// Copyright (c) 2015 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.
/**
 * @unrestricted
 */
export class BezierEditor extends UI.VBox {
  constructor() {
    super(true);
    this.registerRequiredCSS('inline_editor/bezierEditor.css');
    this.contentElement.tabIndex = 0;
    this.setDefaultFocusedElement(this.contentElement);

    // Preview UI
    this._previewElement = this.contentElement.createChild('div', 'bezier-preview-container');
    this._previewElement.createChild('div', 'bezier-preview-animation');
    this._previewElement.addEventListener('click', this._startPreviewAnimation.bind(this));
    this._previewOnion = this.contentElement.createChild('div', 'bezier-preview-onion');
    this._previewOnion.addEventListener('click', this._startPreviewAnimation.bind(this));

    this._outerContainer = this.contentElement.createChild('div', 'bezier-container');

    // Presets UI
    this._presetsContainer = this._outerContainer.createChild('div', 'bezier-presets');
    this._presetUI = new InlineEditor.BezierUI(40, 40, 0, 2, false);
    this._presetCategories = [];
    for (let i = 0; i < Presets.length; i++) {
      this._presetCategories[i] = this._createCategory(Presets[i]);
      this._presetsContainer.appendChild(this._presetCategories[i].icon);
    }

    // Curve UI
    this._curveUI = new InlineEditor.BezierUI(150, 250, 50, 7, true);
    this._curve = this._outerContainer.createSVGChild('svg', 'bezier-curve');
    UI.installDragHandle(
        this._curve, this._dragStart.bind(this), this._dragMove.bind(this), this._dragEnd.bind(this), 'default');

    this._header = this.contentElement.createChild('div', 'bezier-header');
    const minus = this._createPresetModifyIcon(this._header, 'bezier-preset-minus', 'M 12 6 L 8 10 L 12 14');
    const plus = this._createPresetModifyIcon(this._header, 'bezier-preset-plus', 'M 8 6 L 12 10 L 8 14');
    minus.addEventListener('click', this._presetModifyClicked.bind(this, false));
    plus.addEventListener('click', this._presetModifyClicked.bind(this, true));
    this._label = this._header.createChild('span', 'source-code bezier-display-value');
  }

  /**
   * @param {?UI.Geometry.CubicBezier} bezier
   */
  setBezier(bezier) {
    if (!bezier) {
      return;
    }
    this._bezier = bezier;
    this._updateUI();
  }

  /**
   * @return {!UI.Geometry.CubicBezier}
   */
  bezier() {
    return this._bezier;
  }

  /**
   * @override
   */
  wasShown() {
    this._unselectPresets();
    // Check if bezier matches a preset
    for (const category of this._presetCategories) {
      for (let i = 0; i < category.presets.length; i++) {
        if (this._bezier.asCSSText() === category.presets[i].value) {
          category.presetIndex = i;
          this._presetCategorySelected(category);
        }
      }
    }

    this._updateUI();
    this._startPreviewAnimation();
  }

  _onchange() {
    this._updateUI();
    this.dispatchEventToListeners(Events.BezierChanged, this._bezier.asCSSText());
  }

  _updateUI() {
    const labelText = this._selectedCategory ? this._selectedCategory.presets[this._selectedCategory.presetIndex].name :
                                               this._bezier.asCSSText().replace(/\s(-\d\.\d)/g, '$1');
    this._label.textContent = Common.UIString(labelText);
    this._curveUI.drawCurve(this._bezier, this._curve);
    this._previewOnion.removeChildren();
  }

  /**
   * @param {!Event} event
   * @return {boolean}
   */
  _dragStart(event) {
    this._mouseDownPosition = new UI.Geometry.Point(event.x, event.y);
    const ui = this._curveUI;
    this._controlPosition = new UI.Geometry.Point(
        Number.constrain((event.offsetX - ui.radius) / ui.curveWidth(), 0, 1),
        (ui.curveHeight() + ui.marginTop + ui.radius - event.offsetY) / ui.curveHeight());

    const firstControlPointIsCloser = this._controlPosition.distanceTo(this._bezier.controlPoints[0]) <
        this._controlPosition.distanceTo(this._bezier.controlPoints[1]);
    this._selectedPoint = firstControlPointIsCloser ? 0 : 1;

    this._bezier.controlPoints[this._selectedPoint] = this._controlPosition;
    this._unselectPresets();
    this._onchange();

    event.consume(true);
    return true;
  }

  /**
   * @param {number} mouseX
   * @param {number} mouseY
   */
  _updateControlPosition(mouseX, mouseY) {
    const deltaX = (mouseX - this._mouseDownPosition.x) / this._curveUI.curveWidth();
    const deltaY = (mouseY - this._mouseDownPosition.y) / this._curveUI.curveHeight();
    const newPosition = new UI.Geometry.Point(
        Number.constrain(this._controlPosition.x + deltaX, 0, 1), this._controlPosition.y - deltaY);
    this._bezier.controlPoints[this._selectedPoint] = newPosition;
  }

  /**
   * @param {!Event} event
   */
  _dragMove(event) {
    this._updateControlPosition(event.x, event.y);
    this._onchange();
  }

  /**
   * @param {!Event} event
   */
  _dragEnd(event) {
    this._updateControlPosition(event.x, event.y);
    this._onchange();
    this._startPreviewAnimation();
  }

  /**
   * @param {!Array<{name: string, value: string}>} presetGroup
   * @return {!InlineEditor.BezierEditor.PresetCategory}
   */
  _createCategory(presetGroup) {
    const presetElement = createElementWithClass('div', 'bezier-preset-category');
    const iconElement = presetElement.createSVGChild('svg', 'bezier-preset monospace');
    const category = {presets: presetGroup, presetIndex: 0, icon: presetElement};
    this._presetUI.drawCurve(UI.Geometry.CubicBezier.parse(category.presets[0].value), iconElement);
    iconElement.addEventListener('click', this._presetCategorySelected.bind(this, category));
    return category;
  }

  /**
   * @param {!Element} parentElement
   * @param {string} className
   * @param {string} drawPath
   * @return {!Element}
   */
  _createPresetModifyIcon(parentElement, className, drawPath) {
    const icon = parentElement.createSVGChild('svg', 'bezier-preset-modify ' + className);
    icon.setAttribute('width', 20);
    icon.setAttribute('height', 20);
    const path = icon.createSVGChild('path');
    path.setAttribute('d', drawPath);
    return icon;
  }

  _unselectPresets() {
    for (const category of this._presetCategories) {
      category.icon.classList.remove('bezier-preset-selected');
    }
    delete this._selectedCategory;
    this._header.classList.remove('bezier-header-active');
  }

  /**
   * @param {!InlineEditor.BezierEditor.PresetCategory} category
   * @param {!Event=} event
   */
  _presetCategorySelected(category, event) {
    if (this._selectedCategory === category) {
      return;
    }
    this._unselectPresets();
    this._header.classList.add('bezier-header-active');
    this._selectedCategory = category;
    this._selectedCategory.icon.classList.add('bezier-preset-selected');
    this.setBezier(UI.Geometry.CubicBezier.parse(category.presets[category.presetIndex].value));
    this._onchange();
    this._startPreviewAnimation();
    if (event) {
      event.consume(true);
    }
  }

  /**
   * @param {boolean} intensify
   * @param {!Event} event
   */
  _presetModifyClicked(intensify, event) {
    if (!this._selectedCategory) {
      return;
    }

    const length = this._selectedCategory.presets.length;
    this._selectedCategory.presetIndex = (this._selectedCategory.presetIndex + (intensify ? 1 : -1) + length) % length;
    this.setBezier(
        UI.Geometry.CubicBezier.parse(this._selectedCategory.presets[this._selectedCategory.presetIndex].value));
    this._onchange();
    this._startPreviewAnimation();
  }

  _startPreviewAnimation() {
    if (this._previewAnimation) {
      this._previewAnimation.cancel();
    }

    const animationDuration = 1600;
    const numberOnionSlices = 20;

    const keyframes = [
      {offset: 0, transform: 'translateX(0px)', easing: this._bezier.asCSSText(), opacity: 1},
      {offset: 0.9, transform: 'translateX(218px)', opacity: 1},
      {offset: 1, transform: 'translateX(218px)', opacity: 0}
    ];
    this._previewAnimation = this._previewElement.animate(keyframes, animationDuration);
    this._previewOnion.removeChildren();
    for (let i = 0; i <= numberOnionSlices; i++) {
      const slice = this._previewOnion.createChild('div', 'bezier-preview-animation');
      const player = slice.animate(
          [{transform: 'translateX(0px)', easing: this._bezier.asCSSText()}, {transform: 'translateX(218px)'}],
          {duration: animationDuration, fill: 'forwards'});
      player.pause();
      player.currentTime = animationDuration * i / numberOnionSlices;
    }
  }
}

/** @enum {symbol} */
export const Events = {
  BezierChanged: Symbol('BezierChanged')
};

export const Presets = [
  [
    {name: 'ease-in-out', value: 'ease-in-out'}, {name: 'In Out · Sine', value: 'cubic-bezier(0.45, 0.05, 0.55, 0.95)'},
    {name: 'In Out · Quadratic', value: 'cubic-bezier(0.46, 0.03, 0.52, 0.96)'},
    {name: 'In Out · Cubic', value: 'cubic-bezier(0.65, 0.05, 0.36, 1)'},
    {name: 'Fast Out, Slow In', value: 'cubic-bezier(0.4, 0, 0.2, 1)'},
    {name: 'In Out · Back', value: 'cubic-bezier(0.68, -0.55, 0.27, 1.55)'}
  ],
  [
    {name: 'Fast Out, Linear In', value: 'cubic-bezier(0.4, 0, 1, 1)'}, {name: 'ease-in', value: 'ease-in'},
    {name: 'In · Sine', value: 'cubic-bezier(0.47, 0, 0.75, 0.72)'},
    {name: 'In · Quadratic', value: 'cubic-bezier(0.55, 0.09, 0.68, 0.53)'},
    {name: 'In · Cubic', value: 'cubic-bezier(0.55, 0.06, 0.68, 0.19)'},
    {name: 'In · Back', value: 'cubic-bezier(0.6, -0.28, 0.74, 0.05)'}
  ],
  [
    {name: 'ease-out', value: 'ease-out'}, {name: 'Out · Sine', value: 'cubic-bezier(0.39, 0.58, 0.57, 1)'},
    {name: 'Out · Quadratic', value: 'cubic-bezier(0.25, 0.46, 0.45, 0.94)'},
    {name: 'Out · Cubic', value: 'cubic-bezier(0.22, 0.61, 0.36, 1)'},
    {name: 'Linear Out, Slow In', value: 'cubic-bezier(0, 0, 0.2, 1)'},
    {name: 'Out · Back', value: 'cubic-bezier(0.18, 0.89, 0.32, 1.28)'}
  ]
];

/* Legacy exported object */
self.InlineEditor = self.InlineEditor || {};

/* Legacy exported object */
InlineEditor = InlineEditor || {};

/** @constructor */
InlineEditor.BezierEditor = BezierEditor;

InlineEditor.BezierEditor.Events = Events;
InlineEditor.BezierEditor.Presets = Presets;

/** @typedef {{presets: !Array.<{name: string, value: string}>, icon: !Element, presetIndex: number}} */
InlineEditor.BezierEditor.PresetCategory;