/*******************************************************************************
 * Copyright (c) 2013, 2015 Tasktop Technologies, Ericsson and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Tasktop Technologies - initial API and implementation
 *     Sam Davis - improvements for bug 383592
 *******************************************************************************/

package org.eclipse.mylyn.reviews.ui.spi.editor;

import java.text.DateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.eclipse.jface.layout.GridDataFactory;
import org.eclipse.jface.layout.GridLayoutFactory;
import org.eclipse.jface.layout.LayoutConstants;
import org.eclipse.jface.viewers.ColumnViewerToolTipSupport;
import org.eclipse.jface.viewers.DelegatingStyledCellLabelProvider;
import org.eclipse.jface.viewers.IOpenListener;
import org.eclipse.jface.viewers.ITreeSelection;
import org.eclipse.jface.viewers.ITreeViewerListener;
import org.eclipse.jface.viewers.OpenEvent;
import org.eclipse.jface.viewers.TreeExpansionEvent;
import org.eclipse.jface.viewers.TreePath;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.window.ToolTip;
import org.eclipse.mylyn.commons.ui.compatibility.CommonColors;
import org.eclipse.mylyn.commons.workbench.forms.ScalingHyperlink;
import org.eclipse.mylyn.internal.reviews.ui.providers.ReviewsLabelProvider;
import org.eclipse.mylyn.internal.tasks.ui.editors.EditorUtil;
import org.eclipse.mylyn.reviews.core.model.IComment;
import org.eclipse.mylyn.reviews.core.model.ICommit;
import org.eclipse.mylyn.reviews.core.model.IFileItem;
import org.eclipse.mylyn.reviews.core.model.ILocation;
import org.eclipse.mylyn.reviews.core.model.IRepository;
import org.eclipse.mylyn.reviews.core.model.IReview;
import org.eclipse.mylyn.reviews.core.model.IReviewItemSet;
import org.eclipse.mylyn.reviews.core.spi.remote.emf.RemoteEmfConsumer;
import org.eclipse.mylyn.reviews.core.spi.remote.emf.RemoteEmfObserver;
import org.eclipse.mylyn.reviews.internal.core.ReviewFileCommentsMapper;
import org.eclipse.mylyn.reviews.internal.core.TaskBuildStatusMapper;
import org.eclipse.mylyn.tasks.core.data.TaskAttribute;
import org.eclipse.mylyn.tasks.ui.editors.AbstractAttributeEditor;
import org.eclipse.mylyn.tasks.ui.editors.AbstractTaskEditorPage;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Text;
import org.eclipse.swt.widgets.TreeItem;
import org.eclipse.ui.forms.FormColors;
import org.eclipse.ui.forms.IFormColors;
import org.eclipse.ui.forms.events.ExpansionAdapter;
import org.eclipse.ui.forms.events.ExpansionEvent;
import org.eclipse.ui.forms.events.HyperlinkAdapter;
import org.eclipse.ui.forms.events.HyperlinkEvent;
import org.eclipse.ui.forms.widgets.ExpandableComposite;
import org.eclipse.ui.forms.widgets.Section;

/**
 * @author Steffen Pingel
 * @author Miles Parker
 * @author Sam Davis
 */
@SuppressWarnings("restriction")
public class ReviewSetContentSection {

	private static final int MAXIMUM_ITEMS_SHOWN = 30;

	private final ReviewSetSection parentSection;

	private final IReviewItemSet set;

	private final Section section;

	private TreeViewer viewer;

	private final RemoteEmfObserver<IReviewItemSet, List<IFileItem>, String, Long> itemListObserver = new RemoteEmfObserver<IReviewItemSet, List<IFileItem>, String, Long>() {

		@Override
		public void updated(boolean modified) {
			createItemSetTable();
			updateItemSetTable();
			updateMessage();
			createButtons();
		}

		@Override
		public void updating() {
			updateMessage();
		}
	};

	private final RemoteEmfConsumer<IReviewItemSet, List<IFileItem>, String, ?, ?, Long> itemSetConsumer;

	private Composite treeContainer;

	private Composite actionContainer;

	private final RemoteEmfObserver<IRepository, IReview, String, Date> reviewObserver;

	private final AbstractTaskEditorPage page;

	public ReviewSetContentSection(ReviewSetSection parentSection, final IReviewItemSet set,
			AbstractTaskEditorPage page) {
		this.parentSection = parentSection;
		this.set = set;
		this.page = page;
		int style = ExpandableComposite.TWISTIE | ExpandableComposite.CLIENT_INDENT
				| ExpandableComposite.LEFT_TEXT_CLIENT_ALIGNMENT;
		section = parentSection.getToolkit().createSection(parentSection.getComposite(), style);
		GridDataFactory.fillDefaults().grab(true, false).applyTo(section);
		section.setText(set.getName());
		section.setTitleBarForeground(parentSection.getToolkit().getColors().getColor(IFormColors.TITLE));

		parentSection.addTextClient(parentSection.getToolkit(), section, "", false); //$NON-NLS-1$
		itemSetConsumer = getParentSection().getReviewEditorPage()
				.getFactoryProvider()
				.getReviewItemSetContentFactory()
				.getConsumerForLocalKey(set, set.getId());
		itemListObserver.setConsumer(itemSetConsumer);
		final RemoteEmfConsumer<IRepository, IReview, String, ?, ?, Date> reviewConsumer = getParentSection()
				.getReviewEditorPage().getFactoryProvider().getReviewFactory().getConsumerForModel(
						set.getReview().getRepository(), set.getReview());
		reviewObserver = new RemoteEmfObserver<IRepository, IReview, String, Date>() {
			@Override
			public void updated(boolean modified) {
				if (reviewConsumer.getRemoteObject() != null && section.isExpanded() && modified) {
					itemSetConsumer.retrieve(false);
					updateMessage();
					createButtons();
				}
			}
		};
		reviewConsumer.addObserver(reviewObserver);

		section.addExpansionListener(new ExpansionAdapter() {
			@Override
			public void expansionStateChanged(ExpansionEvent e) {
				if (e.getState()) {
					if (set.getItems().isEmpty()) {
						itemSetConsumer.retrieve(false);
					}
					updateMessage();
					createButtons();
				}
			}
		});

		createMainSection();
		createItemSetTable();
		updateItemSetTable();
		updateMessage();
	}

	public void updateMessage() {
		if (section.isDisposed()) {
			return;
		}
		String message;

		if (itemListObserver.getConsumer().getStatus().isOK()) {
			String time = DateFormat.getDateTimeInstance().format(set.getCreationDate());
			int numComments = set.getAllComments().size();
			if (numComments > 0) {
				message = NLS.bind(Messages.ReviewSetContentSection_X_comma_Y_Comments, time, numComments);
			} else {
				message = time;
			}
			if (itemListObserver != null && itemListObserver.getConsumer().isRetrieving()) {
				message += " " + Messages.Reviews_RetrievingContents; //$NON-NLS-1$
			}
		} else {
			message = NLS.bind(Messages.Reviews_UpdateFailure_X,
					itemListObserver.getConsumer().getStatus().getMessage());
		}

		AbstractReviewSection.appendMessage(getSection(), message);
	}

	void createMainSection() {
		Composite composite = parentSection.getToolkit().createComposite(section);
		GridLayoutFactory.fillDefaults().numColumns(2).spacing(60, LayoutConstants.getSpacing().y).applyTo(composite);
		Composite leftColumn = parentSection.getToolkit().createComposite(composite);
		GridLayoutFactory.fillDefaults().numColumns(2).applyTo(leftColumn);
		Composite rightColumn = parentSection.getToolkit().createComposite(composite);
		GridLayoutFactory.fillDefaults().numColumns(2).applyTo(rightColumn);
		section.setClient(composite);
		FormColors colors = parentSection.getToolkit().getColors();

		createAuthorLabel(leftColumn, colors);
		createCommitterLabel(leftColumn, colors);
		createCommitLink(rightColumn, colors);
		createRefLabel(rightColumn, colors);
		createParentsLinks(composite, colors);

		TaskAttribute buildAttribute = parentSection.getTaskData().getRoot().getAttribute("PATCH_SET-" + set.getId()); //$NON-NLS-1$
		if (buildAttribute != null) {
			Composite buildComposite = parentSection.getToolkit().createComposite(composite);
			GridLayoutFactory.fillDefaults().numColumns(2).applyTo(buildComposite);
			GridDataFactory.fillDefaults().span(2, 1).applyTo(buildComposite);
			AbstractAttributeEditor editor = parentSection.getTaskEditorPage()
					.getAttributeEditorFactory()
					.createEditor(TaskBuildStatusMapper.BUILD_RESULT_TYPE, buildAttribute);
			editor.createLabelControl(buildComposite, parentSection.getToolkit());
			editor.createControl(buildComposite, parentSection.getToolkit());
			getTaskEditorPage().getAttributeEditorToolkit().adapt(editor);
		}

		treeContainer = new Composite(composite, SWT.NONE);
		treeContainer.setBackground(Display.getCurrent().getSystemColor(SWT.COLOR_DARK_GRAY));
		GridDataFactory.fillDefaults().span(4, 1).grab(true, true).applyTo(treeContainer);
		GridLayoutFactory.fillDefaults().numColumns(2).applyTo(treeContainer);

		actionContainer = new Composite(composite, SWT.NONE);
		GridDataFactory.fillDefaults().span(4, 1).grab(true, true).applyTo(actionContainer);
		GridLayoutFactory.fillDefaults().numColumns(4).applyTo(actionContainer);
		createButtons();

		reflow();
	}

	private AbstractTaskEditorPage getTaskEditorPage() {
		return page;
	}

	private void createAuthorLabel(Composite composite, FormColors colors) {
		createTitleLabel(composite, colors, Messages.ReviewSetContentSection_Author, SWT.NONE);

		Text authorText = new Text(composite, SWT.READ_ONLY);
		if (set.getAddedBy() != null) {
			authorText.setText(set.getAddedBy().getDisplayName());
		} else {
			authorText.setText(Messages.ReviewSetContentSection_Unspecified);
		}
	}

	private void createCommitterLabel(Composite composite, FormColors colors) {
		Label committerLabel = new Label(composite, SWT.NONE);
		committerLabel.setForeground(colors.getColor(IFormColors.TITLE));
		committerLabel.setText(Messages.ReviewSetContentSection_Committer);

		Text committerText = new Text(composite, SWT.READ_ONLY);
		if (set.getCommittedBy() != null) {
			committerText.setText(set.getCommittedBy().getDisplayName());
		} else {
			committerText.setText(Messages.ReviewSetContentSection_Unspecified);
		}
	}

	private void createCommitLink(Composite composite, FormColors colors) {
		Label commitLabel = new Label(composite, SWT.NONE);
		commitLabel.setForeground(colors.getColor(IFormColors.TITLE));
		commitLabel.setText(Messages.ReviewSetContentSection_Commit);

		ScalingHyperlink commitLink = new ScalingHyperlink(composite, SWT.READ_ONLY);
		commitLink.setText(set.getRevision());
		commitLink.setForeground(CommonColors.HYPERLINK_WIDGET);
		commitLink.registerMouseTrackListener();
		commitLink.addHyperlinkListener(new HyperlinkAdapter() {
			@Override
			public void linkActivated(HyperlinkEvent event) {
				getParentSection().getUiFactoryProvider()
						.getOpenCommitFactory(ReviewSetContentSection.this.getParentSection(), set)
						.execute();
			}
		});
	}

	private void createRefLabel(Composite composite, FormColors colors) {
		Label refLabel = new Label(composite, SWT.NONE);
		refLabel.setForeground(colors.getColor(IFormColors.TITLE));
		refLabel.setText(Messages.ReviewSetContentSection_Ref);

		Text refText = new Text(composite, SWT.READ_ONLY);
		refText.setText(set.getReference());
	}

	private void createParentsLinks(Composite composite, FormColors colors) {
		if (set.getParentCommits().isEmpty()) {
			return;// for Gerrit versions earlier than 2.8 we don't support getting the parents
		}
		Composite parentsComposite = new Composite(composite, SWT.NONE);
		GridLayoutFactory.fillDefaults().numColumns(3).applyTo(parentsComposite);
		GridDataFactory.fillDefaults().span(2, 1).applyTo(parentsComposite);
		Label parentsLabel = new Label(parentsComposite, SWT.NONE);
		parentsLabel.setForeground(colors.getColor(IFormColors.TITLE));
		parentsLabel.setText(Messages.ReviewSetContentSection_Parents);

		final List<String> parentCommitIds = new ArrayList<String>();
		for (ICommit commit : set.getParentCommits()) {
			parentCommitIds.add(commit.getId());
		}

		ScalingHyperlink parentOne = new ScalingHyperlink(parentsComposite, SWT.READ_ONLY);
		GridDataFactory.fillDefaults().indent(13, 0).applyTo(parentOne);
		if (parentCommitIds.size() > 0) {
			addParentCommitHyperlink(parentOne, parentCommitIds.get(0));
		}

		if (parentCommitIds.size() == 2 && parentCommitIds.get(1) != null) {
			ScalingHyperlink parentTwo = new ScalingHyperlink(parentsComposite, SWT.READ_ONLY);
			addParentCommitHyperlink(parentTwo, parentCommitIds.get(1));
		}
	}

	private void addParentCommitHyperlink(ScalingHyperlink commit, final String commitId) {
		commit.setText(commitId);
		commit.setForeground(CommonColors.HYPERLINK_WIDGET);
		commit.registerMouseTrackListener();
		commit.addHyperlinkListener(new HyperlinkAdapter() {
			@Override
			public void linkActivated(HyperlinkEvent event) {
				getParentSection().getUiFactoryProvider()
						.getOpenParentCommitFactory(ReviewSetContentSection.this.getParentSection(), set, commitId)
						.execute();
			}
		});
	}

	private Label createTitleLabel(Composite composite, FormColors colors, String text, int style) {
		Label titleLabel = new Label(composite, style);
		titleLabel.setForeground(colors.getColor(IFormColors.TITLE));
		titleLabel.setText(text);
		return titleLabel;
	}

	public void createItemSetTable() {
		if (viewer == null && !set.getItems().isEmpty()) {

			boolean fixedViewerSize = set.getItems().size() > MAXIMUM_ITEMS_SHOWN;
			int heightHint = fixedViewerSize ? 300 : SWT.DEFAULT;
			int style = SWT.SINGLE | SWT.BORDER | SWT.VIRTUAL;
			if (fixedViewerSize) {
				style |= SWT.V_SCROLL;
			} else {
				style |= SWT.NO_SCROLL;
			}
			viewer = new TreeViewer(treeContainer, style);
			GridDataFactory.fillDefaults()
					.span(2, 1)
					.grab(true, true)
					.hint(500, heightHint)
					.applyTo(viewer.getControl());

			final ReviewSetContentProvider contentProvider = new ReviewSetContentProvider();
			viewer.setContentProvider(contentProvider);

			ColumnViewerToolTipSupport.enableFor(viewer, ToolTip.NO_RECREATE);

			final DelegatingStyledCellLabelProvider styledLabelProvider = new DelegatingStyledCellLabelProvider(
					new ReviewsLabelProvider.Tree(true)) {
				@Override
				public String getToolTipText(Object element) {
					//For some reason tooltips are not delegated..
					return ReviewsLabelProvider.ITEMS_COLUMN.getToolTipText(element);
				};
			};
			viewer.setLabelProvider(styledLabelProvider);
			viewer.addOpenListener(new IOpenListener() {
				public void open(OpenEvent event) {
					ITreeSelection selection = (ITreeSelection) event.getSelection();
					TreePath[] paths = selection.getPaths();
					for (TreePath path : paths) {
						IFileItem file = null;
						IComment comment = null;
						for (int i = 0; i < path.getSegmentCount(); i++) {
							Object o = path.getSegment(i);
							if (o instanceof IFileItem) {
								file = (IFileItem) o;
							} else if (o instanceof ILocation) {
								Object[] children = contentProvider.getChildren(o);
								if (children.length > 0 && children[0] instanceof IComment) {
									comment = (IComment) children[0];
								}
							} else if (o instanceof IComment) {
								comment = (IComment) o;
							}
						}
						if (file != null && comment != null) {
							getParentSection().getUiFactoryProvider()
									.getOpenFileToCommentFactory(ReviewSetContentSection.this.getParentSection(), set,
											file, comment)
									.execute();
						} else if (file != null) {
							getParentSection().getUiFactoryProvider()
									.getOpenFileFactory(ReviewSetContentSection.this.getParentSection(), set, file)
									.execute();
						}
					}
				}
			});
			EditorUtil.addScrollListener(viewer.getTree());
			viewer.setInput(set);
			viewer.addTreeListener(new ITreeViewerListener() {

				@Override
				public void treeExpanded(TreeExpansionEvent event) {
					reflowAsync();
				}

				@Override
				public void treeCollapsed(TreeExpansionEvent event) {
					reflowAsync();
				}
			});
		}
	}

	private void updateItemSetTable() {
		if (set.getItems().size() > 0 && hasViewer()) {
			viewer.setInput(set);
			TaskAttribute fileComments = ReviewSetContentSection.this.page.getModel()
					.getTaskData()
					.getRoot()
					.getAttribute(ReviewFileCommentsMapper.FILE_ITEM_COMMENTS);

			final Set<IComment> toHighlight = new HashSet<IComment>();
			if (fileComments != null) {
				List<IFileItem> files = itemSetConsumer.getModelObject();
				for (IFileItem file : files) {
					for (IComment comment : file.getAllComments()) {
						if (fileComments.getAttribute(comment.getId()) == null) {
							toHighlight.add(comment);
						}
					}
				}
			}

			Display.getDefault().asyncExec(new Runnable() {

				@Override
				public void run() {
					if (hasViewer()) {
						viewer.refresh();
						viewer.expandAll();
						decorateItems(viewer.getTree().getItems(), toHighlight);
						reflow();
					}
				}
			});
		}
	}

	private void decorateItems(TreeItem[] items, Set<IComment> toHighlight) {
		for (TreeItem item : items) {
			if (toHighlight.contains(item.getData())) {
				item.setBackground(getTaskEditorPage().getAttributeEditorToolkit().getColorIncoming());
			}
			decorateItems(item.getItems(), toHighlight);
		}
	}

	public void createButtons() {
		if (!actionContainer.isDisposed()) {
			for (Control oldActionControl : actionContainer.getChildren()) {
				oldActionControl.dispose();
			}
			getParentSection().getUiFactoryProvider().createControls(getParentSection(), actionContainer,
					getParentSection().getToolkit(), set);
			actionContainer.layout();
			reflow();
		}
	}

	public Section getSection() {
		return section;
	}

	public ReviewSetSection getParentSection() {
		return parentSection;
	}

	private void reflowAsync() {
		Display.getDefault().asyncExec(new Runnable() {

			@Override
			public void run() {
				reflow();
			}
		});
	}

	private void reflow() {
		getParentSection().getTaskEditorPage().reflow();
	}

	private boolean hasViewer() {
		return viewer != null && !viewer.getControl().isDisposed();
	}

	public void dispose() {
		itemListObserver.dispose();
		reviewObserver.dispose();
		section.dispose();
	}
}