// Copyright (c) 2022 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import * as LitHtml from '../../lit-html/lit-html.js';
import * as ComponentHelpers from '../helpers/helpers.js';

import twoStatesCounterStyles from './twoStatesCounter.css.js';
const isString = (value: string|undefined): value is string => value !== undefined;

export interface TwoStatesCounterData {
  active: number;
  inactive: number;
  width?: string;
  height?: string;
  activeTitle?: string;
  inactiveTitle?: string;
}

export class TwoStatesCounter extends HTMLElement {
  static readonly litTagName = LitHtml.literal`devtools-two-states-counter`;
  readonly #boundRender = this.#render.bind(this);
  readonly #shadow = this.attachShadow({mode: 'open'});
  #numActive: number = 0;
  #numInactive: number = 0;

  #width = '14px';
  #height = '14px';

  #activeTitle?: string;
  #inactiveTitle?: string;

  connectedCallback(): void {
    this.#shadow.adoptedStyleSheets = [twoStatesCounterStyles];
    void ComponentHelpers.ScheduledRender.scheduleRender(this, this.#boundRender);
  }

  set data(data: TwoStatesCounterData) {
    if (data.active < 0 || data.inactive < 0) {
      throw new Error('Values need to be greater or equal to zero.');
    }
    this.#numActive = data.active;
    this.#numInactive = data.inactive;
    this.#width = isString(data.width) ? data.width : this.#width;
    this.#height = isString(data.height) ? data.height : this.#height;
    this.#activeTitle = data.activeTitle;
    this.#inactiveTitle = data.inactiveTitle;

    void ComponentHelpers.ScheduledRender.scheduleRender(this, this.#boundRender);
  }

  #render(): void {
    if (this.#numActive === 0 && this.#numInactive === 0) {
      return;
    }
    const showBothNumbers = this.#numActive > 0 && this.#numInactive > 0;
    const commonClasses = {
      part: true,
      split: showBothNumbers,
    };
    const activeClassMap = {
      ...commonClasses,
      active: true,
    };
    const inactiveClassMap = {
      ...commonClasses,
      inactive: true,
    };

    // clang-format off
    LitHtml.render(LitHtml.html`
    <div class='counter'>
      ${this.#renderPart(this.#numActive, activeClassMap, this.#activeTitle)}
      ${this.#renderPart(this.#numInactive, inactiveClassMap, this.#inactiveTitle)}
    </div>
    `
    , this.#shadow, {host: this});
    // clang-format on
  }

  #renderPart(count: number, classInfo: {[name: string]: string|boolean|number}, title?: string): unknown {
    const styles = {
      width: this.#width,
      height: this.#height,
    };

    // clang-format off
    return count > 0 ? LitHtml.html`
       <span class=${LitHtml.Directives.classMap(classInfo)} style=${LitHtml.Directives.styleMap(styles)} title=${title}>
          ${count}
       </span>
      ` : LitHtml.nothing;
    // clang-format on
  }
}

ComponentHelpers.CustomElements.defineComponent('devtools-two-states-counter', TwoStatesCounter);

declare global {
  interface HTMLElementTagNameMap {
    'devtools-two-states-counter': TwoStatesCounter;
  }
}