#include <LCDI2C_Multilingual.h>
#include <WiFi.h>
#include <HTTPClient.h>
#include <Arduino_JSON.h>
#include <Encoder.h>

#define BTN_PIN 0

int station_id = 126;

void print_busses();
void print_select_station();

String stringify_field(JSONVar);
int intify_field(JSONVar);
void norm_text(char* text);

Encoder enc(3, 4);
long enc_position = 0;
int last_button_state = 0;

int station_selected = 0;

// set LCD address, number of columns and rows
// if you don't know your display address, run an I2C scanner sketch
LCDI2C_Latin_Symbols lcd(0x27, 20, 4);
char baseEndpoint[] = "https://bgpp.misa.st/api/stations/bg/search?id=";

JSONVar busses;
JSONVar response;
int bus_index = 0;

int busses_updated = 0;
int scroll_updated = 0;
int station_updated = 0;

void setup() {
  pinMode(BTN_PIN, INPUT_PULLUP);
  // initialize LCD
  lcd.init();
  lcd.setAutoNewLine(false);

  // turn on LCD backlight
  lcd.backlight();

  Serial.begin(115200);
  delay(100);

  WiFi.begin("Decentrala", "");

  lcd.setCursor(0, 1);
  lcd.print("Povezujem se");
  Serial.print("\nConnection");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
    lcd.print(".");
  }
  Serial.print("\nConnection OK, IP: ");
  Serial.print(WiFi.localIP());
  Serial.print(" Gateway: ");
  Serial.println(WiFi.gatewayIP());
  Serial.println("You can try to ping me ;-)");
  print_select_station();
}


void loop() {
  int encoder_change = 0;
  int button_pressed = 0;

  int btnState = !digitalRead(BTN_PIN);
  if (btnState != last_button_state) {
    last_button_state = btnState;
    if(btnState){
      button_pressed = 1;
    }
  }
  Serial.println(button_pressed);

  if (!station_selected) {
    if(button_pressed){
      station_selected = 1;
      fetch_busses();
    }
  }else {
    if(button_pressed){
      station_selected = 0;
      print_select_station();
    }
  }


  long newPosition = enc.read();
  if (newPosition != enc_position) {

    encoder_change += (newPosition - enc_position) / 4;
    enc_position = newPosition;
  }

  if (encoder_change && !station_selected) {
    station_id -= encoder_change;
    station_updated = 1;
  }

  if (encoder_change && station_selected) {
    bus_index -= encoder_change;
    scroll_updated = 1;

    if (bus_index < 0) {
      bus_index = 0;
    }
    if (bus_index > busses.length() - 4) {
      bus_index = max(busses.length() - 3, 0);
    }
  }

  if(station_updated){
    print_select_station();
    station_updated = 0;
  }

  if (busses_updated) {
    print_busses();
    busses_updated = 0;
    bus_index = 0;
  }
  if (scroll_updated) {
    print_busses();
    scroll_updated = 0;
  }
  delay(200);
}

void fetch_busses() {
  lcd.clear();
  lcd.setCursor(2, 1);
  lcd.println("Ucitavam...");
  char url[256] = { 0 };
  char id[5] = { 0 };
  strcpy(url, baseEndpoint);
  strcat(url, itoa(station_id, id, 10));

  HTTPClient http;
  http.begin(url);
  int responseCode = http.GET();
  if (responseCode > 0) {
    lcd.clear();
    lcd.setCursor(0, 1);
    lcd.print("HTTP response code: ");
    lcd.print(responseCode);
    String payload = http.getString();
    Serial.println(payload);
    response = JSON.parse(payload);
    if (JSON.typeof_(response) == "undefined") {
      lcd.clear();
      lcd.print("undefined");
    } else {
      // for(response["vehicles"])
      Serial.println(response["vehicles"][0]["lineNumber"]);
      busses = response["vehicles"];
      Serial.println(response["vehicles"]);
    }
    busses_updated = 1;
  } else {
    lcd.clear();
    lcd.setCursor(0, 1);
    lcd.print("error");
  }
  http.end();
}

void print_busses() {
  lcd.clear();
  lcd.setCursor(0, 0);
  String name = stringify_field(response["name"]);
  char namec[20] = { 0 };

  name.toCharArray(namec, 20);
  lcd.print(stringify_field(response["id"]));
  lcd.print(":");
  norm_text(namec);
  lcd.print(namec);
  // for (int i = 0; i < 16; i++) {
  //   lcd.scrollDisplayLeft();
  //   delay(250);
  // }
  // for (int i = 0; i < 16; i++) {
  // lcd.scrollDisplayRight();
  //   delay(250);
  // }

  lcd.setCursor(0, 1);


  if (JSON.typeof_(busses) == "undefined" || JSON.typeof_(busses) == "null") {
    delay(1000);
    Serial.print("no busses");
    lcd.print("nema buseva");
    return;
  }

  for (int i = 0; i < min(busses.length(), 3); i++) {
    int busi = busses.length() - 1 - i - bus_index;
    JSONVar bus = busses[busi];
    String line_number = stringify_field(bus["lineNumber"]);
    int minutes = intify_field(bus["secondsLeft"]) / 60;
    lcd.setCursor(0, i + 1);
    lcd.print(line_number);
    lcd.print(": ");
    lcd.print(stringify_field(bus["stationsBetween"]));
    lcd.print("st ");
    lcd.print(minutes);
    lcd.print("'");
  }
  if (bus_index > 0) {
    lcd.setCursor(19, 1);
    lcd.print("^");
  }
  if (bus_index < busses.length() - 3) {
    lcd.setCursor(19, 3);
    lcd.print(">");
  }
}

void print_select_station() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Izaberite broj stanice:");

  lcd.setCursor(1, 1);
  lcd.print(station_id);
}


int intify_field(JSONVar jfield) {
  if (JSON.typeof_(jfield) != "number") {
    return -1;
  }
  return (int)jfield;
}

String stringify_field(JSONVar jfield) {
  if (JSON.typeof_(jfield) == "number") {
    return (String)(int)jfield;
  }
  String field = JSON.stringify(jfield);
  return field.substring(1, field.length() - 1);
}

void norm_text(char* text) {
  int flag = 0;
  char* t = text;
  while (*t != 0) {
    switch (*t) {
      case 197:
      case 196:
        flag = 1;
        break;
      case 0x86:
      case 0x8c:
        *t = 'C';
      case 0x87:
      case 0x8d:
        *t = 'c';
        break;
      case 0xbd:
        *t = 'Z';
        break;
      case 0xbe:
        *t = 'z';
        break;
      case 0xa0:
        *t = 'S';
        break;
      case 0xa1:
        *t = 's';
        break;
    }
    if (flag) {
      flag = 0;
      char* c = t;
      while (*c != 0) {
        *c = c[1];
        c += 1;
      }
      t -= 1;
    }
    t += 1;
  }
}