/**
 * @license
 * Visual Blocks Editor
 *
 * Copyright 2012 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 Text blocks for Blockly.
 * @author fraser@google.com (Neil Fraser)
 */
'use strict';

goog.provide('Blockly.Blocks.texts');

goog.require('Blockly.Blocks');
goog.require('Blockly.Types');


/**
 * Common HSV hue for all blocks in this category.
 */
Blockly.Blocks.texts.HUE = 160;

Blockly.Blocks['text'] = {
  /**
   * Block for text value.
   * @this Blockly.Block
   */
  init: function() {
    this.setHelpUrl(Blockly.Msg.TEXT_TEXT_HELPURL);
    this.setColour(Blockly.Blocks.texts.HUE);
    this.appendDummyInput()
        .appendField(this.newQuote_(true))
        .appendField(new Blockly.FieldTextInput(''), 'TEXT')
        .appendField(this.newQuote_(false));
    this.setColour("#BD4F8C");
    this.setOutput(true, Blockly.Types.TEXT.output);
    // Assign 'this' to a variable for use in the tooltip closure below.
    var thisBlock = this;
    // Text block is trivial.  Use tooltip of parent block if it exists.
    this.setTooltip(function() {
      var parent = thisBlock.getParent();
      return (parent && parent.getInputsInline() && parent.tooltip) ||
          Blockly.Msg.TEXT_TEXT_TOOLTIP;
    });
  },
  /**
   * Create an image of an open or closed quote.
   * @param {boolean} open True if open quote, false if closed.
   * @return {!Blockly.FieldImage} The field image of the quote.
   * @this Blockly.Block
   * @private
   */
  newQuote_: function(open) {
    if (open == this.RTL) {
      var file = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAwAAAAKCAQAAAAqJXdxAAAAqUlEQVQI1z3KvUpCcRiA8ef9E4JNHhI0aFEacm1o0BsI0Slx8wa8gLauoDnoBhq7DcfWhggONDmJJgqCPA7neJ7p934EOOKOnM8Q7PDElo/4x4lFb2DmuUjcUzS3URnGib9qaPNbuXvBO3sGPHJDRG6fGVdMSeWDP2q99FQdFrz26Gu5Tq7dFMzUvbXy8KXeAj57cOklgA+u1B5AoslLtGIHQMaCVnwDnADZIFIrXsoXrgAAAABJRU5ErkJggg==';
    } else {
      var file = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAwAAAAKCAQAAAAqJXdxAAAAn0lEQVQI1z3OMa5BURSF4f/cQhAKjUQhuQmFNwGJEUi0RKN5rU7FHKhpjEH3TEMtkdBSCY1EIv8r7nFX9e29V7EBAOvu7RPjwmWGH/VuF8CyN9/OAdvqIXYLvtRaNjx9mMTDyo+NjAN1HNcl9ZQ5oQMM3dgDUqDo1l8DzvwmtZN7mnD+PkmLa+4mhrxVA9fRowBWmVBhFy5gYEjKMfz9AylsaRRgGzvZAAAAAElFTkSuQmCC';
    }
    return new Blockly.FieldImage(file, 12, 12, '"');
  },
  /** @return {!string} Type of the block, text block always a string. */
  getBlockType: function() {
    return Blockly.Types.TEXT;
  }
};

Blockly.Blocks['text_join'] = {
  /**
   * Block for creating a string made up of any number of elements of any type.
   * @this Blockly.Block
   */
  init: function() {
    this.setHelpUrl(Blockly.Msg.TEXT_JOIN_HELPURL);
    this.setColour(Blockly.Blocks.texts.HUE);
    this.itemCount_ = 2;
    this.updateShape_();
    this.setOutput(true, Blockly.Types.TEXT.output);
    this.setMutator(new Blockly.Mutator(['text_create_join_item']));
    this.setTooltip(Blockly.Msg.TEXT_JOIN_TOOLTIP);
  },
  /**
   * Create XML to represent number of text inputs.
   * @return {!Element} XML storage element.
   * @this Blockly.Block
   */
  mutationToDom: function() {
    var container = document.createElement('mutation');
    container.setAttribute('items', this.itemCount_);
    return container;
  },
  /**
   * Parse XML to restore the text inputs.
   * @param {!Element} xmlElement XML storage element.
   * @this Blockly.Block
   */
  domToMutation: function(xmlElement) {
    this.itemCount_ = parseInt(xmlElement.getAttribute('items'), 10);
    this.updateShape_();
  },
  /**
   * Populate the mutator's dialog with this block's components.
   * @param {!Blockly.Workspace} workspace Mutator's workspace.
   * @return {!Blockly.Block} Root block in mutator.
   * @this Blockly.Block
   */
  decompose: function(workspace) {
    var containerBlock = workspace.newBlock('text_create_join_container');
    containerBlock.initSvg();
    var connection = containerBlock.getInput('STACK').connection;
    for (var i = 0; i < this.itemCount_; i++) {
      var itemBlock = workspace.newBlock('text_create_join_item');
      itemBlock.initSvg();
      connection.connect(itemBlock.previousConnection);
      connection = itemBlock.nextConnection;
    }
    return containerBlock;
  },
  /**
   * Reconfigure this block based on the mutator dialog's components.
   * @param {!Blockly.Block} containerBlock Root block in mutator.
   * @this Blockly.Block
   */
  compose: function(containerBlock) {
    var itemBlock = containerBlock.getInputTargetBlock('STACK');
    // Count number of inputs.
    var connections = [];
    while (itemBlock) {
      connections.push(itemBlock.valueConnection_);
      itemBlock = itemBlock.nextConnection &&
          itemBlock.nextConnection.targetBlock();
    }
    // Disconnect any children that don't belong.
    for (var i = 0; i < this.itemCount_; i++) {
      var connection = this.getInput('ADD' + i).connection.targetConnection;
      if (connection && connections.indexOf(connection) == -1) {
        connection.disconnect();
      }
    }
    this.itemCount_ = connections.length;
    this.updateShape_();
    // Reconnect any child blocks.
    for (var i = 0; i < this.itemCount_; i++) {
      Blockly.Mutator.reconnect(connections[i], this, 'ADD' + i);
    }
  },
  /**
   * Store pointers to any connected child blocks.
   * @param {!Blockly.Block} containerBlock Root block in mutator.
   * @this Blockly.Block
   */
  saveConnections: function(containerBlock) {
    var itemBlock = containerBlock.getInputTargetBlock('STACK');
    var i = 0;
    while (itemBlock) {
      var input = this.getInput('ADD' + i);
      itemBlock.valueConnection_ = input && input.connection.targetConnection;
      i++;
      itemBlock = itemBlock.nextConnection &&
          itemBlock.nextConnection.targetBlock();
    }
  },
  /**
   * Modify this block to have the correct number of inputs.
   * @private
   * @this Blockly.Block
   */
  updateShape_: function() {
    if (this.itemCount_ && this.getInput('EMPTY')) {
      this.removeInput('EMPTY');
    } else if (!this.itemCount_ && !this.getInput('EMPTY')) {
      this.appendDummyInput('EMPTY')
          .appendField(this.newQuote_(true))
          .appendField(this.newQuote_(false));
    }
    // Add new inputs.
    for (var i = 0; i < this.itemCount_; i++) {
      if (!this.getInput('ADD' + i)) {
        var input = this.appendValueInput('ADD' + i);
        if (i == 0) {
          input.appendField(Blockly.Msg.TEXT_JOIN_TITLE_CREATEWITH);
        }
      }
    }
    // Remove deleted inputs.
    while (this.getInput('ADD' + i)) {
      this.removeInput('ADD' + i);
      i++;
    }
  },
  newQuote_: Blockly.Blocks['text'].newQuote_,
  /** @return {!string} Type of the block, text join always a string. */
  getBlockType: function() {
    return Blockly.Types.TEXT;
  }
};

Blockly.Blocks['text_create_join_container'] = {
  /**
   * Mutator block for container.
   * @this Blockly.Block
   */
  init: function() {
    this.setColour(Blockly.Blocks.texts.HUE);
    this.appendDummyInput()
        .appendField(Blockly.Msg.TEXT_CREATE_JOIN_TITLE_JOIN);
    this.appendStatementInput('STACK');
    this.setTooltip(Blockly.Msg.TEXT_CREATE_JOIN_TOOLTIP);
    this.contextMenu = false;
  }
};

Blockly.Blocks['text_create_join_item'] = {
  /**
   * Mutator block for add items.
   * @this Blockly.Block
   */
  init: function() {
    this.setColour(Blockly.Blocks.texts.HUE);
    this.appendDummyInput()
        .appendField(Blockly.Msg.TEXT_CREATE_JOIN_ITEM_TITLE_ITEM);
    this.setPreviousStatement(true);
    this.setNextStatement(true);
    this.setTooltip(Blockly.Msg.TEXT_CREATE_JOIN_ITEM_TOOLTIP);
    this.contextMenu = false;
  }
};

Blockly.Blocks['text_append'] = {
  /**
   * Block for appending to a variable in place.
   * @this Blockly.Block
   */
  init: function() {
    this.setHelpUrl(Blockly.Msg.TEXT_APPEND_HELPURL);
    this.setColour(Blockly.Blocks.texts.HUE);
    this.appendValueInput('TEXT')
        .appendField(Blockly.Msg.TEXT_APPEND_TO)
        .appendField(new Blockly.FieldVariable(
        Blockly.Msg.TEXT_APPEND_VARIABLE), 'VAR')
        .appendField(Blockly.Msg.TEXT_APPEND_APPENDTEXT);
    this.setPreviousStatement(true);
    this.setNextStatement(true);
    // Assign 'this' to a variable for use in the tooltip closure below.
    var thisBlock = this;
    this.setTooltip(function() {
      return Blockly.Msg.TEXT_APPEND_TOOLTIP.replace('%1',
          thisBlock.getFieldValue('VAR'));
    });
  },
  /**
   * Set's the type of the variable selected in the drop down list. As there is
   * only one possible option, the variable input is not really checked.
   * @param {!string} varName Name of the variable to check type.
   * @return {string} String to indicate the variable type.
   */
  getVarType: function(varName) {
    return Blockly.Types.TEXT;
  }
};

Blockly.Blocks['text_length'] = {
  /**
   * Block for string length.
   * @this Blockly.Block
   */
  init: function() {
    this.jsonInit({
      "message0": Blockly.Msg.TEXT_LENGTH_TITLE,
      "args0": [
        {
          "type": "input_value",
          "name": "VALUE",
          "check": Blockly.Types.TEXT.checkList.concat('Array'),
        }
      ],
      "output": Blockly.Types.NUMBER.output,
      "colour": Blockly.Blocks.texts.HUE,
      "tooltip": Blockly.Msg.TEXT_LENGTH_TOOLTIP,
      "helpUrl": Blockly.Msg.TEXT_LENGTH_HELPURL
    });
  },
  /** @return {!string} Type of the block, text length always an integer. */
  getBlockType: function() {
    return Blockly.Types.NUMBER;
  }
};

Blockly.Blocks['text_isEmpty'] = {
  /**
   * Block for is the string null?
   * @this Blockly.Block
   */
  init: function() {
    this.jsonInit({
      "message0": Blockly.Msg.TEXT_ISEMPTY_TITLE,
      "args0": [
        {
          "type": "input_value",
          "name": "VALUE",
          "check": Blockly.Types.TEXT.checkList.concat('Array'),
        }
      ],
      "output": Blockly.Types.BOOLEAN.output,
      "colour": Blockly.Blocks.texts.HUE,
      "tooltip": Blockly.Msg.TEXT_ISEMPTY_TOOLTIP,
      "helpUrl": Blockly.Msg.TEXT_ISEMPTY_HELPURL
    });
  },
  /** @return {!string} Type of the block, check always returns a boolean. */
  getBlockType: function() {
    return Blockly.Types.BOOLEAN;
  }
};

Blockly.Blocks['text_indexOf'] = {
  /**
   * Block for finding a substring in the text.
   * @this Blockly.Block
   */
  init: function() {
    var OPERATORS =
        [[Blockly.Msg.TEXT_INDEXOF_OPERATOR_FIRST, 'FIRST'],
         [Blockly.Msg.TEXT_INDEXOF_OPERATOR_LAST, 'LAST']];
    this.setHelpUrl(Blockly.Msg.TEXT_INDEXOF_HELPURL);
    this.setColour(Blockly.Blocks.texts.HUE);
    this.setOutput(true, Blockly.Types.NUMBER.output);
    this.appendValueInput('VALUE')
        .setCheck(Blockly.Types.TEXT.checkList)
        .appendField(Blockly.Msg.TEXT_INDEXOF_INPUT_INTEXT);
    this.appendValueInput('FIND')
        .setCheck(Blockly.Types.TEXT.checkList)
        .appendField(new Blockly.FieldDropdown(OPERATORS), 'END');
    if (Blockly.Msg.TEXT_INDEXOF_TAIL) {
      this.appendDummyInput().appendField(Blockly.Msg.TEXT_INDEXOF_TAIL);
    }
    this.setInputsInline(true);
    this.setTooltip(Blockly.Msg.TEXT_INDEXOF_TOOLTIP);
  }
};

Blockly.Blocks['text_charAt'] = {
  /**
   * Block for getting a character from the string.
   * @this Blockly.Block
   */
  init: function() {
    this.WHERE_OPTIONS =
        [[Blockly.Msg.TEXT_CHARAT_FROM_START, 'FROM_START'],
         [Blockly.Msg.TEXT_CHARAT_FROM_END, 'FROM_END'],
         [Blockly.Msg.TEXT_CHARAT_FIRST, 'FIRST'],
         [Blockly.Msg.TEXT_CHARAT_LAST, 'LAST'],
         [Blockly.Msg.TEXT_CHARAT_RANDOM, 'RANDOM']];
    this.setHelpUrl(Blockly.Msg.TEXT_CHARAT_HELPURL);
    this.setColour(Blockly.Blocks.texts.HUE);
    this.setOutput(true, Blockly.Types.TEXT.output);
    this.appendValueInput('VALUE')
        .setCheck(Blockly.Types.TEXT.checkList)
        .appendField(Blockly.Msg.TEXT_CHARAT_INPUT_INTEXT);
    this.appendDummyInput('AT');
    this.setInputsInline(true);
    this.updateAt_(true);
    this.setTooltip(Blockly.Msg.TEXT_CHARAT_TOOLTIP);
  },
  /**
   * Create XML to represent whether there is an 'AT' input.
   * @return {!Element} XML storage element.
   * @this Blockly.Block
   */
  mutationToDom: function() {
    var container = document.createElement('mutation');
    var isAt = this.getInput('AT').type == Blockly.INPUT_VALUE;
    container.setAttribute('at', isAt);
    return container;
  },
  /**
   * Parse XML to restore the 'AT' input.
   * @param {!Element} xmlElement XML storage element.
   * @this Blockly.Block
   */
  domToMutation: function(xmlElement) {
    // Note: Until January 2013 this block did not have mutations,
    // so 'at' defaults to true.
    var isAt = (xmlElement.getAttribute('at') != 'false');
    this.updateAt_(isAt);
  },
  /**
   * Create or delete an input for the numeric index.
   * @param {boolean} isAt True if the input should exist.
   * @private
   * @this Blockly.Block
   */
  updateAt_: function(isAt) {
    // Destroy old 'AT' and 'ORDINAL' inputs.
    this.removeInput('AT');
    this.removeInput('ORDINAL', true);
    // Create either a value 'AT' input or a dummy input.
    if (isAt) {
      this.appendValueInput('AT').setCheck(Blockly.Types.NUMBER.checkList);
      if (Blockly.Msg.ORDINAL_NUMBER_SUFFIX) {
        this.appendDummyInput('ORDINAL')
            .appendField(Blockly.Msg.ORDINAL_NUMBER_SUFFIX);
      }
    } else {
      this.appendDummyInput('AT');
    }
    if (Blockly.Msg.TEXT_CHARAT_TAIL) {
      this.removeInput('TAIL', true);
      this.appendDummyInput('TAIL')
          .appendField(Blockly.Msg.TEXT_CHARAT_TAIL);
    }
    var menu = new Blockly.FieldDropdown(this.WHERE_OPTIONS, function(value) {
      var newAt = (value == 'FROM_START') || (value == 'FROM_END');
      // The 'isAt' variable is available due to this function being a closure.
      if (newAt != isAt) {
        var block = this.sourceBlock_;
        block.updateAt_(newAt);
        // This menu has been destroyed and replaced.  Update the replacement.
        block.setFieldValue(value, 'WHERE');
        return null;
      }
      return undefined;
    });
    this.getInput('AT').appendField(menu, 'WHERE');
  }
};

Blockly.Blocks['text_getSubstring'] = {
  /**
   * Block for getting substring.
   * @this Blockly.Block
   */
  init: function() {
    this['WHERE_OPTIONS_1'] =
        [[Blockly.Msg.TEXT_GET_SUBSTRING_START_FROM_START, 'FROM_START'],
         [Blockly.Msg.TEXT_GET_SUBSTRING_START_FROM_END, 'FROM_END'],
         [Blockly.Msg.TEXT_GET_SUBSTRING_START_FIRST, 'FIRST']];
    this['WHERE_OPTIONS_2'] =
        [[Blockly.Msg.TEXT_GET_SUBSTRING_END_FROM_START, 'FROM_START'],
         [Blockly.Msg.TEXT_GET_SUBSTRING_END_FROM_END, 'FROM_END'],
         [Blockly.Msg.TEXT_GET_SUBSTRING_END_LAST, 'LAST']];
    this.setHelpUrl(Blockly.Msg.TEXT_GET_SUBSTRING_HELPURL);
    this.setColour(Blockly.Blocks.texts.HUE);
    this.appendValueInput('STRING')
        .setCheck(Blockly.Types.TEXT.checkList)
        .appendField(Blockly.Msg.TEXT_GET_SUBSTRING_INPUT_IN_TEXT);
    this.appendDummyInput('AT1');
    this.appendDummyInput('AT2');
    if (Blockly.Msg.TEXT_GET_SUBSTRING_TAIL) {
      this.appendDummyInput('TAIL')
          .appendField(Blockly.Msg.TEXT_GET_SUBSTRING_TAIL);
    }
    this.setInputsInline(true);
    this.setOutput(true, Blockly.Types.TEXT.output);
    this.updateAt_(1, true);
    this.updateAt_(2, true);
    this.setTooltip(Blockly.Msg.TEXT_GET_SUBSTRING_TOOLTIP);
  },
  /**
   * Create XML to represent whether there are 'AT' inputs.
   * @return {!Element} XML storage element.
   * @this Blockly.Block
   */
  mutationToDom: function() {
    var container = document.createElement('mutation');
    var isAt1 = this.getInput('AT1').type == Blockly.INPUT_VALUE;
    container.setAttribute('at1', isAt1);
    var isAt2 = this.getInput('AT2').type == Blockly.INPUT_VALUE;
    container.setAttribute('at2', isAt2);
    return container;
  },
  /**
   * Parse XML to restore the 'AT' inputs.
   * @param {!Element} xmlElement XML storage element.
   * @this Blockly.Block
   */
  domToMutation: function(xmlElement) {
    var isAt1 = (xmlElement.getAttribute('at1') == 'true');
    var isAt2 = (xmlElement.getAttribute('at2') == 'true');
    this.updateAt_(1, isAt1);
    this.updateAt_(2, isAt2);
  },
  /**
   * Create or delete an input for a numeric index.
   * This block has two such inputs, independant of each other.
   * @param {number} n Specify first or second input (1 or 2).
   * @param {boolean} isAt True if the input should exist.
   * @private
   * @this Blockly.Block
   */
  updateAt_: function(n, isAt) {
    // Create or delete an input for the numeric index.
    // Destroy old 'AT' and 'ORDINAL' inputs.
    this.removeInput('AT' + n);
    this.removeInput('ORDINAL' + n, true);
    // Create either a value 'AT' input or a dummy input.
    if (isAt) {
      this.appendValueInput('AT' + n).setCheck(Blockly.Types.NUMBER.checkList);
      if (Blockly.Msg.ORDINAL_NUMBER_SUFFIX) {
        this.appendDummyInput('ORDINAL' + n)
            .appendField(Blockly.Msg.ORDINAL_NUMBER_SUFFIX);
      }
    } else {
      this.appendDummyInput('AT' + n);
    }
    // Move tail, if present, to end of block.
    if (n == 2 && Blockly.Msg.TEXT_GET_SUBSTRING_TAIL) {
      this.removeInput('TAIL', true);
      this.appendDummyInput('TAIL')
          .appendField(Blockly.Msg.TEXT_GET_SUBSTRING_TAIL);
    }
    var menu = new Blockly.FieldDropdown(this['WHERE_OPTIONS_' + n],
        function(value) {
      var newAt = (value == 'FROM_START') || (value == 'FROM_END');
      // The 'isAt' variable is available due to this function being a closure.
      if (newAt != isAt) {
        var block = this.sourceBlock_;
        block.updateAt_(n, newAt);
        // This menu has been destroyed and replaced.  Update the replacement.
        block.setFieldValue(value, 'WHERE' + n);
        return null;
      }
      return undefined;
    });
    this.getInput('AT' + n)
        .appendField(menu, 'WHERE' + n);
    if (n == 1) {
      this.moveInputBefore('AT1', 'AT2');
    }
  }
};

Blockly.Blocks['text_changeCase'] = {
  /**
   * Block for changing capitalization.
   * @this Blockly.Block
   */
  init: function() {
    var OPERATORS =
        [[Blockly.Msg.TEXT_CHANGECASE_OPERATOR_UPPERCASE, 'UPPERCASE'],
         [Blockly.Msg.TEXT_CHANGECASE_OPERATOR_LOWERCASE, 'LOWERCASE'],
         [Blockly.Msg.TEXT_CHANGECASE_OPERATOR_TITLECASE, 'TITLECASE']];
    this.setHelpUrl(Blockly.Msg.TEXT_CHANGECASE_HELPURL);
    this.setColour(Blockly.Blocks.texts.HUE);
    this.appendValueInput('TEXT')
        .setCheck(Blockly.Types.TEXT.checkList)
        .appendField(new Blockly.FieldDropdown(OPERATORS), 'CASE');
    this.setOutput(true, Blockly.Types.TEXT.output);
    this.setTooltip(Blockly.Msg.TEXT_CHANGECASE_TOOLTIP);
  }
};

Blockly.Blocks['text_trim'] = {
  /**
   * Block for trimming spaces.
   * @this Blockly.Block
   */
  init: function() {
    var OPERATORS =
        [[Blockly.Msg.TEXT_TRIM_OPERATOR_BOTH, 'BOTH'],
         [Blockly.Msg.TEXT_TRIM_OPERATOR_LEFT, 'LEFT'],
         [Blockly.Msg.TEXT_TRIM_OPERATOR_RIGHT, 'RIGHT']];
    this.setHelpUrl(Blockly.Msg.TEXT_TRIM_HELPURL);
    this.setColour(Blockly.Blocks.texts.HUE);
    this.appendValueInput('TEXT')
        .setCheck(Blockly.Types.TEXT.checkList)
        .appendField(new Blockly.FieldDropdown(OPERATORS), 'MODE');
    this.setOutput(true, Blockly.Types.TEXT.output);
    this.setTooltip(Blockly.Msg.TEXT_TRIM_TOOLTIP);
  },
  /** Assigns a type to the block, trim always takes and returns a string. */
  getBlockType: function() {
    return Blockly.Types.TEXT;
  }
};

Blockly.Blocks['text_print'] = {
  /**
   * Block for print statement.
   * @this Blockly.Block
   */
  init: function() {
    this.jsonInit({
      "message0": Blockly.Msg.TEXT_PRINT_TITLE,
      "args0": [
        {
          "type": "input_value",
          "name": "TEXT"
        }
      ],
      "previousStatement": null,
      "nextStatement": null,
      "colour": Blockly.Blocks.texts.HUE,
      "tooltip": Blockly.Msg.TEXT_PRINT_TOOLTIP,
      "helpUrl": Blockly.Msg.TEXT_PRINT_HELPURL
    });
  }
};

Blockly.Blocks['text_prompt_ext'] = {
  /**
   * Block for prompt function (external message).
   * @this Blockly.Block
   */
  init: function() {
    var TYPES =
        [[Blockly.Msg.TEXT_PROMPT_TYPE_TEXT, Blockly.Types.TEXT.output],
         [Blockly.Msg.TEXT_PROMPT_TYPE_NUMBER, Blockly.Types.NUMBER.output]];
    this.setHelpUrl(Blockly.Msg.TEXT_PROMPT_HELPURL);
    this.setColour(Blockly.Blocks.texts.HUE);
    // Assign 'this' to a variable for use in the closures below.
    var thisBlock = this;
    var dropdown = new Blockly.FieldDropdown(TYPES, function(newOp) {
      thisBlock.updateType_(newOp);
    });
    this.appendValueInput('TEXT')
        .appendField(dropdown, 'TYPE');
    this.setOutput(true, Blockly.Types.TEXT.output);
    this.setTooltip(function() {
      return (thisBlock.getFieldValue('TYPE') == Blockly.Types.TEXT.output) ?
          Blockly.Msg.TEXT_PROMPT_TOOLTIP_TEXT :
          Blockly.Msg.TEXT_PROMPT_TOOLTIP_NUMBER;
    });
  },
  /**
   * Modify this block to have the correct output type.
   * @param {string} newOp Either 'TEXT' or 'NUMBER'.
   * @private
   * @this Blockly.Block
   */
  updateType_: function(newOp) {
    this.outputConnection.setCheck(newOp == Blockly.Types.NUMBER.output ?
        Blockly.Types.NUMBER.checkList : Blockly.Types.TEXT.checkList);
  },
  /**
   * Create XML to represent the output type.
   * @return {!Element} XML storage element.
   * @this Blockly.Block
   */
  mutationToDom: function() {
    var container = document.createElement('mutation');
    container.setAttribute('type', this.getFieldValue('TYPE'));
    return container;
  },
  /**
   * Parse XML to restore the output type.
   * @param {!Element} xmlElement XML storage element.
   * @this Blockly.Block
   */
  domToMutation: function(xmlElement) {
    this.updateType_(xmlElement.getAttribute('type'));
  },
  /** @return {!string} Type of the block, prompt always returns a string. */
  getBlockType: function() {
    return (this.getFieldValue('TYPE') == Blockly.Types.TEXT.output) ?
        Blockly.Types.TEXT : Blockly.Types.NUMBER;
  }
};

Blockly.Blocks['text_prompt'] = {
  /**
   * Block for prompt function (internal message).
   * The 'text_prompt_ext' block is preferred as it is more flexible.
   * @this Blockly.Block
   */
  init: function() {
    var TYPES =
        [[Blockly.Msg.TEXT_PROMPT_TYPE_TEXT, Blockly.Types.TEXT.output],
         [Blockly.Msg.TEXT_PROMPT_TYPE_NUMBER, Blockly.Types.NUMBER.output]];
    // Assign 'this' to a variable for use in the closure below.
    var thisBlock = this;
    this.setHelpUrl(Blockly.Msg.TEXT_PROMPT_HELPURL);
    this.setColour(Blockly.Blocks.texts.HUE);
    var dropdown = new Blockly.FieldDropdown(TYPES, function(newOp) {
      thisBlock.updateType_(newOp);
    });
    this.appendDummyInput()
        .appendField(dropdown, 'TYPE')
        .appendField(this.newQuote_(true))
        .appendField(new Blockly.FieldTextInput(''), 'TEXT')
        .appendField(this.newQuote_(false));
    this.setOutput(true, Blockly.Types.TEXT.output);
    this.setTooltip(function() {
      return (thisBlock.getFieldValue('TYPE') == Blockly.Types.TEXT.output) ?
          Blockly.Msg.TEXT_PROMPT_TOOLTIP_TEXT :
          Blockly.Msg.TEXT_PROMPT_TOOLTIP_NUMBER;
    });
  },
  newQuote_: Blockly.Blocks['text'].newQuote_,
  updateType_: Blockly.Blocks['text_prompt_ext'].updateType_,
  mutationToDom: Blockly.Blocks['text_prompt_ext'].mutationToDom,
  domToMutation: Blockly.Blocks['text_prompt_ext'].domToMutation,
  /** Assigns a type to the block, prompt always returns a string. */
  getBlockType: function() {
    return (this.getFieldValue('TYPE') == Blockly.Types.NUMBER.output) ?
        Blockly.Types.NUMBER : Blockly.Types.TEXT;
  }
};
