/**
 * @license
 * Visual Blocks Editor
 *
 * Copyright 2011 Google Inc.
 * https://developers.google.com/blockly/
 *
 * 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.
 */

/**
 * @fileoverview Functionality for the right-click context menus.
 * @author fraser@google.com (Neil Fraser)
 */
'use strict';

/**
 * @name Blockly.ContextMenu
 * @namespace
 */
goog.provide('Blockly.ContextMenu');

goog.require('goog.dom');
goog.require('goog.events');
goog.require('goog.style');
goog.require('goog.ui.Menu');
goog.require('goog.ui.MenuItem');


/**
 * Which block is the context menu attached to?
 * @type {Blockly.Block}
 */
Blockly.ContextMenu.currentBlock = null;

/**
 * @type {Array.<!Array>} Opaque data that can be passed to unbindEvent_.
 * @private
 */
Blockly.ContextMenu.eventWrapper_ = null;

/**
 * Construct the menu based on the list of options and show the menu.
 * @param {!Event} e Mouse event.
 * @param {!Array.<!Object>} options Array of menu options.
 * @param {boolean} rtl True if RTL, false if LTR.
 */
Blockly.ContextMenu.show = function(e, options, rtl) {
  Blockly.WidgetDiv.show(Blockly.ContextMenu, rtl, null);
  if (!options.length) {
    Blockly.ContextMenu.hide();
    return;
  }
  var menu = Blockly.ContextMenu.populate_(options, rtl);

  goog.events.listen(menu, goog.ui.Component.EventType.ACTION,
                     Blockly.ContextMenu.hide);

  Blockly.ContextMenu.position_(menu, e, rtl);
  // 1ms delay is required for focusing on context menus because some other
  // mouse event is still waiting in the queue and clears focus.
  setTimeout(function() {menu.getElement().focus();}, 1);
  Blockly.ContextMenu.currentBlock = null;  // May be set by Blockly.Block.
};

/**
 * Create the context menu object and populate it with the given options.
 * @param {!Array.<!Object>} options Array of menu options.
 * @param {boolean} rtl True if RTL, false if LTR.
 * @return {!goog.ui.Menu} The menu that will be shown on right click.
 * @private
 */
Blockly.ContextMenu.populate_ = function(options, rtl) {
  /* Here's what one option object looks like:
    {text: 'Make It So',
     enabled: true,
     callback: Blockly.MakeItSo}
  */
  var menu = new goog.ui.Menu();
  menu.setAllowAutoFocus(true);
  menu.setRightToLeft(rtl);
  for (var i = 0, option; option = options[i]; i++) {
    var menuItem = new goog.ui.MenuItem(option.text);
    menuItem.setRightToLeft(rtl);
    menu.addChild(menuItem, true);
    menuItem.setEnabled(option.enabled);
    if (option.enabled) {
      goog.events.listen(menuItem, goog.ui.Component.EventType.ACTION,
                         option.callback);
      menuItem.handleContextMenu = function(/* e */) {
        // Right-clicking on menu option should count as a click.
        goog.events.dispatchEvent(this, goog.ui.Component.EventType.ACTION);
      };
    }
  }
  return menu;
};

/**
 * Add the menu to the page and position it correctly.
 * @param {!goog.ui.Menu} menu The menu to add and position.
 * @param {!Event} e Mouse event for the right click that is making the context
 *     menu appear.
 * @param {boolean} rtl True if RTL, false if LTR.
 * @private
 */
Blockly.ContextMenu.position_ = function(menu, e, rtl) {
    // Record windowSize and scrollOffset before adding menu.
  var windowSize = goog.dom.getViewportSize();
  var scrollOffset = goog.style.getViewportPageOffset(document);
  var div = Blockly.WidgetDiv.DIV;
  menu.render(div);
  var menuDom = menu.getElement();
  Blockly.utils.addClass(menuDom, 'blocklyContextMenu');
  // Prevent system context menu when right-clicking a Blockly context menu.
  Blockly.bindEventWithChecks_(menuDom, 'contextmenu', null,
                               Blockly.utils.noEvent);
  // Record menuSize after adding menu.
  var menuSize = goog.style.getSize(menuDom);

  // Position the menu.
  var x = e.clientX + scrollOffset.x;
  var y = e.clientY + scrollOffset.y;
  // Flip menu vertically if off the bottom.
  if (e.clientY + menuSize.height >= windowSize.height) {
    y -= menuSize.height;
  }
  // Flip menu horizontally if off the edge.
  if (rtl) {
    if (menuSize.width >= e.clientX) {
      x += menuSize.width;
    }
  } else {
    if (e.clientX + menuSize.width >= windowSize.width) {
      x -= menuSize.width;
    }
  }
  Blockly.WidgetDiv.position(x, y, windowSize, scrollOffset, rtl);
};

/**
 * Hide the context menu.
 */
Blockly.ContextMenu.hide = function() {
  Blockly.WidgetDiv.hideIfOwner(Blockly.ContextMenu);
  Blockly.ContextMenu.currentBlock = null;
  if (Blockly.ContextMenu.eventWrapper_) {
    Blockly.unbindEvent_(Blockly.ContextMenu.eventWrapper_);
  }
};

/**
 * Create a callback function that creates and configures a block,
 *   then places the new block next to the original.
 * @param {!Blockly.Block} block Original block.
 * @param {!Element} xml XML representation of new block.
 * @return {!Function} Function that creates a block.
 */
Blockly.ContextMenu.callbackFactory = function(block, xml) {
  return function() {
    Blockly.Events.disable();
    try {
      var newBlock = Blockly.Xml.domToBlock(xml, block.workspace);
      // Move the new block next to the old block.
      var xy = block.getRelativeToSurfaceXY();
      if (block.RTL) {
        xy.x -= Blockly.SNAP_RADIUS;
      } else {
        xy.x += Blockly.SNAP_RADIUS;
      }
      xy.y += Blockly.SNAP_RADIUS * 2;
      newBlock.moveBy(xy.x, xy.y);
    } finally {
      Blockly.Events.enable();
    }
    if (Blockly.Events.isEnabled() && !newBlock.isShadow()) {
      Blockly.Events.fire(new Blockly.Events.BlockCreate(newBlock));
    }
    newBlock.select();
  };
};

// Helper functions for creating context menu options.

/**
 * Make a context menu option for deleting the current block.
 * @param {!Blockly.BlockSvg} block The block where the right-click originated.
 * @return {!Object} A menu option, containing text, enabled, and a callback.
 * @package
 */
Blockly.ContextMenu.blockDeleteOption = function(block) {
  // Option to delete this block but not blocks lower in the stack.
  // Count the number of blocks that are nested in this block.
  var descendantCount = block.getDescendants(true).length;
  var nextBlock = block.getNextBlock();
  if (nextBlock) {
    // Blocks in the current stack would survive this block's deletion.
    descendantCount -= nextBlock.getDescendants(true).length;
  }
  var deleteOption = {
    text: descendantCount == 1 ? Blockly.Msg.DELETE_BLOCK :
        Blockly.Msg.DELETE_X_BLOCKS.replace('%1', String(descendantCount)),
    enabled: true,
    callback: function() {
      Blockly.Events.setGroup(true);
      block.dispose(true, true);
      Blockly.Events.setGroup(false);
    }
  };
  return deleteOption;
};

/**
 * Make a context menu option for showing help for the current block.
 * @param {!Blockly.BlockSvg} block The block where the right-click originated.
 * @return {!Object} A menu option, containing text, enabled, and a callback.
 * @package
 */
Blockly.ContextMenu.blockHelpOption = function(block) {
  var url = goog.isFunction(block.helpUrl) ? block.helpUrl() : block.helpUrl;
  var helpOption = {
    enabled: !!url,
    text: Blockly.Msg.HELP,
    callback: function() {
      block.showHelp_();
    }
  };
  return helpOption;
};

/**
 * Make a context menu option for duplicating the current block.
 * @param {!Blockly.BlockSvg} block The block where the right-click originated.
 * @return {!Object} A menu option, containing text, enabled, and a callback.
 * @package
 */
Blockly.ContextMenu.blockDuplicateOption = function(block) {
  var duplicateOption = {
    text: Blockly.Msg.DUPLICATE_BLOCK,
    enabled: true,
    callback: block.duplicateAndDragCallback_()
  };
  return duplicateOption;
};

/**
 * Make a context menu option for adding or removing comments on the current
 * block.
 * @param {!Blockly.BlockSvg} block The block where the right-click originated.
 * @return {!Object} A menu option, containing text, enabled, and a callback.
 * @package
 */
Blockly.ContextMenu.blockCommentOption = function(block) {
  var commentOption = {
    enabled: !goog.userAgent.IE
  };
  // If there's already a comment, add an option to delete it.
  if (block.comment) {
    commentOption.text = Blockly.Msg.REMOVE_COMMENT;
    commentOption.callback = function() {
      block.setCommentText(null);
    };
  } else {
    // If there's no comment, add an option to create a comment.
    commentOption.text = Blockly.Msg.ADD_COMMENT;
    commentOption.callback = function() {
      block.setCommentText('');
    };
  }
  return commentOption;
};

/**
 * Make a context menu option for undoing the most recent action on the
 * workspace.
 * @param {!Blockly.WorkspaceSvg} ws The workspace where the right-click
 *     originated.
 * @return {!Object} A menu option, containing text, enabled, and a callback.
 * @package
 */
Blockly.ContextMenu.wsUndoOption = function(ws) {
  return {
    text: Blockly.Msg.UNDO,
    enabled: ws.hasUndoStack(),
    callback: ws.undo.bind(ws, false)
  };
};

/**
 * Make a context menu option for redoing the most recent action on the
 * workspace.
 * @param {!Blockly.WorkspaceSvg} ws The workspace where the right-click
 *     originated.
 * @return {!Object} A menu option, containing text, enabled, and a callback.
 * @package
 */
Blockly.ContextMenu.wsRedoOption = function(ws) {
  return {
    text: Blockly.Msg.REDO,
    enabled: ws.hasRedoStack(),
    callback: ws.undo.bind(ws, true)
  };
};

/**
 * Make a context menu option for cleaning up blocks on the workspace, by
 * aligning them vertically.
 * @param {!Blockly.WorkspaceSvg} ws The workspace where the right-click
 *     originated.
 * @param {number} numTopBlocks The number of top blocks on the workspace.
 * @return {!Object} A menu option, containing text, enabled, and a callback.
 * @package
 */
Blockly.ContextMenu.wsCleanupOption = function(ws, numTopBlocks) {
  return {
    text: Blockly.Msg.CLEAN_UP,
    enabled: numTopBlocks > 1,
    callback: ws.cleanUp.bind(ws, true)
  };
};

/**
 * Helper function for toggling delete state on blocks on the workspace, to be
 * called from a right-click menu.
 * @param {!Array.<!Blockly.BlockSvg>} topBlocks The list of top blocks on the
 *     the workspace.
 * @param {boolean} shouldCollapse True if the blocks should be collapsed, false
 *     if they should be expanded.
 * @private
 */
Blockly.ContextMenu.toggleCollapseFn_ = function(topBlocks, shouldCollapse) {
  // Add a little animation to collapsing and expanding.
  var DELAY = 10;
  var ms = 0;
  for (var i = 0; i < topBlocks.length; i++) {
    var block = topBlocks[i];
    while (block) {
      setTimeout(block.setCollapsed.bind(block, shouldCollapse), ms);
      block = block.getNextBlock();
      ms += DELAY;
    }
  }
};

/**
 * Make a context menu option for collapsing all block stacks on the workspace.
 * @param {boolean} hasExpandedBlocks Whether there are any non-collapsed blocks
 *     on the workspace.
 * @param {!Array.<!Blockly.BlockSvg>} topBlocks The list of top blocks on the
 *     the workspace.
 * @return {!Object} A menu option, containing text, enabled, and a callback.
 * @package
 */
Blockly.ContextMenu.wsCollapseOption = function(hasExpandedBlocks, topBlocks) {
  return {
    enabled: hasExpandedBlocks,
    text: Blockly.Msg.COLLAPSE_ALL,
    callback: function() {
      Blockly.ContextMenu.toggleCollapseFn_(topBlocks, true);
    }
  };
};

/**
 * Make a context menu option for expanding all block stacks on the workspace.
 * @param {boolean} hasCollapsedBlocks Whether there are any collapsed blocks
 *     on the workspace.
 * @param {!Array.<!Blockly.BlockSvg>} topBlocks The list of top blocks on the
 *     the workspace.
 * @return {!Object} A menu option, containing text, enabled, and a callback.
 * @package
 */
Blockly.ContextMenu.wsExpandOption = function(hasCollapsedBlocks, topBlocks) {
  return {
    enabled: hasCollapsedBlocks,
    text: Blockly.Msg.EXPAND_ALL,
    callback: function() {
      Blockly.ContextMenu.toggleCollapseFn_(topBlocks, false);
    }
  };
};

// End helper functions for creating context menu options.