package org.eclipse.jst.jsf.facelet.ui.internal.validation;

import java.io.IOException;
import java.util.Collection;
import java.util.Collections;
import java.util.Set;

import org.eclipse.core.resources.IFile;
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.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.content.IContentType;
import org.eclipse.core.runtime.content.IContentTypeManager;
import org.eclipse.core.runtime.jobs.ISchedulingRule;
import org.eclipse.emf.common.util.Diagnostic;
import org.eclipse.jst.jsf.common.runtime.internal.view.model.common.Namespace;
import org.eclipse.jst.jsf.context.resolver.structureddocument.IDOMContextResolver;
import org.eclipse.jst.jsf.context.resolver.structureddocument.IStructuredDocumentContextResolverFactory;
import org.eclipse.jst.jsf.context.structureddocument.IStructuredDocumentContext;
import org.eclipse.jst.jsf.context.structureddocument.IStructuredDocumentContextFactory;
import org.eclipse.jst.jsf.core.internal.JSFCorePlugin;
import org.eclipse.jst.jsf.designtime.internal.view.model.ITagRegistry;
import org.eclipse.jst.jsf.facelet.core.internal.util.ViewUtil;
import org.eclipse.jst.jsf.facelet.ui.internal.FaceletUiPlugin;
import org.eclipse.jst.jsf.validation.internal.IJSFViewValidator;
import org.eclipse.jst.jsf.validation.internal.JSFValidatorFactory;
import org.eclipse.jst.jsf.validation.internal.ValidationPreferences;
import org.eclipse.jst.jsf.validation.internal.facelet.FaceletDiagnosticFactory;
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.validation.AbstractValidator;
import org.eclipse.wst.validation.ValidationResult;
import org.eclipse.wst.validation.ValidationState;
import org.eclipse.wst.validation.internal.core.ValidationException;
import org.eclipse.wst.validation.internal.operations.LocalizedMessage;
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.IValidationContext;
import org.eclipse.wst.validation.internal.provisional.core.IValidator;
import org.eclipse.wst.xml.core.internal.provisional.document.IDOMAttr;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

/**
 * The Facelet HTML file validator.
 * 
 * @author cbateman
 *
 */
public class HTMLValidator extends AbstractValidator implements IValidator
{
	private FaceletDiagnosticFactory _diagnosticFactory = new FaceletDiagnosticFactory();
    /**
     * @param helper
     * @return no rule, null
     */
    public ISchedulingRule getSchedulingRule(final IValidationContext helper)
    {
        // no rule...
        return null;
    }

    /**
     * @param helper
     * @param reporter
     * @return status of this validation
     * @throws ValidationException
     */
    public IStatus validateInJob(final IValidationContext helper,
            final IReporter reporter) throws ValidationException
    {
        IStatus status = Status.OK_STATUS;
        try
        {
            validate(helper, reporter);
        }
        catch (final ValidationException e)
        {
            status = new Status(IStatus.ERROR, FaceletUiPlugin.PLUGIN_ID,
                    IStatus.ERROR, e.getLocalizedMessage(), e);
        }
        return status;

    }

    public void cleanup(final IReporter reporter)
    {
        // do nothing
    }

    @Override
	public ValidationResult validate(IResource resource, int kind, ValidationState state, IProgressMonitor monitor){
		ValidationResult vr = new ValidationResult();
		if (resource == null || !(resource instanceof IFile)) {
			return vr;
		}
		IFile currentFile = (IFile) resource;
        if (shouldValidate(currentFile)) {
            validateFile(currentFile, vr.getReporter(monitor));
        }
		return vr;
	}

    public void validate(final IValidationContext helper,
            final IReporter reporter) throws ValidationException
    {
        final String[] uris = helper.getURIs();
        final IWorkspaceRoot wsRoot = ResourcesPlugin.getWorkspace().getRoot();
        if (uris.length > 0)
        {
            IFile currentFile = null;

            for (int i = 0; i < uris.length && !reporter.isCancelled(); i++)
            {
                currentFile = wsRoot.getFile(new Path(uris[i]));
                if (currentFile != null && currentFile.exists())
                {
                    if (shouldValidate(currentFile))
                    {
                        final int percent = (i * 100) / uris.length + 1;
                        final IMessage message = new LocalizedMessage(
                                IMessage.LOW_SEVERITY, percent + "% " + uris[i]);
                        reporter.displaySubtask(this, message);

                        validateFile(currentFile, reporter);
                    }
                }
            }
        }

    }

    private void validateFile(final IFile file, final IReporter reporter)
    {
        final IJSFViewValidator validator = JSFValidatorFactory
                .createDefaultXMLValidator();
        final ValidationPreferences prefs = new ValidationPreferences(
                JSFCorePlugin.getDefault().getPreferenceStore());
        prefs.load();

        IStructuredModel model = null;
        try
        {
            model = StructuredModelManager.getModelManager().getModelForRead(
                    file);

            final ValidationReporter jsfReporter = new ValidationReporter(this,
                    reporter, file, prefs, model);
            validator.validateView(file, jsfReporter);
            // TODO: break off into composite strategies
            validateFaceletHtml(file, jsfReporter);
        }
        catch (final CoreException e)
        {
            JSFCorePlugin.log("Error validating JSF", e);
        }
        catch (final IOException e)
        {
            JSFCorePlugin.log("Error validating JSF", e);
        }
        finally
        {
            if (null != model)
            {
                model.releaseFromRead();
            }
        }
    }

    private void validateFaceletHtml(final IFile file,
            final ValidationReporter reporter)
    {
        IStructuredModel model = null;
        try
        {
            model = StructuredModelManager.getModelManager().getModelForRead(
                    file);

            final IStructuredDocument structuredDoc = model
                    .getStructuredDocument();

            validateDocument(structuredDoc, reporter, file.getProject());
        }
        catch (final CoreException e)
        {
            JSFCorePlugin.log("Error validating JSF", e);
        }
        catch (final IOException e)
        {
            JSFCorePlugin.log("Error validating JSF", e);
        }
        finally
        {
            if (null != model)
            {
                model.releaseFromRead();
            }
        }
    }

    private void validateDocument(IStructuredDocument structuredDoc,
            final ValidationReporter reporter, IProject project)
    {
        validateRoot(structuredDoc, reporter, project);
    }

    private void validateRoot(IStructuredDocument structuredDoc,
            ValidationReporter reporter, IProject project)
    {
        final IStructuredDocumentContext context = IStructuredDocumentContextFactory.INSTANCE
                .getContext(structuredDoc, -1);
        final IDOMContextResolver resolver = IStructuredDocumentContextResolverFactory.INSTANCE
                .getDOMContextResolver(context);
        final Document document = resolver.getDOMDocument();
        Element rootElement = document.getDocumentElement();

        if ("html".equals(rootElement.getNodeName()))
        {
            final Set<Attr> declaredNamespaces = ViewUtil
                    .getDeclaredNamespaces(rootElement.getAttributes());
            final ITagRegistry tagRegistry = ViewUtil
                    .getHtmlTagRegistry(project);
            final Collection<? extends Namespace> namespaces;
            if (tagRegistry != null)
            {
                namespaces = tagRegistry.getAllTagLibraries();
            }
            else
            {
                // unexpected
                namespaces = Collections.EMPTY_SET;
                JSFCorePlugin.log(IStatus.ERROR, "Program Error: HTML tag registry not found"); //$NON-NLS-1$
            }

            for (final Attr attr : declaredNamespaces)
            {
                // only validate prefix declarations
                if (attr.getPrefix() != null && attr instanceof IDOMAttr)
                {
                    final String declaredUri = attr.getValue();
                    String findUri = null;
                    SEARCH_NAMESPACES: for (final Namespace ns : namespaces)
                    {
                        if (ns.getNSUri().equals(declaredUri))
                        {
                            findUri = ns.getNSUri();
                            break SEARCH_NAMESPACES;
                        }
                    }

                    if (findUri == null)
                    {
                        final Diagnostic diag = _diagnosticFactory.create_CANNOT_FIND_FACELET_TAGLIB(declaredUri);
                        final IDOMAttr domAttr = (IDOMAttr) attr;
                        reporter.report(diag, domAttr.getValueRegionStartOffset(), domAttr
                                .getValue().length());
                    }
                }
            }
        }
    }
    
    private boolean shouldValidate(final IFile model)
    {
        final IContentTypeManager manager = Platform.getContentTypeManager();
        final IContentType contentType = manager
                .getContentType("org.eclipse.wst.html.core.htmlsource");
        return (contentType.isAssociatedWith(model.getName()))
                && ViewUtil.isFaceletVDLFile(model);
    }
}