#define _POSIX_C_SOURCE 200809L
#include <stdio.h>
#include <stdatomic.h>
#include <pthread.h>
#include <alloca.h>
#include <alsa/asoundlib.h>
#include "raylib.h"
#include "synth.h"
#include "midi.h"

atomic_int gRunning = 1;

static Synth     gSynth = {0};
static MidiState gMidi  = {0};

static void AudioOutputCallback(void *buffer, unsigned int frames)
{
    synthFillBuffer(&gSynth, (int16_t *)buffer, (int)frames);
}

static void drawWaveform(Waveform w, float dutyCycle, int x, int y, int width, int height)
{
    int steps = width;
    for (int i = 0; i < steps - 1; i++) {
        float phase0 = (float)i       / steps;
        float phase1 = (float)(i + 1) / steps;
        float s0 = waveformSample(w, phase0, dutyCycle);
        float s1 = waveformSample(w, phase1, dutyCycle);

        int cx = x + i;
        int cy = y + (int)((1.0f - (s0 * 0.5f + 0.5f)) * height);
        int nx = x + i + 1;
        int ny = y + (int)((1.0f - (s1 * 0.5f + 0.5f)) * height);

        DrawLine(cx, cy, nx, ny, GREEN);
    }
    DrawRectangleLines(x, y, width, height, DARKGRAY);
}

int main(void)
{
    const int sampleRate = 48000;

    if (!midiInit(&gMidi, &gSynth)) return 1;
    midiListInputs(&gMidi);

    int srcClient, srcPort;
    printf("\nEnter client and port to connect (e.g. '20 0'), or -1 -1 to skip: ");
    if (scanf("%d %d", &srcClient, &srcPort) == 2 && srcClient != -1)
        midiConnect(&gMidi, srcClient, srcPort);

    pthread_t midiTid;
    pthread_create(&midiTid, NULL, midiThread, &gMidi);

    synthInit(&gSynth, (float)sampleRate);

    InitWindow(800, 450, "SoundThing");
    InitAudioDevice();
    SetAudioStreamBufferSizeDefault(1024);

    AudioStream stream = LoadAudioStream(sampleRate, 16, 1);
    SetAudioStreamCallback(stream, AudioOutputCallback);
    PlayAudioStream(stream);
    SetTargetFPS(120);

    while (!WindowShouldClose()) {
        if (IsKeyPressed(KEY_UP))
            gSynth.waveform = (gSynth.waveform + 1) % WAVE_COUNT;
        if (IsKeyPressed(KEY_DOWN))
            gSynth.waveform = (gSynth.waveform + WAVE_COUNT - 1) % WAVE_COUNT;

        BeginDrawing();
        ClearBackground(BLACK);

        drawWaveform(gSynth.waveform, gSynth.dutyCycle, 20, 120, 400, 150);

        DrawText("SoundThing", 20, 20, 24, RAYWHITE);
        DrawText(TextFormat("Waveform: %s  (UP/DOWN to change)", waveformName(gSynth.waveform)),
                 20, 55, 20, RAYWHITE);
        DrawText(TextFormat("MIDI: client %d port %d", gMidi.client, gMidi.port),
                 20, 90, 20, GRAY);
        if (gSynth.waveform == WAVE_PULSE)
            DrawText(TextFormat("Duty Cycle: %.2f", gSynth.dutyCycle), 20, 280, 20, GREEN);

        EndDrawing();
    }

    gRunning = 0;
    StopAudioStream(stream);
    UnloadAudioStream(stream);
    CloseAudioDevice();
    CloseWindow();
    pthread_join(midiTid, NULL);
    midiClose(&gMidi);
    return 0;
}