#include <SoftwareSerial.h>
#define RX_PIN D3  // RX NodeMCU -> TX M66
#define TX_PIN D4  // TX NodeMCU -> RX M66

SoftwareSerial M66(RX_PIN, TX_PIN);

const String url = "http://amlakmodaberan.ir/1.html";
// =========================
// Timeout ها
// =========================
const unsigned long AT_TIMEOUT = 15000;
const unsigned long HTTP_TIMEOUT = 30000;

// =========================
// ارسال دستور AT با انتظار پاسخ
// =========================
bool sendAT(String cmd, String expected = "OK", unsigned long timeout = AT_TIMEOUT) {
  Serial.print("[TX] "); Serial.println(cmd);

  while (M66.available()) M66.read(); // پاکسازی بافر

  M66.println(cmd);

  unsigned long start = millis();
  String response = "";

  while (millis() - start < timeout) {
    yield();
    while (M66.available()) {
      char c = M66.read();
      response += c;
      Serial.write(c);

      if (response.indexOf(expected) != -1) return true;
      if (response.indexOf("ERROR") != -1 || response.indexOf("+CME ERROR") != -1) {
        Serial.println("❌ Command failed");
        return false;
      }
    }
  }

  Serial.println("⏱ Timeout waiting for response");
  return false;
}

// =========================
// راه‌اندازی GPRS و HTTP با QIREGAPP
// =========================
bool initGPRS() {
  Serial.println("=== Initializing GPRS ===");
  delay(2000);

  sendAT("ATE0");
  sendAT("AT+CMEE=2");
  sendAT("AT+CFUN=1");
  delay(2000);

  if (!sendAT("AT+CPIN?", "READY")) return false;

  // شبکه ثبت شده
  for (int i = 0; i < 10; i++) {
    if (sendAT("AT+CREG?", "+CREG: 0,1")) break;
    delay(2000);
  }

  if (!sendAT("AT+CGATT=1")) return false;
  delay(5000);

  // reset context
  sendAT("AT+QIFGCNT=0");

  if (!sendAT("AT+QICSGP=1,\"mcinet\",\"\",\"\"")) return false;

  // فعال کردن QIREGAPP به جای QIACT
  if (!sendAT("AT+QIREGAPP", "OK", 30000)) return false;

  // بررسی IP state
  sendAT("AT+QISTAT", "STATE: IP GPRSACT");

  // پیکربندی HTTP
  sendAT("AT+QHTTPCFG=\"contextid\",1");
  sendAT("AT+QHTTPCFG=\"responseheader\",1");
  sendAT("AT+QHTTPCFG=\"timeout\",30000");
  sendAT("AT+QHTTPCFG=\"requestheader\",1");

  Serial.println("✅ GPRS ready!");
  return true;
}

// =========================
// ارسال HTTP GET
// =========================
bool sendHTTPRequest() {
  Serial.println("=== Sending HTTP Request ===");

  int len = url.length();

  if (!sendAT("AT+QHTTPURL=" + String(len) + ",60", "CONNECT", 15000)) {
    Serial.println("❌ URL setup failed");
    return false;
  }

  M66.print(url);
  delay(200);
  M66.write(0x1A); // Ctrl+Z
  delay(1500);

  if (!sendAT("AT+QHTTPGET=80", "OK", HTTP_TIMEOUT)) {
    Serial.println("❌ HTTP GET failed");
    return false;
  }

  if (!sendAT("AT+QHTTPREAD", "+QHTTPREAD:", HTTP_TIMEOUT)) {
    Serial.println("⚠️ No HTTP response body");
    return false;
  }

  Serial.println("✅ HTTP request done!");
  return true;
}

// =========================
// setup
// =========================
void setup() {
  Serial.begin(115200);
  M66.begin(9600);
  delay(2000);

  int retry = 0;
  while (retry < 3) {
    if (initGPRS()) {
      if (sendHTTPRequest()) break;
      else Serial.println("⚠️ HTTP failed, retrying...");
    } else {
      Serial.println("❌ GPRS init failed, retrying...");
    }
    retry++;
    delay(5000);
  }
}

// =========================
// loop
// =========================
void loop() {
  yield(); // جلوگیری از WDT
}