/*******************************************************************************
 * Copyright (c) 2006, 2008 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
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     
 *******************************************************************************/
package org.eclipse.jst.jsp.core.internal.validation;

import java.io.IOException;
import java.util.List;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.Platform;
import org.eclipse.jdt.core.compiler.IProblem;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.Position;
import org.eclipse.jst.jsp.core.internal.Logger;
import org.eclipse.jst.jsp.core.internal.java.IJSPProblem;
import org.eclipse.jst.jsp.core.internal.java.IJSPTranslation;
import org.eclipse.jst.jsp.core.internal.java.JSPTranslation;
import org.eclipse.jst.jsp.core.internal.java.JSPTranslationAdapter;
import org.eclipse.jst.jsp.core.internal.java.JSPTranslationExtension;
import org.eclipse.jst.jsp.core.internal.modelhandler.ModelHandlerForJSP;
import org.eclipse.jst.jsp.core.internal.regions.DOMJSPRegionContexts;
import org.eclipse.wst.sse.core.StructuredModelManager;
import org.eclipse.wst.sse.core.internal.provisional.IStructuredModel;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocument;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocumentRegion;
import org.eclipse.wst.sse.core.internal.provisional.text.ITextRegion;
import org.eclipse.wst.validation.internal.provisional.core.IMessage;
import org.eclipse.wst.validation.internal.provisional.core.IReporter;
import org.eclipse.wst.validation.internal.provisional.core.IValidator;
import org.eclipse.wst.xml.core.internal.provisional.document.IDOMDocument;
import org.eclipse.wst.xml.core.internal.provisional.document.IDOMModel;

public class JSPJavaValidator extends JSPValidator {
	private static final boolean DEBUG = Boolean.valueOf(Platform.getDebugOption("org.eclipse.jst.jsp.core/debug/jspvalidator")).booleanValue(); //$NON-NLS-1$
	private IValidator fMessageOriginator;

	public JSPJavaValidator() {
		this.fMessageOriginator = this;
	}

	public JSPJavaValidator(IValidator validator) {
		this.fMessageOriginator = validator;
	}

	/**
	 * Assumed the message offset is an indirect position. In other words, an
	 * error from an included file.
	 * 
	 * @param m
	 * @param translation
	 */
	private void adjustIndirectPosition(IMessage m, IJSPTranslation translation) {

		if (!(translation instanceof JSPTranslationExtension))
			return;

		IDocument jspDoc = ((JSPTranslationExtension) translation).getJspDocument();
		if (!(jspDoc instanceof IStructuredDocument))
			return;

		IStructuredDocument sDoc = (IStructuredDocument) jspDoc;
		IStructuredDocumentRegion[] regions = sDoc.getStructuredDocumentRegions(0, m.getOffset() + m.getLength());
		// iterate backwards until you hit the include directive
		for (int i = regions.length - 1; i >= 0; i--) {

			IStructuredDocumentRegion region = regions[i];
			if (region.getType() == DOMJSPRegionContexts.JSP_DIRECTIVE_NAME) {
				if (getDirectiveName(region).equals("include")) { //$NON-NLS-1$
					ITextRegion fileValueRegion = getAttributeValueRegion(region, "file"); //$NON-NLS-1$
					if(fileValueRegion != null) {
						m.setOffset(region.getStartOffset(fileValueRegion));
						m.setLength(fileValueRegion.getTextLength());
					}
					else {
						m.setOffset(region.getStartOffset());
						m.setLength(region.getTextLength());
					}
					break;
				}
			}
		}
	}

	/**
	 * Creates an IMessage from an IProblem
	 * 
	 * @param problem
	 * @param f
	 * @param translation
	 * @param structuredDoc
	 * @return message representation of the problem, or null if it could not
	 *         create one
	 */
	private IMessage createMessageFromProblem(IProblem problem, IFile f, IJSPTranslation translation, IStructuredDocument structuredDoc) {

		int sev = problem.isError() ? IMessage.HIGH_SEVERITY : IMessage.NORMAL_SEVERITY;
		int sourceStart = problem.getSourceStart();
		int sourceEnd = problem.getSourceEnd();
		if (!((problem instanceof IJSPProblem) && (((IJSPProblem) problem).getEID() & IJSPProblem.F_PROBLEM_ID_LITERAL) != 0)) {
			sourceStart = translation.getJspOffset(problem.getSourceStart());
			sourceEnd = translation.getJspOffset(problem.getSourceEnd());
		}
		if (sourceStart == -1) {
			int problemID = problem.getID();
			/*
			 * Quoting IProblem doc: "When a problem is tagged as Internal, it
			 * means that no change other than a local source code change can
			 * fix the corresponding problem." Assuming that our generated
			 * code is correct, that should reduce the reported problems to
			 * those the user can correct.
			 */
			if (((problemID & IProblem.Internal) != 0) && ((problemID & IProblem.Syntax) != 0) && translation instanceof JSPTranslation) {
				// Attach to the last code scripting section
				JSPTranslation jspTranslation = ((JSPTranslation) translation);
				Position[] jspPositions = (Position[]) jspTranslation.getJsp2JavaMap().keySet().toArray(new Position[jspTranslation.getJsp2JavaMap().size()]);
				for (int i = 0; i < jspPositions.length; i++) {
					sourceStart = Math.max(sourceStart, jspPositions[i].getOffset());
				}
				IMessage m = new LocalizedMessage(sev, problem.getMessage(), f);
				m.setOffset(sourceStart);
				m.setLength(1);
				return m;
			}
			else {
 				return null;
			}
		}

		// line number for marker starts @ 1
		// line number from document starts @ 0
		int lineNo = structuredDoc.getLineOfOffset(sourceStart) + 1;

		IMessage m = new LocalizedMessage(sev, problem.getMessage(), f);

		m.setLineNo(lineNo);
		m.setOffset(sourceStart);
		m.setLength(sourceEnd - sourceStart + 1);

		// need additional adjustment for problems from
		// indirect (included) files
		// https://bugs.eclipse.org/bugs/show_bug.cgi?id=119633
		if (translation.isIndirect(problem.getSourceStart())) {
			adjustIndirectPosition(m, translation);
		}

		return m;
	}

	void performValidation(IFile f, IReporter reporter, IStructuredModel model) {
		if (model instanceof IDOMModel) {
			IDOMModel domModel = (IDOMModel) model;
			ModelHandlerForJSP.ensureTranslationAdapterFactory(domModel);

			IDOMDocument xmlDoc = domModel.getDocument();
			JSPTranslationAdapter translationAdapter = (JSPTranslationAdapter) xmlDoc.getAdapterFor(IJSPTranslation.class);
			IJSPTranslation translation = translationAdapter.getJSPTranslation();

			if (!reporter.isCancelled()) {
				translation.setProblemCollectingActive(true);
				translation.reconcileCompilationUnit();
				List problems = translation.getProblems();
				// add new messages
				for (int i = 0; i < problems.size() && !reporter.isCancelled(); i++) {
					IMessage m = createMessageFromProblem((IProblem) problems.get(i), f, translation, domModel.getStructuredDocument());
					if (m != null)
						reporter.addMessage(fMessageOriginator, m);
				}
			}
		}
	}

	/**
	 * Validate one file. It's assumed that the file has JSP content type.
	 * 
	 * @param f
	 * @param reporter
	 */
	protected void validateFile(IFile f, IReporter reporter) {
		if (DEBUG) {
			Logger.log(Logger.INFO, getClass().getName() + " validating: " + f); //$NON-NLS-1$
		}

		IStructuredModel model = null;
		try {
			// get jsp model, get tranlsation
			model = StructuredModelManager.getModelManager().getModelForRead(f);
			if (!reporter.isCancelled() && model != null) {
				// get jsp model, get translation
				if (model instanceof IDOMModel) {
					reporter.removeAllMessages(fMessageOriginator, f);
					performValidation(f, reporter, model);
				}
			}
		}
		catch (IOException e) {
			Logger.logException(e);
		}
		catch (CoreException e) {
			Logger.logException(e);
		}
		finally {
			if (model != null)
				model.releaseFromRead();
		}
	}
}