#include "dac161p997.h"
#include "delay.h"

static dac161p997_t _handle;

static void dac161p997_output_0()
{
    _handle.io->set(*_handle.io);
    delay_us(DUTY_CYCLE_25);
    _handle.io->reset(*_handle.io);
    delay_us(DUTY_CYCLE_75);
}

static void dac161p997_output_1()
{
    _handle.io->set(*_handle.io);
    delay_us(DUTY_CYCLE_75);
    _handle.io->reset(*_handle.io);
    delay_us(DUTY_CYCLE_25);
}

static void dac161p997_output_d()
{
    _handle.io->set(*_handle.io);
    delay_us(DUTY_CYCLE_50);
    _handle.io->reset(*_handle.io);
    delay_us(DUTY_CYCLE_50);
}

/**
 * @brief 输出DAC161符号
 *
 * 根据传入的符号类型，调用相应的DAC161输出函数。
 *
 * @param sym 符号类型，可以是ZERO_SYM、ONE_SYM或其他值。
 */
static void dac161p997_output_symbol(uint8_t sym)
{
    switch (sym)
    {
    case ZERO_SYM:
        dac161p997_output_0();
        break;
    case ONE_SYM:
        dac161p997_output_1();
        break;
    default:
        dac161p997_output_d();
        break;
    }
}

/**
 * @brief 向DAC161写入寄存器
 *
 * 向DAC161写入一个16位的数据，并附加一个8位的标签。
 * 芯片会回复一个应答信号，此处忽略应答信号。可以通过设置寄存器关闭应答信号。
 * @param data 要写入的数据，16位。
 * @param tag 附加的标签，8位。tag = 0时，写DAC寄存器；tag = 1时，写配置寄存器。
 */
void dac161p997_swif_write_reg(uint16_t data, uint8_t tag)
{
    uint8_t plow, phigh;
    uint16_t i, tmp;

    /* compute parity low */
    tmp = data & 0x00ff; // get least significant byte
    for (plow = 0; tmp != 0; tmp >>= 1)
    {
        if (tmp & 0x1) // test if lsb is 1
            plow++;    // count number of bits equal to 1
    }

    if (plow & 0x1) // check if number of 1s is odd
        plow = 0;   // set even parity
    else
        plow = 1; // else set odd parity

    /* compute parity high */
    tmp = (data & 0xff00) >> 8; // get most significant byte
    for (phigh = 0; tmp != 0; tmp >>= 1)
    {
        if (tmp & 0x1) // test if lsb is 1
            phigh++;   // count number of bits equal to 1
    }

    if (phigh & 0x1) // check if number of 1s is odd
        phigh = 0;   // set even parity
    else
        phigh = 1; // set odd parity

    phigh = phigh ^ tag; // parity high is for high slice = tag + 1 byte

    dac161p997_output_symbol(IDLE_SYM); // Frame start: send an idle symbol first
    dac161p997_output_symbol(tag);

    tmp = data;
    for (i = 0; i < 16; i++) // send 16 data bits msb to lsb
    {
        if (tmp & 0x8000)
        {
            dac161p997_output_symbol(ONE_SYM); // send 1
        }
        else
        {
            dac161p997_output_symbol(ZERO_SYM); // send 0
        }

        tmp = tmp << 1; // move next data bit to msb
    }

    dac161p997_output_symbol(phigh); // send parity high bit
    dac161p997_output_symbol(plow);  // send parity low bit

    dac161p997_output_symbol(IDLE_SYM); // send idle
}

/**
 * @brief 设置DAC161输出电流
 *
 * 通过向DAC161写入指定的电流值来设置其输出电流,输出电流持续时间100ms。
 *
 * @param current 要设置的电流值
 */
void dac161p997_output_current(float32 current)
{
    uint8_t adc = (uint16_t)(current * DAC161P997_CURRENT_SLOPE) >> 8;
    static uint8_t last_adc;
    if (adc == last_adc)
    {
        last_adc = adc;
        return;
    }

    dac161p997_swif_write_reg(DAC161P997_LCK_REG_UNLOCK, CONFIG_WRITE);
    dac161p997_swif_write_reg(DAC161P997_ERR_LOW_REG + adc, CONFIG_WRITE);
    dac161p997_swif_write_reg(DAC161P997_LCK_REG_LOCK, CONFIG_WRITE);
}

/**
 * @brief 初始化DAC161设备
 *
 * 此函数用于初始化DAC161设备，进行必要的配置，以便设备正常工作。
 * 写寄存器之前要先解锁，具体配置寄存器根据需要配置的寄存器而定
 * 具体步骤包括：
 * 1. 解锁DAC161的配置寄存器
 * 2. 配置DAC161的错误下限寄存器
 * 3. 锁定DAC161的配置寄存器
 */
void dac161p997_init()
{
    _handle.io = gpio_create(DAC161P997_IO_PORT, DAC161P997_IO_PIN);
    dac161p997_swif_write_reg(DAC161P997_LCK_REG_UNLOCK, CONFIG_WRITE);
    dac161p997_swif_write_reg(DAC161P997_CONFIG2_REG +
                                  DAC161P997_CONFIG2_REG_LOOP +
                                  DAC161P997_CONFIG2_REG_CHANNEL +
                                  DAC161P997_CONFIG2_REG_PARITY +
                                  DAC161P997_CONFIG2_REG_FRAME,
                              CONFIG_WRITE);
    dac161p997_swif_write_reg(DAC161P997_LCK_REG_LOCK, CONFIG_WRITE);
}