#include "mp3_driver.h"
#include "elog.h"
#include <string.h>

/* 外部UART句柄声明 */
extern UART_HandleTypeDef huart3;

/**
 * @brief 计算MP3命令校验和
 * @param cmd 命令数组（不包含校验位）
 * @param len 数据长度
 * @return 校验和（高位在前，低位在后）
 * @note 校验算法：从版本号开始，到数据结束，所有字节相加后取反再加1
 */
static void MP3_CalcChecksum(const uint8_t *cmd, uint8_t len, uint8_t *high, uint8_t *low)
{
    uint16_t sum = 0;

    // 从版本号(索引1)开始累加，到数据结束
    for (uint8_t i = 1; i < len; i++) {
        sum += cmd[i];
    }

    // 取反加1 (即0x10000 - sum)
    sum = 0x10000 - sum;

    // 高位在前，低位在后
    *high = (sum >> 8) & 0xFF;
    *low = sum & 0xFF;
}

/**
 * @brief 发送MP3命令
 * @param cmd 命令数组
 * @param len 命令长度
 * @return HAL状态
 */
static HAL_StatusTypeDef MP3_SendCommand(const uint8_t *cmd, uint16_t len)
{
    return HAL_UART_Transmit(&huart3, (uint8_t *)cmd, len, 100);
}

/**
 * @brief MP3模块初始化
 * @return HAL状态
 */
HAL_StatusTypeDef MP3_Init(void)
{
    elog_d("MP3", "开始初始化MP3模块...");

    // 命令1：开启声音 (0x06 - 0x00 - 0x00 - 0x1E)
    // 0x1E = 30, 表示音量为30
    uint8_t init_cmd1[] = {0x7E, 0xFF, 0x06, 0x06, 0x00, 0x00, 0x1E, 0xFE, 0xD7, 0xEF};
    uint8_t high1, low1;
    MP3_CalcChecksum(init_cmd1, 7, &high1, &low1);
    init_cmd1[7] = high1;
    init_cmd1[8] = low1;

    HAL_StatusTypeDef ret1 = MP3_SendCommand(init_cmd1, sizeof(init_cmd1));
    elog_d("MP3", "开启声音命令返回值: %d", ret1);

    // 延时等待模块响应
    HAL_Delay(100);

    // 命令2：选择TF卡作为音源 (0x09 - 0x00 - 0x00 - 0x02)
    uint8_t init_cmd2[] = {0x7E, 0xFF, 0x06, 0x09, 0x00, 0x00, 0x02, 0xFE, 0xF0, 0xEF};
    uint8_t high2, low2;
    MP3_CalcChecksum(init_cmd2, 7, &high2, &low2);
    init_cmd2[7] = high2;
    init_cmd2[8] = low2;

    HAL_StatusTypeDef ret2 = MP3_SendCommand(init_cmd2, sizeof(init_cmd2));
    elog_d("MP3", "选择TF卡命令返回值: %d", ret2);

    if (ret1 == HAL_OK && ret2 == HAL_OK) {
        elog_i("MP3", "MP3模块初始化完成");
        return HAL_OK;
    } else {
        elog_e("MP3", "MP3模块初始化失败");
        return HAL_ERROR;
    }
}

/**
 * @brief 按索引播放指定曲目
 * @param index 曲目索引 (1-9999)
 * @return HAL状态
 */
HAL_StatusTypeDef MP3_Play(uint16_t index)
{
    if (index == 0 || index > 9999) {
        elog_e("MP3", "无效的曲目索引: %d", index);
        return HAL_ERROR;
    }

    // 构建播放命令：0x7E 0xFF 0x06 0x12 0x00 high(索引) low(索引) checksum1 checksum2 0xEF
    uint8_t play_cmd[10];
    play_cmd[0] = MP3_HEADER;
    play_cmd[1] = MP3_VERSION;
    play_cmd[2] = MP3_LENGTH;
    play_cmd[3] = MP3_CMD_PLAY_INDEX;
    play_cmd[4] = 0x00;
    play_cmd[5] = (index >> 8) & 0xFF;  // 索引高字节
    play_cmd[6] = index & 0xFF;          // 索引低字节

    // 计算校验和
    uint8_t high, low;
    MP3_CalcChecksum(play_cmd, 7, &high, &low);
    play_cmd[7] = high;
    play_cmd[8] = low;
    play_cmd[9] = MP3_FOOTER;

    // 发送命令
    HAL_StatusTypeDef ret = MP3_SendCommand(play_cmd, sizeof(play_cmd));
    if (ret == HAL_OK) {
        elog_d("MP3", "播放曲目 %d", index);
    } else {
        elog_e("MP3", "播放曲目 %d 失败", index);
    }

    return ret;
}

/**
 * @brief 停止播放
 * @return HAL状态
 */
HAL_StatusTypeDef MP3_Stop(void)
{
    // 构建停止命令：0x7E 0xFF 0x06 0x16 0x00 0x00 0x00 checksum1 checksum2 0xEF
    uint8_t stop_cmd[10];
    stop_cmd[0] = MP3_HEADER;
    stop_cmd[1] = MP3_VERSION;
    stop_cmd[2] = MP3_LENGTH;
    stop_cmd[3] = MP3_CMD_STOP;
    stop_cmd[4] = 0x00;
    stop_cmd[5] = 0x00;
    stop_cmd[6] = 0x00;

    // 计算校验和
    uint8_t high, low;
    MP3_CalcChecksum(stop_cmd, 7, &high, &low);
    stop_cmd[7] = high;
    stop_cmd[8] = low;
    stop_cmd[9] = MP3_FOOTER;

    HAL_StatusTypeDef ret = MP3_SendCommand(stop_cmd, sizeof(stop_cmd));
    if (ret == HAL_OK) {
        elog_d("MP3", "停止播放");
    } else {
        elog_e("MP3", "停止播放失败");
    }

    return ret;
}

/**
 * @brief 暂停播放
 * @return HAL状态
 */
HAL_StatusTypeDef MP3_Pause(void)
{
    // 构建暂停命令：0x7E 0xFF 0x06 0x0E 0x00 0x00 0x00 checksum1 checksum2 0xEF
    uint8_t pause_cmd[10];
    pause_cmd[0] = MP3_HEADER;
    pause_cmd[1] = MP3_VERSION;
    pause_cmd[2] = MP3_LENGTH;
    pause_cmd[3] = MP3_CMD_PAUSE;
    pause_cmd[4] = 0x00;
    pause_cmd[5] = 0x00;
    pause_cmd[6] = 0x00;

    // 计算校验和
    uint8_t high, low;
    MP3_CalcChecksum(pause_cmd, 7, &high, &low);
    pause_cmd[7] = high;
    pause_cmd[8] = low;
    pause_cmd[9] = MP3_FOOTER;

    HAL_StatusTypeDef ret = MP3_SendCommand(pause_cmd, sizeof(pause_cmd));
    if (ret == HAL_OK) {
        elog_d("MP3", "暂停播放");
    } else {
        elog_e("MP3", "暂停播放失败");
    }

    return ret;
}

/**
 * @brief 设置音量
 * @param volume 音量值 (0-30)
 * @return HAL状态
 */
HAL_StatusTypeDef MP3_SetVolume(uint8_t volume)
{
    if (volume > 30) {
        volume = 30;  // 最大音量30
    }

    // 构建音量设置命令：0x7E 0xFF 0x06 0x06 0x00 0x00 volume checksum1 checksum2 0xEF
    uint8_t vol_cmd[10];
    vol_cmd[0] = MP3_HEADER;
    vol_cmd[1] = MP3_VERSION;
    vol_cmd[2] = MP3_LENGTH;
    vol_cmd[3] = MP3_CMD_SET_VOLUME;
    vol_cmd[4] = 0x00;
    vol_cmd[5] = 0x00;
    vol_cmd[6] = volume;

    // 计算校验和
    uint8_t high, low;
    MP3_CalcChecksum(vol_cmd, 7, &high, &low);
    vol_cmd[7] = high;
    vol_cmd[8] = low;
    vol_cmd[9] = MP3_FOOTER;

    HAL_StatusTypeDef ret = MP3_SendCommand(vol_cmd, sizeof(vol_cmd));
    if (ret == HAL_OK) {
        elog_d("MP3", "设置音量: %d", volume);
    } else {
        elog_e("MP3", "设置音量失败");
    }

    return ret;
}

/**
 * @brief 设置音源
 * @param source 音源类型 (1=U盘, 2=SD卡/TF卡)
 * @return HAL状态
 */
HAL_StatusTypeDef MP3_SetSource(uint8_t source)
{
    if (source != MP3_SOURCE_U_DISK && source != MP3_SOURCE_SD_CARD) {
        elog_e("MP3", "无效的音源类型: %d", source);
        return HAL_ERROR;
    }

    // 构建音源设置命令：0x7E 0xFF 0x06 0x09 0x00 0x00 source checksum1 checksum2 0xEF
    uint8_t source_cmd[10];
    source_cmd[0] = MP3_HEADER;
    source_cmd[1] = MP3_VERSION;
    source_cmd[2] = MP3_LENGTH;
    source_cmd[3] = MP3_CMD_SET_SOURCE;
    source_cmd[4] = 0x00;
    source_cmd[5] = 0x00;
    source_cmd[6] = source;

    // 计算校验和
    uint8_t high, low;
    MP3_CalcChecksum(source_cmd, 7, &high, &low);
    source_cmd[7] = high;
    source_cmd[8] = low;
    source_cmd[9] = MP3_FOOTER;

    HAL_StatusTypeDef ret = MP3_SendCommand(source_cmd, sizeof(source_cmd));
    if (ret == HAL_OK) {
        elog_d("MP3", "设置音源: %d", source);
    } else {
        elog_e("MP3", "设置音源失败");
    }

    return ret;
}