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

#define DHT_PIN 15
#define DHT_TYPE DHT22
DHT dht(DHT_PIN, DHT_TYPE);

const char* ssid = "FIRELINK";
const char* password = "06101111";

const String apiKey = "VGIH0VJY05I73ISC"; 
const int channelID = 3174042;


const char* backendHost = "host.wokwi.internal";  
const int backendPort = 3000;
const char* backendEndpoint = "/api/data";

const char* discordWebhook = "https://discord.com/api/webhooks/1447591817595060278/cM-XEDpPEsoQiSOjqDGMfcBnIuFhaFOYBLtqLxeEyBTS4JovpbTbox5dhcy56Ke2uIJs";

const float HIGH_TEMP_THRESHOLD = 30.0;  
const float LOW_TEMP_THRESHOLD = 10.0;   
const float HIGH_HUMIDITY_THRESHOLD = 80.0;  
const float LOW_HUMIDITY_THRESHOLD = 20.0;   

unsigned long previousRead = 0;
unsigned long previousUpload = 0;
unsigned long previousDiscordAlert = 0;

const unsigned long READ_INTERVAL = 3000;      
const unsigned long UPLOAD_INTERVAL = 5000;    
const unsigned long DISCORD_ALERT_INTERVAL = 5000;  

float temperature = 0;
float humidity = 0;
bool alertSent = false;

void connectWiFi();
void readSensor();
void uploadToThingSpeak(float temp, float humi);
void uploadToBackend(float temp, float humi);
void sendDiscordAlert(const char* message);
void checkThresholdsAndAlert();
String getTimeString();
void printSystemInfo();

void connectWiFi() {
  Serial1.print("Connecting to WiFi");
  WiFi.begin(ssid, password);

  int attempts = 0;
  while (WiFi.status() != WL_CONNECTED && attempts < 20) {
    delay(500);
    Serial.print(".");
    attempts++;
  }

  if (WiFi.status() == WL_CONNECTED) {
    Serial1.println("\n WiFi connected!");
    Serial1.print("IP Address: ");
    Serial1.println(WiFi.localIP());
  } else {
    Serial1.println("\n WiFi connection failed!");
  }
}

void readSensor() {
  float t = dht.readTemperature();
  float h = dht.readHumidity();

  if (isnan(t) || isnan(h)) {
    Serial1.println(" Sensor read error!");
    return;
  }

  temperature = t;
  humidity = h;

  Serial1.print("[");
  Serial1.print(getTimeString());
  Serial1.print("] Temp: ");
  Serial1.print(temperature);
  Serial1.print("°C | Humidity: ");
  Serial1.print(humidity);
  Serial1.println("%");
}

void uploadToThingSpeak(float temp, float humi) {
  if (WiFi.status() != WL_CONNECTED) {
    Serial1.println(" WiFi disconnected. Reconnecting...");
    connectWiFi();
    return;
  }
  
  HTTPClient http;
  
  String url = "http://api.thingspeak.com/update?api_key=" + apiKey +
               "&field1=" + String(temp, 2) +
               "&field2=" + String(humi, 2);

  Serial1.println(" Sending to ThingSpeak...");

  http.begin(url);
  int httpResponse = http.GET();

  if (httpResponse > 0) {
    Serial1.print("ThingSpeak Response: ");
    Serial1.println(httpResponse);
  } else {
    Serial1.print("HTTP Error: ");
    Serial1.println(httpResponse);
  }

  http.end();
}

void uploadToBackend(float temp, float humi) {
  if (WiFi.status() != WL_CONNECTED) {
    Serial1.println(" WiFi not connected for backend upload");
    return;
  }

  HTTPClient http;
  

  String url = "http://" + String(backendHost) + ":" + String(backendPort) + backendEndpoint;
  
  Serial1.print("Sending to backend: ");
  Serial1.println(url);


  StaticJsonDocument<200> jsonDoc;
  jsonDoc["temperature"] = temp;
  jsonDoc["humidity"] = humi;
  jsonDoc["device_id"] = "pico_w_jami";
  jsonDoc["timestamp"] = getTimeString();

  String payload;
  serializeJson(jsonDoc, payload);

  http.begin(url);
  http.addHeader("Content-Type", "application/json");
  http.addHeader("User-Agent", "PicoW-DHT22/1.0");

  Serial.println("Payload: " + payload);

  int httpResponse = http.POST(payload);

  if (httpResponse > 0) {
    String response = http.getString();
    Serial1.print("Backend Response (");
    Serial1.print(httpResponse);
    Serial1.print("): ");
    Serial1.println(response);
  } else {
    Serial1.print("Backend Error: ");
    Serial1.println(httpResponse);
    Serial1.println("Error: " + http.errorToString(httpResponse));
  }

  http.end();
}

void sendDiscordAlert(const char* message) {
  if (WiFi.status() != WL_CONNECTED) {
    return;
  }

  unsigned long currentTime = millis();
  if (currentTime - previousDiscordAlert < DISCORD_ALERT_INTERVAL) {
    return;
  }

  HTTPClient http;
  
  http.begin(discordWebhook);
  http.addHeader("Content-Type", "application/json");

  String payload = "{";
  payload += "\"embeds\": [{";
  payload += "\"title\": \"Pico W Sensor Alert\",";
  payload += "\"description\": \"" + String(message) + "\",";
  payload += "\"color\": 16711680,";  
  payload += "\"fields\": [";
  payload += "{\"name\": \" Temperature\", \"value\": \"" + String(temperature, 1) + "°C\", \"inline\": true},";
  payload += "{\"name\": \" Humidity\", \"value\": \"" + String(humidity, 1) + "%\", \"inline\": true},";
  payload += "{\"name\": \" Time\", \"value\": \"" + getTimeString() + "\", \"inline\": false}";
  payload += "],";
  payload += "\"footer\": {\"text\": \"Pico W DHT22 Monitor\"}";
  payload += "}]";
  payload += "}";

  Serial1.println(" Sending Discord alert...");
  
  int httpResponse = http.POST(payload);

  if (httpResponse > 0) {
    Serial1.print("Discord alert sent (");
    Serial1.print(httpResponse);
    Serial1.println(")");
    previousDiscordAlert = currentTime;
    alertSent = true;
  } else {
    Serial1.print("Discord error: ");
    Serial1.println(httpResponse);
  }

  http.end();
}

void checkThresholdsAndAlert() {
  char alertMessage[200];
  bool shouldAlert = false;

  if (temperature >= HIGH_TEMP_THRESHOLD) {
    snprintf(alertMessage, sizeof(alertMessage),
             "**HIGH TEMPERATURE ALERT**\nTemperature is %.1f°C (Threshold: %.1f°C)",
             temperature, HIGH_TEMP_THRESHOLD);
    shouldAlert = true;
  } else if (temperature <= LOW_TEMP_THRESHOLD) {
    snprintf(alertMessage, sizeof(alertMessage),
             " **LOW TEMPERATURE ALERT**\nTemperature is %.1f°C (Threshold: %.1f°C)",
             temperature, LOW_TEMP_THRESHOLD);
    shouldAlert = true;
  }

  if (humidity >= HIGH_HUMIDITY_THRESHOLD) {
    snprintf(alertMessage, sizeof(alertMessage),
             " **HIGH HUMIDITY ALERT**\nHumidity is %.1f%% (Threshold: %.1f%%)",
             humidity, HIGH_HUMIDITY_THRESHOLD);
    shouldAlert = true;
  } else if (humidity <= LOW_HUMIDITY_THRESHOLD) {
    snprintf(alertMessage, sizeof(alertMessage),
             " **LOW HUMIDITY ALERT**\nHumidity is %.1f%% (Threshold: %.1f%%)",
             humidity, LOW_HUMIDITY_THRESHOLD);
    shouldAlert = true;
  }

  if (shouldAlert && !alertSent) {
    sendDiscordAlert(alertMessage);
  }

  if (temperature < HIGH_TEMP_THRESHOLD && temperature > LOW_TEMP_THRESHOLD &&
      humidity < HIGH_HUMIDITY_THRESHOLD && humidity > LOW_HUMIDITY_THRESHOLD) {
    alertSent = false;
  }
}

String getTimeString() {
  unsigned long seconds = millis() / 1000;
  unsigned long minutes = seconds / 60;
  unsigned long hours = minutes / 60;
  
  seconds %= 60;
  minutes %= 60;
  
  char timeStr[20];
  snprintf(timeStr, sizeof(timeStr), "%02lu:%02lu:%02lu", hours, minutes, seconds);
  return String(timeStr);
}

void printSystemInfo() {
  Serial1.println("\nSYSTEM INFORMATION");
  Serial1.println("========================");
  Serial1.print("WiFi SSID: ");
  Serial1.println(ssid);
  Serial.print("WiFi Status: ");
  Serial1.println(WiFi.status() == WL_CONNECTED ? "Connected" : "Disconnected");
  Serial1.print("Backend Server: ");
  Serial1.print(backendHost);
  Serial1.print(":");
  Serial1.println(backendPort);
  Serial1.println("Alert Thresholds:");
  Serial1.print("  Temperature: ");
  Serial1.print(LOW_TEMP_THRESHOLD);
  Serial1.print("°C - ");
  Serial1.print(HIGH_TEMP_THRESHOLD);
  Serial1.println("°C");
  Serial1.print("  Humidity: ");
  Serial1.print(LOW_HUMIDITY_THRESHOLD);
  Serial1.print("% - ");
  Serial1.print(HIGH_HUMIDITY_THRESHOLD);
  Serial1.println("%");
  Serial1.println("========================");
}

void setup() {
  Serial1.begin(115200);
  delay(2000);  // Wait for serial monitor

  Serial1.println("\nStarting Pico W DHT22 Monitor");
  Serial1.println("=================================");
  
  dht.begin();
  delay(2000);  // Let DHT sensor stabilize

  connectWiFi();
  printSystemInfo();

  Serial1.println("\n System initialized and ready!");
  Serial1.println("=================================\n");
}

void loop() {
  unsigned long now = millis();


  if (now - previousRead >= READ_INTERVAL) {
    readSensor();
    previousRead = now;

    checkThresholdsAndAlert();
  }

 
  if (now - previousUpload >= UPLOAD_INTERVAL) {
    if (temperature != 0 && humidity != 0) {
      Serial1.println("\nUPLOAD CYCLE STARTED");
      Serial1.println("---------------------");
     
      uploadToThingSpeak(temperature, humidity);
      
      uploadToBackend(temperature, humidity);
      
      checkThresholdsAndAlert();
      
      Serial1.println("---------------------");
      Serial1.println("UPLOAD CYCLE COMPLETE\n");
    }
    previousUpload = now;
  }

  static unsigned long lastStatusPrint = 0;
  if (now - lastStatusPrint >= 60000) {
    printSystemInfo();
    lastStatusPrint = now;
  }

  delay(100);
}