#include <WiFi.h>
#include <WiFiClientSecure.h> 
#include <HTTPClient.h>
#include <ArduinoJson.h>
#include <DHT.h>

// --- FUNCTION PROTOTYPES (Prevents scope errors) ---
void setFanHardware(int speedLevel, String direction);
void updateDatabaseSensors(int currentSpeed, String currentDir);
void fetchAndApplyLogic();

// --- WIFI & SUPABASE CREDENTIALS ---
const char* ssid = "Wokwi-GUEST"; 
const char* password = "";
const String supabaseUrl = "https://sippgekvqvpjrsmjxmoh.supabase.co/rest/v1/vent_system?id=eq.1";
const String supabaseKey = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZSIsInJlZiI6InNpcHBnZWt2cXZwanJzbWp4bW9oIiwicm9sZSI6ImFub24iLCJpYXQiOjE3NzA0NjQyNDYsImV4cCI6MjA4NjA0MDI0Nn0.G2u1c99HDmRJjUXX2xp81KlUCDrrnUq5PPs6b1OxJYE"; 

// --- PIN DEFINITIONS ---
const int FAN_ENA = 13; 
const int FAN_IN1 = 12; 
const int FAN_IN2 = 14; 
const int GAS_SENSOR_PIN = 34; 
const int PIR_PIN = 5;           
const int DHT_IN_PIN = 4; 
const int DHT_OUT_PIN = 15;    
const int LDR_PIN = 35; 

#define DHTTYPE DHT22
DHT dhtIn(DHT_IN_PIN, DHTTYPE);
DHT dhtOut(DHT_OUT_PIN, DHTTYPE);

// --- GLOBALS & TIMERS ---
WiFiClientSecure secureClient; 

unsigned long lastClimateUpdate = 0;
const long climateInterval = 10000; // 10 seconds sync interval
unsigned long lastMotionReset = 0;
const long motionInterval = 600000; // 10 minutes

float tempIn = 0.0, humIn = 0.0, tempOut = 0.0, humOut = 0.0;
int gasLevel = 0;
int lightLevel = 0; 
bool motionDetected = false; 
bool rainDetected = false;
bool forceFirstRun = true;

void setup() {
  Serial.begin(115200);
  
  pinMode(FAN_ENA, OUTPUT);
  pinMode(FAN_IN1, OUTPUT);
  pinMode(FAN_IN2, OUTPUT);
  analogWrite(FAN_ENA, 0);
  digitalWrite(FAN_IN1, LOW);
  digitalWrite(FAN_IN2, LOW);

  pinMode(PIR_PIN, INPUT);
  
  dhtIn.begin();
  dhtOut.begin();

  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) { 
    delay(500); 
    Serial.print("."); 
  }
  Serial.println("\n✅ Connected to WiFi!");
  
  secureClient.setInsecure();
}

void loop() {
  // 1. CONTINUOUS SENSOR READINGS
  gasLevel = analogRead(GAS_SENSOR_PIN);
  lightLevel = analogRead(LDR_PIN); 
  rainDetected = (humOut > 70.0);
  
  // Motion Retrigger Logic
  if (digitalRead(PIR_PIN) == HIGH) {
    if (!motionDetected) {
      Serial.println("🏃 Motion Detected! Occupancy set to TRUE. Timer restarted.");
    }
    motionDetected = true;
    lastMotionReset = millis();
  }
  if (motionDetected && (millis() - lastMotionReset >= motionInterval)) {
    Serial.println("⏱️ 10 Minutes with ZERO motion. Occupancy set to FALSE.");
    motionDetected = false;
  }

  // 2. EMERGENCY OVERRIDE (Highest Priority)
  if (gasLevel > 2500) {
    Serial.println("🚨 EMERGENCY: Gas > 2500ppm! FORCING MAX EXHAUST.");
    setFanHardware(5, "EXHAUST"); 
    updateDatabaseSensors(5, "EXHAUST");
    delay(2000); 
    return; 
  }

  // 3. DATABASE SYNC TIMER
  if (forceFirstRun || millis() - lastClimateUpdate >= climateInterval) {
    lastClimateUpdate = millis();
    forceFirstRun = false;

    // Read DHT Sensors
    float newTempIn = dhtIn.readTemperature();
    float newHumIn = dhtIn.readHumidity();
    if (!isnan(newTempIn) && !isnan(newHumIn)) {
      tempIn = newTempIn;
      humIn = newHumIn;
    }

    float newTempOut = dhtOut.readTemperature();
    float newHumOut = dhtOut.readHumidity();
    if (!isnan(newTempOut) && !isnan(newHumOut)) {
      tempOut = newTempOut;
      humOut = newHumOut;
    }

    Serial.printf("📊 IN: %.1f°C/%.1f%% | OUT: %.1f°C/%.1f%% | Gas: %d | Light: %d\n", 
                  tempIn, humIn, tempOut, humOut, gasLevel, lightLevel);

    fetchAndApplyLogic();
  }
}

void fetchAndApplyLogic() {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http; 
    http.begin(secureClient, supabaseUrl + "&select=*");
    http.addHeader("apikey", supabaseKey);
    http.addHeader("Authorization", "Bearer " + supabaseKey);
    
    int httpResponseCode = http.GET();
    int currentAppliedSpeed = 0;
    String targetDirection = "EXHAUST";
    
    if (httpResponseCode == 200) {
      String payload = http.getString();
      DynamicJsonDocument doc(1024);
      deserializeJson(doc, payload);
      
      JsonObject data = doc[0];
      bool isManualMode = data["manual_mode"];
      bool isEcoMode = data["eco_mode"]; 
      int dbFanSpeed = data["fan_speed"];
      String dbFanDirection = data["fan_direction"].as<String>();
      int targetSpeed = 0;

      // 🚨 1. EMERGENCY GAS OVERRIDE HAPPENS FIRST
      if (gasLevel > 2500) { 
        targetSpeed = 5;
        targetDirection = "EXHAUST";
        Serial.println("🚨 EMERGENCY: Gas > 2500! Forcing MAX EXHAUST.");
      } 
      // ⚙️ 2. IF NO EMERGENCY, CHECK MANUAL MODE
      else if (isManualMode) {
        targetSpeed = dbFanSpeed;
        targetDirection = dbFanDirection;
        
        if (isEcoMode && targetSpeed > 2) {
          targetSpeed = 2;
          Serial.println("⚙️ Manual + Eco: Capping speed to Level 2");
        } else {
          Serial.printf("⚙️ Manual Mode | Speed: %d | Dir: %s\n", targetSpeed, targetDirection.c_str());
        }
      } 
      // 🤖 3. IF NO EMERGENCY AND NOT MANUAL, DO AUTO MODE
      else {
        // --- AUTO MODE (Based on Temp Difference) ---
        float tempDifference = abs(tempIn - tempOut); 

        if (tempDifference < 1.0) targetSpeed = 1;
        else if (tempDifference >= 1.0 && tempDifference < 3.0) targetSpeed = 2;
        else if (tempDifference >= 3.0 && tempDifference < 5.0) targetSpeed = 3;
        else if (tempDifference >= 5.0 && tempDifference < 7.0) targetSpeed = 4;
        else targetSpeed = 5; 

        // Night Mode Speed Cap 
        if (lightLevel < 500 && targetSpeed > 2) {
            targetSpeed = 2; 
            Serial.println("🌙 Auto Night Mode: Capping to Level 2.");
        }

        // Calculate Direction
        if (tempIn > tempOut) {
          targetDirection = "INTAKE";
        } else {
          targetDirection = "EXHAUST";
        }
      } // 🚀 FIXED: Added the missing bracket here!

      setFanHardware(targetSpeed, targetDirection);
      currentAppliedSpeed = targetSpeed;
    } else {
      Serial.printf("⚠️ Error fetching DB. HTTP: %d\n", httpResponseCode);
    }
    http.end();
    
    updateDatabaseSensors(currentAppliedSpeed, targetDirection);
  }
}

void updateDatabaseSensors(int currentSpeed, String currentDir) {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http; 
    http.begin(secureClient, supabaseUrl); 
    http.addHeader("apikey", supabaseKey);
    http.addHeader("Authorization", "Bearer " + supabaseKey);
    http.addHeader("Content-Type", "application/json");
    http.addHeader("Prefer", "return=representation");

    DynamicJsonDocument doc(512);
    doc["temp_indoor"] = tempIn;
    doc["humidity_indoor"] = humIn;
    doc["temp_outdoor"] = tempOut;
    doc["humidity_outdoor"] = humOut;
    doc["gas_level"] = gasLevel;
    doc["fan_speed"] = currentSpeed; 
    doc["fan_direction"] = currentDir;
    doc["motion_detected"] = motionDetected;
    doc["rain_detected"] = rainDetected;
    doc["light_level"] = lightLevel; 
   
    String requestBody;
    serializeJson(doc, requestBody);
    
    int patchResponseCode = http.sendRequest("PATCH", requestBody);
    
    if (patchResponseCode > 0) {
      if (patchResponseCode >= 300) {
         String response = http.getString();
         Serial.println("⚠️ DB Error Message: " + response);
      } else {
         Serial.println("✅ DB Updated Successfully");
      }
    } else {
      Serial.printf("⚠️ ESP32 Network Error: %d\n", patchResponseCode);
    }
    
    http.end();
  }
}

void setFanHardware(int speedLevel, String direction) {
  int pwmValue = map(speedLevel, 0, 5, 0, 255);
  
  if (speedLevel == 0) {
    digitalWrite(FAN_IN1, LOW); 
    digitalWrite(FAN_IN2, LOW);
  } else if (direction == "EXHAUST") {
    digitalWrite(FAN_IN1, HIGH); 
    digitalWrite(FAN_IN2, LOW);
  } else {
    digitalWrite(FAN_IN1, LOW); 
    digitalWrite(FAN_IN2, HIGH);
  }
  
  analogWrite(FAN_ENA, pwmValue);
}