#include <mutex>
#include "AudioThread.h"
#include "SharedState.h"
#include <I2S.h>
#include <math.h>
#include "synth_engine.h"

// I2S Pin definitions
// You may need to change these to match your hardware setup (e.g., for a specific DAC).
const int I2S_BCLK_PIN = 9;  // Bit Clock (GP9)
const int I2S_LRC_PIN  = 10; // Left-Right Clock (GP10)
const int I2S_DOUT_PIN = 11; // Data Out (GP11)

// Audio parameters
const int SAMPLE_RATE = 44100;
const int16_t AMPLITUDE = 16383; // Use a lower amplitude to avoid clipping (max is 32767 for 16-bit)

// Create an I2S output object
I2S i2s(OUTPUT);

extern SynthEngine* globalSynth;

// --- Synthesizer State ---
float currentFrequency = 440.0f;
double phase = 0.0;
unsigned long lastNoteChangeTime = 0;
// ---

void setupAudio() {
  // Configure I2S pins
  i2s.setBCLK(I2S_BCLK_PIN);
  i2s.setDATA(I2S_DOUT_PIN);

  // Set the sample rate and start I2S communication
  i2s.setFrequency(SAMPLE_RATE);
  if (!i2s.begin()) {
    Serial.println("Failed to initialize I2S!");
    while (1); // Halt on error
  }

  // Seed the random number generator from an unconnected analog pin
  randomSeed(analogRead(A0));
  
  // Initialize the portable synth engine
  globalSynth = new SynthEngine(SAMPLE_RATE);
}

void loopAudio() {
  unsigned long now = millis();

  // Every 500ms, pick a new random note to play
  if (now - lastNoteChangeTime > 500) {
    lastNoteChangeTime = now;
    int noteIndex = random(0, SCALES[currentScaleIndex].numNotes);
    
    // Calculate frequency based on key, scale, and octave
    const float baseFrequency = 261.63f; // C4
    float keyFrequency = baseFrequency * pow(2.0f, currentKeyIndex / 12.0f);
    int semitoneOffset = SCALES[currentScaleIndex].semitones[noteIndex];
    currentFrequency = keyFrequency * pow(2.0f, semitoneOffset / 12.0f);

    if (globalSynth) {
        globalSynth->setFrequency(currentFrequency);
        globalSynth->setGate(true); // Trigger envelope
    }
    Serial.println("Playing note: " + String(currentFrequency) + " Hz");
  }

  // Process a small batch of samples
  int16_t samples[32];
  if (globalSynth) globalSynth->process(samples, 32);
  else memset(samples, 0, sizeof(samples));

  for (int i = 0; i < 32; ++i) {
      i2s.write(samples[i]);
      i2s.write(samples[i]);
  }
}