#include <Arduino.h>
#include <DHT.h>
#include <PubSubClient.h>
#include <WiFiManager.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>
#include <Wire.h>
#include "esp_system.h"
#include "esp_wifi.h"

// Initialize with default values (can be overridden by user configuration)
char mqttServer[40] = "192.168.1.100";
int mqttPort = 1883;
char mqttUsername[40] = "";
char mqttPassword[40] = "";
char mqttClientId[] = "ESP-VTOXI";

// #define BEEPER_PIN D3
// #define DHT1_PIN D4
// #define DHT2_PIN D5
// #define DHT3_PIN D6
// #define DHT4_PIN D7

#define BEEPER_PIN 4  // GPIO4 for the beeper
#define DHT1_PIN 17   // GPIO17 for DHT1
#define DHT2_PIN 18   // GPIO18 for DHT2
#define DHT3_PIN 19   // GPIO19 for DHT3
#define DHT4_PIN 21   // GPIO21 for DHT4

#define DHT_TYPE DHT11
DHT dht1(DHT1_PIN, DHT_TYPE);
DHT dht2(DHT2_PIN, DHT_TYPE);
DHT dht3(DHT3_PIN, DHT_TYPE);
DHT dht4(DHT4_PIN, DHT_TYPE);

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET -1    // Reset pin # (or -1 if sharing Arduino reset pin)
#define SDA_PIN 21       // I2C SDA pin for ESP32
#define SCL_PIN 22       // I2C SCL pin for ESP32
#define SSD1306_I2C_ADDRESS 0x3C

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

unsigned long previousMillis = 0;
const long interval = 5 * 1000;

WiFiClient espClient;
PubSubClient client(espClient);

uint64_t uniqueId;

// Function forward declarations
void generateMqttClientId();
void initializeHardware();
bool initializeDisplay();
void displayScrollingText(String data);
void connectToWiFi();
void connectToMQTT();
void handleMQTT();
void callback(char *topic, byte *payload, unsigned int length);
void processPingMessage(const char *topic, const char *payload);
void reconnect();
void readAndPublishSensorData();
void publishSensorData(const char *topic, const String &data);

void setup()
{
    initializeHardware();
    generateMqttClientId();
    connectToWiFi();
    connectToMQTT();
}

void loop()
{
    handleMQTT();
    unsigned long currentMillis = millis();

    if (currentMillis - previousMillis >= interval)
    {
        previousMillis = currentMillis;
        readAndPublishSensorData(); // Perform sensor data reading and publishing
    }
}

void generateMqttClientId()
{
    snprintf(mqttClientId, sizeof(mqttClientId), "ESP-%llu", uniqueId);
}

void initializeHardware()
{
    Serial.begin(115200);
    uint8_t mac[6];
    esp_read_mac(mac, ESP_MAC_WIFI_STA);
    uniqueId = ESP.getEfuseMac();
    Serial.print("Unique Chip ID: ");
    Serial.println(uniqueId);

    pinMode(BUILTIN_LED, OUTPUT); // Initialize the LED pin as an output
    pinMode(BEEPER_PIN, OUTPUT);  // Beeper

    if (!initializeDisplay())
    {
        Serial.println(F("SSD1306 initialization failed"));
    }
}

bool initializeDisplay()
{
    if (!display.begin(SSD1306_I2C_ADDRESS, SDA_PIN, SCL_PIN))
    {
        return false; // Return false if display initialization fails
    }
    display.clearDisplay();
    display.setTextSize(1);
    display.setTextColor(SSD1306_WHITE);
    display.setCursor(0, 0);

    displayScrollingText("Pins: D4 - DHT#1, D5 - DHT#2, D6 - DHT#3, D7 - DHT#4, D3: Beeper");
    return true;
}

void displayScrollingText(String data)
{
    String textToScroll = data;
    int textWidth = textToScroll.length() * 6;

    for (int x = 0; x > -textWidth; x--)
    {
        display.clearDisplay();
        display.setCursor(x, 0);
        display.println(textToScroll);
        display.display();
        delay(50); // Adjust the scrolling speed by changing the delay value
    }
}

void connectToWiFi()
{
    WiFiManager wifiManager;
    WiFiManagerParameter custom_mqtt_server("mqtt_server", "MQTT Server", mqttServer, 40);
    WiFiManagerParameter custom_mqtt_port("mqtt_port", "MQTT Port", String(mqttPort).c_str(), 5);
    WiFiManagerParameter custom_mqtt_username("mqtt_username", "MQTT Username", mqttUsername, 40);
    WiFiManagerParameter custom_mqtt_password("mqtt_password", "MQTT Password", mqttPassword, 40);
    wifiManager.addParameter(&custom_mqtt_server);
    wifiManager.addParameter(&custom_mqtt_port);
    wifiManager.addParameter(&custom_mqtt_username);
    wifiManager.addParameter(&custom_mqtt_password);
    wifiManager.autoConnect("ESP-" + uniqueId);
    strncpy(mqttServer, custom_mqtt_server.getValue(), sizeof(mqttServer));
    mqttPort = atoi(custom_mqtt_port.getValue());
    strncpy(mqttUsername, custom_mqtt_username.getValue(), sizeof(mqttUsername));
    strncpy(mqttPassword, custom_mqtt_password.getValue(), sizeof(mqttPassword));
}

void connectToMQTT()
{
    client.setServer(mqttServer, mqttPort);
    client.setCallback(callback);
}

void handleMQTT()
{
    if (!client.connected())
    {
        reconnect();
    }
    client.loop();
}

void reconnect()
{
    while (!client.connected())
    {
        Serial.println("Connecting to MQTT...");
        displayScrollingText("Connecting to MQTT...");
        if (client.connect(mqttClientId, mqttUsername, mqttPassword))
        {
            Serial.println("Connected to MQTT");
            displayScrollingText("Connected to MQTT");
            char pingTopic[64];
            snprintf(pingTopic, sizeof(pingTopic), "%llu/ping", uniqueId);
            client.subscribe(pingTopic);
        }
        else
        {
            Serial.print("Failed, rc=");
            Serial.print(client.state());
            Serial.println(" Retrying in 5 seconds...");
            displayScrollingText("MQTT connection Failed, Retry in 5 seconds...");
            delay(5000);
        }
    }
}

void callback(char *topic, byte *payload, unsigned int length)
{
    // Handle MQTT messages here
    char pingTopic[64];
    snprintf(pingTopic, sizeof(pingTopic), "%llu/ping", uniqueId);

    if (strcmp(topic, pingTopic) == 0) // 0 means both strings are equal
    {
        processPingMessage(topic, (const char *)payload);
    }
}

void processPingMessage(const char *topic, const char *payload)
{
    if (strcmp(payload, "1") == 0)
    {
        // If the payload is "1", blink the LED
        digitalWrite(BUILTIN_LED, HIGH); // Turn the LED on
        tone(BEEPER_PIN, 1000);
        delay(100);
        digitalWrite(BUILTIN_LED, LOW); // Turn the LED off
        noTone(BEEPER_PIN);             // Turn off the beep
    }
}

void readAndPublishSensorData()
{

    char statusTopic[64];
    char temperatureTopic[64];
    char humidityTopic[64];

    float temperature1 = dht1.readTemperature();
    float humidity1 = dht1.readHumidity();
    float temperature2 = dht2.readTemperature();
    float humidity2 = dht2.readHumidity();
    float temperature3 = dht3.readTemperature();
    float humidity3 = dht3.readHumidity();
    float temperature4 = dht4.readTemperature();
    float humidity4 = dht4.readHumidity();

    if (!isnan(temperature1) && !isnan(humidity1))
    {
        snprintf(temperatureTopic, sizeof(temperatureTopic), "%llu/temperature/1", uniqueId);
        snprintf(humidityTopic, sizeof(humidityTopic), "%llu/humidity/1", uniqueId);

        String temperatureString = String(temperature1, 1);
        String humidityString = String(humidity1, 1);

        publishSensorData(temperatureTopic, temperatureString);
        publishSensorData(humidityTopic, humidityString);
    }
    else
    {
        snprintf(statusTopic, sizeof(statusTopic), "%llu/status/1", uniqueId);
        publishSensorData(statusTopic, "Failed to read DHT1 sensor data.");
        Serial.println("Failed to read DHT1 sensor data.");
    }

    if (!isnan(temperature2) && !isnan(humidity2))
    {
        snprintf(temperatureTopic, sizeof(temperatureTopic), "%llu/temperature/2", uniqueId);
        snprintf(humidityTopic, sizeof(humidityTopic), "%llu/humidity/2", uniqueId);

        String temperatureString = String(temperature2, 1);
        String humidityString = String(humidity2, 1);

        publishSensorData(temperatureTopic, temperatureString);
        publishSensorData(humidityTopic, humidityString);
    }
    else
    {
        snprintf(statusTopic, sizeof(statusTopic), "%llu/status/2", uniqueId);
        publishSensorData(statusTopic, "Failed to read DHT2 sensor data.");
        Serial.println("Failed to read DHT2 sensor data.");
    }

    if (!isnan(temperature3) && !isnan(humidity3))
    {
        snprintf(temperatureTopic, sizeof(temperatureTopic), "%llu/temperature/3", uniqueId);
        snprintf(humidityTopic, sizeof(humidityTopic), "%llu/humidity/3", uniqueId);

        String temperatureString = String(temperature3, 1);
        String humidityString = String(humidity3, 1);

        publishSensorData(temperatureTopic, temperatureString);
        publishSensorData(humidityTopic, humidityString);
    }
    else
    {
        snprintf(statusTopic, sizeof(statusTopic), "%llu/status/3", uniqueId);
        publishSensorData(statusTopic, "Failed to read DHT3 sensor data.");
        Serial.println("Failed to read DHT3 sensor data.");
    }

    if (!isnan(temperature4) && !isnan(humidity4))
    {
        snprintf(temperatureTopic, sizeof(temperatureTopic), "%llu/temperature/4", uniqueId);
        snprintf(humidityTopic, sizeof(humidityTopic), "%llu/humidity/4", uniqueId);

        String temperatureString = String(temperature4, 1);
        String humidityString = String(humidity4, 1);

        publishSensorData(temperatureTopic, temperatureString);
        publishSensorData(humidityTopic, humidityString);
    }
    else
    {
        snprintf(statusTopic, sizeof(statusTopic), "%llu/status/4", uniqueId);
        publishSensorData(statusTopic, "Failed to read DHT4 sensor data.");
        Serial.println("Failed to read DHT4 sensor data.");
    }
}

void publishSensorData(const char *topic, const String &data)
{
    if (client.publish(topic, data.c_str()))
    {
        Serial.println("Data published successfully on topic: " + String(topic));
    }
    else
    {
        Serial.println("Failed to publish data on topic: " + String(topic));
    }
}