/*
 * FredyGames: the PortAudio V18 calls of Jason Rohrer's minorGems games, on top of SDL2 audio
 * (float32 stereo, one callback). Public domain, like the games.
 */
#include <SDL2/SDL.h>
#include <stdlib.h>
#include "portaudio.h"

struct FgStream {
    SDL_AudioDeviceID device;
    PortAudioCallback *callback;
    void *userData;
    unsigned long frames;
};

static void fgAudioCallback(void *userdata, Uint8 *stream, int len) {
    FgStream *s = (FgStream *)userdata;
    unsigned long frames = (unsigned long)len / (2 * sizeof(float));
    s->callback(NULL, stream, frames, 0, s->userData);
}

PaError Pa_Initialize(void) {
    if (SDL_WasInit(SDL_INIT_AUDIO)) return paNoError;
    return SDL_InitSubSystem(SDL_INIT_AUDIO) == 0 ? paNoError : paHostError;
}

PaError Pa_Terminate(void) { return paNoError; }

const char *Pa_GetErrorText(PaError) { return SDL_GetError(); }

PaDeviceID Pa_GetDefaultOutputDeviceID(void) { return 0; }

PaError Pa_OpenStream(PortAudioStream **stream, PaDeviceID, int, PaSampleFormat, void *, PaDeviceID, int,
                      PaSampleFormat, void *, double sampleRate, unsigned long framesPerBuffer, unsigned long,
                      unsigned long, PortAudioCallback *callback, void *userData) {
    FgStream *s = (FgStream *)calloc(1, sizeof(FgStream));
    s->callback = callback;
    s->userData = userData;
    s->frames = framesPerBuffer;
    SDL_AudioSpec want;
    SDL_zero(want);
    want.freq = (int)sampleRate;
    want.format = AUDIO_F32SYS;
    want.channels = 2;
    want.samples = (Uint16)framesPerBuffer;
    want.callback = fgAudioCallback;
    want.userdata = s;
    s->device = SDL_OpenAudioDevice(NULL, 0, &want, NULL, 0);
    if (s->device == 0) {
        free(s);
        return paHostError;
    }
    *stream = s;
    return paNoError;
}

PaError Pa_StartStream(PortAudioStream *stream) {
    SDL_PauseAudioDevice(((FgStream *)stream)->device, 0);
    return paNoError;
}

PaError Pa_StopStream(PortAudioStream *stream) {
    SDL_PauseAudioDevice(((FgStream *)stream)->device, 1);
    return paNoError;
}

PaError Pa_CloseStream(PortAudioStream *stream) {
    FgStream *s = (FgStream *)stream;
    SDL_CloseAudioDevice(s->device);
    free(s);
    return paNoError;
}