#include <WiFi.h> 
//Includes from ESP8266audio
#include "AudioFileSourceICYStream.h" //input stream
#include "AudioFileSourceBuffer.h"    //input buffer
#include "AudioGeneratorMP3.h"        //decoder
#include "AudioOutputI2S.h"           //output stream
//library for LCD display
#include <LiquidCrystal_I2C.h>
//library for rotary encoder
#include "AiEsp32RotaryEncoder.h"
//esp32 library to save preferences in flash
#include <Preferences.h>

//WLAN access fill with your credentials
#define SSID "Wokwi-GUEST"
#define PSK ""

//used pins for rotary encoder
#define ROTARY_ENCODER_A_PIN 33
#define ROTARY_ENCODER_B_PIN 32
#define ROTARY_ENCODER_BUTTON_PIN 34
#define ROTARY_ENCODER_VCC_PIN -1 /* 27 put -1 of Rotary encoder Vcc is connected directly to 3,3V; else you can use declared output pin for powering rotary encoder */

//depending on your encoder - try 1,2 or 4 to get expected behaviour
//#define ROTARY_ENCODER_STEPS 1
//#define ROTARY_ENCODER_STEPS 2
#define ROTARY_ENCODER_STEPS 4

//structure for station list
typedef struct {
  char * url;  //stream url
  char * name; //stations name
} Station;

#define STATIONS 1 //number of stations in the list
Station stationlist[STATIONS] PROGMEM = {
{"http://absolut-hot.live-sm.absolutradio.de/absolut-hot/stream/mp3","Absolut-HOT"},
};

//buffer size for stream buffering
const int preallocateBufferSize = 80*1024;
const int preallocateCodecSize = 29192;         // MP3 codec max mem needed
//pointer to preallocated memory
void *preallocateBuffer = NULL;
void *preallocateCodec = NULL;

//instance of prefernces
Preferences pref;
//instance for rotary encoder
AiEsp32RotaryEncoder rotaryEncoder = AiEsp32RotaryEncoder(ROTARY_ENCODER_A_PIN, ROTARY_ENCODER_B_PIN, ROTARY_ENCODER_BUTTON_PIN, ROTARY_ENCODER_VCC_PIN, ROTARY_ENCODER_STEPS);
//instance for LCD display
LiquidCrystal_I2C lcd(0x27,16,2);  // set the LCD address to 0x27 for a 16 chars and 2 line display
//instances for audio components
AudioGenerator *decoder = NULL;
AudioFileSourceICYStream *file = NULL;
AudioFileSourceBuffer *buff = NULL;
AudioOutputI2S *out;

//Special character to show a speaker icon for current station
uint8_t speaker[8]  = {0x3,0x5,0x19,0x11,0x19,0x5,0x3};
//global variables
uint8_t curStation = 0;   //index for current selected station in stationlist
uint8_t actStation = 0;   //index for current station in station list used for streaming 
uint32_t lastchange = 0;  //time of last selection change

//callback function will be called if meta data were found in input stream
void MDCallback(void *cbData, const char *type, bool isUnicode, const char *string)
{
  const char *ptr = reinterpret_cast<const char *>(cbData);
  (void) isUnicode; // Punt this ball for now
  // Note that the type and string may be in PROGMEM, so copy them to RAM for printf
  char s1[32], s2[64];
  strncpy_P(s1, type, sizeof(s1));
  s1[sizeof(s1)-1]=0;
  strncpy_P(s2, string, sizeof(s2));
  s2[sizeof(s2)-1]=0;
  Serial.printf("METADATA(%s) '%s' = '%s'\n", ptr, s1, s2);
  Serial.flush();
}

//stop playing the input stream release memory, delete instances
void stopPlaying() {
  if (decoder)  {
    decoder->stop();
    delete decoder;
    decoder = NULL;
  }
  if (buff)  {
    buff->close();
    delete buff;
    buff = NULL;
  }
  if (file)  {
    file->close();
    delete file;
    file = NULL;
  }
}

//start playing a stream from current active station
void startUrl() {
  stopPlaying();  //first close existing streams
  //open input file for selected url
  Serial.printf("Active station %s\n",stationlist[actStation].url);
  file = new AudioFileSourceICYStream(stationlist[actStation].url);
  //register callback for meta data
  file->RegisterMetadataCB(MDCallback, NULL); 
  //create a new buffer which uses the preallocated memory
  buff = new AudioFileSourceBuffer(file, preallocateBuffer, preallocateBufferSize);
  Serial.printf_P(PSTR("sourcebuffer created - Free mem=%d\n"), ESP.getFreeHeap());
  //create and start a new decoder
  decoder = (AudioGenerator*) new AudioGeneratorMP3(preallocateCodec, preallocateCodecSize);
  Serial.printf_P(PSTR("created decoder\n"));
  Serial.printf_P("Decoder start...\n");
  decoder->begin(buff, out);
}

//show name of current station on LCD display
//show the speaker symbol in front if current station = active station
void showStation() {
  lcd.clear();
  if (curStation == actStation) {
    lcd.home();
    lcd.print(char(1));
  }
  lcd.setCursor(2,0);
  String name = String(stationlist[curStation].name);
  if (name.length() < 15)
    lcd.print(name);
  else {
    uint8_t p = name.lastIndexOf(" ",15); //if name does not fit, split line on space
    lcd.print(name.substring(0,p));
    lcd.setCursor(0,1);
    lcd.print(name.substring(p+1,p+17));
  }
}

//handle events from rotary encoder
void rotary_loop()
{
  //dont do anything unless value changed
  if (rotaryEncoder.encoderChanged())
  {
    uint16_t v = rotaryEncoder.readEncoder();
    Serial.printf("Station: %i\n",v);
    //set new currtent station and show its name
    if (v < STATIONS) {
      curStation = v;
      showStation();
      lastchange = millis();
    }
  }
  //if no change happened within 10s set active station as current station
  if ((lastchange > 0) && ((millis()-lastchange) > 10000)){
    curStation = actStation;
    lastchange = 0;
    showStation();
  }
  //react on rotary encoder switch
  if (rotaryEncoder.isEncoderButtonClicked())
  {
    //set current station as active station and start streaming
    actStation = curStation;
    Serial.printf("Active station %s\n",stationlist[actStation].name);
    pref.putUShort("station",curStation);
    startUrl();
    //call show station to display the speaker symbol
    showStation();
  }
}

//interrupt handling for rotary encoder
void IRAM_ATTR readEncoderISR()
{
  rotaryEncoder.readEncoder_ISR();
}

//setup
void setup() {
  Serial.begin(115200);
  delay(1000);
  //reserve buffer für for decoder and stream
  preallocateBuffer = malloc(preallocateBufferSize);          // Stream-file-buffer
  preallocateCodec = malloc(preallocateCodecSize);            // Decoder- buffer
  if (!preallocateBuffer || !preallocateCodec)
  {
    Serial.printf_P(PSTR("FATAL ERROR:  Unable to preallocate %d bytes for app\n"), preallocateBufferSize+preallocateCodecSize);
    while(1){
      yield(); // Infinite halt
    }
  } 
  //start rotary encoder instance
  rotaryEncoder.begin();
  rotaryEncoder.setup(readEncoderISR);
  rotaryEncoder.setBoundaries(0, STATIONS, true); //minValue, maxValue, circleValues true|false (when max go to min and vice versa)
  rotaryEncoder.disableAcceleration();
  //init WiFi
  Serial.println("Connecting to WiFi");
  WiFi.disconnect();
  WiFi.softAPdisconnect(true);
  WiFi.mode(WIFI_STA);
  WiFi.begin(SSID, PSK);
  // Try forever
  while (WiFi.status() != WL_CONNECTED) {
    Serial.println("...Connecting to WiFi");
    delay(1000);
  }
  Serial.println("Connected");
  //create I2S output do use with decoder
  //the second parameter 1 means use the internal DAC
  out = new AudioOutputI2S(0,1);
  //init the LCD display
  lcd.init();
  lcd.backlight();
  lcd.createChar(1, speaker);
  //set current station to 0
  curStation = 0;
  //start preferences instance
  pref.begin("radio", false);
  //set current station to saved value if available
  if (pref.isKey("station")) curStation = pref.getUShort("station");
  Serial.printf("Gespeicherte Station %i von %i\n",curStation,STATIONS);
  if (curStation >= STATIONS) curStation = 0;
  //set active station to current station 
  //show on display and start streaming
  //curStation = 6;
  actStation = curStation;
  showStation();
  startUrl();
}

void loop() {
  //check if stream has ended normally not on ICY streams
  if (decoder->isRunning()) {
    if (!decoder->loop()) {
      decoder->stop();
    }
  } else {
    Serial.printf("MP3 done\n");

    // Restart ESP when streaming is done or errored
    delay(10000);

    ESP.restart();
  }
  //read events from rotary encoder
  rotary_loop();

}