#include "sht40.h"
#include "i2cs.h"
#include "delay.h"
#define SHT40_SDA_PORT I2C1_SDA_GPIO_Port
#define SHT40_SDA_PIN I2C1_SDA_Pin
#define SHT40_SCL_PORT I2C1_SCL_GPIO_Port
#define SHT40_SCL_PIN I2C1_SCL_Pin

#define SHT40_I2C_ADDRESS 0x44
#define SHT40_MEASURE_CMD 0xFD // 2*8-bit T-data:8-bit CRC:2*8-bit RH-data: 8-bit CRC

static i2c_t *_sht40_i2c;
static TIM_TypeDef *_timer_us;
static uint8_t crc8(uint8_t *data, uint8_t len);

static void _delay_us(uint32_t us)
{
    if (_timer_us != NULL)
    {
        delay_hardware_us(_timer_us, us);
    }
    else
    {
        delay_us(us);
    }
}

void sht40_test(void)
{
    float32 temperature = 0;
    float32 humidity = 0;
    sht40_read(&temperature, &humidity);

    __NOP();
}
/**
 * @brief 初始化 SHT40 传感器
 *
 * 该函数用于初始化 SHT40 传感器，包括创建 I2C 通讯所需的 GPIO 引脚和 I2C 通讯对象。
 *
 * 初始化完成后，sht40_i2c 变量将用于后续的 SHT40 传感器通信。
 */
void sht40_init(TIM_TypeDef *timer_us)
{
    DBG_ASSERT(timer_us != NULL __DBG_LINE);
    if (timer_us != NULL)
    {
        _timer_us = timer_us;
        ENABLE_TIM_COUNT(_timer_us);
    }

    i2c_gpio_group_t gpios;
    gpios.scl = gpio_create(SHT40_SCL_PORT, SHT40_SCL_PIN);
    gpios.sda = gpio_create(SHT40_SDA_PORT, SHT40_SDA_PIN);

    _sht40_i2c = i2c_create(gpios, 10);
    DBG_ASSERT(_sht40_i2c != NULL __DBG_LINE);

    // sht40_test(); // 测试 SHT40
}

/**
 * @brief 初始化 SHT40 传感器
 *
 * 此函数用于初始化 SHT40 温湿度传感器，以便进行后续的温度和湿度测量。
 *
 * 注意：该函数没有返回值，也不接受任何参数。
 */
void sht40_dinit(void)
{
    GPIO_SET_ANALOG(SHT40_SDA_PORT, SHT40_SDA_PIN);
    GPIO_SET_ANALOG(SHT40_SCL_PORT, SHT40_SCL_PIN);
}

/**
 * @brief 读取温湿度传感器数据
 *
 * 从温湿度传感器读取温度和湿度数据，并将读取到的数据存储在传入的浮点数指针指向的位置。
 *
 * @param temperature 用于存储读取到的温度值的浮点数指针
 * @param humidity 用于存储读取到的湿度值的浮点数指针
 */
BOOL sht40_read(float32 *temperature, float32 *humidity)
{
    uint8_t data[6];

    osel_memset(data, 0, ARRAY_LEN(data));
    // 发送开始信号
    _sht40_i2c->interface.start(_sht40_i2c);
    // 发送写入地址命令
    _sht40_i2c->interface.write_byte(_sht40_i2c, SHT40_I2C_ADDRESS << 1);
    // 等待写入地址命令响应
    if (_sht40_i2c->interface.wait_ack(_sht40_i2c) == FALSE)
    {
        return FALSE;
    }
    // 发送测量命令
    _sht40_i2c->interface.write_byte(_sht40_i2c, SHT40_MEASURE_CMD);
    // 等待测量命令响应
    if (_sht40_i2c->interface.wait_ack(_sht40_i2c) == FALSE)
    {
        return FALSE;
    }
    // 停止I2C总线
    _sht40_i2c->interface.stop(_sht40_i2c);

    _delay_us(10000); // 根据 SHT40 数据手册，等待至少 10ms

    // 发送开始信号
    _sht40_i2c->interface.start(_sht40_i2c);
    // 发送写入地址命令
    _sht40_i2c->interface.write_byte(_sht40_i2c, (SHT40_I2C_ADDRESS << 1) | 1);
    // 等待写入地址命令响应
    if (_sht40_i2c->interface.wait_ack(_sht40_i2c) == FALSE)
    {
        return FALSE;
    }

    for (uint8_t i = 0; i < ARRAY_LEN(data); i++)
    {
        if (i == 5)
        {
            data[i] = _sht40_i2c->interface.read_byte(_sht40_i2c, FALSE);
        }
        else
        {
            data[i] = _sht40_i2c->interface.read_byte(_sht40_i2c, TRUE);
        }
    }

    // 停止I2C总线
    _sht40_i2c->interface.stop(_sht40_i2c);

    *temperature = 0;
    *humidity = 0;
    if (crc8(&data[0], 2) != data[2] || crc8(&data[3], 2) != data[5])
    {
        return FALSE;
    }
    else
    {
        *temperature = (float32)((uint16_t)data[0] << 8 | data[1]) * 175 / 65535 - 45;
        *humidity = (float32)((uint16_t)data[3] << 8 | data[4]) * 125 / 65535 - 6;
        if (*humidity > 100)
        {
            *humidity = 100;
        }
        if (*humidity < 0)
        {
            *humidity = 0;
        }

        return TRUE;
    }
}

/**
 *  @brief  crc8校验函数，多项式为 x^8 + x^5 + x^4 + 1
 *  @param  data 要校验的数据
 *  @param  len 要校验的数据的字节数
 *  @retval 校验结果
 *  @note   该校验适合SHT3温湿度传感器的数据校验
 */
static uint8_t crc8(uint8_t *data, uint8_t len)
{
    const uint8_t polynomial = 0x31;
    uint8_t crc = 0xFF;
    int i, j;

    for (i = 0; i < len; ++i)
    {
        crc ^= *data++;

        for (j = 0; j < 8; ++j)
        {
            crc = (crc & 0x80) ? (crc << 1) ^ polynomial : (crc << 1);
        }
    }

    return crc;
}