// Copyright 2024 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 '../../../../ui/components/markdown_view/markdown_view.js';

import * as Common from '../../../../core/common/common.js';
import * as i18n from '../../../../core/i18n/i18n.js';
import type * as Protocol from '../../../../generated/protocol.js';
import type {InsightModel} from '../../../../models/trace/insights/types.js';
import * as Trace from '../../../../models/trace/trace.js';
import * as Buttons from '../../../../ui/components/buttons/buttons.js';
import * as ComponentHelpers from '../../../../ui/components/helpers/helpers.js';
import * as Lit from '../../../../ui/lit/lit.js';
import * as VisualLogging from '../../../../ui/visual_logging/visual_logging.js';
import type * as Overlays from '../../overlays/overlays.js';
import {md} from '../../utils/Helpers.js';

import baseInsightComponentStylesRaw from './baseInsightComponent.css.js';
import * as SidebarInsight from './SidebarInsight.js';
import type {TableState} from './Table.js';

// TODO(crbug.com/391381439): Fully migrate off of constructed style sheets.
const baseInsightComponentStyles = new CSSStyleSheet();
baseInsightComponentStyles.replaceSync(baseInsightComponentStylesRaw.cssContent);

const {html} = Lit;

const UIStrings = {
  /**
   * @description Text to tell the user the estimated time or size savings for this insight. "&" means "and" - space is limited to prefer abbreviated terms if possible. Text will still fit if not short, it just won't look very good, so using no abbreviations is fine if necessary.
   * @example {401 ms} PH1
   * @example {112 kB} PH1
   */
  estimatedSavings: 'Est savings: {PH1}',
  /**
   * @description Text to tell the user the estimated time and size savings for this insight. "&" means "and", "Est" means "Estimated" - space is limited to prefer abbreviated terms if possible. Text will still fit if not short, it just won't look very good, so using no abbreviations is fine if necessary.
   * @example {401 ms} PH1
   * @example {112 kB} PH2
   */
  estimatedSavingsTimingAndBytes: 'Est savings: {PH1} & {PH2}',
  /**
   * @description Used for screen-readers as a label on the button to expand an insight to view details
   * @example {LCP by phase} PH1
   */
  viewDetails: 'View details for {PH1}',
};

const str_ = i18n.i18n.registerUIStrings('panels/timeline/components/insights/BaseInsightComponent.ts', UIStrings);
const i18nString = i18n.i18n.getLocalizedString.bind(undefined, str_);

export interface BaseInsightData {
  bounds: Trace.Types.Timing.TraceWindowMicro|null;
  /** The key into `insights` that contains this particular insight. */
  insightSetKey: string|null;
}

export abstract class BaseInsightComponent<T extends InsightModel<{}, {}>> extends HTMLElement {
  abstract internalName: string;
  // So we can use the TypeScript BaseInsight class without getting warnings
  // about litTagName. Every child should overrwrite this.
  static readonly litTagName = Lit.StaticHtml.literal``;

  readonly #shadowRoot = this.attachShadow({mode: 'open'});

  #selected = false;
  #model: T|null = null;
  #parsedTrace: Trace.Handlers.Types.ParsedTrace|null = null;

  get model(): T|null {
    return this.#model;
  }

  protected data: BaseInsightData = {
    bounds: null,
    insightSetKey: null,
  };

  readonly #boundRender = this.#render.bind(this);
  readonly sharedTableState: TableState = {
    selectedRowEl: null,
    selectionIsSticky: false,
  };
  #initialOverlays: Overlays.Overlays.TimelineOverlay[]|null = null;

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

  connectedCallback(): void {
    this.#shadowRoot.adoptedStyleSheets.push(baseInsightComponentStyles);
    this.setAttribute('jslog', `${VisualLogging.section(`timeline.insights.${this.internalName}`)}`);
    // Used for unit test purposes when querying the DOM.
    this.dataset.insightName = this.internalName;
  }

  set selected(selected: boolean) {
    if (!this.#selected && selected) {
      this.dispatchEvent(
          new SidebarInsight.InsightProvideOverlays(this.getInitialOverlays(), {updateTraceWindow: true}));
    }

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

  get selected(): boolean {
    return this.#selected;
  }

  set model(model: T) {
    this.#model = model;
    void ComponentHelpers.ScheduledRender.scheduleRender(this, this.#boundRender);
  }

  set insightSetKey(insightSetKey: string|null) {
    this.data.insightSetKey = insightSetKey;
    void ComponentHelpers.ScheduledRender.scheduleRender(this, this.#boundRender);
  }

  get bounds(): Trace.Types.Timing.TraceWindowMicro|null {
    return this.data.bounds;
  }

  set bounds(bounds: Trace.Types.Timing.TraceWindowMicro|null) {
    this.data.bounds = bounds;
    void ComponentHelpers.ScheduledRender.scheduleRender(this, this.#boundRender);
  }

  set parsedTrace(parsedTrace: Trace.Handlers.Types.ParsedTrace) {
    this.#parsedTrace = parsedTrace;
  }

  #dispatchInsightToggle(): void {
    if (this.#selected) {
      this.dispatchEvent(new SidebarInsight.InsightDeactivated());
      return;
    }

    if (!this.data.insightSetKey) {
      // Shouldn't happen, but needed to satisfy TS.
      return;
    }

    this.sharedTableState.selectedRowEl?.classList.remove('selected');
    this.sharedTableState.selectedRowEl = null;
    this.sharedTableState.selectionIsSticky = false;

    this.dispatchEvent(new SidebarInsight.InsightActivated(this.model, this.data.insightSetKey));
  }

  #renderHoverIcon(insightIsActive: boolean): Lit.TemplateResult {
    // clang-format off
    const containerClasses = Lit.Directives.classMap({
      'insight-hover-icon': true,
      active: insightIsActive,
    });
    return html`
      <div class=${containerClasses} inert>
        <devtools-button .data=${{
          variant: Buttons.Button.Variant.ICON,
          iconName: 'chevron-down',
          size: Buttons.Button.Size.SMALL,
        } as Buttons.Button.ButtonData}
      ></devtools-button>
      </div>

    `;
    // clang-format on
  }

  /**
   * Ensure that if the user presses enter or space on a header, we treat it
   * like a click and toggle the insight.
   */
  #handleHeaderKeyDown(event: KeyboardEvent): void {
    if (event.key === 'Enter' || event.key === ' ') {
      event.preventDefault();
      event.stopPropagation();
      this.#dispatchInsightToggle();
    }
  }

  /**
   * Replaces the initial insight overlays with the ones provided.
   *
   * If `overlays` is null, reverts back to the initial overlays.
   *
   * This allows insights to provide an initial set of overlays,
   * and later temporarily replace all of those insights with a different set.
   * This enables the hover/click table interactions.
   */
  toggleTemporaryOverlays(
      overlays: Overlays.Overlays.TimelineOverlay[]|null, options: Overlays.Overlays.TimelineOverlaySetOptions): void {
    if (!this.#selected) {
      return;
    }

    this.dispatchEvent(new SidebarInsight.InsightProvideOverlays(overlays ?? this.getInitialOverlays(), options));
  }

  getInitialOverlays(): Overlays.Overlays.TimelineOverlay[] {
    if (this.#initialOverlays) {
      return this.#initialOverlays;
    }

    this.#initialOverlays = this.createOverlays();
    return this.#initialOverlays;
  }

  protected abstract createOverlays(): Overlays.Overlays.TimelineOverlay[];

  protected abstract renderContent(): Lit.LitTemplate;

  #render(): void {
    if (!this.model) {
      return;
    }

    const output = this.renderContent();
    this.#renderWithContent(output);
  }

  getEstimatedSavingsTime(): Trace.Types.Timing.Milli|null {
    return null;
  }

  getEstimatedSavingsBytes(): number|null {
    return null;
  }

  #getEstimatedSavingsString(): string|null {
    const savingsTime = this.getEstimatedSavingsTime();
    const savingsBytes = this.getEstimatedSavingsBytes();

    let timeString, bytesString;
    if (savingsTime) {
      timeString = i18n.TimeUtilities.millisToString(savingsTime);
    }
    if (savingsBytes) {
      bytesString = i18n.ByteUtilities.bytesToString(savingsBytes);
    }

    if (timeString && bytesString) {
      return i18nString(UIStrings.estimatedSavingsTimingAndBytes, {
        PH1: timeString,
        PH2: bytesString,
      });
    }
    if (timeString) {
      return i18nString(UIStrings.estimatedSavings, {
        PH1: timeString,
      });
    }
    if (bytesString) {
      return i18nString(UIStrings.estimatedSavings, {
        PH1: bytesString,
      });
    }

    return null;
  }

  protected renderNode(backendNodeId: Protocol.DOM.BackendNodeId, fallbackText?: string): Lit.LitTemplate {
    const fallback = fallbackText ?? Lit.nothing;
    if (!this.#parsedTrace) {
      return html`${fallback}`;
    }

    const domNodePromise =
        Trace.Extras.FetchNodes.domNodeForBackendNodeID(this.#parsedTrace, backendNodeId).then((node): unknown => {
          if (!node) {
            return fallback;
          }
          return Common.Linkifier.Linkifier.linkify(node);
        });

    return html`${Lit.Directives.until(domNodePromise, fallback)}`;
  }

  #renderWithContent(content: Lit.LitTemplate): void {
    if (!this.#model) {
      Lit.render(Lit.nothing, this.#shadowRoot, {host: this});
      return;
    }

    const containerClasses = Lit.Directives.classMap({
      insight: true,
      closed: !this.#selected,
    });
    const estimatedSavingsString = this.#getEstimatedSavingsString();

    // clang-format off
    const output = html`
      <div class=${containerClasses}>
        <header @click=${this.#dispatchInsightToggle}
          @keydown=${this.#handleHeaderKeyDown}
          jslog=${VisualLogging.action(`timeline.toggle-insight.${this.internalName}`).track({click: true})}
          tabIndex="0"
          role="button"
          aria-expanded=${this.#selected}
          aria-label=${i18nString(UIStrings.viewDetails, {PH1: this.#model.title})}
        >
          ${this.#renderHoverIcon(this.#selected)}
          <h3 class="insight-title">${this.#model?.title}</h3>
          ${estimatedSavingsString ?
            html`
            <slot name="insight-savings" class="insight-savings">
              ${estimatedSavingsString}
            </slot>
          </div>`
          : Lit.nothing}
        </header>
        ${this.#selected ? html`
          <div class="insight-body">
            <div class="insight-description">${md(this.#model.description)}</div>
            <div class="insight-content">${content}</div>
          </div>`
          : Lit.nothing
        }
      </div>
    `;
    // clang-format on

    Lit.render(output, this.#shadowRoot, {host: this});

    if (this.#selected) {
      requestAnimationFrame(() => requestAnimationFrame(() => this.scrollIntoViewIfNeeded()));
    }
  }
}