/**
 * @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 Core JavaScript library for Blockly.
 * @author fraser@google.com (Neil Fraser)
 */
'use strict';

/**
 * The top level namespace used to access the Blockly library.
 * @namespace Blockly
 */
goog.provide('Blockly');

goog.require('Blockly.BlockSvg.render');
goog.require('Blockly.Events');
goog.require('Blockly.FieldAngle');
goog.require('Blockly.FieldCheckbox');
goog.require('Blockly.FieldColour');
// Date picker commented out since it increases footprint by 60%.
// Add it only if you need it.
//goog.require('Blockly.FieldDate');
goog.require('Blockly.FieldDropdown');
goog.require('Blockly.FieldImage');
goog.require('Blockly.FieldClickImage');
goog.require('Blockly.FieldTextInput');
goog.require('Blockly.FieldTextArea');
goog.require('Blockly.FieldTable');
goog.require('Blockly.FieldNumber');
goog.require('Blockly.FieldVariable');
goog.require('Blockly.Generator');
goog.require('Blockly.Msg');
goog.require('Blockly.Procedures');
goog.require('Blockly.Toolbox');
goog.require('Blockly.Touch');
goog.require('Blockly.WidgetDiv');
goog.require('Blockly.WorkspaceSvg');
goog.require('Blockly.constants');
goog.require('Blockly.inject');
goog.require('Blockly.utils');
goog.require('goog.color');
goog.require('goog.userAgent');


// Turn off debugging when compiled.
var CLOSURE_DEFINES = {'goog.DEBUG': false};

/**
 * The main workspace most recently used.
 * Set by Blockly.WorkspaceSvg.prototype.markFocused
 * @type {Blockly.Workspace}
 */
Blockly.mainWorkspace = null;

/**
 * Currently selected block.
 * @type {Blockly.Block}
 */
Blockly.selected = null;

/**
 * Currently highlighted connection (during a drag).
 * @type {Blockly.Connection}
 * @private
 */
Blockly.highlightedConnection_ = null;

/**
 * Connection on dragged block that matches the highlighted connection.
 * @type {Blockly.Connection}
 * @private
 */
Blockly.localConnection_ = null;

/**
 * All of the connections on blocks that are currently being dragged.
 * @type {!Array.<!Blockly.Connection>}
 * @private
 */
Blockly.draggingConnections_ = [];

/**
 * Contents of the local clipboard.
 * @type {Element}
 * @private
 */
Blockly.clipboardXml_ = null;

/**
 * Source of the local clipboard.
 * @type {Blockly.WorkspaceSvg}
 * @private
 */
Blockly.clipboardSource_ = null;

/**
 * Is the mouse dragging a block?
 * DRAG_NONE - No drag operation.
 * DRAG_STICKY - Still inside the sticky DRAG_RADIUS.
 * DRAG_FREE - Freely draggable.
 * @private
 */
Blockly.dragMode_ = Blockly.DRAG_NONE;

/**
 * Map from function names to callbacks, for deciding what to do when a button
 * is clicked.
 * @type {!Object<string, function(!Blockly.FlyoutButton)>}
 */
Blockly.flyoutButtonCallbacks_ = {};

/**
 * Register a callback function associated with a given key, for clicks on
 * buttons and labels in the flyout.
 * For instance, a button specified by the XML
 * <button text="create variable" callbackKey="CREATE_VARIABLE"></button>
 * should be matched by a call to
 * registerButtonCallback("CREATE_VARIABLE", yourCallbackFunction).
 * @param {string} key The name to use to look up this function.
 * @param {function(!Blockly.FlyoutButton)} func The function to call when the
 *     given button is clicked.
 */
Blockly.registerButtonCallback = function(key, func) {
  Blockly.flyoutButtonCallbacks_[key] = func;
};

/**
 * Convert a hue (HSV model) into an RGB hex triplet.
 * @param {number} hue Hue on a colour wheel (0-360).
 * @return {string} RGB code, e.g. '#5ba65b'.
 */
Blockly.hueToRgb = function(hue) {
  return goog.color.hsvToHex(hue, Blockly.HSV_SATURATION,
      Blockly.HSV_VALUE * 255);
};

/**
 * Returns the dimensions of the specified SVG image.
 * @param {!Element} svg SVG image.
 * @return {!Object} Contains width and height properties.
 */
Blockly.svgSize = function(svg) {
  return {width: svg.cachedWidth_,
          height: svg.cachedHeight_};
};

/**
 * Size the workspace when the contents change.  This also updates
 * scrollbars accordingly.
 * @param {!Blockly.WorkspaceSvg} workspace The workspace to resize.
 */
Blockly.resizeSvgContents = function(workspace) {
  workspace.resizeContents();
};

/**
 * Size the SVG image to completely fill its container. Call this when the view
 * actually changes sizes (e.g. on a window resize/device orientation change).
 * See Blockly.resizeSvgContents to resize the workspace when the contents
 * change (e.g. when a block is added or removed).
 * Record the height/width of the SVG image.
 * @param {!Blockly.WorkspaceSvg} workspace Any workspace in the SVG.
 */
Blockly.svgResize = function(workspace) {
  var mainWorkspace = workspace;
  while (mainWorkspace.options.parentWorkspace) {
    mainWorkspace = mainWorkspace.options.parentWorkspace;
  }
  var svg = mainWorkspace.getParentSvg();
  var div = svg.parentNode;
  if (!div) {
    // Workspace deleted, or something.
    return;
  }
  var width = div.offsetWidth;
  var height = div.offsetHeight;
  if (svg.cachedWidth_ != width) {
    svg.setAttribute('width', width + 'px');
    svg.cachedWidth_ = width;
  }
  if (svg.cachedHeight_ != height) {
    svg.setAttribute('height', height + 'px');
    svg.cachedHeight_ = height;
  }
  mainWorkspace.resize();
};

/**
 * Handle a key-down on SVG drawing surface.
 * @param {!Event} e Key down event.
 * @private
 */
Blockly.onKeyDown_ = function(e) {
  if (Blockly.mainWorkspace.options.readOnly || Blockly.isTargetInput_(e)) {
    // No key actions on readonly workspaces.
    // When focused on an HTML text input widget, don't trap any keys.
    return;
  }
  var deleteBlock = false;
  if (e.keyCode == 27) {
    // Pressing esc closes the context menu.
    Blockly.hideChaff();
  } else if (e.keyCode == 8 || e.keyCode == 46) {
    // Delete or backspace.
    // Stop the browser from going back to the previous page.
    // Do this first to prevent an error in the delete code from resulting in
    // data loss.
    e.preventDefault();
    if (Blockly.selected && Blockly.selected.isDeletable()) {
      deleteBlock = true;
    }
  } else if (e.altKey || e.ctrlKey || e.metaKey) {
    if (Blockly.selected &&
        Blockly.selected.isDeletable() && Blockly.selected.isMovable()) {
      if (e.keyCode == 67) {
        // 'c' for copy.
        Blockly.hideChaff();
        Blockly.copy_(Blockly.selected);
      } else if (e.keyCode == 88) {
        // 'x' for cut.
        Blockly.copy_(Blockly.selected);
        deleteBlock = true;
      }
    }
    if (e.keyCode == 86) {
      // 'v' for paste.
      Blockly.mainWorkspace.pasteFromClipboard();
    } else if (e.keyCode == 90) {
        // 'z' for undo
        //Blockly.getMainWorkspace().undo();
        Blockly.hideChaff();
        Blockly.mainWorkspace.undo(false);
    } else if (e.keyCode == 89) {
        // 'y' for undo
        //Blockly.getMainWorkspace().redo();
        Blockly.hideChaff();
        Blockly.mainWorkspace.undo(true);
    }
  }
  if (deleteBlock) {
    // Common code for delete and cut.
    Blockly.Events.setGroup(true);
    Blockly.hideChaff();
    var heal = Blockly.dragMode_ != Blockly.DRAG_FREE;
    Blockly.selected.dispose(heal, true);
    if (Blockly.highlightedConnection_) {
      Blockly.highlightedConnection_.unhighlight();
      Blockly.highlightedConnection_ = null;
    }
    Blockly.Events.setGroup(false);
  }
};

/**
 * Stop binding to the global mouseup and mousemove events.
 * @private
 */
Blockly.terminateDrag_ = function() {
  Blockly.BlockSvg.terminateDrag();
  Blockly.Flyout.terminateDrag_();
};

/**
 * Copy a block onto the local clipboard.
 * @param {!Blockly.Block} block Block to be copied.
 * @private
 */
Blockly.copy_ = function(block) {
  var xmlBlock = Blockly.Xml.blockToDom(block);
  if (Blockly.dragMode_ != Blockly.DRAG_FREE) {
    Blockly.Xml.deleteNext(xmlBlock);
  }
  // Encode start position in XML.
  var xy = block.getRelativeToSurfaceXY();
  xmlBlock.setAttribute('x', block.RTL ? -xy.x : xy.x);
  xmlBlock.setAttribute('y', xy.y);
  Blockly.clipboardXml_ = xmlBlock;
  Blockly.clipboardSource_ = block.workspace;
  localStorage.setItem('_blockly_clipboardXml_', Blockly.Xml.domToText(xmlBlock));
};

/**
 * Duplicate this block and its children.
 * @param {!Blockly.Block} block Block to be copied.
 * @private
 */
Blockly.duplicate_ = function(block) {
  // Save the clipboard.
  var clipboardXml = Blockly.clipboardXml_;
  var clipboardSource = Blockly.clipboardSource_;

  // Create a duplicate via a copy/paste operation.
  Blockly.copy_(block);
  block.workspace.paste(Blockly.clipboardXml_);

  // Restore the clipboard.
  Blockly.clipboardXml_ = clipboardXml;
  Blockly.clipboardSource_ = clipboardSource;
};

/**
 * Cancel the native context menu, unless the focus is on an HTML input widget.
 * @param {!Event} e Mouse down event.
 * @private
 */
Blockly.onContextMenu_ = function(e) {
  if (!Blockly.isTargetInput_(e)) {
    // When focused on an HTML text input widget, don't cancel the context menu.
    e.preventDefault();
  }
};

/**
 * Close tooltips, context menus, dropdown selections, etc.
 * @param {boolean=} opt_allowToolbox If true, don't close the toolbox.
 */
Blockly.hideChaff = function(opt_allowToolbox) {
  Blockly.Tooltip.hide();
  Blockly.WidgetDiv.hide();
  if (!opt_allowToolbox) {
    var workspace = Blockly.getMainWorkspace();
    if (workspace.toolbox_ &&
        workspace.toolbox_.flyout_ &&
        workspace.toolbox_.flyout_.autoClose) {
      workspace.toolbox_.clearSelection();
    }
  }
};

/**
 * When something in Blockly's workspace changes, call a function.
 * @param {!Function} func Function to call.
 * @return {!Array.<!Array>} Opaque data that can be passed to
 *     removeChangeListener.
 * @deprecated April 2015
 */
Blockly.addChangeListener = function(func) {
  // Backwards compatability from before there could be multiple workspaces.
  console.warn('Deprecated call to Blockly.addChangeListener, ' +
               'use workspace.addChangeListener instead.');
  return Blockly.getMainWorkspace().addChangeListener(func);
};

/**
 * Returns the main workspace.  Returns the last used main workspace (based on
 * focus).  Try not to use this function, particularly if there are multiple
 * Blockly instances on a page.
 * @return {!Blockly.Workspace} The main workspace.
 */
Blockly.getMainWorkspace = function() {
  return Blockly.mainWorkspace;
};

/**
 * Wrapper to window.alert() that app developers may override to
 * provide alternatives to the modal browser window.
 * @param {string} message The message to display to the user.
 * @param {function()=} opt_callback The callback when the alert is dismissed.
 */
Blockly.alert = function(message, opt_callback) {
  window.alert(message);
  if (opt_callback) {
    opt_callback();
  }
};

/**
 * Wrapper to window.confirm() that app developers may override to
 * provide alternatives to the modal browser window.
 * @param {string} message The message to display to the user.
 * @param {!function(boolean)} callback The callback for handling user response.
 */
Blockly.confirm = function(message, callback) {
  callback(window.confirm(message));
};

/**
 * Wrapper to window.prompt() that app developers may override to provide
 * alternatives to the modal browser window. Built-in browser prompts are
 * often used for better text input experience on mobile device. We strongly
 * recommend testing mobile when overriding this.
 * @param {string} message The message to display to the user.
 * @param {string} defaultValue The value to initialize the prompt with.
 * @param {!function(string)} callback The callback for handling user reponse.
 */
Blockly.prompt = function(message, defaultValue, callback) {
  callback(window.prompt(message, defaultValue));
};

/**
 * Helper function for defining a block from JSON.  The resulting function has
 * the correct value of jsonDef at the point in code where jsonInit is called.
 * @param {!Object} jsonDef The JSON definition of a block.
 * @return {function} A function that calls jsonInit with the correct value
 *     of jsonDef.
 * @private
 */
Blockly.jsonInitFactory_ = function(jsonDef) {
  return function() {
    this.jsonInit(jsonDef);
  };
};

/**
 * Define blocks from an array of JSON block definitions, as might be generated
 * by the Blockly Developer Tools.
 * @param {!Array.<!Object>} jsonArray An array of JSON block definitions.
 */
Blockly.defineBlocksWithJsonArray = function(jsonArray) {
  for (var i = 0, elem; elem = jsonArray[i]; i++) {
    Blockly.Blocks[elem.type] = {
      init: Blockly.jsonInitFactory_(elem)
    };
  }
};

// IE9 does not have a console.  Create a stub to stop errors.
if (!goog.global['console']) {
  goog.global['console'] = {
    'log': function() {},
    'warn': function() {}
  };
}

// Export symbols that would otherwise be renamed by Closure compiler.
if (!goog.global['Blockly']) {
  goog.global['Blockly'] = {};
}
goog.global['Blockly']['getMainWorkspace'] = Blockly.getMainWorkspace;
goog.global['Blockly']['addChangeListener'] = Blockly.addChangeListener;
