#include <ESP8266WiFi.h>
#include <WiFiClientSecure.h>
#include <ESP8266HTTPClient.h>
#include <ArduinoJson.h>
#include "secrets.h"

// --- WiFi & Telegram Config ---
const char* ssid = WIFI_SSID;
const char* password = WIFI_PASS;
const char* botToken = TELEGRAM_BOT_TOKEN;
const char* chatID = TELEGRAM_CHAT_ID;

WiFiClientSecure telegramClient;

// --- Timing ---
long lastUpdateId = 0;
unsigned long lastTelegramCheck = 0;
const unsigned long telegramCheckInterval = 10000;  // 10 seconds
unsigned long lastLDRSend = 0;
const unsigned long ldrSendInterval = 5UL * 60UL * 1000UL; // 5 minutes

// --- Utility: URL Encode ---
String urlencode(const String& str) {
  String encoded = "";
  char c;
  char code0, code1;
  for (unsigned int i = 0; i < str.length(); i++) {
    c = str.charAt(i);
    if (isalnum(c) || c == '-' || c == '_' || c == '.' || c == '~') {
      encoded += c;
    } else {
      code1 = (c & 0xf) + '0';
      if ((c & 0xf) > 9) code1 = (c & 0xf) - 10 + 'A';
      c = (c >> 4) & 0xf;
      code0 = c + '0';
      if (c > 9) code0 = c - 10 + 'A';
      encoded += '%';
      encoded += code0;
      encoded += code1;
    }
  }
  return encoded;
}

// --- Telegram Messaging ---
void sendTelegramMessage(String message) {
  if (WiFi.status() != WL_CONNECTED) return;
  HTTPClient http;
  String url = "https://api.telegram.org/bot" + String(botToken) +
               "/sendMessage?chat_id=" + String(chatID) +
               "&text=" + urlencode(message);
  http.begin(telegramClient, url);
  int httpCode = http.GET();
  http.end();
}

// --- LDR Handling ---
void sendLDRToTelegram() {
  Serial.write('R');
  unsigned long start = millis();
  String ldrValue = "";
  while (millis() - start < 2000) { // wait up to 2 seconds
    if (Serial.available()) {
      ldrValue = Serial.readStringUntil('\n');
      ldrValue.trim();
      break;
    }
  }
  if (ldrValue.length() > 0) {
    sendTelegramMessage("Current LDR value: " + ldrValue);
  } else {
    sendTelegramMessage("Failed to read LDR value from Arduino.");
  }
}

// --- Telegram Command Handling ---
void checkTelegramCommands() {
  HTTPClient http;
  String url = "https://api.telegram.org/bot" + String(botToken) +
               "/getUpdates?offset=" + String(lastUpdateId + 1);
  http.begin(telegramClient, url);
  int httpCode = http.GET();
  if (httpCode == HTTP_CODE_OK) {
    String payload = http.getString();
    DynamicJsonDocument doc(2048);
    DeserializationError error = deserializeJson(doc, payload);
    if (error) {
      http.end();
      return;
    }
    JsonArray results = doc["result"].as<JsonArray>();
    for (JsonObject msg : results) {
      lastUpdateId = msg["update_id"];
      long fromId = msg["message"]["from"]["id"];
      String text = msg["message"]["text"];
      if (String(fromId) != chatID) {
        continue;
      }
      if (text == "/open_chickencoop") {
        Serial.write('O');
        sendTelegramMessage("Opening chicken coop.");
      } else if (text == "/close_chickencoop") {
        Serial.write('C');
        sendTelegramMessage("Closing chicken coop.");
      } else if (text == "/ldr") {
        sendLDRToTelegram();
      } else {
        sendTelegramMessage("Unknown command.");
      }
    }
  }
  http.end();
}

// --- Sync lastUpdateId on startup ---
void syncLastUpdateId() {
  HTTPClient http;
  String url = "https://api.telegram.org/bot" + String(botToken) + "/getUpdates";
  http.begin(telegramClient, url);
  int httpCode = http.GET();
  if (httpCode == HTTP_CODE_OK) {
    String payload = http.getString();
    DynamicJsonDocument doc(4096);
    DeserializationError error = deserializeJson(doc, payload);
    if (!error) {
      JsonArray results = doc["result"].as<JsonArray>();
      for (JsonObject msg : results) {
        long updateId = msg["update_id"];
        if (updateId > lastUpdateId) lastUpdateId = updateId;
      }
    }
  }
  http.end();
}

// --- Setup ---
void setup() {
  Serial.begin(9600);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
  }
  telegramClient.setInsecure();
  syncLastUpdateId();
  sendTelegramMessage("ESP8266 connected. IP: " + WiFi.localIP().toString());
}

// --- Main Loop ---
void loop() {
  unsigned long now = millis();
  if (now - lastTelegramCheck >= telegramCheckInterval) {
    lastTelegramCheck = now;
    checkTelegramCommands();
  }
  if (now - lastLDRSend >= ldrSendInterval) {
    lastLDRSend = now;
    sendLDRToTelegram();
  }
}