#include "zh_aht.h"

static const char *TAG = "zh_aht";

#define ZH_LOGI(msg, ...) ESP_LOGI(TAG, msg, ##__VA_ARGS__)
#define ZH_LOGE(msg, err, ...) ESP_LOGE(TAG, "[%s:%d:%s] " msg, __FILE__, __LINE__, esp_err_to_name(err), ##__VA_ARGS__)

#define ZH_ERROR_CHECK(cond, err, cleanup, msg, ...) \
    if (!(cond))                                     \
    {                                                \
        ZH_LOGE(msg, err, ##__VA_ARGS__);            \
        cleanup;                                     \
        return err;                                  \
    }

#define ZH_ERROR_CHECK_CONT(cond, cleanup, msg, ...) \
    if (!(cond))                                     \
    {                                                \
        ZH_LOGE(msg, ESP_FAIL, ##__VA_ARGS__);       \
        cleanup;                                     \
    }

/**
 * @brief Handle structure for AHT sensor.
 *
 * Internal structure managing the I2C device connection.
 */
struct _zh_aht_handle_t
{
    i2c_master_dev_handle_t dev_handle; /*!< I2C device handle for sensor communication */
};

static const uint8_t _aht_reset_command = 0xBA;                /*!< Reset command for AHT sensor */
static const uint8_t _aht_read_command[] = {0xAC, 0x33, 0x00}; /*!< Command sequence to initiate sensor data read */
static const uint8_t _aht_init_command[] = {0xBE, 0x08, 0x00}; /*!< Init command */
static zh_aht_stats_t _stats = {0};                            /*!< Global statistics structure for error tracking */

/**
 * @brief Validate initialization configuration.
 *
 * Checks I2C address, frequency, and handle validity.
 *
 * @param config Pointer to initialization configuration
 *
 * @return ESP_OK on success
 * @return ESP_ERR_INVALID_ARG if any configuration parameter is invalid
 */
static esp_err_t _zh_aht_validate_config(const zh_aht_init_config_t *config);

/**
 * @brief Initialize I2C communication with AHT sensor.
 *
 * Configures I2C device, probes sensor, and performs initialization command if needed.
 *
 * @param config Pointer to initialization configuration
 * @param handle Pointer to handle structure to store device handle
 *
 * @return ESP_OK on success
 * @return ESP_FAIL on I2C communication errors
 * @return ESP_ERR_NOT_FOUND if sensor is not detected
 */
static esp_err_t _zh_aht_i2c_init(const zh_aht_init_config_t *config, zh_aht_handle_t *handle);

/**
 * @brief Calculate CRC8 for data validation.
 *
 * Implements CRC8 algorithm using polynomial 0x31 for sensor data integrity check.
 *
 * @param buf Pointer to data buffer
 * @param len Length of data buffer
 *
 * @return Calculated CRC8 value
 */
static uint8_t _zh_aht_calc_crc(const uint8_t *buf, size_t len);

esp_err_t zh_aht_init(const zh_aht_init_config_t *config, zh_aht_handle_t **handle)
{
    ZH_LOGI("AHT initialization begin.");
    ZH_ERROR_CHECK(config != NULL && handle != NULL, ESP_ERR_INVALID_ARG, NULL, "AHT initialization failed. Invalid argument.");
    ZH_ERROR_CHECK(_zh_aht_validate_config(config) == ESP_OK, ESP_ERR_INVALID_ARG, NULL, "AHT initialization failed. Invalid config.");
    ZH_ERROR_CHECK(*handle == NULL, ESP_ERR_INVALID_STATE, NULL, "AHT initialization failed. AHT is already initialized.");
    *handle = heap_caps_calloc(1, sizeof(zh_aht_handle_t), MALLOC_CAP_8BIT);
    ZH_ERROR_CHECK(*handle != NULL, ESP_ERR_NO_MEM, NULL, "AHT initialization failed. Failed to allocate AHT handle.");
    ZH_ERROR_CHECK(_zh_aht_i2c_init(config, *handle) == ESP_OK, ESP_FAIL, heap_caps_free(*handle); *handle = NULL, "AHT initialization failed. I2C init failed.");
    ZH_LOGI("AHT initialization completed successfully.");
    return ESP_OK;
}

esp_err_t zh_aht_deinit(zh_aht_handle_t **handle)
{
    ZH_LOGI("AHT deinitialization started.");
    ZH_ERROR_CHECK(handle != NULL && *handle != NULL, ESP_ERR_INVALID_ARG, NULL, "AHT deinitialization failed. Invalid argument.");
    ZH_ERROR_CHECK(i2c_master_bus_rm_device((*handle)->dev_handle) == ESP_OK, ESP_FAIL, NULL, "AHT deinitialization failed. I2C remove device failed.");
    heap_caps_free(*handle);
    *handle = NULL;
    ZH_LOGI("AHT deinitialization completed successfully.");
    return ESP_OK;
}

esp_err_t zh_aht_read(zh_aht_handle_t **handle, float *humidity, float *temperature)
{
    ZH_LOGI("AHT read begin.");
    ZH_ERROR_CHECK(handle != NULL && *handle != NULL && humidity != NULL && temperature != NULL, ESP_ERR_INVALID_ARG, NULL, "AHT read fail. Invalid argument.");
    uint8_t sensor_data[7] = {0};
    ZH_ERROR_CHECK(i2c_master_transmit((*handle)->dev_handle, _aht_read_command, sizeof(_aht_read_command), 100) == ESP_OK, ESP_FAIL,
                   ++_stats.i2c_driver_error, "AHT read fail. I2C driver error.");
    vTaskDelay(80 / portTICK_PERIOD_MS);
    ZH_ERROR_CHECK(i2c_master_receive((*handle)->dev_handle, sensor_data, sizeof(sensor_data), 100) == ESP_OK, ESP_FAIL,
                   ++_stats.i2c_driver_error, "AHT read fail. I2C driver error.");
    ZH_ERROR_CHECK((sensor_data[0] & 0x08) != 0, ESP_ERR_INVALID_STATE, NULL, "AHT read fail. Sensor not calibrated.");
    ZH_ERROR_CHECK((sensor_data[0] & 0x80) == 0, ESP_ERR_TIMEOUT, NULL, "AHT read fail. Timeout exceeded.");
    ZH_ERROR_CHECK(_zh_aht_calc_crc(sensor_data, 6) == sensor_data[6], ESP_ERR_INVALID_CRC, NULL, "AHT read fail. Invalid CRC.");
    *humidity = (((((uint32_t)sensor_data[1]) << 16) | (((uint32_t)sensor_data[2]) << 8) | (((uint32_t)sensor_data[3]) << 0)) >> 4) / 1048576.0 * 100.0;
    *temperature = (((((uint32_t)sensor_data[3]) << 16) | (((uint32_t)sensor_data[4]) << 8) | (((uint32_t)sensor_data[5]) << 0)) & 0xFFFFF) / 1048576.0 * 200.0 - 50.0;
    ZH_LOGI("AHT read completed successfully.");
    return ESP_OK;
}

esp_err_t zh_aht_reset(zh_aht_handle_t **handle)
{
    ZH_LOGI("AHT reset begin.");
    ZH_ERROR_CHECK(handle != NULL && *handle != NULL, ESP_ERR_INVALID_ARG, NULL, "AHT reset fail. Invalid argument.");
    ZH_ERROR_CHECK(i2c_master_transmit((*handle)->dev_handle, &_aht_reset_command, sizeof(_aht_reset_command), 100) == ESP_OK,
                   ESP_FAIL, ++_stats.i2c_driver_error, "AHT reset fail. I2C driver error (reset cmd).");
    vTaskDelay(20 / portTICK_PERIOD_MS);
    uint8_t status_cmd = 0x71;
    uint8_t status = 0;
    ZH_ERROR_CHECK(i2c_master_transmit((*handle)->dev_handle, &status_cmd, sizeof(status_cmd), 100) == ESP_OK, ESP_FAIL,
                   ++_stats.i2c_driver_error, "AHT reset fail. I2C driver error (status cmd).");
    vTaskDelay(10 / portTICK_PERIOD_MS);
    ZH_ERROR_CHECK(i2c_master_receive((*handle)->dev_handle, &status, sizeof(status), 100) == ESP_OK, ESP_FAIL,
                   ++_stats.i2c_driver_error, "AHT reset fail. I2C driver error (status read).");
    if ((status & 0x08) == 0)
    {
        ZH_ERROR_CHECK(i2c_master_transmit((*handle)->dev_handle, _aht_init_command, sizeof(_aht_init_command), 100) == ESP_OK, ESP_FAIL,
                       ++_stats.i2c_driver_error, "AHT reset fail. I2C driver error (init cmd AHT20+).");
        vTaskDelay(20 / portTICK_PERIOD_MS);
    }
    ZH_LOGI("AHT reset completed successfully.");
    return ESP_OK;
}

const zh_aht_stats_t *zh_aht_get_stats(void)
{
    return &_stats;
}

void zh_aht_reset_stats(void)
{
    ZH_LOGI("Error statistic reset started.");
    _stats.i2c_driver_error = 0;
    ZH_LOGI("Error statistic reset successfully.");
}

static esp_err_t _zh_aht_validate_config(const zh_aht_init_config_t *config)
{
    ZH_ERROR_CHECK(config->i2c_address == 0x38 || config->i2c_address == 0x39 || config->i2c_address == 0x44, ESP_ERR_INVALID_ARG, NULL, "Invalid I2C address.");
    ZH_ERROR_CHECK(config->i2c_frequency <= 400000 && config->i2c_frequency > 0, ESP_ERR_INVALID_ARG, NULL, "Invalid I2C frequency.");
    ZH_ERROR_CHECK(config->i2c_handle != NULL, ESP_ERR_INVALID_ARG, NULL, "Invalid I2C handle.");
    return ESP_OK;
}

static esp_err_t _zh_aht_i2c_init(const zh_aht_init_config_t *config, zh_aht_handle_t *handle)
{
    i2c_device_config_t aht_config = {
        .dev_addr_length = I2C_ADDR_BIT_LEN_7,
        .device_address = config->i2c_address,
        .scl_speed_hz = config->i2c_frequency,
    };
    i2c_master_dev_handle_t _dev_handle = NULL;
    ZH_ERROR_CHECK(i2c_master_bus_add_device(config->i2c_handle, &aht_config, &_dev_handle) == ESP_OK, ESP_FAIL, NULL, "Add I2C device failed.");
    vTaskDelay(100 / portTICK_PERIOD_MS);
    ZH_ERROR_CHECK(i2c_master_probe(config->i2c_handle, config->i2c_address, 100) == ESP_OK, ESP_ERR_NOT_FOUND,
                   {ZH_ERROR_CHECK_CONT(i2c_master_bus_rm_device(_dev_handle) == ESP_OK, NULL, "I2C remove device failed.")}, "Sensor not connected or not responded.");
    uint8_t status_cmd = 0x71;
    uint8_t sensor_data = 0;
    ZH_ERROR_CHECK(i2c_master_transmit(_dev_handle, &status_cmd, sizeof(status_cmd), 100) == ESP_OK, ESP_FAIL,
                   {ZH_ERROR_CHECK_CONT(i2c_master_bus_rm_device(_dev_handle) == ESP_OK, NULL, "I2C remove device failed.")}, "I2C driver error (status cmd).");
    vTaskDelay(10 / portTICK_PERIOD_MS);
    ZH_ERROR_CHECK(i2c_master_receive(_dev_handle, &sensor_data, sizeof(sensor_data), 100) == ESP_OK, ESP_FAIL,
                   {ZH_ERROR_CHECK_CONT(i2c_master_bus_rm_device(_dev_handle) == ESP_OK, NULL, "I2C remove device failed.")}, "I2C driver error (status read).");
    if ((sensor_data & 0x08) == 0)
    {
        ZH_ERROR_CHECK(i2c_master_transmit(_dev_handle, _aht_init_command, sizeof(_aht_init_command), 100) == ESP_OK, ESP_FAIL,
                       {ZH_ERROR_CHECK_CONT(i2c_master_bus_rm_device(_dev_handle) == ESP_OK, NULL, "I2C remove device failed.")}, "I2C driver error (init cmd).");
        vTaskDelay(20 / portTICK_PERIOD_MS);
    }
    handle->dev_handle = _dev_handle;
    return ESP_OK;
}

static uint8_t _zh_aht_calc_crc(const uint8_t *buf, size_t len)
{
    uint8_t crc = 0xFF;
    for (uint8_t byte = 0; byte < len; byte++)
    {
        crc ^= buf[byte];
        for (uint8_t i = 8; i > 0; --i)
        {
            if ((crc & 0x80) != 0)
            {
                crc = (crc << 1) ^ 0x31;
            }
            else
            {
                crc = crc << 1;
            }
        }
    }
    return crc;
}