#include <Arduino.h>
#include <driver/i2s.h>
#include <MP3DecoderHelix.h>
#include "positive_sound_mp3.h"

using namespace libhelix;

constexpr i2s_port_t I2S_PORT = I2S_NUM_0;
constexpr int I2S_BCLK = 6;
constexpr int I2S_LRC = 7;
constexpr int I2S_DIN = 5;
constexpr float OUTPUT_GAIN = 0.35f;

MP3DecoderHelix mp3;

bool i2s_initialized = false;
int current_sample_rate = 0;
int current_channels = 0;

void configureI2s(int sample_rate, int channels) {
  if (!i2s_initialized) {
    i2s_config_t i2s_config = {};
    i2s_config.mode = static_cast<i2s_mode_t>(I2S_MODE_MASTER | I2S_MODE_TX);
    i2s_config.sample_rate = sample_rate;
    i2s_config.bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT;
    i2s_config.channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT;
    i2s_config.communication_format = I2S_COMM_FORMAT_STAND_I2S;
    i2s_config.intr_alloc_flags = ESP_INTR_FLAG_LEVEL1;
    i2s_config.dma_buf_count = 8;
    i2s_config.dma_buf_len = 256;
    i2s_config.use_apll = false;
    i2s_config.tx_desc_auto_clear = true;
    i2s_config.fixed_mclk = 0;

    i2s_pin_config_t pin_config = {};
    pin_config.bck_io_num = I2S_BCLK;
    pin_config.ws_io_num = I2S_LRC;
    pin_config.data_out_num = I2S_DIN;
    pin_config.data_in_num = I2S_PIN_NO_CHANGE;

    i2s_driver_install(I2S_PORT, &i2s_config, 0, nullptr);
    i2s_set_pin(I2S_PORT, &pin_config);
    i2s_zero_dma_buffer(I2S_PORT);
    i2s_initialized = true;
  }

  if (sample_rate != current_sample_rate || channels != current_channels) {
    i2s_channel_t channel_mode =
        channels == 1 ? I2S_CHANNEL_MONO : I2S_CHANNEL_STEREO;
    i2s_set_clk(I2S_PORT, sample_rate, I2S_BITS_PER_SAMPLE_16BIT, channel_mode);
    current_sample_rate = sample_rate;
    current_channels = channels;
  }
}

void audioDataCallback(MP3FrameInfo &info, int16_t *pcm_buffer, size_t len, void *) {
  configureI2s(info.samprate, info.nChans);

  for (size_t i = 0; i < len; ++i) {
    pcm_buffer[i] = static_cast<int16_t>(pcm_buffer[i] * OUTPUT_GAIN);
  }

  size_t bytes_written = 0;
  i2s_write(I2S_PORT, pcm_buffer, len * sizeof(int16_t), &bytes_written,
            portMAX_DELAY);
}

void setup() {
  Serial.begin(115200);
  mp3.setDataCallback(audioDataCallback);
  mp3.begin();
  Serial.println("MP3 playback started");
}

void loop() {
  mp3.write(positive_sound_short_mp3, positive_sound_short_mp3_len);
  mp3.begin();
  delay(20);
}