#include <stdio.h>
#include "esp_rom_gpio.h"
#include "driver/i2c.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/adc.h"

#define I2C_MASTER_SCL_IO          22          // Pin SCL
#define I2C_MASTER_SDA_IO          21          // Pin SDA
#define I2C_MASTER_NUM             I2C_NUM_0   // I2C port number
#define I2C_MASTER_FREQ_HZ         100000      // I2C clock frequency
#define I2C_MASTER_TX_BUF_DISABLE  0
#define I2C_MASTER_RX_BUF_DISABLE  0
#define I2C_LCD_ADDR               0x27        // LCD I2C address

#define SENSOR_PIN                 34          // Pin sensor gas (MQ2)

// LED pins
#define LED_RED_PIN                27
#define LED_YELLOW_PIN             26
#define LED_GREEN_PIN              25

// Fungsi untuk inisialisasi I2C
void i2c_master_init() {
    i2c_config_t conf = {
        .mode = I2C_MODE_MASTER,
        .sda_io_num = I2C_MASTER_SDA_IO,
        .scl_io_num = I2C_MASTER_SCL_IO,
        .sda_pullup_en = GPIO_PULLUP_ENABLE,
        .scl_pullup_en = GPIO_PULLUP_ENABLE,
        .master.clk_speed = I2C_MASTER_FREQ_HZ,
    };
    i2c_param_config(I2C_MASTER_NUM, &conf);
    i2c_driver_install(I2C_MASTER_NUM, conf.mode,
                       I2C_MASTER_RX_BUF_DISABLE,
                       I2C_MASTER_TX_BUF_DISABLE, 0);
}

// Fungsi untuk mengirimkan command ke LCD
void lcd_send_cmd(char cmd) {
    char upper = cmd & 0xF0;
    char lower = (cmd << 4) & 0xF0;
    char data_t[4];
    data_t[0] = upper | 0x0C;
    data_t[1] = upper | 0x08;
    data_t[2] = lower | 0x0C;
    data_t[3] = lower | 0x08;

    i2c_cmd_handle_t handle = i2c_cmd_link_create();
    i2c_master_start(handle);
    i2c_master_write_byte(handle, (I2C_LCD_ADDR << 1) | I2C_MASTER_WRITE, true);
    i2c_master_write(handle, (uint8_t *) data_t, 4, true);
    i2c_master_stop(handle);
    i2c_master_cmd_begin(I2C_MASTER_NUM, handle, 1000 / portTICK_PERIOD_MS);
    i2c_cmd_link_delete(handle);
    vTaskDelay(5 / portTICK_PERIOD_MS);
}

// Fungsi untuk mengirimkan data ke LCD
void lcd_send_data(char data) {
    char upper = data & 0xF0;
    char lower = (data << 4) & 0xF0;
    char data_t[4];
    data_t[0] = upper | 0x0D;
    data_t[1] = upper | 0x09;
    data_t[2] = lower | 0x0D;
    data_t[3] = lower | 0x09;

    i2c_cmd_handle_t handle = i2c_cmd_link_create();
    i2c_master_start(handle);
    i2c_master_write_byte(handle, (I2C_LCD_ADDR << 1) | I2C_MASTER_WRITE, true);
    i2c_master_write(handle, (uint8_t *) data_t, 4, true);
    i2c_master_stop(handle);
    i2c_master_cmd_begin(I2C_MASTER_NUM, handle, 1000 / portTICK_PERIOD_MS);
    i2c_cmd_link_delete(handle);
    vTaskDelay(5 / portTICK_PERIOD_MS);
}

// Fungsi untuk inisialisasi LCD
void lcd_init() {
    lcd_send_cmd(0x02);  // Initialize LCD in 4-bit mode
    lcd_send_cmd(0x28);  // 2 lines, 5x7 matrix
    lcd_send_cmd(0x0C);  // Display ON, cursor OFF
    lcd_send_cmd(0x06);  // Entry mode
    lcd_send_cmd(0x01);  // Clear display
    vTaskDelay(50 / portTICK_PERIOD_MS);
}

// Fungsi untuk menampilkan string pada LCD
void lcd_send_string(const char* str) {
    while (*str) {
        lcd_send_data(*str++);
    }
}

// Fungsi untuk membaca nilai sensor gas
int read_gas_sensor() {
    // Pastikan channel ADC benar-benar valid
    adc1_config_width(ADC_WIDTH_BIT_12); // Set ADC resolution to 12-bit
    adc1_config_channel_atten(ADC1_CHANNEL_6, ADC_ATTEN_DB_0); // No attenuation for this channel

    return adc1_get_raw(ADC1_CHANNEL_6); // Read sensor value from channel 6 (GPIO34)
}

// Fungsi untuk mengendalikan LED berdasarkan pembacaan sensor
void control_led(int sensor_value) {
    if (sensor_value < 1627) {
        // Kualitas udara baik (LED hijau)
        gpio_set_level(LED_GREEN_PIN, 1);
        gpio_set_level(LED_YELLOW_PIN, 0);
        gpio_set_level(LED_RED_PIN, 0);
    } else if (sensor_value < 2410) {
        // Kualitas udara sedang (LED kuning)
        gpio_set_level(LED_GREEN_PIN, 0);
        gpio_set_level(LED_YELLOW_PIN, 1);
        gpio_set_level(LED_RED_PIN, 0);
    } else {
        // Kualitas udara buruk (LED merah)
        gpio_set_level(LED_GREEN_PIN, 0);
        gpio_set_level(LED_YELLOW_PIN, 0);
        gpio_set_level(LED_RED_PIN, 1);
    }
}

void app_main() {
    // Inisialisasi GPIO untuk LED
    esp_rom_gpio_pad_select_gpio(LED_RED_PIN);
    gpio_set_direction(LED_RED_PIN, GPIO_MODE_OUTPUT);

    esp_rom_gpio_pad_select_gpio(LED_YELLOW_PIN);
    gpio_set_direction(LED_YELLOW_PIN, GPIO_MODE_OUTPUT);

    esp_rom_gpio_pad_select_gpio(LED_GREEN_PIN);
    gpio_set_direction(LED_GREEN_PIN, GPIO_MODE_OUTPUT);

    // Inisialisasi I2C dan LCD
    i2c_master_init();
    lcd_init();

    while (1) {
        // Baca nilai sensor gas
        int sensor_value = read_gas_sensor();
        printf("Sensor Value: %d\n", sensor_value);

        // Tampilkan status pada LCD
        lcd_send_cmd(0x80);  // Move to first line
        lcd_send_string("Kualitas Udara:");

        lcd_send_cmd(0xC0);  // Baris kedua
        lcd_send_string("                ");
        
        lcd_send_cmd(0xC0);  // Move to second line
        if (sensor_value < 1790) {
            lcd_send_string("Baik");
        } else if (sensor_value < 2410) {
            lcd_send_string("Sedang");
        } else {
            lcd_send_string("Buruk");
        }

        // Kendalikan LED berdasarkan pembacaan sensor
        control_led(sensor_value);

        vTaskDelay(500 / portTICK_PERIOD_MS);  // Delay selama 2 detik
    }
}