import type { PropertyValues } from 'lit';
import { html } from 'lit';
import { customElement, property, query, state } from 'lit/decorators.js';
import WebAwesomeElement from '../../internal/webawesome-element.js';
import { LocalizeController } from '../../utilities/localize.js';
import styles from './progress-ring.css';

/**
 * @summary Progress rings are used to show the progress of a determinate operation in a circular fashion.
 * @documentation https://backers.webawesome.com/docs/components/progress-ring
 * @status stable
 * @since 2.0
 *
 * @slot - A label to show inside the ring.
 *
 * @csspart base - The component's base wrapper.
 * @csspart label - The progress ring label.
 *
 * @cssproperty --size - The diameter of the progress ring (cannot be a percentage).
 * @cssproperty --track-width - The width of the track.
 * @cssproperty --track-color - The color of the track.
 * @cssproperty --indicator-width - The width of the indicator. Defaults to the track width.
 * @cssproperty --indicator-color - The color of the indicator.
 * @cssproperty --indicator-transition-duration - The duration of the indicator's transition when the value changes.
 */
@customElement('wa-progress-ring')
export default class WaProgressRing extends WebAwesomeElement {
  static shadowStyle = styles;

  private readonly localize = new LocalizeController(this);

  @query('.indicator') indicator: SVGCircleElement;

  @state() indicatorOffset: string;

  /** The current progress as a percentage, 0 to 100. */
  @property({ type: Number, reflect: true }) value = 0;

  /** A custom label for assistive devices. */
  @property() label = '';

  updated(changedProperties: PropertyValues<this>) {
    super.updated(changedProperties);

    //
    // This block is only required for Safari because it doesn't transition the circle when the custom properties
    // change, possibly because of a mix of pixel + unit-less values in the calc() function. It seems like a Safari bug,
    // but I couldn't pinpoint it so this works around the problem.
    //
    if (changedProperties.has('value')) {
      const radius = parseFloat(getComputedStyle(this.indicator).getPropertyValue('r'));
      const circumference = 2 * Math.PI * radius;
      const offset = circumference - (this.value / 100) * circumference;

      this.indicatorOffset = `${offset}px`;
    }
  }

  render() {
    return html`
      <div
        part="base"
        class="progress-ring"
        role="progressbar"
        aria-label=${this.label.length > 0 ? this.label : this.localize.term('progress')}
        aria-describedby="label"
        aria-valuemin="0"
        aria-valuemax="100"
        aria-valuenow="${this.value}"
        style="--percentage: ${this.value / 100}"
      >
        <svg class="image">
          <circle class="track"></circle>
          <circle class="indicator" style="stroke-dashoffset: ${this.indicatorOffset}"></circle>
        </svg>

        <slot id="label" part="label" class="label"></slot>
      </div>
    `;
  }
}

declare global {
  interface HTMLElementTagNameMap {
    'wa-progress-ring': WaProgressRing;
  }
}
