// This file is part of the 64k demo project.
// It tests the procedural audio generation functions.

#include "audio/gen.h"
#include "audio/dct.h"
#include <vector>
#include <cassert>
#include <iostream>
#include <cmath>

void test_generate_note() {
    NoteParams params;
    params.base_freq = 440.0f;
    params.duration_sec = 0.1f; // ~3 frames
    params.amplitude = 0.5f;
    params.attack_sec = 0.01f;
    params.decay_sec = 0.0f;
    params.vibrato_rate = 0.0f;
    params.vibrato_depth = 0.0f;
    params.num_harmonics = 1;
    params.harmonic_decay = 1.0f;
    params.pitch_randomness = 0.0f;
    params.amp_randomness = 0.0f;

    int num_frames = 0;
    std::vector<float> data = generate_note_spectrogram(params, &num_frames);

    assert(num_frames > 0);
    assert(data.size() == (size_t)num_frames * DCT_SIZE);
    
    // Check if data is not all zero
    bool non_zero = false;
    for (float v : data) {
        if (std::abs(v) > 1e-6f) {
            non_zero = true;
            break;
        }
    }
    assert(non_zero);
}

void test_paste() {
    std::vector<float> dest;
    int dest_frames = 0;
    std::vector<float> src(DCT_SIZE * 2, 1.0f); // 2 frames of 1.0s
    
    paste_spectrogram(dest, &dest_frames, src, 2, 0);
    assert(dest_frames == 2);
    assert(dest.size() == 2 * DCT_SIZE);
    assert(dest[0] == 1.0f);

    // Paste with offset
    paste_spectrogram(dest, &dest_frames, src, 2, 1);
    // Dest was 2 frames. We paste 2 frames at offset 1.
    // Result should be 1 + 2 = 3 frames.
    assert(dest_frames == 3);
    assert(dest.size() == 3 * DCT_SIZE);
    // Overlap at frame 1: 1.0 + 1.0 = 2.0
    assert(dest[DCT_SIZE] == 2.0f); 
    // Frame 2: 0.0 (original) + 1.0 (new) = 1.0
    assert(dest[2 * DCT_SIZE] == 1.0f);
}

void test_filters() {
    int num_frames = 1;
    std::vector<float> data(DCT_SIZE, 1.0f);

    // Lowpass
    apply_spectral_lowpass(data, num_frames, 0.5f);
    // Bins >= 256 should be 0
    assert(data[0] == 1.0f);
    assert(data[DCT_SIZE - 1] == 0.0f);
    assert(data[256] == 0.0f);
    assert(data[255] == 1.0f); // Boundary check

    // Comb
    data.assign(DCT_SIZE, 1.0f);
    apply_spectral_comb(data, num_frames, 10.0f, 1.0f);
    // Just check modification
    assert(data[0] != 1.0f || data[1] != 1.0f); // It should change values

    // Noise
    data.assign(DCT_SIZE, 1.0f);
    srand(42);
    apply_spectral_noise(data, num_frames, 0.5f);
    // Should be noisy
    assert(data[0] != 1.0f); 
}

int main() {
    std::cout << "Running Audio Gen tests..." << std::endl;
    test_generate_note();
    test_paste();
    test_filters();
    std::cout << "Audio Gen tests PASSED" << std::endl;
    return 0;
}