/*******************************************************************************
 * @file    parser.c
 * @brief   BLE command parser
 *
 * Packet format : [TAG 4B] [DATA NB] [CRC16 2B]
 ******************************************************************************/
#include <stdint.h>
#include <string.h>

#include "parser.h"
#include "cmd_common.h"
#include "cmd_table.h"
#include "debug_print.h"

/* 파서 엔트리 */
int ble_cmd_dispatch(const uint8_t *buf, uint16_t len)
{
    //DBG_CORE("[PARSER] enter len=%u\r\n", len);
    //DBG_CORE("[CMD] RX len=%u\r\n", len);

    char raw_tag[5] = { '?', '?', '?', '?', '\0' };
    for (uint16_t i = 0; i < len && i < 4U; i++)
    {
        raw_tag[i] = (char)buf[i];
    }

    if (len < 7U)
    {
        DBG_ERR("[CMD] Too short (%u)\r\n", len);
        if (cmd_send_response_tag_echo("rxs:", raw_tag) != 0)
        {
            DBG_ERR("[CMD] rxs tx failed\r\n");
        }
        return -1;
    }

    uint16_t calc_crc = cmd_crc16_compute(buf, len - 2U);
    uint16_t recv_crc = (uint16_t)(buf[len - 2U]) | ((uint16_t)(buf[len - 1U]) << 8);

    if (calc_crc != recv_crc)
    {
        DBG_ERR("[CMD] CRC fail tag=%s calc=0x%04X recv=0x%04X\r\n", raw_tag, calc_crc, recv_crc);
        if (cmd_send_response_tag_echo("rxc:", raw_tag) != 0)
        {
            DBG_ERR("[CMD] rxc tx failed\r\n");
        }
        return -1;
    }

    char tag[5] =
    {
        cmd_ascii_to_lower((char)buf[0]),
        cmd_ascii_to_lower((char)buf[1]),
        cmd_ascii_to_lower((char)buf[2]),
        cmd_ascii_to_lower((char)buf[3]),
        '\0'
    };

    const uint8_t *data = buf + 4;
    uint8_t data_len = (uint8_t)(len - 4U - 2U);

    for (int i = 0; i < cmd_table_size; i++)
    {
        if (memcmp(tag, cmd_table[i].tag, 4) == 0)
        {
            if (cmd_table[i].handler == NULL)
            {
                DBG_ERR("[CMD] Null handler: %s\r\n", cmd_table[i].tag);
                if (cmd_send_response_tag_echo("rxn:", raw_tag) != 0)
                {
                    DBG_ERR("[CMD] rxn tx failed\r\n");
                }
                return -1;
            }

            return cmd_table[i].handler(data, data_len);
        }
    }

    DBG_ERR("[CMD] Unknown: raw=%s normalized=%s\r\n", raw_tag, tag);
    if (cmd_send_response_tag_echo("rxx:", raw_tag) != 0)
    {
        DBG_ERR("[CMD] rxx tx failed\r\n");
    }
    return 0;
}