/**
 * @license
 * Copyright 2012 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * @fileoverview Object representing a mutator dialog.  A mutator allows the
 * user to change the shape of a block using a nested blocks editor.
 */

/**
 * Object representing a mutator dialog.  A mutator allows the
 * user to change the shape of a block using a nested blocks editor.
 * @class
 */
import * as goog from '../closure/goog/goog.js';
goog.declareModuleId('Blockly.Mutator');

// Unused import preserved for side-effects. Remove if unneeded.
import './events/events_bubble_open.js';

import type {Block} from './block.js';
import type {BlockSvg} from './block_svg.js';
import type {BlocklyOptions} from './blockly_options.js';
import {Bubble} from './bubble.js';
import {config} from './config.js';
import type {Connection} from './connection.js';
import type {Abstract} from './events/events_abstract.js';
import {BlockChange} from './events/events_block_change.js';
import * as eventUtils from './events/utils.js';
import {Icon} from './icon.js';
import {Options} from './options.js';
import type {Coordinate} from './utils/coordinate.js';
import * as dom from './utils/dom.js';
import {Svg} from './utils/svg.js';
import * as toolbox from './utils/toolbox.js';
import * as xml from './utils/xml.js';
import type {WorkspaceSvg} from './workspace_svg.js';


/**
 * Class for a mutator dialog.
 * @alias Blockly.Mutator
 */
export class Mutator extends Icon {
  quarkNames_: AnyDuringMigration;

  /** Workspace in the mutator's bubble. */
  private workspace_: WorkspaceSvg|null = null;

  /** Width of workspace. */
  private workspaceWidth_ = 0;

  /** Height of workspace. */
  private workspaceHeight_ = 0;

  /**
   * The SVG element that is the parent of the mutator workspace, or null if
   * not created.
   */
  private svgDialog_: SVGSVGElement|null = null;

  /**
   * The root block of the mutator workspace, created by decomposing the
   * source block.
   */
  private rootBlock_: BlockSvg|null = null;

  /**
   * Function registered on the main workspace to update the mutator contents
   * when the main workspace changes.
   */
  private sourceListener_: Function|null = null;

  /**
   * The PID associated with the updateWorkpace_ timeout, or 0 if no timeout
   * is currently running.
   */
  private updateWorkspacePid_: AnyDuringMigration = 0;

  /** @param quarkNames List of names of sub-blocks for flyout. */
  constructor(block: BlockSvg, quarkNames: string[]) {
    super(block);
    this.quarkNames_ = quarkNames;
  }

  /**
   * Set the block this mutator is associated with.
   * @param block The block associated with this mutator.
   * @internal
   */
  setBlock(block: BlockSvg) {
    this.block_ = block;
  }

  /**
   * Returns the workspace inside this mutator icon's bubble.
   * @return The workspace inside this mutator icon's bubble or null if the
   *     mutator isn't open.
   * @internal
   */
  getWorkspace(): WorkspaceSvg|null {
    return this.workspace_;
  }

  /**
   * Draw the mutator icon.
   * @param group The icon group.
   */
  protected override drawIcon_(group: Element) {
    // Square with rounded corners.
    dom.createSvgElement(
        Svg.RECT, {
          'class': 'blocklyIconShape',
          'rx': '4',
          'ry': '4',
          'height': '16',
          'width': '16',
        },
        group);
    // Gear teeth.
    dom.createSvgElement(
        Svg.PATH, {
          'class': 'blocklyIconSymbol',
          'd': 'm4.203,7.296 0,1.368 -0.92,0.677 -0.11,0.41 0.9,1.559 0.41,' +
              '0.11 1.043,-0.457 1.187,0.683 0.127,1.134 0.3,0.3 1.8,0 0.3,' +
              '-0.299 0.127,-1.138 1.185,-0.682 1.046,0.458 0.409,-0.11 0.9,' +
              '-1.559 -0.11,-0.41 -0.92,-0.677 0,-1.366 0.92,-0.677 0.11,' +
              '-0.41 -0.9,-1.559 -0.409,-0.109 -1.046,0.458 -1.185,-0.682 ' +
              '-0.127,-1.138 -0.3,-0.299 -1.8,0 -0.3,0.3 -0.126,1.135 -1.187,' +
              '0.682 -1.043,-0.457 -0.41,0.11 -0.899,1.559 0.108,0.409z',
        },
        group);
    // Axle hole.
    dom.createSvgElement(
        Svg.CIRCLE,
        {'class': 'blocklyIconShape', 'r': '2.7', 'cx': '8', 'cy': '8'}, group);
  }

  /**
   * Clicking on the icon toggles if the mutator bubble is visible.
   * Disable if block is uneditable.
   * @param e Mouse click event.
   */
  protected override iconClick_(e: Event) {
    if (this.block_.isEditable()) {
      super.iconClick_(e);
    }
  }

  /**
   * Create the editor for the mutator's bubble.
   * @return The top-level node of the editor.
   */
  private createEditor_(): SVGElement {
    /* Create the editor.  Here's the markup that will be generated:
        <svg>
          [Workspace]
        </svg>
        */
    this.svgDialog_ = dom.createSvgElement(
        Svg.SVG, {'x': Bubble.BORDER_WIDTH, 'y': Bubble.BORDER_WIDTH});
    // Convert the list of names into a list of XML objects for the flyout.
    let quarkXml;
    if (this.quarkNames_.length) {
      quarkXml = xml.createElement('xml');
      for (let i = 0, quarkName; quarkName = this.quarkNames_[i]; i++) {
        const element = xml.createElement('block');
        element.setAttribute('type', quarkName);
        quarkXml.appendChild(element);
      }
    } else {
      quarkXml = null;
    }
    const workspaceOptions = new Options(({
      // If you want to enable disabling, also remove the
      // event filter from workspaceChanged_ .
      'disable': false,
      'parentWorkspace': this.block_.workspace,
      'media': this.block_.workspace.options.pathToMedia,
      'rtl': this.block_.RTL,
      'horizontalLayout': false,
      'renderer': this.block_.workspace.options.renderer,
      'rendererOverrides': this.block_.workspace.options.rendererOverrides,
    } as BlocklyOptions));
    workspaceOptions.toolboxPosition =
        this.block_.RTL ? toolbox.Position.RIGHT : toolbox.Position.LEFT;
    const hasFlyout = !!quarkXml;
    if (hasFlyout) {
      workspaceOptions.languageTree = toolbox.convertToolboxDefToJson(quarkXml);
    }
    this.workspace_ = this.newWorkspaceSvg(workspaceOptions);
    this.workspace_.isMutator = true;
    this.workspace_.addChangeListener(eventUtils.disableOrphans);

    // Mutator flyouts go inside the mutator workspace's <g> rather than in
    // a top level SVG. Instead of handling scale themselves, mutators
    // inherit scale from the parent workspace.
    // To fix this, scale needs to be applied at a different level in the DOM.
    const flyoutSvg = hasFlyout ? this.workspace_.addFlyout(Svg.G) : null;
    const background = this.workspace_.createDom('blocklyMutatorBackground');

    if (flyoutSvg) {
      // Insert the flyout after the <rect> but before the block canvas so that
      // the flyout is underneath in z-order.  This makes blocks layering during
      // dragging work properly.
      background.insertBefore(flyoutSvg, this.workspace_.svgBlockCanvas_);
    }
    this.svgDialog_!.appendChild(background);

    // AnyDuringMigration because:  Type 'SVGSVGElement | null' is not
    // assignable to type 'SVGElement'.
    return this.svgDialog_ as AnyDuringMigration;
  }

  /**
   * @internal
   */
  newWorkspaceSvg(options: Options): WorkspaceSvg {
    throw new Error(
        'The implementation of newWorkspaceSvg should be ' +
        'monkey-patched in by blockly.ts');
  }

  /** Add or remove the UI indicating if this icon may be clicked or not. */
  override updateEditable() {
    super.updateEditable();
    if (!this.block_.isInFlyout) {
      if (this.block_.isEditable()) {
        if (this.iconGroup_) {
          dom.removeClass(
              this.iconGroup_ as Element, 'blocklyIconGroupReadonly');
        }
      } else {
        // Close any mutator bubble.  Icon is not clickable.
        this.setVisible(false);
        if (this.iconGroup_) {
          dom.addClass(this.iconGroup_ as Element, 'blocklyIconGroupReadonly');
        }
      }
    }
  }

  /** Resize the bubble to match the size of the workspace. */
  private resizeBubble_() {
    const doubleBorderWidth = 2 * Bubble.BORDER_WIDTH;
    const workspaceSize = this.workspace_!.getCanvas().getBBox();
    let width = workspaceSize.width + workspaceSize.x;
    let height = workspaceSize.height + doubleBorderWidth * 3;
    const flyout = this.workspace_!.getFlyout();
    if (flyout) {
      const flyoutScrollMetrics =
          flyout.getWorkspace().getMetricsManager().getScrollMetrics();
      height = Math.max(height, flyoutScrollMetrics.height + 20);
      width += flyout.getWidth();
    }
    if (this.block_.RTL) {
      width = -workspaceSize.x;
    }
    width += doubleBorderWidth * 3;
    // Only resize if the size difference is significant.  Eliminates
    // shuddering.
    if (Math.abs(this.workspaceWidth_ - width) > doubleBorderWidth ||
        Math.abs(this.workspaceHeight_ - height) > doubleBorderWidth) {
      // Record some layout information for workspace metrics.
      this.workspaceWidth_ = width;
      this.workspaceHeight_ = height;
      // Resize the bubble.
      this.bubble_!.setBubbleSize(
          width + doubleBorderWidth, height + doubleBorderWidth);
      // AnyDuringMigration because:  Argument of type 'number' is not
      // assignable to parameter of type 'string'.
      this.svgDialog_!.setAttribute(
          'width', this.workspaceWidth_ as AnyDuringMigration);
      // AnyDuringMigration because:  Argument of type 'number' is not
      // assignable to parameter of type 'string'.
      this.svgDialog_!.setAttribute(
          'height', this.workspaceHeight_ as AnyDuringMigration);
      this.workspace_!.setCachedParentSvgSize(
          this.workspaceWidth_, this.workspaceHeight_);
    }

    if (this.block_.RTL) {
      // Scroll the workspace to always left-align.
      const translation = 'translate(' + this.workspaceWidth_ + ',0)';
      this.workspace_!.getCanvas().setAttribute('transform', translation);
    }
    this.workspace_!.resize();
  }

  /** A method handler for when the bubble is moved. */
  private onBubbleMove_() {
    if (this.workspace_) {
      this.workspace_.recordDragTargets();
    }
  }

  /**
   * Show or hide the mutator bubble.
   * @param visible True if the bubble should be visible.
   */
  override setVisible(visible: boolean) {
    if (visible === this.isVisible()) {
      // No change.
      return;
    }
    eventUtils.fire(new (eventUtils.get(eventUtils.BUBBLE_OPEN))!
                    (this.block_, visible, 'mutator'));
    if (visible) {
      // Create the bubble.
      this.bubble_ = new Bubble(
          (this.block_.workspace as WorkspaceSvg), this.createEditor_(),
          this.block_.pathObject.svgPath, (this.iconXY_ as Coordinate), null,
          null);
      // Expose this mutator's block's ID on its top-level SVG group.
      this.bubble_.setSvgId(this.block_.id);
      this.bubble_.registerMoveEvent(this.onBubbleMove_.bind(this));
      const tree = this.workspace_!.options.languageTree;
      const flyout = this.workspace_!.getFlyout();
      if (tree) {
        flyout!.init(this.workspace_!);
        flyout!.show(tree);
      }

      this.rootBlock_ = this.block_!.decompose!(this.workspace_!)!;
      const blocks = this.rootBlock_!.getDescendants(false);
      for (let i = 0, child; child = blocks[i]; i++) {
        child.render();
      }
      // The root block should not be draggable or deletable.
      this.rootBlock_!.setMovable(false);
      this.rootBlock_!.setDeletable(false);
      let margin;
      let x;
      if (flyout) {
        margin = flyout.CORNER_RADIUS * 2;
        x = this.rootBlock_!.RTL ? flyout.getWidth() + margin : margin;
      } else {
        margin = 16;
        x = margin;
      }
      if (this.block_.RTL) {
        x = -x;
      }
      this.rootBlock_!.moveBy(x, margin);
      // Save the initial connections, then listen for further changes.
      if (this.block_.saveConnections) {
        const thisRootBlock = this.rootBlock_;
        this.block_.saveConnections(thisRootBlock);
        this.sourceListener_ = () => {
          if (this.block_ && this.block_.saveConnections) {
            this.block_.saveConnections(thisRootBlock);
          }
        };
        this.block_.workspace.addChangeListener(this.sourceListener_);
      }
      this.resizeBubble_();
      // When the mutator's workspace changes, update the source block.
      this.workspace_!.addChangeListener(this.workspaceChanged_.bind(this));
      // Update the source block immediately after the bubble becomes visible.
      this.updateWorkspace_();
      this.applyColour();
    } else {
      // Dispose of the bubble.
      this.svgDialog_ = null;
      this.workspace_!.dispose();
      this.workspace_ = null;
      this.rootBlock_ = null;
      this.bubble_?.dispose();
      this.bubble_ = null;
      this.workspaceWidth_ = 0;
      this.workspaceHeight_ = 0;
      if (this.sourceListener_) {
        this.block_.workspace.removeChangeListener(this.sourceListener_);
        this.sourceListener_ = null;
      }
    }
  }

  /**
   * Fired whenever a change is made to the mutator's workspace.
   * @param e Custom data for event.
   */
  private workspaceChanged_(e: Abstract) {
    if (!this.shouldIgnoreMutatorEvent_(e) && !this.updateWorkspacePid_) {
      this.updateWorkspacePid_ = setTimeout(() => {
        this.updateWorkspacePid_ = 0;
        this.updateWorkspace_();
      }, 0);
    }
  }

  /**
   * Returns whether the given event in the mutator workspace should be ignored
   * when deciding whether to update the workspace and compose the block or not.
   * @param e The event.
   * @return Whether to ignore the event or not.
   */
  shouldIgnoreMutatorEvent_(e: Abstract) {
    return e.isUiEvent || e.type === eventUtils.CREATE ||
        e.type === eventUtils.CHANGE &&
        (e as BlockChange).element === 'disabled';
  }

  /**
   * Updates the source block when the mutator's blocks are changed.
   * Bump down any block that's too high.
   */
  private updateWorkspace_() {
    if (!this.workspace_!.isDragging()) {
      const blocks = this.workspace_!.getTopBlocks(false);
      const MARGIN = 20;

      for (let b = 0, block; block = blocks[b]; b++) {
        const blockXY = block.getRelativeToSurfaceXY();

        // Bump any block that's above the top back inside.
        if (blockXY.y < MARGIN) {
          block.moveBy(0, MARGIN - blockXY.y);
        }
        // Bump any block overlapping the flyout back inside.
        if (block.RTL) {
          let right = -MARGIN;
          const flyout = this.workspace_!.getFlyout();
          if (flyout) {
            right -= flyout.getWidth();
          }
          if (blockXY.x > right) {
            block.moveBy(right - blockXY.x, 0);
          }
        } else if (blockXY.x < MARGIN) {
          block.moveBy(MARGIN - blockXY.x, 0);
        }
      }
    }

    // When the mutator's workspace changes, update the source block.
    if (this.rootBlock_ && this.rootBlock_.workspace === this.workspace_) {
      const existingGroup = eventUtils.getGroup();
      if (!existingGroup) {
        eventUtils.setGroup(true);
      }
      const block = this.block_ as BlockSvg;
      const oldExtraState = BlockChange.getExtraBlockState_(block);

      // Switch off rendering while the source block is rebuilt.
      const savedRendered = block.rendered;
      // TODO(#4288): We should not be setting the rendered property to false.
      block.rendered = false;

      // Allow the source block to rebuild itself.
      block.compose!(this.rootBlock_);
      // Restore rendering and show the changes.
      block.rendered = savedRendered;
      // Mutation may have added some elements that need initializing.
      block.initSvg();

      if (block.rendered) {
        block.render();
      }

      const newExtraState = BlockChange.getExtraBlockState_(block);
      if (oldExtraState !== newExtraState) {
        eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CHANGE))!(
            block, 'mutation', null, oldExtraState, newExtraState));
        // Ensure that any bump is part of this mutation's event group.
        const mutationGroup = eventUtils.getGroup();
        setTimeout(function() {
          const oldGroup = eventUtils.getGroup();
          eventUtils.setGroup(mutationGroup);
          block.bumpNeighbours();
          eventUtils.setGroup(oldGroup);
        }, config.bumpDelay);
      }

      // Don't update the bubble until the drag has ended, to avoid moving
      // blocks under the cursor.
      if (!this.workspace_!.isDragging()) {
        setTimeout(() => this.resizeBubble_(), 0);
      }
      eventUtils.setGroup(existingGroup);
    }
  }

  /** Dispose of this mutator. */
  override dispose() {
    this.block_.mutator = null;
    super.dispose();
  }

  /** Update the styles on all blocks in the mutator. */
  updateBlockStyle() {
    const ws = this.workspace_;

    if (ws && ws.getAllBlocks(false)) {
      const workspaceBlocks = ws.getAllBlocks(false);
      for (let i = 0, block; block = workspaceBlocks[i]; i++) {
        block.setStyle(block.getStyleName());
      }

      const flyout = ws.getFlyout();
      if (flyout) {
        const flyoutBlocks = flyout.getWorkspace().getAllBlocks(false);
        for (let i = 0, block; block = flyoutBlocks[i]; i++) {
          block.setStyle(block.getStyleName());
        }
      }
    }
  }

  /**
   * Reconnect an block to a mutated input.
   * @param connectionChild Connection on child block.
   * @param block Parent block.
   * @param inputName Name of input on parent block.
   * @return True iff a reconnection was made, false otherwise.
   */
  static reconnect(
      connectionChild: Connection, block: Block, inputName: string): boolean {
    if (!connectionChild || !connectionChild.getSourceBlock().workspace) {
      return false;  // No connection or block has been deleted.
    }
    const connectionParent = block.getInput(inputName)!.connection;
    const currentParent = connectionChild.targetBlock();
    if ((!currentParent || currentParent === block) && connectionParent &&
        connectionParent.targetConnection !== connectionChild) {
      if (connectionParent.isConnected()) {
        // There's already something connected here.  Get rid of it.
        connectionParent.disconnect();
      }
      connectionParent.connect(connectionChild);
      return true;
    }
    return false;
  }

  /**
   * Get the parent workspace of a workspace that is inside a mutator, taking
   * into account whether it is a flyout.
   * @param workspace The workspace that is inside a mutator.
   * @return The mutator's parent workspace or null.
   */
  static findParentWs(workspace: WorkspaceSvg): WorkspaceSvg|null {
    let outerWs = null;
    if (workspace && workspace.options) {
      const parent = workspace.options.parentWorkspace;
      // If we were in a flyout in a mutator, need to go up two levels to find
      // the actual parent.
      if (workspace.isFlyout) {
        if (parent && parent.options) {
          outerWs = parent.options.parentWorkspace;
        }
      } else if (parent) {
        outerWs = parent;
      }
    }
    return outerWs;
  }
}