/**
* @license
* Copyright (C) 2018 "IoT.bzh"
* Author Sebastien Douheret <sebastien@iot.bzh>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

import { Component, ElementRef, ViewChild, Input, Output, HostListener, EventEmitter, AfterViewInit } from '@angular/core';
import { Observable } from 'rxjs/Observable';

import { Terminal } from 'xterm';
import * as fit from 'xterm/lib/addons/fit/fit';

export interface ITerminalFont {
  fontFamily: string;
  fontSize: string;
  lineHeight: number;
  charWidth: number;
  charHeight: number;
}


@Component({
  selector: 'xds-terminal',
  styles: [],
  template: `
    <div #terminalContainer></div>
  `,
})
export class TerminalComponent implements AfterViewInit {

  private _xterm: Terminal;
  private _initDone: boolean;

  @ViewChild('terminalContainer') termContainer: ElementRef;

  @Output() stdin = new EventEmitter<any>();
  @Output() resize = new EventEmitter<{ cols: number, rows: number }>();


  constructor() {
    this._initDone = false;
    Terminal.applyAddon(fit);

    this._xterm = new Terminal({
      cursorBlink: true,
      // useStyle: true,
      scrollback: 1000,
      rows: 24,
      cols: 80,
    });
  }

  // getting the nativeElement only possible after view init
  ngAfterViewInit() {

    // this now finds the #terminal element
    this._xterm.open(this.termContainer.nativeElement);

    // the number of rows will determine the size of the terminal screen
    (<any>this._xterm).fit();

    // Bind input key
    this._xterm.on('data', (data) => {
      // console.log(data.charCodeAt(0));
      this.stdin.emit(this._sanitizeInput(data));
      return false;
    });

    this._initDone = true;
  }

  @Input('stdout')
  set writeData(data) {
    if (this._initDone && data !== undefined) {
      this._xterm.write(data);
    }
  }

  @Input('disable')
  set disable(value: boolean) {
    if (!this._initDone) {
      return;
    }

    this._xterm.setOption('disableStdin', value);

    if (value) {
      this._xterm.blur();
    } else {
      this._xterm.focus();
    }
    this._resize();
  }

  @HostListener('window:resize', ['$event'])
  onWindowResize(event) {
    this._resize();
  }

  /*** Private functions ***/

  private _sanitizeInput(d) {
    // TODO sanitize ?
    return d;
  }

  private _resize() {
    const geom = fit.proposeGeometry(this._xterm);

    // console.log('DEBUG  cols ' + String(geom.cols) + ' rows ' + String(geom.rows));

    if (geom.cols < 0 || geom.cols > 2000 || geom.rows < 0 || geom.rows > 2000) {
      return;
    }

    // Update xterm size
    this._xterm.resize(geom.cols, geom.rows);

    // Send resize event to update remote terminal
    this.resize.emit({ cols: geom.cols, rows: geom.rows });
  }

}