// This file is part of the 64k demo project.
// It serves as the application entry point.
// Orchestrates platform initialization, main loop, and subsystem coordination.

#include "assets.h" // Include generated asset header
#include "audio/audio.h"
#include "audio/synth.h"
#include "gpu/gpu.h"
#include "platform.h"
#include "util/math.h"
#include <GLFW/glfw3.h>
#include <math.h>
#include <stdio.h>
#include <string.h>

#define DEMO_BPM 128.0f
#define SECONDS_PER_BEAT (60.0f / DEMO_BPM)
#define SPEC_FRAMES 16

struct SpecHeader {
  char magic[4];
  int32_t version;
  int32_t dct_size;
  int32_t num_frames;
};

int register_spec_asset(AssetId id) {
  size_t size;
  const uint8_t *data = GetAsset(id, &size);
  if (!data || size < sizeof(SpecHeader))
    return -1;

  const SpecHeader *header = (const SpecHeader *)data;
  const float *spectral_data = (const float *)(data + sizeof(SpecHeader));

  Spectrogram spec;
  spec.spectral_data_a = spectral_data;
  spec.spectral_data_b = spectral_data; // No double-buffer for static assets
  spec.num_frames = header->num_frames;

  return synth_register_spectrogram(&spec);
}

static float g_spec_buffer_a[SPEC_FRAMES * DCT_SIZE];
static float g_spec_buffer_b[SPEC_FRAMES * DCT_SIZE];

void generate_tone(float *buffer, float freq) {
  memset(buffer, 0, SPEC_FRAMES * DCT_SIZE * sizeof(float));
  for (int frame = 0; frame < SPEC_FRAMES; ++frame) {
    float *spec_frame = buffer + frame * DCT_SIZE;
    float amplitude = powf(1.0f - (float)frame / SPEC_FRAMES, 2.0f);

    int bin = (int)(freq / (32000.0f / 2.0f) * DCT_SIZE);
    if (bin > 0 && bin < DCT_SIZE) {
      spec_frame[bin] = amplitude;
    }
  }
}

int main(int argc, char **argv) {
  bool fullscreen_enabled = false;

#ifndef STRIP_ALL
  for (int i = 1; i < argc; ++i) {
    if (strcmp(argv[i], "--fullscreen") == 0) {
      fullscreen_enabled = true;
      break;
    }
  }
#else
  (void)argc;
  (void)argv;
  fullscreen_enabled = true;
#endif

  platform_init_window(fullscreen_enabled);
  gpu_init(platform_get_window());
  audio_init();

  // Register drum assets
  int kick_id = register_spec_asset(AssetId::ASSET_KICK_1);
  int snare_id = register_spec_asset(AssetId::ASSET_SNARE_1);
  int hihat_id = register_spec_asset(AssetId::ASSET_HIHAT_1);

  // Still keep the dynamic tone for bass
  generate_tone(g_spec_buffer_a, 110.0f); // A2
  generate_tone(g_spec_buffer_b, 110.0f);
  const Spectrogram bass_spec = {g_spec_buffer_a, g_spec_buffer_b, SPEC_FRAMES};
  int bass_id = synth_register_spectrogram(&bass_spec);

  double last_beat_time = 0.0;
  int beat_count = 0;

  while (!platform_should_close()) {
    platform_poll();

    double current_time = platform_get_time();
    if (current_time - last_beat_time > SECONDS_PER_BEAT / 2.0) { // 8th notes
      last_beat_time = current_time;

      const int step = beat_count % 16;

      // Kick on 1, 9, 11, 14...
      if (step == 0 || step == 8 || step == 10 || step == 13) {
        synth_trigger_voice(kick_id, 1.0f, 0.0f);
      }

      // Snare on 4, 12
      if (step == 4 || step == 12) {
        synth_trigger_voice(snare_id, 0.8f, 0.0f);
      }

      // Hihat on every offbeat
      if (step % 2 == 1) {
        synth_trigger_voice(hihat_id, 0.5f, 0.3f);
      }

      // Bass pattern
      if (step % 4 == 0) {
        float bass_freq = (step < 8) ? 110.0f : 82.41f; // A2 then E2
        float *back_buffer = synth_begin_update(bass_id);
        if (back_buffer) {
          generate_tone(back_buffer, bass_freq);
          synth_commit_update(bass_id);
        }
        synth_trigger_voice(bass_id, 0.6f, -0.2f);
      }

      beat_count++;
    }

    int width, height;
    glfwGetFramebufferSize(platform_get_window(), &width, &height);
    float aspect_ratio = (float)width / (float)height;

    // Adjusted multiplier for visuals (preventing constant 1.0 saturation)
    float raw_peak = synth_get_output_peak();
    float visual_peak = fminf(raw_peak * 8.0f, 1.0f);

    gpu_draw(visual_peak, aspect_ratio, (float)current_time);
    audio_update();
  }

  audio_shutdown();
  gpu_shutdown();
  platform_shutdown();
  return 0;
}