/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

// import 'vs/css!./progressbar';
import { Disposable } from '../../../../../vs/base/common/lifecycle';
import { Color } from '../../../../../vs/base/common/color';
import { mixin } from '../../../../../vs/base/common/objects';
import { show } from '../../../../../vs/base/browser/dom';
import { RunOnceScheduler } from '../../../../../vs/base/common/async';

const CSS_DONE = 'done';
const CSS_ACTIVE = 'active';
const CSS_INFINITE = 'infinite';
const CSS_DISCRETE = 'discrete';

export interface IProgressBarOptions extends IProgressBarStyles {}

export interface IProgressBarStyles {
  progressBarBackground?: Color;
}

const defaultOpts = {
  progressBarBackground: Color.fromHex('#0E70C0'),
};

/**
 * A progress bar with support for infinite or discrete progress.
 */
export class ProgressBar extends Disposable {
  private options: IProgressBarOptions;
  private workedVal: number;
  private element!: HTMLElement;
  private bit!: HTMLElement;
  private totalWork: number | undefined;
  private progressBarBackground: Color | undefined;
  private showDelayedScheduler: RunOnceScheduler;

  constructor(container: HTMLElement, options?: IProgressBarOptions) {
    super();

    this.options = options || Object.create(null);
    mixin(this.options, defaultOpts, false);

    this.workedVal = 0;

    this.progressBarBackground = this.options.progressBarBackground;

    this._register(
      (this.showDelayedScheduler = new RunOnceScheduler(
        () => show(this.element),
        0
      ))
    );

    this.create(container);
  }

  private create(container: HTMLElement): void {
    this.element = document.createElement('div');
    this.element.classList.add('monaco-progress-container');
    this.element.setAttribute('role', 'progressbar');
    this.element.setAttribute('aria-valuemin', '0');
    container.appendChild(this.element);

    this.bit = document.createElement('div');
    this.bit.classList.add('progress-bit');
    this.element.appendChild(this.bit);

    this.applyStyles();
  }

  private off(): void {
    this.bit.style.width = 'inherit';
    this.bit.style.opacity = '1';
    this.element.classList.remove(CSS_ACTIVE, CSS_INFINITE, CSS_DISCRETE);

    this.workedVal = 0;
    this.totalWork = undefined;
  }

  /**
   * Stops the progressbar from showing any progress instantly without fading out.
   */
  stop(): ProgressBar {
    return this.doDone(false);
  }

  private doDone(delayed: boolean): ProgressBar {
    this.element.classList.add(CSS_DONE);

    // let it grow to 100% width and hide afterwards
    if (!this.element.classList.contains(CSS_INFINITE)) {
      this.bit.style.width = 'inherit';

      if (delayed) {
        setTimeout(() => this.off(), 200);
      } else {
        this.off();
      }
    }

    // let it fade out and hide afterwards
    else {
      this.bit.style.opacity = '0';
      if (delayed) {
        setTimeout(() => this.off(), 200);
      } else {
        this.off();
      }
    }

    return this;
  }

  /**
   * Use this mode to indicate progress that has no total number of work units.
   */
  infinite(): ProgressBar {
    this.bit.style.width = '2%';
    this.bit.style.opacity = '1';

    this.element.classList.remove(CSS_DISCRETE, CSS_DONE);
    this.element.classList.add(CSS_ACTIVE, CSS_INFINITE);

    return this;
  }

  getContainer(): HTMLElement {
    return this.element;
  }

  style(styles: IProgressBarStyles): void {
    this.progressBarBackground = styles.progressBarBackground;

    this.applyStyles();
  }

  protected applyStyles(): void {
    if (this.bit) {
      const background = this.progressBarBackground
        ? this.progressBarBackground.toString()
        : '';

      this.bit.style.backgroundColor = background;
    }
  }
}