#include "freertos/FreeRTOS.h"
#include "esp_wifi.h"
#include "esp_system.h"
#include "esp_event.h"
#include "esp_event_loop.h"
#include "nvs_flash.h"
#include "driver/gpio.h"
#include "bme280.h"
#include "driver/i2c.h"

#define I2C_MASTER_TX_BUF_DISABLE 0 /*!< I2C master doesn't need buffer */
#define I2C_MASTER_RX_BUF_DISABLE 0 /*!< I2C master doesn't need buffer */
#define WRITE_BIT I2C_MASTER_WRITE  /*!< I2C master write */
#define READ_BIT I2C_MASTER_READ    /*!< I2C master read */
#define ACK_CHECK_EN 0x1            /*!< I2C master will check ack from slave*/
#define ACK_CHECK_DIS 0x0           /*!< I2C master will not check ack from slave */
#define ACK_VAL 0x0                 /*!< I2C ack value */
#define NACK_VAL 0x1                /*!< I2C nack value */

static struct {
    struct arg_int *port;
    struct arg_int *freq;
    struct arg_int *sda;
    struct arg_int *scl;
    struct arg_end *end;
} i2cconfig_args;

static struct {
    struct arg_int *chip_address;
    struct arg_int *register_address;
    struct arg_int *data_length;
    struct arg_end *end;
} i2cget_args;

static struct {
    struct arg_int *chip_address;
    struct arg_int *register_address;
    struct arg_int *data;
    struct arg_end *end;
} i2cset_args;

static int do_i2cget_cmd(int argc, char **argv)
{
    int nerrors = arg_parse(argc, argv, (void **)&i2cget_args);
    if (nerrors != 0) {
        arg_print_errors(stderr, i2cget_args.end, argv[0]);
        return 0;
    }

    /* Check chip address: "-c" option */
    int chip_addr = i2cget_args.chip_address->ival[0];
    /* Check register address: "-r" option */
    int data_addr = -1;
    if (i2cget_args.register_address->count) {
        data_addr = i2cget_args.register_address->ival[0];
    }
    /* Check data length: "-l" option */
    int len = 1;
    if (i2cget_args.data_length->count) {
        len = i2cget_args.data_length->ival[0];
    }
    uint8_t *data = malloc(len);

    i2c_master_driver_initialize();
    i2c_driver_install(i2c_port, I2C_MODE_MASTER, I2C_MASTER_RX_BUF_DISABLE, I2C_MASTER_TX_BUF_DISABLE, 0);
    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    if (data_addr != -1) {
        i2c_master_write_byte(cmd, chip_addr << 1 | WRITE_BIT, ACK_CHECK_EN);
        i2c_master_write_byte(cmd, data_addr, ACK_CHECK_EN);
        i2c_master_start(cmd);
    }
    i2c_master_write_byte(cmd, chip_addr << 1 | READ_BIT, ACK_CHECK_EN);
    if (len > 1) {
        i2c_master_read(cmd, data, len - 1, ACK_VAL);
    }
    i2c_master_read_byte(cmd, data + len - 1, NACK_VAL);
    i2c_master_stop(cmd);
    esp_err_t ret = i2c_master_cmd_begin(i2c_port, cmd, 1000 / portTICK_RATE_MS);
    i2c_cmd_link_delete(cmd);
    if (ret == ESP_OK) {
        for (int i = 0; i < len; i++) {
            printf("0x%02x ", data[i]);
            if ((i + 1) % 16 == 0) {
                printf("\r\n");
            }
        }
        if (len % 16) {
            printf("\r\n");
        }
    } else if (ret == ESP_ERR_TIMEOUT) {
        ESP_LOGW(TAG, "Bus is busy");
    } else {
        ESP_LOGW(TAG, "Read failed");
    }
    free(data);
    i2c_driver_delete(i2c_port);
    return 0;
}

static int do_i2cset_cmd(int argc, char **argv)
{
    int nerrors = arg_parse(argc, argv, (void **)&i2cset_args);
    if (nerrors != 0) {
        arg_print_errors(stderr, i2cset_args.end, argv[0]);
        return 0;
    }

    /* Check chip address: "-c" option */
    int chip_addr = i2cset_args.chip_address->ival[0];
    /* Check register address: "-r" option */
    int data_addr = 0;
    if (i2cset_args.register_address->count) {
        data_addr = i2cset_args.register_address->ival[0];
    }
    /* Check data: "-d" option */
    int len = i2cset_args.data->count;

    i2c_master_driver_initialize();
    i2c_driver_install(i2c_port, I2C_MODE_MASTER, I2C_MASTER_RX_BUF_DISABLE, I2C_MASTER_TX_BUF_DISABLE, 0);
    i2c_cmd_handle_t cmd = i2c_cmd_link_create();
    i2c_master_start(cmd);
    i2c_master_write_byte(cmd, chip_addr << 1 | WRITE_BIT, ACK_CHECK_EN);
    if (i2cset_args.register_address->count) {
        i2c_master_write_byte(cmd, data_addr, ACK_CHECK_EN);
    }
    for (int i = 0; i < len; i++) {
        i2c_master_write_byte(cmd, i2cset_args.data->ival[i], ACK_CHECK_EN);
    }
    i2c_master_stop(cmd);
    esp_err_t ret = i2c_master_cmd_begin(i2c_port, cmd, 1000 / portTICK_RATE_MS);
    i2c_cmd_link_delete(cmd);
    if (ret == ESP_OK) {
        ESP_LOGI(TAG, "Write OK");
    } else if (ret == ESP_ERR_TIMEOUT) {
        ESP_LOGW(TAG, "Bus is busy");
    } else {
        ESP_LOGW(TAG, "Write Failed");
    }
    i2c_driver_delete(i2c_port);
    return 0;
}

static int do_i2cconfig_cmd(int argc, char **argv)
{
    int nerrors = arg_parse(argc, argv, (void **)&i2cconfig_args);
    if (nerrors != 0) {
        arg_print_errors(stderr, i2cconfig_args.end, argv[0]);
        return 0;
    }

    /* Check "--port" option */
    if (i2cconfig_args.port->count) {
        if (i2c_get_port(i2cconfig_args.port->ival[0], &i2c_port) != ESP_OK) {
            return 1;
        }
    }
    /* Check "--freq" option */
    if (i2cconfig_args.freq->count) {
        i2c_frequency = i2cconfig_args.freq->ival[0];
    }
    /* Check "--sda" option */
    i2c_gpio_sda = i2cconfig_args.sda->ival[0];
    /* Check "--scl" option */
    i2c_gpio_scl = i2cconfig_args.scl->ival[0];
    return 0;
}

int fd;

void user_delay_ms(uint32_t period);

void print_sensor_data(struct bme280_data *comp_data);

int8_t user_i2c_read(uint8_t id, uint8_t reg_addr, uint8_t *data, uint16_t len);

int8_t user_i2c_write(uint8_t id, uint8_t reg_addr, uint8_t *data, uint16_t len);

int8_t stream_sensor_data_forced_mode(struct bme280_dev *dev);

/*!
 * @brief This function reading the sensor's registers through I2C bus.
 */
int8_t user_i2c_read(uint8_t id, uint8_t reg_addr, uint8_t *data, uint16_t len)
{
    write(fd, &reg_addr, 1);
    read(fd, data, len);

    return 0;
}

/*!
 * @brief This function provides the delay for required time (Microseconds) as per the input provided in some of the
 * APIs
 */
void user_delay_ms(uint32_t period)
{
    /* Milliseconds convert to microseconds */
    usleep(period * 1000);
}

/*!
 * @brief This function for writing the sensor's registers through I2C bus.
 */
int8_t user_i2c_write(uint8_t id, uint8_t reg_addr, uint8_t *data, uint16_t len)
{
    int8_t *buf;

    buf = malloc(len + 1);
    buf[0] = reg_addr;
    memcpy(buf + 1, data, len);
    if (write(fd, buf, len + 1) < len)
    {
        return BME280_E_COMM_FAIL;
    }

    free(buf);

    return BME280_OK;
}

/*!
 * @brief This API used to print the sensor temperature, pressure and humidity data.
 */
void print_sensor_data(struct bme280_data *comp_data)
{
    float temp, press, hum;

#ifdef BME280_FLOAT_ENABLE
    temp = comp_data->temperature;
    press = 0.01 * comp_data->pressure;
    hum = comp_data->humidity;
#else
#ifdef BME280_64BIT_ENABLE
    temp = 0.01f * comp_data->temperature;
    press = 0.0001f * comp_data->pressure;
    hum = 1.0f / 1024.0f * comp_data->humidity;
#else
    temp = 0.01f * comp_data->temperature;
    press = 0.01f * comp_data->pressure;
    hum = 1.0f / 1024.0f * comp_data->humidity;
#endif
#endif
    printf("%0.2lf deg C, %0.2lf hPa, %0.2lf%%\n", temp, press, hum);
}

/*!
 * @brief This API reads the sensor temperature, pressure and humidity data in forced mode.
 */
int8_t stream_sensor_data_forced_mode(struct bme280_dev *dev)
{
    /* Variable to define the result */
    int8_t rslt = BME280_OK;

    /* Variable to define the selecting sensors */
    uint8_t settings_sel = 0;

    /* Variable to store minimum wait time between consecutive measurement in force mode */
    uint32_t req_delay;

    /* Structure to get the pressure, temperature and humidity values */
    struct bme280_data comp_data;

    /* Recommended mode of operation: Indoor navigation */
    dev->settings.osr_h = BME280_OVERSAMPLING_1X;
    dev->settings.osr_p = BME280_OVERSAMPLING_16X;
    dev->settings.osr_t = BME280_OVERSAMPLING_2X;
    dev->settings.filter = BME280_FILTER_COEFF_16;

    settings_sel = BME280_OSR_PRESS_SEL | BME280_OSR_TEMP_SEL | BME280_OSR_HUM_SEL | BME280_FILTER_SEL;

    /* Set the sensor settings */
    rslt = bme280_set_sensor_settings(settings_sel, dev);
    if (rslt != BME280_OK)
    {
        fprintf(stderr, "Failed to set sensor settings (code %+d).", rslt);

        return rslt;
    }

    printf("Temperature, Pressure, Humidity\n");

    /*Calculate the minimum delay required between consecutive measurement based upon the sensor enabled
     *  and the oversampling configuration. */
    req_delay = bme280_cal_meas_delay(&dev->settings);

    /* Continuously stream sensor data */
    while (1)
    {
        /* Set the sensor to forced mode */
        rslt = bme280_set_sensor_mode(BME280_FORCED_MODE, dev);
        if (rslt != BME280_OK)
        {
            fprintf(stderr, "Failed to set sensor mode (code %+d).", rslt);
            break;
        }

        /* Wait for the measurement to complete and print data */
        dev->delay_ms(req_delay);
        rslt = bme280_get_sensor_data(BME280_ALL, &comp_data, dev);
        if (rslt != BME280_OK)
        {
            fprintf(stderr, "Failed to get sensor data (code %+d).", rslt);
            break;
        }

        print_sensor_data(&comp_data);
    }

    return rslt;
}

static esp_err_t i2c_master_driver_initialize()
{
    i2c_config_t conf = {
        .mode = I2C_MODE_MASTER,
        .sda_io_num = i2c_gpio_sda,
        .sda_pullup_en = GPIO_PULLUP_ENABLE,
        .scl_io_num = i2c_gpio_scl,
        .scl_pullup_en = GPIO_PULLUP_ENABLE,
        .master.clk_speed = i2c_frequency
    };
    return i2c_param_config(i2c_port, &conf);
}

void app_main(void)
{

	struct bme280_dev dev;

	    /* Variable to define the result */
	    int8_t rslt = BME280_OK;

	    /* Make sure to select BME280_I2C_ADDR_PRIM or BME280_I2C_ADDR_SEC as needed */
	    dev.dev_id = BME280_I2C_ADDR_PRIM;

	    /* dev.dev_id = BME280_I2C_ADDR_SEC; */
	    dev.intf = BME280_I2C_INTF;
	    dev.read = user_i2c_read;
	    dev.write = user_i2c_write;
	    dev.delay_ms = user_delay_ms;

	    if ((fd = open(argv[1], O_RDWR)) < 0)
	    {
	        fprintf(stderr, "Failed to open the i2c bus %s\n", argv[1]);
	        exit(1);
	    }

	#ifdef __KERNEL__
	    if (ioctl(fd, I2C_SLAVE, dev.dev_id) < 0)
	    {
	        fprintf(stderr, "Failed to acquire bus access and/or talk to slave.\n");
	        exit(1);
	    }
	#endif

	    /* Initialize the bme280 */
	    rslt = bme280_init(&dev);
	    if (rslt != BME280_OK)
	    {
	        fprintf(stderr, "Failed to initialize the device (code %+d).\n", rslt);
	        exit(1);
	    }

	    rslt = stream_sensor_data_forced_mode(&dev);
	    if (rslt != BME280_OK)
	    {
	        fprintf(stderr, "Failed to stream sensor data (code %+d).\n", rslt);
	        exit(1);
	    }

	    return ;
}