import ansi from 'ansi';
const { stdout, stdin } = process;

let listeners = [];

const prefix = '\u001b';
const keys = {
  right: `${prefix}[C`,
  up: `${prefix}[A`,
  left: `${prefix}[D`,
  down: `${prefix}[B`,
  exit: '\u0003',
  space: ' '
}

export default class Interface {
  constructor(output = stdout, input = stdin) {
    this.output = output;
    this.input = input;

    this.input.setRawMode(true);
    this.input.setEncoding('utf8');

    this.cursor = ansi(this.output).hide();

    this.columns = this.output.columns;
    this.rows = this.output.rows;

    this.input.addListener('data', data => {
      let key = Object.keys(keys).find((value, i) => {
        return keys[value] === data;
      });

      if ( key === 'exit' ) process.exit();

      let match = listeners.filter(listener => {
        return listener.key === key || listener.key === data;
      });

      match.forEach(listener => listener.fn());
    })
  }

  clear() {
    this.output.write('\u001b[2J\u001b[0;0H');
  }

  write(...args) {
    this.cursor.write(...args);
  }

  onKey(key, fn) {
    listeners.push({ key, fn });
  }
}