/*******************************************************************************
 * Copyright (c) 2000, 2007 IBM Corporation 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
 *

 * 			(report 36180: Callers/Callees view)
 *******************************************************************************/
package org.eclipse.dltk.internal.ui.callhierarchy;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.dltk.core.IMember;
import org.eclipse.dltk.core.IMethod;
import org.eclipse.dltk.core.IModelElement;
import org.eclipse.dltk.core.ISourceRange;
import org.eclipse.dltk.core.ModelException;
import org.eclipse.dltk.internal.corext.callhierarchy.CallHierarchy;
import org.eclipse.dltk.internal.corext.callhierarchy.CallLocation;
import org.eclipse.dltk.internal.corext.callhierarchy.MethodWrapper;
import org.eclipse.dltk.internal.corext.util.Messages;
import org.eclipse.dltk.internal.ui.IDLTKStatusConstants;
import org.eclipse.dltk.internal.ui.actions.OpenActionUtil;
import org.eclipse.dltk.internal.ui.editor.EditorUtility;
import org.eclipse.dltk.ui.DLTKUIPlugin;
import org.eclipse.dltk.ui.util.ExceptionHandler;
import org.eclipse.jface.dialogs.ErrorDialog;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.util.OpenStrategy;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.texteditor.ITextEditor;

public class CallHierarchyUI {
	private static final int DEFAULT_MAX_CALL_DEPTH = 10;
	private static final String PREF_MAX_CALL_DEPTH = "PREF_MAX_CALL_DEPTH"; //$NON-NLS-1$

	private static CallHierarchyUI fgInstance;

	private CallHierarchyUI() {
		// Do nothing
	}

	public static CallHierarchyUI getDefault() {
		if (fgInstance == null) {
			fgInstance = new CallHierarchyUI();
		}

		return fgInstance;
	}

	/**
	 * Returns the maximum tree level allowed
	 *
	 * @return int
	 */
	public int getMaxCallDepth() {
		int maxCallDepth;

		IPreferenceStore settings = DLTKUIPlugin.getDefault().getPreferenceStore();
		maxCallDepth = settings.getInt(PREF_MAX_CALL_DEPTH);
		if (maxCallDepth < 1 || maxCallDepth > 99) {
			maxCallDepth = DEFAULT_MAX_CALL_DEPTH;
		}

		return maxCallDepth;
	}

	public void setMaxCallDepth(int maxCallDepth) {
		IPreferenceStore settings = DLTKUIPlugin.getDefault().getPreferenceStore();
		settings.setValue(PREF_MAX_CALL_DEPTH, maxCallDepth);
	}

	public static void jumpToMember(IModelElement element) {
		if (element != null) {
			try {
				IEditorPart methodEditor = EditorUtility.openInEditor(element, true);
				EditorUtility.revealInEditor(methodEditor, element);
			} catch (ModelException e) {
				DLTKUIPlugin.log(e);
			} catch (PartInitException e) {
				DLTKUIPlugin.log(e);
			}
		}
	}

	public static void jumpToLocation(CallLocation callLocation) {
		try {
			IEditorPart methodEditor = EditorUtility.openInEditor(callLocation.getMember(), false);

			if (methodEditor instanceof ITextEditor) {
				ITextEditor editor = (ITextEditor) methodEditor;
				editor.selectAndReveal(callLocation.getStart(), (callLocation.getEnd() - callLocation.getStart()));
			}
		} catch (ModelException e) {
			DLTKUIPlugin.log(e);
		} catch (PartInitException e) {
			DLTKUIPlugin.log(e);
		}
	}

	/**
	 * @return <code>true</code> iff no error occurred while trying to open the
	 *         editor, <code>false</code> iff an error dialog was raised.
	 */
	public static boolean openInEditor(Object element, Shell shell, String title) {
		CallLocation callLocation = CallHierarchy.getCallLocation(element);

		try {
			IModelElement enclosingMember;
			int selectionStart;
			int selectionLength;

			if (callLocation != null) {
				enclosingMember = callLocation.getMember();
				selectionStart = callLocation.getStart();
				selectionLength = callLocation.getEnd() - selectionStart;
			} else if (element instanceof MethodWrapper) {
				enclosingMember = ((MethodWrapper) element).getMember();
				ISourceRange selectionRange = null;
				if (enclosingMember instanceof IMember) {
					selectionRange = ((IMember) enclosingMember).getNameRange();
				}
				if (selectionRange == null && enclosingMember instanceof IMember)
					selectionRange = ((IMember) enclosingMember).getSourceRange();
				if (selectionRange == null)
					return true;
				selectionStart = selectionRange.getOffset();
				selectionLength = selectionRange.getLength();
			} else {
				return true;
			}

			boolean activateOnOpen = OpenStrategy.activateOnOpen();

			IEditorPart methodEditor = EditorUtility.openInEditor(enclosingMember, activateOnOpen);

			if (methodEditor instanceof ITextEditor) {
				ITextEditor editor = (ITextEditor) methodEditor;
				editor.selectAndReveal(selectionStart, selectionLength);
			}
			return true;
		} catch (ModelException e) {
			DLTKUIPlugin.log(new Status(IStatus.ERROR, DLTKUIPlugin.getPluginId(), IDLTKStatusConstants.INTERNAL_ERROR,
					CallHierarchyMessages.CallHierarchyUI_open_in_editor_error_message, e));

			ErrorDialog.openError(shell, title, CallHierarchyMessages.CallHierarchyUI_open_in_editor_error_message,
					e.getStatus());
			return false;
		} catch (PartInitException x) {
			String name;
			if (callLocation != null)
				name = callLocation.getCalledMember().getElementName();
			else if (element instanceof MethodWrapper)
				name = ((MethodWrapper) element).getName();
			else
				name = ""; //$NON-NLS-1$
			MessageDialog.openError(shell, title, Messages.format(
					CallHierarchyMessages.CallHierarchyUI_open_in_editor_error_messageArgs, name, x.getMessage()));
			return false;
		}
	}

	public static IEditorPart isOpenInEditor(Object elem) {
		IModelElement modelElement = null;
		if (elem instanceof MethodWrapper) {
			modelElement = ((MethodWrapper) elem).getMember();
		} else if (elem instanceof CallLocation) {
			modelElement = ((CallLocation) elem).getCalledMember();
		}
		if (modelElement != null) {
			return EditorUtility.isOpenInEditor(modelElement);
		}
		return null;
	}

	/**
	 * Converts the input to a possible input candidates
	 */
	public static IModelElement[] getCandidates(Object input) {
		if (!(input instanceof IModelElement)) {
			return null;
		}
		IModelElement elem = (IModelElement) input;
		if (elem.getElementType() == IModelElement.METHOD) {
			return new IModelElement[] { elem };
		}
		return null;
	}

	public static CallHierarchyViewPart open(IModelElement[] candidates, IWorkbenchWindow window, String partID) {
		Assert.isTrue(candidates != null && candidates.length != 0);

		IModelElement input = null;
		if (candidates.length > 1) {
			String title = CallHierarchyMessages.CallHierarchyUI_selectionDialog_title;
			String message = CallHierarchyMessages.CallHierarchyUI_selectionDialog_message;
			input = OpenActionUtil.selectModelElement(candidates, window.getShell(), title, message);
		} else {
			input = candidates[0];
		}
		if (input == null)
			return null;

		return openInViewPart(window, input, partID);
	}

	private static void openEditor(Object input, boolean activate) throws PartInitException, ModelException {
		IEditorPart part = EditorUtility.openInEditor(input, activate);
		if (input instanceof IModelElement)
			EditorUtility.revealInEditor(part, (IModelElement) input);
	}

	private static CallHierarchyViewPart openInViewPart(IWorkbenchWindow window, IModelElement input, String partID) {
		IWorkbenchPage page = window.getActivePage();
		try {
			CallHierarchyViewPart result = (CallHierarchyViewPart) page.showView(partID);
			result.setMethod((IMethod) input);
			openEditor(input, false);
			return result;
		} catch (CoreException e) {
			ExceptionHandler.handle(e, window.getShell(), CallHierarchyMessages.CallHierarchyUI_error_open_view,
					e.getMessage());
		}
		return null;
	}

	/**
	 * Converts an ISelection (containing MethodWrapper instances) to an ISelection
	 * with the MethodWrapper's replaced by their corresponding IMembers. If the
	 * selection contains elements which are not MethodWrapper instances or not
	 * already IMember instances they are discarded.
	 *
	 * @param selection The selection to convert.
	 * @return An ISelection containing IMember's in place of MethodWrapper
	 *         instances.
	 */
	static ISelection convertSelection(ISelection selection) {
		if (selection.isEmpty()) {
			return selection;
		}

		if (selection instanceof IStructuredSelection) {
			IStructuredSelection structuredSelection = (IStructuredSelection) selection;
			List modelElements = new ArrayList();
			for (Iterator iter = structuredSelection.iterator(); iter.hasNext();) {
				Object element = iter.next();
				if (element instanceof MethodWrapper) {
					IModelElement member = ((MethodWrapper) element).getMember();
					if (member != null) {
						modelElements.add(member);
					}
				} else if (element instanceof IMember) {
					modelElements.add(element);
				} else if (element instanceof CallLocation) {
					IModelElement member = ((CallLocation) element).getMember();
					modelElements.add(member);
				}
			}
			return new StructuredSelection(modelElements);
		}
		return StructuredSelection.EMPTY;
	}
}