#include "diaodu.h"

#define DIAODU_RX_LEN 256

static uint16_t diaodu_rx_status = 0;
static uint16_t diaodu_rx_length = 0;
static uint8_t diaodu_rx_buffer[DIAODU_RX_LEN] = {0};

static void diaodu_unpacking(uint8_t *buffer, uint16_t length);

void diaodu_init(void)
{
}

void diaodu_process(void)
{
    if (diaodu_rx_status & 0x8000)
    {
        diaodu_unpacking(diaodu_rx_buffer, diaodu_rx_status & 0x7FFF);

        diaodu_rx_status = 0;

        diaodu_rx_length = 0;
    }
}

void diaodu_concat_byte(uint8_t data)
{
    if (diaodu_rx_status & 0x8000)
        return;

    if (diaodu_rx_status > DIAODU_RX_LEN)
        diaodu_rx_status = 0;

    diaodu_rx_buffer[diaodu_rx_status++] = data;

    if (diaodu_rx_status == 1)
    {
        if (data != 0x7E)
            diaodu_rx_status = 0;
    }
    else if (diaodu_rx_status == 4)
    {
        if (diaodu_rx_buffer[3] != 0x32)
            diaodu_rx_status = 0;
    }
    else if (diaodu_rx_status == 7)
    {
        diaodu_rx_length = (diaodu_rx_buffer[5] << 8 & 0xFF00) | (diaodu_rx_buffer[6] & 0xFF);
        diaodu_rx_length += 9;
    }
    else if (diaodu_rx_status == diaodu_rx_length)
    {
        if (diaodu_rx_buffer[diaodu_rx_status - 1] == 0x7F)
            diaodu_rx_status |= 0x8000;
        else
        {
            diaodu_rx_status = 0;
            diaodu_rx_length = 0;
        }
    }
}

__weak void diaodu_arrival_or_departure_parsing(uint8_t status) {}

static uint8_t diaodu_check(uint8_t *buffer, uint16_t index, uint16_t length)
{
    uint8_t data = 0;

    for (uint16_t i = index; i < length; i++)
        data ^= buffer[i];

    return data;
}

static void diaodu_unpacking(uint8_t *buffer, uint16_t length)
{
    uint8_t crc = 0x00;

    for (uint16_t i = 0; i < length - 2; i++)
        crc ^= buffer[i];

    if (crc == buffer[length - 2])
    {
        uint16_t len = 0;

        for (uint8_t i = 7; i < length; i += 4)
        {
            /* 到、离站类型 */
            if (buffer[i] == 0x04)
            {
                diaodu_arrival_or_departure_parsing(buffer[i + 3]);
                return;
            }
        }
    }
}