsFixed() {
  // Turn off all LEDs first
  digitalWrite(LED_GREEN, LOW);
  digitalWrite(LED_YELLOW1, LOW);
  digitalWrite(LED_YELLOW2, LOW);
  digitalWrite(LED_BLUE, LOW);
  
  // === WATER LEVEL LED CONTROL (FIXED) ===
  if (tamperDetected) {
    // TAMPER DETECTED - Flash all water LEDs
    bool fastFlash = (millis() / 300) % 2;
    digitalWrite(LED_GREEN, fastFlash);
    digitalWrite(LED_YELLOW1, fastFlash);
    digitalWrite(LED_YELLOW2, fastFlash);
  } else if (waterStatus == "CRITICAL_FLOOD") {
    // FLOOD EMERGENCY - Flash all water LEDs
    bool emergencyFlash = (millis() / 400) % 2;
    digitalWrite(LED_GREEN, emergencyFlash);
    digitalWrite(LED_YELLOW1, emergencyFlash);
    digitalWrite(LED_YELLOW2, emergencyFlash);
  } else if (waterStatus == "WARNING_2") {
    // HIGH WATER - Only Yellow LED 2
    digitalWrite(LED_YELLOW2, HIGH);
  } else if (waterStatus == "WARNING_1") {
    // MEDIUM WATER - Only Yellow LED 1
    digitalWrite(LED_YELLOW1, HIGH);
  } else if (waterStatus == "NORMAL") {
    // LOW WATER - Only Green LED
    digitalWrite(LED_GREEN, HIGH);
  }
  // If SENSOR_ERROR, all water LEDs stay OFF
  
  // === GAS LEVEL BLUE LED CONTROL (FIXED) ===
  if (tamperDetected) {
    // TAMPER - Fast flash blue LED
    digitalWrite(LED_BLUE, (millis() / 200) % 2);
  } else if (gasStatus == "DANGEROUS") {
    // TOXIC GAS - Fast flash
    digitalWrite(LED_BLUE, (millis() / 200) % 2);
  } else if (gasStatus == "WARNING") {
    // GAS WARNING - Slow flash
    digitalWrite(LED_BLUE, (millis() / 800) % 2);
  } else if (gasStatus == "ELEVATED") {
    // ELEVATED GAS - Steady on
    digitalWrite(LED_BLUE, HIGH);
  }
  // If SAFE gas, blue LED stays OFF
  
  // === RELAY CONTROL ===
  bool activateRelay = (waterStatus == "CRITICAL_FLOOD" || 
                       gasStatus == "DANGEROUS" || 
                       tamperDetected);
  digitalWrite(RELAY_PIN, activateRelay);
}

void displayDetailedStatus() {
  Serial.println("\n");
  Serial.println("📊 ═══════════════ SENSOR STATUS REPORT ═══════════════");
  Serial.println("⏰ Timestamp: " + String(millis()/1000) + " seconds");
  Serial.println("📍 Location: Marina Beach Drainage Node, Chennai");
  Serial.println("");
  
  // Water level status
  Serial.println("🌊 WATER LEVEL MONITORING:");
  Serial.println("   📏 Distance Reading: " + String(distance, 1) + " cm");
  Serial.println("   💧 Water Level: " + waterStatus);
  String waterIcon = "🟢";
  if (waterStatus == "WARNING_1") waterIcon = "🟡";
  else if (waterStatus == "WARNING_2") waterIcon = "🟠";
  else if (waterStatus == "CRITICAL_FLOOD") waterIcon = "🔴";
  Serial.println("   " + waterIcon + " Status Indicator: " + getWaterDescription());
  
  // Gas detection status
  Serial.println("\n🧪 GAS DETECTION SYSTEM:");
  Serial.println("   📈 Raw Sensor Value: " + String(gasRaw) + " (0-4095 range)");
  Serial.println("   💨 Estimated PPM: " + String(gasPPM));
  Serial.println("   ☠️ Gas Level: " + gasStatus);
  String gasIcon = "🟢";
  if (gasStatus == "ELEVATED") gasIcon = "🟡";
  else if (gasStatus == "WARNING") gasIcon = "🟠";
  else if (gasStatus == "DANGEROUS") gasIcon = "🔴";
  Serial.println("   " + gasIcon + " Status Indicator: " + getGasDescription());
  
  // Security status
  Serial.println("\n🔒 SECURITY MONITORING:");
  Serial.println("   🚪 Tamper Detection: " + String(tamperDetected ? "⚠️ BREACH DETECTED!" : "✅ Secure"));
  
  // System outputs - REAL-TIME LED STATUS
  Serial.println("\n⚡ SYSTEM RESPONSES (LIVE LED STATUS):");
  Serial.println("   🟢 Green LED (Normal): " + String(digitalRead(LED_GREEN) ? "ON" : "OFF"));
  Serial.println("   🟡 Yellow LED 1 (Warn1): " + String(digitalRead(LED_YELLOW1) ? "ON" : "OFF"));
  Serial.println("   🟠 Yellow LED 2 (Warn2): " + String(digitalRead(LED_YELLOW2) ? "ON" : "OFF"));
  Serial.println("   🔵 Blue LED (Gas): " + String(digitalRead(LED_BLUE) ? "ON" : "OFF"));
  Serial.println("   🔄 Pump Relay: " + String(digitalRead(RELAY_PIN) ? "ACTIVE" : "STANDBY"));
  
  // LED behavior explanation
  Serial.println("\n💡 LED BEHAVIOR LOGIC:");
  Serial.println("   Water LEDs: " + getWaterLEDStatus());
  Serial.println("   Gas LED: " + getGasLEDStatus());
  
  // Overall system status
  Serial.println("\n🚨 OVERALL SYSTEM ALERT LEVEL:");
  Serial.println("   " + overallAlert);
  
  // Emergency messages
  if (waterStatus == "CRITICAL_FLOOD") {
    Serial.println("\n🚨🌊 FLOOD EMERGENCY: Critical water level detected!");
    Serial.println("   ➤ Immediate evacuation may be required");
    Serial.println("   ➤ Emergency pump activated");
  }
  
  if (gasStatus == "DANGEROUS") {
    Serial.println("\n🚨☠️ GAS EMERGENCY: Dangerous gas levels detected!");
    Serial.println("   ➤ Area evacuation required immediately");
    Serial.println("   ➤ Do not enter confined spaces");
  }
  
  if (tamperDetected) {
    Serial.println("\n🚨🔒 SECURITY ALERT: Unauthorized access detected!");
    Serial.println("   ➤ Possible equipment tampering");
    Serial.println("   ➤ Security response required");
  }
  
  Serial.println("══════════════════════════════════════════════════════════════════");
  
  // Add some spacing for readability
  delay(500);
}

String getWaterLEDStatus() {
  if (tamperDetected || waterStatus == "CRITICAL_FLOOD") {
    return "All flashing (Emergency)";
  } else if (waterStatus == "WARNING_2") {
    return "Yellow 2 only (High water)";
  } else if (waterStatus == "WARNING_1") {
    return "Yellow 1 only (Medium water)";
  } else if (waterStatus == "NORMAL") {
    return "Green only (Normal water)";
  } else {
    return "All off (Sensor error)";
  }
}

String getGasLEDStatus() {
  if (tamperDetected || gasStatus == "DANGEROUS") {
    return "Fast flash (Emergency)";
  } else if (gasStatus == "WARNING") {
    return "Slow flash (Warning)";
  } else if (gasStatus == "ELEVATED") {
    return "Steady on (Elevated)";
  } else {
    return "Off (Safe)";
  }
}

String getWaterDescription() {
  if (waterStatus == "NORMAL") return "Low water, normal drainage";
  else if (waterStatus == "WARNING_1") return "Medium water level, monitor closely";
  else if (waterStatus == "WARNING_2") return "High water level, flood risk increasing";
  else if (waterStatus == "CRITICAL_FLOOD") return "FLOOD CONDITIONS - Emergency response!";
  else return "Sensor malfunction detected";
}

String getGasDescription() {
  if (gasStatus == "SAFE") return "Air quality normal, safe environment";
  else if (gasStatus == "ELEVATED") return "Slightly elevated gas levels detected";
  else if (gasStatus == "WARNING") return "Concerning gas levels, caution advised";
  else if (gasStatus == "DANGEROUS") return "TOXIC LEVELS - Evacuate immediately!";
  else return "Unknown gas status";
}