/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Eclipse Public License, Version 1.0 (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.eclipse.org/org/documents/epl-v10.php
 *
 * 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.android.ide.eclipse.adt.internal.editors.ui.tree;

import com.android.ide.eclipse.adt.AdtPlugin;
import com.android.ide.eclipse.adt.internal.editors.AndroidXmlEditor;
import com.android.ide.eclipse.adt.internal.editors.uimodel.UiDocumentNode;
import com.android.ide.eclipse.adt.internal.editors.uimodel.UiElementNode;

import org.eclipse.jface.action.Action;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.swt.dnd.Clipboard;
import org.eclipse.swt.dnd.TextTransfer;
import org.eclipse.ui.ISharedImages;
import org.eclipse.ui.PlatformUI;
import org.eclipse.wst.sse.core.internal.provisional.IndexedRegion;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocument;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocumentRegion;
import org.eclipse.wst.xml.core.internal.document.NodeContainer;
import org.w3c.dom.Node;


/**
 * Provides Paste operation for the tree nodes
 */
@SuppressWarnings("restriction")
public class PasteAction extends Action {
    private UiElementNode mUiNode;
    private final AndroidXmlEditor mEditor;
    private final Clipboard mClipboard;

    public PasteAction(AndroidXmlEditor editor, Clipboard clipboard, UiElementNode ui_node) {
        super("Paste");
        mEditor = editor;
        mClipboard = clipboard;

        ISharedImages images = PlatformUI.getWorkbench().getSharedImages();
        setImageDescriptor(images.getImageDescriptor(ISharedImages.IMG_TOOL_PASTE));
        setHoverImageDescriptor(images.getImageDescriptor(ISharedImages.IMG_TOOL_PASTE));
        setDisabledImageDescriptor(
                images.getImageDescriptor(ISharedImages.IMG_TOOL_PASTE_DISABLED));

        mUiNode = ui_node;
    }

    /**
     * Performs the paste operation.
     */
    @Override
    public void run() {
        super.run();

        final String data = (String) mClipboard.getContents(TextTransfer.getInstance());
        if (data != null) {
            mEditor.wrapEditXmlModel(new Runnable() {
                @Override
                public void run() {
                    try {
                        IStructuredDocument sse_doc = mEditor.getStructuredDocument();
                        if (sse_doc != null) {
                            if (mUiNode.getDescriptor().hasChildren()) {
                                // This UI Node can have children. The new XML is
                                // inserted as the first child.

                                if (mUiNode.getUiChildren().size() > 0) {
                                    // There's already at least one child,
                                    // so insert right before it.
                                    Node xml_node = mUiNode.getUiChildren().get(0).getXmlNode();

                                    if (xml_node instanceof IndexedRegion) {
                                        IndexedRegion region = (IndexedRegion) xml_node;
                                        sse_doc.replace(region.getStartOffset(), 0, data);
                                        return; // we're done, no need to try the other cases
                                    }
                                }

                                // If there's no first XML node child. Create one by
                                // inserting at the end of the *start* tag.
                                Node xml_node = mUiNode.getXmlNode();
                                if (xml_node instanceof NodeContainer) {
                                    NodeContainer container = (NodeContainer) xml_node;
                                    IStructuredDocumentRegion start_tag =
                                        container.getStartStructuredDocumentRegion();
                                    if (start_tag != null) {
                                        sse_doc.replace(start_tag.getEndOffset(), 0, data);
                                        return; // we're done, no need to try the other case
                                    }
                                }
                            }

                            // This UI Node doesn't accept children. The new XML is inserted as the
                            // next sibling. This also serves as a fallback if all the previous
                            // attempts failed. However, this is not possible if the current node
                            // has for parent a document -- an XML document can only have one root,
                            // with no siblings.
                            if (!(mUiNode.getUiParent() instanceof UiDocumentNode)) {
                                Node xml_node = mUiNode.getXmlNode();
                                if (xml_node instanceof IndexedRegion) {
                                    IndexedRegion region = (IndexedRegion) xml_node;
                                    sse_doc.replace(region.getEndOffset(), 0, data);
                                }
                            }
                        }

                    } catch (BadLocationException e) {
                        AdtPlugin.log(e,
                                "ParseAction failed for UI Node %2$s, content '%1$s'", //$NON-NLS-1$
                                mUiNode.getBreadcrumbTrailDescription(true), data);
                    }
                }
            });
        }
    }
}