#include "AudioThread.h"
#include "SharedState.h"
#include <I2S.h>
#include <math.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);

// --- Synthesizer State ---
// Frequencies for a C-Major scale to pick from
const float NOTE_FREQUENCIES[] = {
  261.63, 293.66, 329.63, 349.23, 392.00, 440.00, 493.88, 523.25
};
const int NUM_NOTES = sizeof(NOTE_FREQUENCIES) / sizeof(NOTE_FREQUENCIES[0]);

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));
}

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, NUM_NOTES);
    currentFrequency = NOTE_FREQUENCIES[noteIndex];
    Serial.println("Playing note: " + String(currentFrequency) + " Hz");
  }

  // Generate the sine wave sample
  double phaseIncrement = 2.0 * M_PI * currentFrequency / SAMPLE_RATE;
  phase = fmod(phase + phaseIncrement, 2.0 * M_PI);
  int16_t sample = static_cast<int16_t>(AMPLITUDE * sin(phase));

  // Write the same sample to both left and right channels (mono audio).
  // This call is blocking and will wait until there is space in the DMA buffer.
  i2s.write(sample);
  i2s.write(sample);
}