#include <OneWire.h>
#include <DallasTemperature.h>
#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <HTTPClient.h>

// Pins
#define POTENTIOMETER_PIN 34
#define DS18B20_PIN 4
#define MQ2_PIN 35
#define RED_LED_PIN 26
#define GREEN_LED_PIN 27

const char* ssid = "Wokwi-GUEST";
const char* password = "";

const char* thingSpeakServer = "api.thingspeak.com";
const char* writeAPIKey = "QYYFF61W9IZO6AV7";

const char* googleScriptUrl = "https://script.google.com/macros/s/AKfycbzqET0BFMskcnB7ZGL00S0GKIh56M4L52CDGIC78e6Z4W8HNeoChTOxUfstp-D7BNfK/exec";

OneWire oneWire(DS18B20_PIN);
DallasTemperature sensors(&oneWire);

WiFiClientSecure client;
HTTPClient https;

unsigned long previousLedMillis = 0;
const unsigned long ledToggleInterval = 250; // blink every 250ms

enum LedMode {
  LED_OFF,
  LED_RED_BLINK,
  LED_GREEN_BLINK
};

LedMode currentLedMode = LED_OFF;
bool ledState = LOW;

const char* getHttpErrorDescription(int code) {
  switch (code) {
    case -1: return "Connection failed or timeout";
    case -2: return "Send header failed";
    case -3: return "Send payload failed";
    case -4: return "Not connected";
    case -5: return "Connection lost";
    case -6: return "No stream available";
    case -7: return "No HTTP server";
    case -8: return "Out of memory";
    case -9: return "Encoding error";
    case -10: return "Local network error";
    case -11: return "Timeout";
    case 302: return "Redirect (Check URL)";
    case 403: return "Forbidden - Check API key or permissions";
    case 404: return "Not found - Check URL";
    case 500: return "Server error";
    default: return "Unknown error";
  }
}

void connectToWiFi() {
  Serial.print("Connecting to WiFi");
  WiFi.begin(ssid, password);
  int retries = 0;
  while (WiFi.status() != WL_CONNECTED && retries < 20) {
    delay(500);
    Serial.print(".");
    retries++;
  }
  if (WiFi.status() == WL_CONNECTED) {
    Serial.println(" Connected");
  } else {
    Serial.println(" Failed to connect to WiFi");
  }
}

void setup() {
  Serial.begin(115200);
  sensors.begin();
  analogSetAttenuation(ADC_11db);
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);
  digitalWrite(RED_LED_PIN, LOW);
  digitalWrite(GREEN_LED_PIN, LOW);

  connectToWiFi();

  if (WiFi.status() == WL_CONNECTED) {
    configTime(0, 0, "pool.ntp.org", "time.nist.gov");
    Serial.println("Waiting for NTP time sync...");
    int timeRetries = 0;
    struct tm timeinfo;
    while (!getLocalTime(&timeinfo, 1000) && timeRetries < 20) {
      delay(500);
      Serial.print(".");
      timeRetries++;
    }
    Serial.println();
  }

  client.setInsecure(); // Disable SSL cert validation (for dev/testing)
}

void sendSensorData(float temperatureC, int airQualityIndex, int soilMoisturePercent) {
  if (temperatureC == -127.0) {
    Serial.println("DS18B20 sensor error, skipping upload.");
    return;
  }
  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("WiFi disconnected, reconnecting...");
    connectToWiFi();
    if (WiFi.status() != WL_CONNECTED) {
      Serial.println("WiFi reconnect failed, skipping data upload.");
      return;
    }
  }

  // ThingSpeak (HTTP)
  HTTPClient http;
  char url[256];
  snprintf(url, sizeof(url), "http://%s/update?api_key=%s&field1=%.2f&field2=%d&field3=%d",
           thingSpeakServer, writeAPIKey, temperatureC, airQualityIndex, soilMoisturePercent);
  Serial.println("Sending to ThingSpeak...");
  http.begin(url);
  int httpCode = http.GET();
  if (httpCode == 200) {
    Serial.println("ThingSpeak: Success");
  } else {
    Serial.printf("ThingSpeak HTTP %d (%s)\n", httpCode, getHttpErrorDescription(httpCode));
  }
  http.end();

  delay(500);

  // Google Sheets (HTTPS)
  https.begin(client, googleScriptUrl);
  https.addHeader("Content-Type", "application/json");

  char jsonPayload[256];
  snprintf(jsonPayload, sizeof(jsonPayload),
           "{\"temperature\":%.2f,\"airQuality\":%d,\"soilMoisture\":%d}",
           temperatureC, airQualityIndex, soilMoisturePercent);
  Serial.println("Sending to Google Sheets...");
  httpCode = https.POST(jsonPayload);
  if (httpCode == 200) {
    Serial.println("Google Sheets: Success");
  } else {
    Serial.printf("Google Sheets HTTP %d (%s)\n", httpCode, getHttpErrorDescription(httpCode));
  }
  https.end();
}

void updateLedBlink() {
  unsigned long currentMillis = millis();
  if (currentMillis - previousLedMillis >= ledToggleInterval) {
    previousLedMillis = currentMillis;
    ledState = !ledState;

    switch (currentLedMode) {
      case LED_RED_BLINK:
        digitalWrite(RED_LED_PIN, ledState);
        digitalWrite(GREEN_LED_PIN, LOW);
        break;
      case LED_GREEN_BLINK:
        digitalWrite(GREEN_LED_PIN, ledState);
        digitalWrite(RED_LED_PIN, LOW);
        break;
      case LED_OFF:
      default:
        digitalWrite(RED_LED_PIN, LOW);
        digitalWrite(GREEN_LED_PIN, LOW);
        ledState = LOW;  // reset
        break;
    }
  }
}

void loop() {
  static unsigned long lastSendMillis = 0;
  unsigned long currentMillis = millis();

  // Send and read data every 2 seconds
  if (currentMillis - lastSendMillis >= 2000) {
    lastSendMillis = currentMillis;

    sensors.requestTemperatures();
    float temperatureC = sensors.getTempCByIndex(0);
    int potValue = analogRead(POTENTIOMETER_PIN);
    int soilMoisturePercent = map(potValue, 0, 4095, 100, 0);
    int mq2Value = analogRead(MQ2_PIN);
    int airQualityIndex = map(mq2Value, 0, 4095, 0, 100);

    Serial.printf("Temp: %.2f C, Soil: %d %%, Air: %d\n", temperatureC, soilMoisturePercent, airQualityIndex);

    sendSensorData(temperatureC, airQualityIndex, soilMoisturePercent);

    LedMode newMode = LED_OFF;
    if (temperatureC > 35 && soilMoisturePercent > 50 && airQualityIndex > 50) {
      newMode = LED_RED_BLINK;
    } else if (temperatureC < 35 && soilMoisturePercent < 50 && airQualityIndex < 50) {
      newMode = LED_GREEN_BLINK;
    }

    if (newMode != currentLedMode) {
      currentLedMode = newMode;
      ledState = LOW;
      previousLedMillis = currentMillis;
      digitalWrite(RED_LED_PIN, LOW);
      digitalWrite(GREEN_LED_PIN, LOW);
      Serial.print("LED mode changed to: ");
      if (newMode == LED_RED_BLINK) Serial.println("RED BLINK");
      else if (newMode == LED_GREEN_BLINK) Serial.println("GREEN BLINK");
      else Serial.println("LED OFF");
    }
  }

  updateLedBlink();
}