// #include <stdio.h>

// void app_main(void)
// {

// }


#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/i2c.h"
#include "bme680.h"

#define I2C_PORT        I2C_NUM_0
#define I2C_SDA_PIN     0   // GPIO0
#define I2C_SCL_PIN     2   // GPIO2
#define I2C_FREQ_HZ     100000
#define BME680_ADDR     BME680_I2C_ADDR_PRIMARY   // 0x76 (SDO=GND)
// #define BME680_ADDR  BME680_I2C_ADDR_SECONDARY // 0x77 (SDO=VCC)

// --- I2C helpers (ESP-IDF style) ---
static int8_t i2c_read(uint8_t dev_id, uint8_t reg_addr, uint8_t *data, uint16_t len) {
    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, (dev_id << 1) | I2C_MASTER_WRITE, true);
    i2c_master_write_byte(cmd, reg_addr, true);
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, (dev_id << 1) | I2C_MASTER_READ, true);
    if (len > 1) {
        i2c_master_read(cmd, data, len - 1, I2C_MASTER_ACK);
    }
    i2c_master_read_byte(cmd, data + len - 1, I2C_MASTER_NACK);
    i2c_master_stop(cmd);
    esp_err_t ret = i2c_master_cmd_begin(I2C_PORT, cmd, pdMS_TO_TICKS(1000));
    i2c_cmd_link_delete(cmd);
    return (ret == ESP_OK) ? BME680_OK : BME680_E_COM_FAIL;
}

static int8_t i2c_write(uint8_t dev_id, uint8_t reg_addr, const uint8_t *data, uint16_t len) {
    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, (dev_id << 1) | I2C_MASTER_WRITE, true);
    i2c_master_write_byte(cmd, reg_addr, true);
    i2c_master_write(cmd, (uint8_t*)data, len, true);
    i2c_master_stop(cmd);
    esp_err_t ret = i2c_master_cmd_begin(I2C_PORT, cmd, pdMS_TO_TICKS(1000));
    i2c_cmd_link_delete(cmd);
    return (ret == ESP_OK) ? BME680_OK : BME680_E_COM_FAIL;
}

static void delay_ms(uint32_t period_ms) { vTaskDelay(pdMS_TO_TICKS(period_ms)); }

static void i2c_init(void) {
    i2c_config_t conf = {
        .mode = I2C_MODE_MASTER,
        .sda_io_num = I2C_SDA_PIN,
        .scl_io_num = I2C_SCL_PIN,
        .sda_pullup_en = GPIO_PULLUP_ENABLE,
        .scl_pullup_en = GPIO_PULLUP_ENABLE,
        .master.clk_speed = I2C_FREQ_HZ,
    };
    i2c_param_config(I2C_PORT, &conf);
    i2c_driver_install(I2C_PORT, conf.mode, 0, 0, 0);
}

void app_main(void) {
    i2c_init();

    struct bme680_dev dev = {0};
    dev.dev_id = BME680_ADDR;
    dev.intf = BME680_I2C_INTF;
    dev.read = i2c_read;
    dev.write = i2c_write;
    dev.delay_ms = delay_ms;

    if (bme680_init(&dev) != BME680_OK) {
        printf("BME680 init failed\n");
        return;
    }

    // Oversampling / filter
    dev.tph_sett.os_hum = BME680_OS_2X;
    dev.tph_sett.os_pres = BME680_OS_4X;
    dev.tph_sett.os_temp = BME680_OS_8X;
    dev.tph_sett.filter = BME680_FILTER_SIZE_3;

    // Gas sensor
    dev.gas_sett.run_gas = BME680_ENABLE_GAS_MEAS;
    dev.gas_sett.heatr_temp = 320;   // °C
    dev.gas_sett.heatr_dur  = 150;   // ms

    uint8_t set_required_settings = BME680_OST_SEL | BME680_OSP_SEL |
                                    BME680_OSH_SEL | BME680_FILTER_SEL |
                                    BME680_GAS_SENSOR_SEL;

    if (bme680_set_sensor_settings(set_required_settings, &dev) != BME680_OK) {
        printf("Sensor settings failed\n");
        return;
    }

    while (1) {
        // Force mode, one-shot
        if (bme680_set_sensor_mode(&dev) != BME680_OK) {
            printf("Set mode failed\n");
            vTaskDelay(pdMS_TO_TICKS(1000));
            continue;
        }

        // Wait for measurement time
        uint16_t meas_period;
        bme680_get_profile_dur(&meas_period, &dev);
        vTaskDelay(pdMS_TO_TICKS(meas_period));

        struct bme680_field_data data;
        if (bme680_get_sensor_data(&data, &dev) == BME680_OK) {
            printf("T=%.2f °C  RH=%.2f %%  P=%.2f hPa  Gas=%.2f kΩ\n",
                   data.temperature / 100.0f,
                   data.humidity / 1000.0f,
                   data.pressure / 100.0f,
                   data.gas_resistance / 1000.0f);
        } else {
            printf("Read failed\n");
        }

        vTaskDelay(pdMS_TO_TICKS(2000));
    }
}