#include <Wire.h>
#include <RtcDS3231.h>
#include <NimBLEDevice.h>
#include "driver/ledc.h"

RtcDS3231<TwoWire> rtc(Wire);

NimBLEServer* pServer = nullptr;
NimBLECharacteristic* pCharacteristic = nullptr;

const int buzzerPin = 10;
const int ledPin = 2;
const int resolution = 8;

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

void setup() {
    pinMode(buzzerPin, OUTPUT);
    pinMode(ledPin, OUTPUT);
    Serial.begin(115200);

    Wire.begin(8, 9); // Initialize I2C with GPIO8 as SDA and GPIO9 as SCL

    rtc.Begin();

    if (!rtc.IsDateTimeValid()) {
        Serial.println("RTC lost confidence in the DateTime!");
        rtc.SetDateTime(RtcDateTime(__DATE__, __TIME__));
    }

    if (!rtc.GetIsRunning()) {
        Serial.println("RTC was not actively running, starting now");
        rtc.SetIsRunning(true);
    }

    // Set an alarm for 10 seconds from now
    RtcDateTime now = rtc.GetDateTime();
    RtcDateTime alarmTime = now + 10; // 10 seconds later
    DS3231AlarmOne alarm(
        alarmTime.Day(),
        alarmTime.Hour(),
        alarmTime.Minute(),
        alarmTime.Second(),
        DS3231AlarmOneControl_HoursMinutesSecondsMatch
    );
    rtc.SetAlarmOne(alarm);
    rtc.LatchAlarmsTriggeredFlags(); // Clear any existing alarms

    NimBLEDevice::init("ESP32_C3_Audio");
    pServer = NimBLEDevice::createServer();
    NimBLEService* pService = pServer->createService("12345678-1234-1234-1234-123456789012");
    pCharacteristic = pService->createCharacteristic(
                        "87654321-4321-4321-4321-210987654321",
                        NIMBLE_PROPERTY::READ | NIMBLE_PROPERTY::WRITE
                      );
    pService->start();
    pServer->getAdvertising()->start();
    Serial.println("The device started, now you can pair it with Bluetooth!");

    ledc_timer_config_t ledc_timer = {
        .speed_mode = LEDC_LOW_SPEED_MODE,
        .duty_resolution = (ledc_timer_bit_t)resolution,
        .timer_num = LEDC_TIMER_0,
        .freq_hz = 1000,
        .clk_cfg = LEDC_AUTO_CLK
    };
    ledc_timer_config(&ledc_timer);

    ledc_channel_config_t ledc_channel = {
        .gpio_num = buzzerPin,
        .speed_mode = LEDC_LOW_SPEED_MODE,
        .channel = LEDC_CHANNEL_0,
        .intr_type = LEDC_INTR_DISABLE,
        .timer_sel = LEDC_TIMER_0,
        .duty = 0,
        .hpoint = 0
    };
    ledc_channel_config(&ledc_channel);
}

void loop() {
    unsigned long currentMillis = millis();
    if (currentMillis - previousMillis >= interval) {
        previousMillis = currentMillis;
        RtcDateTime now = rtc.GetDateTime();
        Serial.print(now.Year());
        Serial.print('/');
        Serial.print(now.Month());
        Serial.print('/');
        Serial.print(now.Day());
        Serial.print(" ");
        Serial.print(now.Hour());
        Serial.print(':');
        Serial.print(now.Minute());
        Serial.print(':');
        Serial.print(now.Second());
        Serial.println();
    }

    if (pCharacteristic->getValue().length() > 0) {
        String data = pCharacteristic->getValue().c_str();
        if (data.length() == 14) {
            int year = data.substring(0, 4).toInt();
            int month = data.substring(4, 6).toInt();
            int day = data.substring(6, 8).toInt();
            int hour = data.substring(8, 10).toInt();
            int minute = data.substring(10, 12).toInt();
            int second = data.substring(12, 14).toInt();
            if (year > 2000 && month > 0 && month <= 12 && day > 0 && day <= 31 &&
                hour >= 0 && hour < 24 && minute >= 0 && minute < 60 && second >= 0 && second < 60) {
                rtc.SetDateTime(RtcDateTime(year, month, day, hour, minute, second));
                Serial.println("Time updated via Bluetooth");
            } else {
                Serial.println("Invalid DateTime format received via Bluetooth");
            }
        } else {
            int freq = data.toInt();
            if (freq > 0) {
                ledc_set_freq(LEDC_LOW_SPEED_MODE, LEDC_TIMER_0, freq);
                digitalWrite(ledPin, HIGH);
                delay(100);
                digitalWrite(ledPin, LOW);
            } else {
                Serial.println("Invalid frequency received via Bluetooth");
            }
        }
        pCharacteristic->setValue("");
    }

    if (rtc.GetAlarmOneTriggered()) {
        Serial.println("Alarm One Triggered!");
        rtc.LatchAlarmsTriggeredFlags(); // Clear the alarm flag
        digitalWrite(buzzerPin, HIGH);
        delay(1000); // Buzzer on for 1 second
        digitalWrite(buzzerPin, LOW);
    }
}