/*=============================================================================#
 # Copyright (c) 2005, 2021 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.ltk.ui.sourceediting;

import static org.eclipse.statet.jcommons.lang.ObjectUtils.nonNullAssert;

import org.eclipse.core.filesystem.EFS;
import org.eclipse.core.filesystem.IFileStore;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.SubMonitor;
import org.eclipse.jface.text.AbstractDocument;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.source.IAnnotationModel;
import org.eclipse.ui.IURIEditorInput;
import org.eclipse.ui.editors.text.TextFileDocumentProvider;
import org.eclipse.ui.part.FileEditorInput;

import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;

import org.eclipse.statet.ecommons.text.PartitionerDocumentSetupParticipant;

import org.eclipse.statet.ltk.core.Ltk;
import org.eclipse.statet.ltk.issues.core.ProblemRequestor;
import org.eclipse.statet.ltk.model.core.DocumentModelProvider;
import org.eclipse.statet.ltk.model.core.LtkModels;
import org.eclipse.statet.ltk.model.core.SourceUnitManager;
import org.eclipse.statet.ltk.model.core.element.SourceUnit;
import org.eclipse.statet.ltk.model.core.element.WorkspaceSourceUnit;


@NonNullByDefault
public class SourceDocumentProvider<T extends SourceUnit> extends TextFileDocumentProvider
		implements DocumentModelProvider {
	
	
	public static class SourceFileInfo extends FileInfo {
		
		private @Nullable SourceUnit workingCopy;
		
	}
	
	
	private final String modelTypeId;
	private final @Nullable PartitionerDocumentSetupParticipant documentSetupParticipant;
	
	
	public SourceDocumentProvider(final String modelTypeId,
			final @Nullable PartitionerDocumentSetupParticipant documentSetupParticipant) {
		this.modelTypeId= nonNullAssert(modelTypeId);
		this.documentSetupParticipant= documentSetupParticipant;
//		final IDocumentProvider provider= new ForwardingDocumentProvider(documentSetupParticipant.getPartitioningId(),
//				this.documentSetupParticipant, new TextFileDocumentProvider());
//		setParentDocumentProvider(provider);
	}
	
	
	@Override
	protected FileInfo createEmptyFileInfo() {
		return new SourceFileInfo();
	}
	
	@Override
	public void disconnect(final Object element) {
		final FileInfo info= getFileInfo(element);
		if (info instanceof SourceFileInfo) {
			final SourceFileInfo rinfo= (SourceFileInfo) info;
			if (rinfo.fCount == 1 && rinfo.workingCopy != null) {
				final SubMonitor m= SubMonitor.convert(getProgressMonitor(), 1);
				try {
					rinfo.workingCopy.disconnect(m.newChild(1));
				}
				finally {
					rinfo.workingCopy= null;
					m.done();
				}
			}
		}
		super.disconnect(element);
	}
	
	@Override
	protected @Nullable FileInfo createFileInfo(final Object element) throws CoreException {
		final FileInfo info= super.createFileInfo(element);
		
		if (!(info instanceof SourceFileInfo)) {
			return null;
		}
		
		{	final IDocument document= getDocument(element);
			if (document instanceof AbstractDocument) {
				setupDocument((AbstractDocument) document);
			}
		}
		
		final IAdaptable adaptable= (IAdaptable) element;
		final SourceFileInfo sourceInfo= (SourceFileInfo) info;
		
		final SubMonitor m= SubMonitor.convert(getProgressMonitor());
		try {
			final Object ifile= adaptable.getAdapter(IFile.class);
			final SourceUnitManager suManager= LtkModels.getSourceUnitManager();
			if (ifile != null) {
				m.setWorkRemaining(2);
				final SourceUnit pUnit= suManager.getSourceUnit(this.modelTypeId, Ltk.PERSISTENCE_CONTEXT,
						ifile, true, m.newChild(1) );
				sourceInfo.workingCopy= suManager.getSourceUnit(this.modelTypeId, Ltk.EDITOR_CONTEXT,
						pUnit, true, m.newChild(1) );
			}
			else if (element instanceof IURIEditorInput) {
				m.setWorkRemaining(1);
				final IFileStore store;
				try {
					store= EFS.getStore(((IURIEditorInput) element).getURI());
				}
				catch (final CoreException e) {
					return sourceInfo;
				}
				sourceInfo.workingCopy= suManager.getSourceUnit(this.modelTypeId, Ltk.EDITOR_CONTEXT,
						store, true, m.newChild(1) );
			}
		}
		finally {
			m.done();
		}
		
		return sourceInfo;
	}
	
	protected void setupDocument(final AbstractDocument document) {
		if (this.documentSetupParticipant != null) {
			this.documentSetupParticipant.setup(document);
		}
	}
	
	@Override
	@SuppressWarnings("unchecked")
	public @Nullable T getWorkingCopy(final Object element) {
		final FileInfo fileInfo= getFileInfo(element);
		if (fileInfo instanceof SourceFileInfo) {
			return (T)((SourceFileInfo)fileInfo).workingCopy;
		}
		return null;
	}
	
	@Override
	public @Nullable IAnnotationModel getAnnotationModel(@Nullable Object element) {
		if (element instanceof WorkspaceSourceUnit) {
			element= new FileEditorInput((IFile)((WorkspaceSourceUnit)element).getResource());
		}
		return super.getAnnotationModel(element);
	}
	
	public @Nullable ProblemRequestor createProblemRequestor(final SourceUnit element) {
		final IAnnotationModel annotationModel= getAnnotationModel(element);
		if (annotationModel instanceof SourceAnnotationModel) {
			return ((SourceAnnotationModel) annotationModel).createProblemRequestor();
		}
		return null;
	}
	
}