#include <EEPROM.h>
#include <ESP8266WiFi.h>

#define SSID_SIZE   64
#define PWD_SIZE    64
#define EEPROM_SIZE SSID_SIZE+PWD_SIZE

String VERSION = "0.0.0-alpha.0";
String wifi_ssid = "";
String wifi_password = "";

int init_config = 0;

void printBanner() {
  Serial.println(" ____                      _        __        ___               _     ");
  Serial.println("|  _ \\ ___ _ __ ___   ___ | |_ ___  \\ \\      / / |__   ___  ___| |___ ");
  Serial.println("| |_) / _ \\ '_ ` _ \\ / _ \\| __/ _ \\  \\ \\ /\\ / /| '_ \\ / _ \\/ _ \\ / __|");
  Serial.println("|  _ <  __/ | | | | | (_) | ||  __/   \\ V  V / | | | |  __/  __/ \\__ \\");
  Serial.println("|_| \\_\\___|_| |_| |_|\\___/ \\__\\___|    \\_/\\_/  |_| |_|\\___|\\___|_|___/");
  Serial.println("v" + VERSION);
  Serial.println();
  Serial.println("Digita `aiuto` per una lista di comandi.");
  Serial.println("Se è la prima volta che configuri il dispositivo, esegui `init`.");
  Serial.println();
}

void connectWifi() {
  WiFi.begin(wifi_ssid.c_str(), wifi_password.c_str());

  int i = 0;
  Serial.print("Connessione in corso alla rete WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    i++;

    if (i == 5) break;
    Serial.print(".");
  }
  Serial.println();

  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("WiFi non connesso");
  } else {
    Serial.println("WiFi connesso con IP: " + WiFi.localIP());
  }
}

void checkWifiStatus() {
  if (WiFi.status() != WL_CONNECTED) {
    digitalWrite(BUILTIN_LED, HIGH);
  } else {
    digitalWrite(BUILTIN_LED, LOW);
  }
}

void erase(int from, int to) {
  for (int i = from ; i < to ; i++)
    EEPROM.write(i, '\0');
}

int writeWord(int address, String str) {
  delay(10);

  for (int i = 0; i < str.length(); i++, address++) {
    EEPROM.write(address, str[i]);
  }

  EEPROM.write(address, '\0');
  EEPROM.commit();

  return address;
}

String readWord(int address) {
  String str;
  char readChar;
  int i = address;

  while ((readChar = char(EEPROM.read(i))) != '\0') {
    delay(10);
    str += readChar;

    i++;
  }

  return str;
}

void printHelp() {
  Serial.println("print|set ssid");
  Serial.println("    Visualizza o imposta l'SSID del wifi.");
  Serial.println();

  Serial.println("print|set password");
  Serial.println("    Visualizza o imposta la password del wifi.");
  Serial.println();

  Serial.println("print config");
  Serial.println("    Visualizza l'attuale configurazione wifi.");
  Serial.println();
}

void loadConfig() {
  wifi_ssid     = readWord(0);
  wifi_password = readWord(SSID_SIZE + 1);
}

void printConfig() {
  Serial.println("Configurazione");
  Serial.println("  SSID:     <" + wifi_ssid + ">");
  Serial.println("  Password: <" + wifi_password + ">");

  Serial.print("  EEPROM:   <");
  Serial.print(EEPROM.length());
  Serial.println(">");

  Serial.print("  IP:       <");
  Serial.print(WiFi.localIP());
  Serial.println(">");
}

String readString() {
  while (Serial.available() == 0) { }
  
  String cmd = Serial.readString();
  cmd.trim();

  return cmd;
}

String readCommand() {
  String cmd = Serial.readString();
  cmd.trim();

  return cmd;
}

void initConfig() {
  printBanner();
  String cmd;
  while (!(cmd = readString()).equals("exit")) {
    Serial.println("$ " + cmd);

    if (cmd.equals("aiuto")) {
      printHelp();
    } else if (cmd.equals("set ssid")) {
      Serial.print("Inserisci SSID: ");
      wifi_ssid = readString();
      Serial.println(wifi_ssid);
      erase(0, SSID_SIZE);
      writeWord(0, wifi_ssid);
    } else if (cmd.equals("set password")) {
      Serial.print("Inserisci la password: ");
      wifi_password = readString();
      Serial.println(wifi_password);
      erase(SSID_SIZE + 1, PWD_SIZE);
      writeWord(SSID_SIZE + 1, wifi_password);
    } else if (cmd.equals("print ssid")) {
    } else if (cmd.equals("print password")) {
    } else if (cmd.equals("print config")) {
      printConfig();
    } else if (cmd.equals("load config")) {
      loadConfig();
      printConfig();
    } else if (cmd.equals("init")) {
      Serial.println("Formattazione della EEPROM...");
      erase(0, EEPROM.length());
      Serial.println("EEPROM formattata.");
    } else {
      Serial.println("Comando sconosciuto.");
    }

    Serial.println();
  }

  Serial.println("Esco dalla configurazione.");
  Serial.println();
}

void parseCommand() {
  String cmd = readCommand();
  if (cmd.equals("config")) {
    initConfig();
  } else if (cmd.equals("connetti")) {
    connectWifi();
  }
}

void setup()
{
  delay(3000);
  Serial.begin(9600);
  EEPROM.begin(EEPROM_SIZE);

  loadConfig();
  connectWifi();

  pinMode(BUILTIN_LED, OUTPUT);
}

void loop()
{
  parseCommand();
  checkWifiStatus();
}