// Copyright 2012 Google Inc. All Rights Reserved.
//
// 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.

package com.google.collide.client.editor;

import com.google.collide.client.editor.input.CommonActions;
import com.google.collide.client.editor.input.DefaultActionExecutor;
import com.google.collide.client.editor.input.InputScheme;
import com.google.collide.client.editor.input.Shortcut;
import com.google.collide.client.editor.selection.SelectionModel;
import com.google.collide.shared.document.Line;
import com.google.collide.shared.document.LineInfo;
import com.google.collide.shared.document.Position;
import com.google.collide.shared.document.util.LineUtils;

import org.waveprotocol.wave.client.common.util.SignalEvent;

/**
 * Implementation of some common textual actions.
 */
public class TextActions extends DefaultActionExecutor {

  public static final TextActions INSTANCE = new TextActions();

  private TextActions() {
    addAction(CommonActions.SPLIT_LINE, new Shortcut(){
      @Override
      public boolean event(InputScheme scheme, SignalEvent event) {
        splitLine(scheme.getInputController().getEditor());
        return true;
      }
    });

    addAction(CommonActions.START_NEW_LINE, new Shortcut(){
      @Override
      public boolean event(InputScheme scheme, SignalEvent event) {
        startNewLine(scheme.getInputController().getEditor());
        return true;
      }
    });
  }

  private void startNewLine(Editor editor) {
    SelectionModel selection = editor.getSelection();
    selection.deselect();
    Line line = selection.getCursorLine();
    int lineNumber = selection.getCursorLineNumber();
    int lastCursorColumn = LineUtils.getLastCursorColumn(line);
    selection.setCursorPosition(new LineInfo(line, lineNumber), lastCursorColumn);
    editor.getEditorDocumentMutator().insertText(line, lineNumber, lastCursorColumn, "\n");
  }

  private void splitLine(Editor editor) {
    // TODO: Add language specific logic (i.e. string splitting).
    SelectionModel selection = editor.getSelection();
    Position[] selectionRange = selection.getSelectionRange(false);
    Position cursor = selectionRange[0];

    editor.getEditorDocumentMutator().insertText(cursor.getLine(), cursor.getLineNumber(),
        cursor.getColumn(), "\n", true);
    selection.setCursorPosition(cursor.getLineInfo(), cursor.getColumn());
  }
}