#include <ArduinoJson.h>
#include <HardwareSerial.h>

// --- SIM7080G Pin Definitions ---
#define LTE_RX_PIN 16 // ESP32 GPIO16 connected to SIM7080G TX
#define LTE_TX_PIN 17 // ESP32 GPIO17 connected to SIM7080G RX
#define PWRKEY_PIN 4  // ESP32 GPIO4 connected to SIM7080G PWRKEY

// --- Network Configuration ---
const char *HOLOGRAM_APN = "hologram";

// --- Global Variables ---
String currentIMEI = "";

// --- Function Prototypes ---
void powerOnModule();
void powerOffModule();
String sendATCommand(String command, unsigned long timeoutMs = 3000);
String getIMEI();
bool activatePDPContextAndBearer();
void getGpsLocation(); // Function to get and print GPS data

void setup() {
	Serial.begin(115200);
	while (!Serial) {
		delay(10);
	}
	Serial.println("--- Starting ESP32 to SIM7080G GPS Test (Final) ---");

	Serial2.begin(115200, SERIAL_8N1, LTE_RX_PIN, LTE_TX_PIN);

	powerOffModule();
	delay(3000);
	powerOnModule();

	// Step 1: "Nudge and Listen" for the initial boot-up.
	Serial.println(
		"Waiting for initial module boot (90s timeout)...");
	unsigned long startTime = millis();
	unsigned long lastNudgeTime = 0;
	const unsigned long NUDGE_INTERVAL = 3000;
	bool moduleBooted = false;
	String bootResponse = "";

	while (millis() - startTime < 90000 && !moduleBooted) {
		while (Serial2.available()) {
			char c = Serial2.read();
			Serial.write(c);
			bootResponse += c;
			if (bootResponse.indexOf("SMS Ready") != -1) {
				moduleBooted = true;
				break;
			}
		}
		if (moduleBooted) {
			break;
		}
		if (millis() - lastNudgeTime > NUDGE_INTERVAL) {
			Serial2.println("AT");
			lastNudgeTime = millis();
		}
	}

	if (!moduleBooted) {
		Serial.println("Module did not complete initial boot. Halting.");
		while (true)
			;
	}
	Serial.println("\nInitial boot successful!");

	// Step 2: Apply the proven network configuration from your manual test.
	Serial.println("\nApplying network configuration...");
	sendATCommand("AT+CMEE=1", 1000);
	sendATCommand("AT+CNMP=38", 5000);
	sendATCommand("AT+CMNB=3", 5000);

	// Step 3: Perform the full CFUN reset cycle to apply settings.
	Serial.println("Applying settings with full CFUN reset...");
	sendATCommand("AT+CFUN=0", 5000);
	delay(5000);
	sendATCommand("AT+CFUN=1", 10000);

	// Step 4: Wait for the modem to apply settings and find the network.
	Serial.println(
		"Waiting 45 seconds for modem to apply settings and find network...");
	delay(45000);

	Serial.println("\nChecking network status...");
	currentIMEI = getIMEI();

	// Step 5: Check for network registration.
	unsigned long networkRegStartTime = millis();
	bool networkRegistered = false;
	while (millis() - networkRegStartTime < 120000 && !networkRegistered) {
		String regResponse = sendATCommand("AT+CGREG?", 3000);
		if (regResponse.indexOf("+CGREG: 0,1") != -1 ||
		    regResponse.indexOf("+CGREG: 0,5") != -1) {
			networkRegistered = true;
		}
		if (networkRegistered) {
			Serial.println("Network registration successful!");
			break;
		}
		Serial.println("Not yet registered. Retrying...");
		delay(5000);
	}

	if (!networkRegistered) {
		Serial.println("Failed to register to network. Halting.");
		while (true)
			;
	}

	// --- GPS INITIALIZATION ---
	Serial.println("\n--- Turning on GPS ---");
	sendATCommand("AT+CGPS=1", 1000); // Turn on the GPS receiver
	Serial.println(
		"GPS is on. It may take several minutes to get the first fix.");

	Serial.println("\n--- Setup complete. Starting main loop. ---");
}

void loop() {
	Serial.println("\n--- Requesting GPS Location ---");
	getGpsLocation();
	delay(30000); // Wait 30 seconds before the next request
}

void getGpsLocation() {
	String response = sendATCommand("AT+CGPSINFO", 5000);

	if (response.indexOf("+CGPSINFO:") != -1) {
		response.replace("+CGPSINFO: ", "");
		response.trim();

		if (response.startsWith(",")) {
			Serial.println("GPS has no fix yet.");
			return;
		}

		int firstComma = response.indexOf(',');
		String latDDMM = response.substring(0, firstComma);
		int secondComma = response.indexOf(',', firstComma + 1);
		String nsIndicator = response.substring(firstComma + 1, secondComma);
		int thirdComma = response.indexOf(',', secondComma + 1);
		String lonDDMM = response.substring(secondComma + 1, thirdComma);
		int fourthComma = response.indexOf(',', thirdComma + 1);
		String ewIndicator = response.substring(thirdComma + 1, fourthComma);

		double latitude = 0.0;
		if (latDDMM.length() > 2) {
			double degrees = latDDMM.substring(0, 2).toDouble();
			double minutes = latDDMM.substring(2).toDouble();
			latitude = degrees + (minutes / 60.0);
			if (nsIndicator == "S") {
				latitude = -latitude;
			}
		}

		double longitude = 0.0;
		if (lonDDMM.length() > 3) {
			double degrees = lonDDMM.substring(0, 3).toDouble();
			double minutes = lonDDMM.substring(3).toDouble();
			longitude = degrees + (minutes / 60.0);
			if (ewIndicator == "W") {
				longitude = -longitude;
			}
		}

		Serial.print("Latitude: ");
		Serial.println(latitude, 6);
		Serial.print("Longitude: ");
		Serial.println(longitude, 6);

	} else {
		Serial.println("Failed to get GPS info from module.");
	}
}

// --- All other helper functions remain the same ---

void powerOnModule() {
	Serial.println("Executing SIM7080G power-on sequence...");
	pinMode(PWRKEY_PIN, OUTPUT);
	digitalWrite(PWRKEY_PIN, HIGH);
	delay(100);
	digitalWrite(PWRKEY_PIN, LOW);
	delay(2000);
	digitalWrite(PWRKEY_PIN, HIGH);
}

void powerOffModule() {
	Serial.println("Executing SIM7080G power-off sequence...");
	pinMode(PWRKEY_PIN, OUTPUT);
	digitalWrite(PWRKEY_PIN, HIGH);
	delay(100);
	digitalWrite(PWRKEY_PIN, LOW);
	delay(2000);
	digitalWrite(PWRKEY_PIN, HIGH);
}

String sendATCommand(String command, unsigned long timeoutMs) {
	Serial.print("Sending: ");
	Serial.println(command);
	while (Serial2.available()) {
		Serial2.read();
	}
	Serial2.println(command);
	String response = "";
	unsigned long startTime = millis();
	while (millis() - startTime < timeoutMs) {
		while (Serial2.available()) {
			char c = (char)Serial2.read();
			response += c;
			startTime = millis();
			if (response.endsWith("OK\r\n") || response.endsWith("ERROR\r\n") ||
			    response.endsWith("FAIL\r\n")) {
				response.trim();
				return response;
			}
		}
	}
	response.trim();
	return response;
}

String getIMEI() {
	String response = sendATCommand("AT+CGSN", 5000);
	int currentPos = 0;
	while (currentPos < response.length()) {
		int nextNewline = response.indexOf('\n', currentPos);
		String line = (nextNewline == -1)
		                  ? response.substring(currentPos)
		                  : response.substring(currentPos, nextNewline);
		currentPos = (nextNewline == -1) ? response.length() : nextNewline + 1;
		line.trim();
		if (line.length() == 15) {
			bool allDigits = true;
			for (int i = 0; i < line.length(); i++) {
				if (!isDigit(line.charAt(i))) {
					allDigits = false;
					break;
				}
			}
			if (allDigits) {
				return line;
			}
		}
	}
	return "";
}

// This function is no longer called in setup, but is kept for future use
bool activatePDPContextAndBearer() {
	Serial.println("Defining PDP Context...");
	String response = sendATCommand(
		"AT+CGDCONT=1,\"IP\",\"" + String(HOLOGRAM_APN) + "\"", 5000);
	if (response.indexOf("OK") == -1)
		return false;

	Serial.println("Activating PDP Context...");
	response = sendATCommand("AT+CGACT=1,1", 10000);
	if (response.indexOf("OK") == -1)
		return false;

	Serial.println("Waiting 5 seconds for IP assignment...");
	delay(5000);

	Serial.println("Checking IP address...");
	response = sendATCommand("AT+CGPADDR=1", 5000);
	if (response.indexOf("+CGPADDR: 1,") == -1)
		return false;

	return true;
}