// This file is part of the 64k demo project.
// It implements the production audio backend using miniaudio.
// Moved from audio.cc to enable backend abstraction for testing.

#include "miniaudio_backend.h"
#include "synth.h"
#include <stdio.h>

// Static callback for miniaudio (C API requirement)
void MiniaudioBackend::audio_callback(ma_device* pDevice, void* pOutput,
                                       const void* pInput,
                                       ma_uint32 frameCount) {
  (void)pDevice;
  (void)pInput;
  float* fOutput = (float*)pOutput;
  synth_render(fOutput, (int)frameCount);
}

MiniaudioBackend::MiniaudioBackend() : initialized_(false) {
}

MiniaudioBackend::~MiniaudioBackend() {
  if (initialized_) {
    shutdown();
  }
}

void MiniaudioBackend::init() {
  if (initialized_) {
    return;
  }

  ma_device_config config = ma_device_config_init(ma_device_type_playback);
  config.playback.format = ma_format_f32;
  config.playback.channels = 2;
  config.sampleRate = 32000;
  config.dataCallback = MiniaudioBackend::audio_callback;
  config.pUserData = this;

  if (ma_device_init(NULL, &config, &device_) != MA_SUCCESS) {
    printf("Failed to open playback device.\n");
    return;
  }

  initialized_ = true;
}

void MiniaudioBackend::start() {
  if (!initialized_) {
    printf("Cannot start: backend not initialized.\n");
    return;
  }

  if (ma_device_start(&device_) != MA_SUCCESS) {
    printf("Failed to start playback device.\n");
    ma_device_uninit(&device_);
    initialized_ = false;
    return;
  }
}

void MiniaudioBackend::shutdown() {
  if (!initialized_) {
    return;
  }

  ma_device_stop(&device_);
  ma_device_uninit(&device_);
  initialized_ = false;
}