// beep.c
// Build (Linux/macOS): cc beep.c -lm -o beep
// Build (Windows MSVC): cl /O2 beep.c

#define MINIAUDIO_IMPLEMENTATION
#include "miniaudio.h"

#include <math.h>
#include <stdint.h>
#include <stdio.h>

typedef struct {
    double phase;
    double phase_inc;
    uint32_t frames_left;
    ma_uint32 channels;
} beep_state;

static void data_callback(ma_device* dev, void* out, const void* in, ma_uint32 frameCount)
{
    (void)in;
    beep_state* s = (beep_state*)dev->pUserData;
    float* output = (float*)out;

    ma_uint32 framesToWrite = frameCount;
    if (s->frames_left < framesToWrite) framesToWrite = s->frames_left;

    for (ma_uint32 i = 0; i < framesToWrite; i++) {
        float sample = (float)sin(s->phase) * 0.2f; // volume
        s->phase += s->phase_inc;

        // keep phase bounded (optional)
        if (s->phase >= (2.0 * M_PI)) s->phase -= (2.0 * M_PI);

        for (ma_uint32 ch = 0; ch < s->channels; ch++) {
            output[i * s->channels + ch] = sample;
        }
    }

    // If we ran out early, zero the rest (silence).
    for (ma_uint32 i = framesToWrite; i < frameCount; i++) {
        for (ma_uint32 ch = 0; ch < s->channels; ch++) {
            output[i * s->channels + ch] = 0.0f;
        }
    }

    s->frames_left -= framesToWrite;

    // Stop after the beep finishes.
    if (s->frames_left == 0) {
        ma_device_stop(dev); // safe to request stop
    }
}

int main(void)
{
    const double freq = 440.0;
    const ma_uint32 sampleRate = 48000;
    const double durationSec = 1.0;

    beep_state s = {0};
    s.phase = 0.0;
    s.phase_inc = (2.0 * M_PI * freq) / (double)sampleRate;
    s.frames_left = (uint32_t)(durationSec * (double)sampleRate);

    ma_device_config cfg = ma_device_config_init(ma_device_type_playback);
    cfg.playback.format   = ma_format_f32;
    cfg.playback.channels = 2;
    cfg.sampleRate        = sampleRate;
    cfg.dataCallback      = data_callback;
    cfg.pUserData         = &s;

    ma_device dev;
    if (ma_device_init(NULL, &cfg, &dev) != MA_SUCCESS) {
        fprintf(stderr, "Failed to init audio device\n");
        return 1;
    }

    s.channels = dev.playback.channels; // in case backend adjusts

    if (ma_device_start(&dev) != MA_SUCCESS) {
        fprintf(stderr, "Failed to start audio device\n");
        ma_device_uninit(&dev);
        return 1;
    }

    // Wait until callback stops the device.
    while (ma_device_is_started(&dev)) {
        ma_sleep(10);
    }

    ma_device_uninit(&dev);
    return 0;
}