package audio

import "core:math"
import "core:math/rand"
import raylib "vendor:raylib"

// All sounds are synthesized at startup, so no audio files are needed

SAMPLE_RATE :: 44100

Sound_Effect :: enum {
    FLIP,
    MATCH,
    MISMATCH,
    WIN,
    CLICK,
}

sounds: [Sound_Effect]raylib.Sound
ready: bool

@(private)
Tone :: struct {
    start:    f32, // seconds
    freq:     f32, // Hz
    duration: f32, // seconds
    amp:      f32,
}

// Sine with a little 2nd/3rd harmonic, soft attack and exponential decay: a small bell
@(private)
add_tone :: proc(samples: []f32, tone: Tone) {
    first := int(tone.start * SAMPLE_RATE)
    count := int(tone.duration * SAMPLE_RATE)
    attack: f32 = 0.006
    for i in 0 ..< count {
        idx := first + i
        if idx >= len(samples) { break }
        t := f32(i) / SAMPLE_RATE
        env := min(t / attack, 1) * math.exp(-5 * t / tone.duration)
        phase := 2 * math.PI * tone.freq * t
        s := math.sin(phase) + 0.25 * math.sin(2 * phase) + 0.08 * math.sin(3 * phase)
        samples[idx] += tone.amp * env * s
    }
}

// Card "snap": low-passed noise with a fast decay over a short low thump
@(private)
add_flip :: proc(samples: []f32) {
    lp: f32 = 0
    for i in 0 ..< len(samples) {
        t := f32(i) / SAMPLE_RATE
        noise := rand.float32_range(-1, 1)
        lp += 0.35 * (noise - lp)
        swish := lp * math.exp(-t * 55) * min(t / 0.004, 1)
        thump := math.sin(2 * math.PI * 150 * t) * math.exp(-t * 70)
        samples[i] += 0.55 * swish + 0.35 * thump
    }
}

@(private)
make_sound :: proc(samples: []f32) -> raylib.Sound {
    pcm := make([]i16, len(samples))
    defer delete(pcm)
    for s, i in samples {
        pcm[i] = i16(math.clamp(s, -1, 1) * 32000)
    }
    wave := raylib.Wave{
        frameCount = u32(len(pcm)),
        sampleRate = SAMPLE_RATE,
        sampleSize = 16,
        channels   = 1,
        data       = raw_data(pcm),
    }
    // LoadSoundFromWave copies the samples into its own buffer
    return raylib.LoadSoundFromWave(wave)
}

@(private)
build :: proc(duration: f32, tones: []Tone, flip := false) -> raylib.Sound {
    samples := make([]f32, int(duration * SAMPLE_RATE))
    defer delete(samples)
    if flip { add_flip(samples) }
    for tone in tones { add_tone(samples, tone) }
    return make_sound(samples)
}

// Call after raylib.InitAudioDevice
load :: proc() {
    if !raylib.IsAudioDeviceReady() { return }

    E5 :: 659.25
    A5 :: 880.00
    B5 :: 987.77
    C5 :: 523.25
    G5 :: 783.99
    C6 :: 1046.50
    E6 :: 1318.51

    sounds[.FLIP] = build(0.12, {}, flip = true)
    sounds[.MATCH] = build(0.6, {
        {start = 0.00, freq = E5, duration = 0.35, amp = 0.30},
        {start = 0.09, freq = B5, duration = 0.50, amp = 0.28},
    })
    sounds[.MISMATCH] = build(0.45, {
        {start = 0.00, freq = 330, duration = 0.20, amp = 0.20},
        {start = 0.11, freq = 262, duration = 0.30, amp = 0.20},
    })
    sounds[.WIN] = build(1.3, {
        {start = 0.00, freq = C5, duration = 0.40, amp = 0.18},
        {start = 0.11, freq = E5, duration = 0.40, amp = 0.18},
        {start = 0.22, freq = G5, duration = 0.40, amp = 0.18},
        {start = 0.33, freq = C6, duration = 0.90, amp = 0.2},
        {start = 0.33, freq = E6, duration = 0.90, amp = 0.07},
    })
    sounds[.CLICK] = build(0.08, {{start = 0, freq = A5, duration = 0.06, amp = 0.15}})

    raylib.SetSoundVolume(sounds[.FLIP], 0.7)
    ready = true
}

unload :: proc() {
    if !ready { return }
    for s in sounds { raylib.UnloadSound(s) }
    ready = false
}

play :: proc(effect: Sound_Effect) {
    if !ready { return }
    if effect == .FLIP {
        // Slight pitch variation so repeated flips don't sound identical
        raylib.SetSoundPitch(sounds[.FLIP], rand.float32_range(0.9, 1.12))
    }
    raylib.PlaySound(sounds[effect])
}