/*******************************************************************************
 * Copyright (c) 2004, 2012 QNX Software Systems and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     QNX Software Systems - initial API and implementation
 *******************************************************************************/
package org.eclipse.cdt.internal.ui.wizards.classwizard;

import java.util.ArrayList;

import org.eclipse.cdt.core.model.CoreModel;
import org.eclipse.cdt.core.model.ICContainer;
import org.eclipse.cdt.core.model.ICElement;
import org.eclipse.cdt.core.model.ICModel;
import org.eclipse.cdt.core.model.ICProject;
import org.eclipse.cdt.core.model.ITranslationUnit;
import org.eclipse.cdt.internal.corext.util.CModelUtil;
import org.eclipse.cdt.internal.ui.dialogs.StatusInfo;
import org.eclipse.cdt.internal.ui.dialogs.StatusUtil;
import org.eclipse.cdt.internal.ui.dialogs.TypedViewerFilter;
import org.eclipse.cdt.internal.ui.wizards.dialogfields.DialogField;
import org.eclipse.cdt.internal.ui.wizards.dialogfields.IDialogFieldListener;
import org.eclipse.cdt.internal.ui.wizards.dialogfields.LayoutUtil;
import org.eclipse.cdt.internal.ui.wizards.dialogfields.StringDialogField;
import org.eclipse.cdt.ui.CElementContentProvider;
import org.eclipse.cdt.ui.CElementLabelProvider;
import org.eclipse.cdt.ui.CElementSorter;
import org.eclipse.cdt.utils.PathUtil;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IWorkspaceRoot;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Path;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.viewers.DoubleClickEvent;
import org.eclipse.jface.viewers.IDoubleClickListener;
import org.eclipse.jface.viewers.ILabelProvider;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.osgi.util.NLS;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.BusyIndicator;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Tree;
import org.eclipse.ui.dialogs.SelectionStatusDialog;

public class SourceFileSelectionDialog extends SelectionStatusDialog {

	TreeViewer fViewer;
	private final ITreeContentProvider fContentProvider = new CElementContentProvider();
	private final ILabelProvider fLabelProvider = new CElementLabelProvider(CElementLabelProvider.SHOW_DEFAULT);
	IStatus fCurrStatus = new StatusInfo();
	IStatus fFolderNameStatus = new StatusInfo();
	IStatus fFileNameStatus = new StatusInfo();
	ICElement fInput;
	private int fWidth = 60;
	private int fHeight = 18;
	StringDialogField fFolderNameDialogField;
	StringDialogField fFileNameDialogField;
	private IWorkspaceRoot fWorkspaceRoot;
	private final FieldsAdapter fFieldsAdapter = new FieldsAdapter();

	private ICElement fCurrentFolder = null;
	private String fCurrentFileString = null;
	String fInitialFolderName = null;
	String fInitialFileName = null;

	private final class FieldsAdapter extends SelectionAdapter
			implements ISelectionChangedListener, IDoubleClickListener, IDialogFieldListener {

		// -- SelectionAdapter --
		@Override
		public void widgetDefaultSelected(SelectionEvent e) {
			doStatusUpdate();
			if (fCurrStatus.isOK())
				buttonPressed(IDialogConstants.OK_ID);
		}

		// -- ISelectionChangedListener --
		@Override
		public void selectionChanged(SelectionChangedEvent event) {
			setResult(((IStructuredSelection) event.getSelection()).toList());
			ISelection sel = event.getSelection();
			if (sel instanceof IStructuredSelection) {
				Object obj = ((IStructuredSelection) sel).getFirstElement();
				if (obj instanceof ICElement) {
					ICElement elem = (ICElement) obj;
					IPath path = elem.getPath();
					String fileName = fFileNameDialogField.getText();
					String folderName = fFolderNameDialogField.getText();
					if (elem instanceof ICContainer || elem instanceof ICProject) {
						folderName = path.toString();
					} else {
						folderName = path.removeLastSegments(1).toString();
						fileName = path.lastSegment();
					}
					setPathFields(folderName, fileName);
				}
			}
			doStatusUpdate();
		}

		// -- IDoubleClickListener --
		@Override
		public void doubleClick(DoubleClickEvent event) {
			doStatusUpdate();

			ISelection selection = event.getSelection();
			if (selection instanceof IStructuredSelection) {
				Object item = ((IStructuredSelection) selection).getFirstElement();
				if (fCurrStatus.getSeverity() != IStatus.ERROR) {
					if (item instanceof ITranslationUnit) {
						setResult(((IStructuredSelection) selection).toList());
						close();
						return;
					}
				}
				if (fViewer.getExpandedState(item))
					fViewer.collapseToLevel(item, 1);
				else
					fViewer.expandToLevel(item, 1);
			}
		}

		// -- IDialogFieldListener --
		@Override
		public void dialogFieldChanged(DialogField field) {
			if (field == fFolderNameDialogField) {
				fFolderNameStatus = folderNameChanged();
				fFileNameStatus = fileNameChanged();
			} else if (field == fFileNameDialogField) {
				fFileNameStatus = fileNameChanged();
			}
			doStatusUpdate();
		}
	}

	static final Class<?>[] FILTER_TYPES = new Class[] { ICModel.class, ICProject.class, ICContainer.class,
			ITranslationUnit.class };

	private final class Filter extends TypedViewerFilter {

		private Filter() {
			super(FILTER_TYPES);
		}

		@Override
		public boolean select(Viewer viewer, Object parent, Object obj) {
			if (obj instanceof ICElement) {
				ICElement elem = (ICElement) obj;
				if (!(fInput instanceof ICModel)) {
					return elem.getCProject().equals(fInput.getCProject());
				}
				return true;
			}
			return super.select(viewer, parent, obj);
		}
	}

	/**
	 * Constructs an instance of <code>ElementTreeSelectionDialog</code>.
	 *
	 * @param parent
	 *            The parent shell for the dialog
	 */
	public SourceFileSelectionDialog(Shell parent) {
		super(parent);

		fWorkspaceRoot = ResourcesPlugin.getWorkspace().getRoot();
		fInput = CoreModel.create(fWorkspaceRoot);

		fFolderNameDialogField = new StringDialogField();
		fFolderNameDialogField.setDialogFieldListener(fFieldsAdapter);
		fFolderNameDialogField.setLabelText(NewClassWizardMessages.SourceFileSelectionDialog_folderName_label);

		fFileNameDialogField = new StringDialogField();
		fFileNameDialogField.setDialogFieldListener(fFieldsAdapter);
		fFileNameDialogField.setLabelText(NewClassWizardMessages.SourceFileSelectionDialog_fileName_label);

		setResult(new ArrayList<>(0));
		setStatusLineAboveButtons(true);

		int shellStyle = getShellStyle();
		setShellStyle(shellStyle | SWT.MAX | SWT.RESIZE);
	}

	/**
	 * Sets the tree input.
	 *
	 * @param input
	 *            the tree input.
	 */
	public void setInput(ICElement input) {
		fInput = input;
	}

	protected void doStatusUpdate() {
		// status of all used components
		IStatus[] status = new IStatus[] { fFolderNameStatus, fFileNameStatus };

		// the mode severe status will be displayed and the ok button enabled/disabled.
		updateStatus(status);
	}

	/**
	 * Updates the status line and the ok button according to the given status
	 *
	 * @param status status to apply
	 */
	@Override
	protected void updateStatus(IStatus status) {
		fCurrStatus = status;
		super.updateStatus(status);
	}

	/**
	 * Updates the status line and the ok button according to the status evaluate from
	 * an array of status. The most severe error is taken.  In case that two status with
	 * the same severity exists, the status with lower index is taken.
	 *
	 * @param status the array of status
	 */
	protected void updateStatus(IStatus[] status) {
		updateStatus(StatusUtil.getMostSevere(status));
	}

	IStatus folderNameChanged() {
		StatusInfo status = new StatusInfo();

		fCurrentFolder = null;
		String str = fFolderNameDialogField.getText();
		if (str.length() == 0) {
			status.setError(NewClassWizardMessages.SourceFileSelectionDialog_error_EnterFolderName);
			return status;
		}

		IPath path = new Path(str);
		IResource res = fWorkspaceRoot.findMember(path);
		if (res != null && res.exists()) {
			int resType = res.getType();
			if (resType == IResource.PROJECT || resType == IResource.FOLDER) {
				IProject proj = res.getProject();
				if (!proj.isOpen()) {
					status.setError(NLS.bind(NewClassWizardMessages.SourceFileSelectionDialog_error_NotAFolder, str));
					return status;
				}
				ICElement e = CoreModel.getDefault().create(res.getFullPath());
				fCurrentFolder = CModelUtil.getSourceFolder(e);
				if (fCurrentFolder == null) {
					status.setError(
							NLS.bind(NewClassWizardMessages.SourceFileSelectionDialog_error_NotASourceFolder, str));
					return status;
				}
				if (!CoreModel.hasCCNature(proj) && !CoreModel.hasCNature(proj)) {
					if (resType == IResource.PROJECT) {
						status.setError(NewClassWizardMessages.SourceFileSelectionDialog_warning_NotACProject);
						return status;
					}
					status.setWarning(NewClassWizardMessages.SourceFileSelectionDialog_warning_NotInACProject);
				}
			} else {
				status.setError(NLS.bind(NewClassWizardMessages.SourceFileSelectionDialog_error_NotAFolder, str));
				return status;
			}
		} else {
			status.setError(NLS.bind(NewClassWizardMessages.SourceFileSelectionDialog_error_FolderDoesNotExist, str));
			return status;
		}
		return status;
	}

	IStatus fileNameChanged() {
		StatusInfo status = new StatusInfo();

		fCurrentFileString = null;
		ICElement existingFile = null;
		String str = fFileNameDialogField.getText();
		if (str.length() == 0) {
			status.setError(NewClassWizardMessages.SourceFileSelectionDialog_error_EnterFileName);
			return status;
		}

		if (fCurrentFolder != null) {
			IPath folderPath = fCurrentFolder.getPath();
			IPath path = new Path(str);
			IResource res = fWorkspaceRoot.findMember(folderPath.append(path));
			if (res == null)
				res = fWorkspaceRoot.findMember(path);
			if (res != null && res.exists()) {
				int resType = res.getType();
				if (resType == IResource.FILE) {
					IProject proj = res.getProject();
					if (!proj.isOpen()) {
						status.setError(NLS.bind(NewClassWizardMessages.SourceFileSelectionDialog_error_NotAFile, str));
						return status;
					}
					ICElement e = CoreModel.getDefault().create(res.getFullPath());
					if (e instanceof ITranslationUnit) {
						existingFile = e;
					}
					if (existingFile == null) {
						status.setError(
								NLS.bind(NewClassWizardMessages.SourceFileSelectionDialog_error_NotASourceFile, str));
						return status;
					}
					if (!CoreModel.hasCCNature(proj) && !CoreModel.hasCNature(proj)) {
						status.setWarning(NewClassWizardMessages.SourceFileSelectionDialog_warning_NotInACProject);
					}
				} else {
					status.setError(NLS.bind(NewClassWizardMessages.SourceFileSelectionDialog_error_NotAFile, str));
					return status;
				}
			}
		}
		if (existingFile != null) {
			status.setWarning(NLS.bind(NewClassWizardMessages.SourceFileSelectionDialog_warning_SourceFileExists, str));
		}
		fCurrentFileString = str;
		return status;
	}

	@Override
	public int open() {
		super.open();
		return getReturnCode();
	}

	/**
	 * Handles cancel button pressed event.
	 */
	@Override
	protected void cancelPressed() {
		setResult(null);
		super.cancelPressed();
	}

	/*
	 * @see SelectionStatusDialog#computeResult()
	 */
	@Override
	protected void computeResult() {
		setResult(((IStructuredSelection) fViewer.getSelection()).toList());
	}

	@Override
	public void create() {
		BusyIndicator.showWhile(null, () -> {
			superCreate();
			fViewer.setSelection(new StructuredSelection(getInitialElementSelections()), true);
			setPathFields(fInitialFolderName, fInitialFileName);
			fFileNameDialogField.setFocus();
			doStatusUpdate();
		});
	}

	void superCreate() {
		super.create();
	}

	/*
	 * @see Dialog#createDialogArea(Composite)
	 */
	@Override
	protected Control createDialogArea(Composite parent) {
		Composite composite = (Composite) super.createDialogArea(parent);
		// Label messageLabel = createMessageArea(composite);
		int nColumns = 4;
		fFolderNameDialogField.doFillIntoGrid(composite, nColumns - 1);
		DialogField.createEmptySpace(composite);
		LayoutUtil.setWidthHint(fFolderNameDialogField.getTextControl(null), getMaxFieldWidth());

		TreeViewer treeViewer = createTreeViewer(composite);

		GridData data = new GridData(GridData.FILL_BOTH);
		data.widthHint = convertWidthInCharsToPixels(fWidth);
		data.heightHint = convertHeightInCharsToPixels(fHeight);

		Tree treeWidget = treeViewer.getTree();
		treeWidget.setLayoutData(data);
		treeWidget.setFont(parent.getFont());

		fFileNameDialogField.doFillIntoGrid(composite, nColumns - 1);
		DialogField.createEmptySpace(composite);
		LayoutUtil.setWidthHint(fFileNameDialogField.getTextControl(null), getMaxFieldWidth());

		return composite;
	}

	/**
	 * Returns the recommended maximum width for text fields (in pixels). This
	 * method requires that createContent has been called before this method is
	 * call. Subclasses may override to change the maximum width for text
	 * fields.
	 *
	 * @return the recommended maximum width for text fields.
	 */
	protected int getMaxFieldWidth() {
		return convertWidthInCharsToPixels(60);
	}

	/**
	 * Creates the tree viewer.
	 *
	 * @param parent
	 *            the parent composite
	 * @return the tree viewer
	 */
	protected TreeViewer createTreeViewer(Composite parent) {
		int style = (SWT.BORDER | SWT.SINGLE);

		fViewer = new TreeViewer(new Tree(parent, style));
		fViewer.setContentProvider(fContentProvider);
		fViewer.setLabelProvider(fLabelProvider);
		fViewer.addSelectionChangedListener(fFieldsAdapter);

		fViewer.setSorter(new CElementSorter());
		fViewer.addFilter(new Filter());

		Tree tree = fViewer.getTree();
		tree.addSelectionListener(fFieldsAdapter);
		fViewer.addDoubleClickListener(fFieldsAdapter);

		fViewer.setInput(fInput.getCModel());

		return fViewer;
	}

	/**
	 * Returns the tree viewer.
	 *
	 * @return the tree viewer
	 */
	protected TreeViewer getTreeViewer() {
		return fViewer;
	}

	/**
	 * @see org.eclipse.jface.window.Window#handleShellCloseEvent()
	 */
	@Override
	protected void handleShellCloseEvent() {
		super.handleShellCloseEvent();

		//Handle the closing of the shell by selecting the close icon
		if (getReturnCode() == CANCEL)
			setResult(null);
	}

	public String getFolderName() {
		if (fCurrentFolder != null) {
			return fCurrentFolder.getPath().toString();
		}
		return null;
	}

	public String getFileName() {
		return fCurrentFileString;
	}

	public IPath getFilePath() {
		IPath path = null;
		if (fCurrentFolder != null) {
			path = fCurrentFolder.getPath();
			if (fCurrentFileString != null)
				path = path.append(fCurrentFileString);
		} else if (fCurrentFileString != null) {
			path = new Path(fCurrentFileString);
		}
		return path;
	}

	void setPathFields(String folderName, String fileName) {
		fFolderNameDialogField.setTextWithoutUpdate(folderName != null ? folderName : ""); //$NON-NLS-1$
		fFileNameDialogField.setTextWithoutUpdate(fileName != null ? fileName : ""); //$NON-NLS-1$
		fFolderNameStatus = folderNameChanged();
		fFileNameStatus = fileNameChanged();
	}

	/**
	 * Sets the initial selection. Convenience method.
	 */
	public void setInitialSelection(String folderName, String fileName) {
		fInitialFileName = (fileName != null && fileName.length() > 0) ? fileName : null;
		fInitialFolderName = null;
		if (folderName != null && folderName.length() > 0) {
			// find a folder that actually exists
			IPath initialFolderPath = new Path(folderName);
			final IPath folderPath = PathUtil.getValidEnclosingFolder(initialFolderPath);
			if (folderPath != null) {
				fInitialFolderName = folderPath.toString();
				if (fInput != null) {
					final ICElement[] foundElem = { /*base_folder*/ null, /*exact_folder*/ null, /*exact_file*/ null };
					try {
						fInput.accept(elem -> {
							IPath path = elem.getPath();
							if (path.isPrefixOf(folderPath)) {
								if (foundElem[0] == null
										|| path.segmentCount() > foundElem[0].getPath().segmentCount()) {
									foundElem[0] = elem; /*base_folder*/
								}
								if (path.equals(folderPath)) {
									foundElem[1] = elem; /*exact_folder*/
									if (fInitialFileName == null)
										return false; // no need to search children
								} else if (fInitialFileName != null && elem.getElementName().equals(fInitialFileName)) {
									foundElem[2] = elem; /*exact_file*/
									return false; // no need to search children
								}
								return true;
							}
							return false;
						});

						ICElement selectedElement = foundElem[2]; /*exact_file*/
						if (selectedElement == null)
							selectedElement = foundElem[1]; /*exact_folder*/
						if (selectedElement == null)
							selectedElement = foundElem[0]; /*base_folder*/

						if (selectedElement != null) {
							setInitialSelections(new Object[] { selectedElement });
						}
					} catch (CoreException e) {
					}
				}
			}
		}
	}
}