/**
 * Copyright (c) Microsoft Corporation.
 *
 * 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 { stringifySelector } from '../../utils/isomorphic/selectorParser';
import type { ParsedSelector } from '../../utils/isomorphic/selectorParser';
import type { InjectedScript } from './injectedScript';
import { asLocator } from '../../utils/isomorphic/locatorGenerators';
import type { Language } from '../../utils/isomorphic/locatorGenerators';

type HighlightEntry = {
  targetElement: Element,
  highlightElement: HTMLElement,
  tooltipElement?: HTMLElement,
  box?: DOMRect,
  tooltipTop?: number,
  tooltipLeft?: number,
  tooltipText?: string,
};

export class Highlight {
  private _glassPaneElement: HTMLElement;
  private _glassPaneShadow: ShadowRoot;
  private _highlightEntries: HighlightEntry[] = [];
  private _actionPointElement: HTMLElement;
  private _isUnderTest: boolean;
  private _injectedScript: InjectedScript;
  private _rafRequest: number | undefined;
  private _language: Language = 'javascript';

  constructor(injectedScript: InjectedScript) {
    this._injectedScript = injectedScript;
    const document = injectedScript.document;
    this._isUnderTest = injectedScript.isUnderTest;
    this._glassPaneElement = document.createElement('x-pw-glass');
    this._glassPaneElement.style.position = 'fixed';
    this._glassPaneElement.style.top = '0';
    this._glassPaneElement.style.right = '0';
    this._glassPaneElement.style.bottom = '0';
    this._glassPaneElement.style.left = '0';
    this._glassPaneElement.style.zIndex = '2147483647';
    this._glassPaneElement.style.pointerEvents = 'none';
    this._glassPaneElement.style.display = 'flex';

    this._actionPointElement = document.createElement('x-pw-action-point');
    this._actionPointElement.setAttribute('hidden', 'true');
    this._glassPaneShadow = this._glassPaneElement.attachShadow({ mode: this._isUnderTest ? 'open' : 'closed' });
    this._glassPaneShadow.appendChild(this._actionPointElement);
    const styleElement = document.createElement('style');
    styleElement.textContent = `
        x-pw-tooltip {
          align-items: center;
          backdrop-filter: blur(5px);
          background-color: rgba(0, 0, 0, 0.7);
          border-radius: 2px;
          box-shadow: rgba(0, 0, 0, 0.1) 0px 3.6px 3.7px,
                      rgba(0, 0, 0, 0.15) 0px 12.1px 12.3px,
                      rgba(0, 0, 0, 0.1) 0px -2px 4px,
                      rgba(0, 0, 0, 0.15) 0px -12.1px 24px,
                      rgba(0, 0, 0, 0.25) 0px 54px 55px;
          color: rgb(204, 204, 204);
          display: none;
          font-family: 'Dank Mono', 'Operator Mono', Inconsolata, 'Fira Mono',
                      'SF Mono', Monaco, 'Droid Sans Mono', 'Source Code Pro', monospace;
          font-size: 12.8px;
          font-weight: normal;
          left: 0;
          line-height: 1.5;
          max-width: 600px;
          padding: 3.2px 5.12px 3.2px;
          position: absolute;
          top: 0;
        }
        x-pw-action-point {
          position: absolute;
          width: 20px;
          height: 20px;
          background: red;
          border-radius: 10px;
          pointer-events: none;
          margin: -10px 0 0 -10px;
          z-index: 2;
        }
        *[hidden] {
          display: none !important;
        }
    `;
    this._glassPaneShadow.appendChild(styleElement);
  }

  install() {
    this._injectedScript.document.documentElement.appendChild(this._glassPaneElement);
  }

  setLanguage(language: Language) {
    this._language = language;
  }

  runHighlightOnRaf(selector: ParsedSelector) {
    if (this._rafRequest)
      cancelAnimationFrame(this._rafRequest);
    this.updateHighlight(this._injectedScript.querySelectorAll(selector, this._injectedScript.document.documentElement), stringifySelector(selector), false);
    this._rafRequest = requestAnimationFrame(() => this.runHighlightOnRaf(selector));
  }

  uninstall() {
    if (this._rafRequest)
      cancelAnimationFrame(this._rafRequest);
    this._glassPaneElement.remove();
  }

  isInstalled(): boolean {
    return this._glassPaneElement.parentElement === this._injectedScript.document.documentElement && !this._glassPaneElement.nextElementSibling;
  }

  showActionPoint(x: number, y: number) {
    this._actionPointElement.style.top = y + 'px';
    this._actionPointElement.style.left = x + 'px';
    this._actionPointElement.hidden = false;
    if (this._isUnderTest)
      console.error('Action point for test: ' + JSON.stringify({ x, y })); // eslint-disable-line no-console
  }

  hideActionPoint() {
    this._actionPointElement.hidden = true;
  }

  clearHighlight() {
    for (const entry of this._highlightEntries) {
      entry.highlightElement?.remove();
      entry.tooltipElement?.remove();
    }
    this._highlightEntries = [];
  }

  updateHighlight(elements: Element[], selector: string, isRecording: boolean) {
    let color: string;
    if (isRecording)
      color = '#dc6f6f7f';
    else
      color = elements.length > 1 ? '#f6b26b7f' : '#6fa8dc7f';
    this._innerUpdateHighlight(elements, { color, tooltipText: selector ? asLocator(this._language, selector) : '' });
  }

  maskElements(elements: Element[]) {
    this._innerUpdateHighlight(elements, { color: '#F0F' });
  }

  private _innerUpdateHighlight(elements: Element[], options: { color: string, tooltipText?: string }) {
    // Code below should trigger one layout and leave with the
    // destroyed layout.

    if (this._highlightIsUpToDate(elements, options.tooltipText))
      return;

    // 1. Destroy the layout
    this.clearHighlight();

    for (let i = 0; i < elements.length; ++i) {
      const highlightElement = this._createHighlightElement();
      this._glassPaneShadow.appendChild(highlightElement);

      let tooltipElement;
      if (options.tooltipText) {
        tooltipElement = this._injectedScript.document.createElement('x-pw-tooltip');
        this._glassPaneShadow.appendChild(tooltipElement);
        const suffix = elements.length > 1 ? ` [${i + 1} of ${elements.length}]` : '';
        tooltipElement.textContent = options.tooltipText + suffix;
        tooltipElement.style.top = '0';
        tooltipElement.style.left = '0';
        tooltipElement.style.display = 'flex';
      }
      this._highlightEntries.push({ targetElement: elements[i], tooltipElement, highlightElement, tooltipText: options.tooltipText });
    }

    // 2. Trigger layout while positioning tooltips and computing bounding boxes.
    for (const entry of this._highlightEntries) {
      entry.box = entry.targetElement.getBoundingClientRect();
      if (!entry.tooltipElement)
        continue;

      // Position tooltip, if any.
      const tooltipWidth = entry.tooltipElement.offsetWidth;
      const tooltipHeight = entry.tooltipElement.offsetHeight;
      const totalWidth = this._glassPaneElement.offsetWidth;
      const totalHeight = this._glassPaneElement.offsetHeight;

      let anchorLeft = entry.box.left;
      if (anchorLeft + tooltipWidth > totalWidth - 5)
        anchorLeft = totalWidth - tooltipWidth - 5;
      let anchorTop = entry.box.bottom + 5;
      if (anchorTop + tooltipHeight > totalHeight - 5) {
        // If can't fit below, either position above...
        if (entry.box.top > tooltipHeight + 5) {
          anchorTop = entry.box.top - tooltipHeight - 5;
        } else {
          // Or on top in case of large element
          anchorTop = totalHeight - 5 - tooltipHeight;
        }
      }
      entry.tooltipTop = anchorTop;
      entry.tooltipLeft = anchorLeft;
    }

    // 3. Destroy the layout again.

    // If there are more than 1 box - we are evaluating a non-unique (potentially bad) selector.
    for (const entry of this._highlightEntries) {
      if (entry.tooltipElement) {
        entry.tooltipElement.style.top = entry.tooltipTop + 'px';
        entry.tooltipElement.style.left = entry.tooltipLeft + 'px';
      }
      const box = entry.box!;
      entry.highlightElement.style.backgroundColor = options.color;
      entry.highlightElement.style.left = box.x + 'px';
      entry.highlightElement.style.top = box.y + 'px';
      entry.highlightElement.style.width = box.width + 'px';
      entry.highlightElement.style.height = box.height + 'px';
      entry.highlightElement.style.display = 'block';

      if (this._isUnderTest)
        console.error('Highlight box for test: ' + JSON.stringify({ x: box.x, y: box.y, width: box.width, height: box.height })); // eslint-disable-line no-console
    }
  }
  private _highlightIsUpToDate(elements: Element[], tooltipText: string | undefined): boolean {
    if (elements.length !== this._highlightEntries.length)
      return false;
    for (let i = 0; i < this._highlightEntries.length; ++i) {
      if (tooltipText !== this._highlightEntries[i].tooltipText)
        return false;
      if (elements[i] !== this._highlightEntries[i].targetElement)
        return false;
      const oldBox = this._highlightEntries[i].box;
      if (!oldBox)
        return false;
      const box = elements[i].getBoundingClientRect();
      if (box.top !== oldBox.top || box.right !== oldBox.right || box.bottom !== oldBox.bottom || box.left !== oldBox.left)
        return false;
    }
    return true;
  }

  private _createHighlightElement(): HTMLElement {
    const highlightElement = this._injectedScript.document.createElement('x-pw-highlight');
    highlightElement.style.position = 'absolute';
    highlightElement.style.top = '0';
    highlightElement.style.left = '0';
    highlightElement.style.width = '0';
    highlightElement.style.height = '0';
    highlightElement.style.boxSizing = 'border-box';
    return highlightElement;
  }
}