#include "sound.h"

sound::sound()
{

}
#define BUFFER_SIZE 1024
unsigned int buffer_time = 1000000; // 设置缓冲区时间为 1000 ms
unsigned int period_time = 100000;  // 设置周期时间为 100 ms

// 计算 RMS (均方根)
double sound:: calculate_rms(const int16_t *buffer, size_t len)
{
    double sum = 0.0;
    for (size_t i = 0; i < len; ++i)
    {
        sum += buffer[i] * buffer[i];
    }
    return sqrt(sum / len);
}

// 计算 dB (分贝)
double sound::calculate_db(double rms, double reference)
{
    reference = 32768.0;
    return 20.0 * log10(rms / reference);
}

void sound::main_sound()
{
    snd_pcm_t *capture_handle;
    snd_pcm_hw_params_t *hw_params;
    int16_t buffer[BUFFER_SIZE];
    unsigned int rate = 44100; // 采样率 44100 Hz
    int err;

    // 打开默认音频设备进行捕获
    if ((err = snd_pcm_open(&capture_handle, "hw:0,1", SND_PCM_STREAM_CAPTURE, 0)) < 0)
    {
        std::cerr << "Cannot open audio device (" << snd_strerror(err) << ")" << std::endl;
        return ;
    }

    // 设置音频设备硬件参数
    snd_pcm_hw_params_alloca(&hw_params);
    snd_pcm_hw_params_any(capture_handle, hw_params);
    snd_pcm_hw_params_set_access(capture_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
    snd_pcm_hw_params_set_format(capture_handle, hw_params, SND_PCM_FORMAT_S16_LE);
    snd_pcm_hw_params_set_rate_near(capture_handle, hw_params, &rate, 0);
    snd_pcm_hw_params_set_channels(capture_handle, hw_params, 1); // 单声道
    snd_pcm_hw_params_set_buffer_time_near(capture_handle, hw_params, &buffer_time, 0);
    snd_pcm_hw_params_set_period_time_near(capture_handle, hw_params, &period_time, 0);

    if ((err = snd_pcm_hw_params(capture_handle, hw_params)) < 0)
    {
        std::cerr << "Cannot set hardware parameters (" << snd_strerror(err) << ")" << std::endl;
        return ;
    }

    // 准备捕获
    if ((err = snd_pcm_prepare(capture_handle)) < 0)
    {
        std::cerr << "Cannot prepare audio interface for use (" << snd_strerror(err) << ")" << std::endl;
        return ;
    }

    // 累积音频数据，直到积累了1秒的数据
    std::vector<int16_t> accumulated_data;
    size_t samples_per_second = rate; // 1秒内的样本数

    while (true)
    {
        err = snd_pcm_readi(capture_handle, buffer, BUFFER_SIZE);
        if (err == -EPIPE)
        {
            // 处理缓冲区溢出
            snd_pcm_prepare(capture_handle);
            std::cerr << "Buffer overrun occurred" << std::endl;
        }
        else if (err < 0)
        {
            std::cerr << "Read from audio interface failed (" << snd_strerror(err) << ")" << std::endl;
            break;
        }
        else
        {
            // 将读取的数据累积到向量中
            accumulated_data.insert(accumulated_data.end(), buffer, buffer + err);

            // 如果累积的数据达到1秒，则处理数据
            if (accumulated_data.size() >= samples_per_second)
            {
                double rms = calculate_rms(accumulated_data.data(), accumulated_data.size());
                double db = calculate_db(rms);
                qDebug()<<db<<"111111111";
                sound_db = db;
                std::cout << "RMS: " << rms << ", dB: " << db << std::endl;

                // 清空累积的数据，准备下一次读取
                accumulated_data.clear();
                break;
            }
        }
    }

    // 关闭音频设备
    snd_pcm_close(capture_handle);
    return ;
}