// This file is part of the 64k demo project.
// It defines the public interface and data structures for the synth.
// Supports spectrogram registration, voice triggering, and real-time rendering.

#pragma once

#include "dct.h"
#include <cstdint>

#define MAX_VOICES 48 // Per tracker_compiler: required=24, recommended=48
#define MAX_SPECTROGRAMS                                                       \
  32 // Current track: 14 unique, 32 provides comfortable headroom

#define SPEC_VERSION_V1 1
#define SPEC_VERSION_V2_OLA 2

struct Spectrogram {
  const float* spectral_data_a; // Front buffer
  const float* spectral_data_b; // Back buffer (for double-buffering)
  int num_frames;
  int version; // SPEC_VERSION_V1 or SPEC_VERSION_V2_OLA
};

void synth_init();
void synth_shutdown();

// Register a spectrogram for playback. Returns an ID or -1.
int synth_register_spectrogram(const Spectrogram* spec);
void synth_unregister_spectrogram(int spectrogram_id);

// Double-buffering API for thread-safe updates
float* synth_begin_update(int spectrogram_id);
void synth_commit_update(int spectrogram_id);

void synth_trigger_voice(int spectrogram_id, float volume, float pan,
                         int start_offset_samples = 0);
void synth_render(float* output_buffer, int num_frames);
void synth_set_tempo_scale(
    float tempo_scale); // Set playback speed (1.0 = normal)
float synth_get_tempo_scale();

int synth_get_active_voice_count();

// Get peak amplitude of synthesized audio (measured at ring buffer write time)
// NOTE: For audio-visual synchronization, use audio_get_realtime_peak() instead
// This function measures peak ~400ms ahead of playback (at synth_render time)
float synth_get_output_peak();