/*=============================================================================#
 # Copyright (c) 2009, 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.model.core.build;

import java.util.concurrent.CancellationException;

import org.eclipse.core.runtime.IProgressMonitor;

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

import org.eclipse.statet.ltk.ast.core.AstInfo;
import org.eclipse.statet.ltk.core.Ltk;
import org.eclipse.statet.ltk.core.SourceContent;
import org.eclipse.statet.ltk.core.WorkingContext;
import org.eclipse.statet.ltk.issues.core.ProblemRequestor;
import org.eclipse.statet.ltk.model.core.ModelManager;
import org.eclipse.statet.ltk.model.core.element.SourceUnit;
import org.eclipse.statet.ltk.model.core.element.SourceUnitModelInfo;
import org.eclipse.statet.ltk.model.core.element.WorkspaceSourceUnit;


@NonNullByDefault
public abstract class SourceUnitModelContainer<TSourceUnit extends SourceUnit, TModelInfo extends SourceUnitModelInfo> {
	
	
	private final @Nullable WorkingContext mode;
	
	private final TSourceUnit unit;
	
	private @Nullable AstInfo astInfo;
	
	private @Nullable TModelInfo modelInfo;
	
	
	public SourceUnitModelContainer(final TSourceUnit unit) {
		this.unit= unit;
		this.mode= getMode(unit);
	}
	
	
	public abstract boolean isContainerFor(String modelTypeId);
	
	public abstract Class<?> getAdapterClass();
	
	
	protected @Nullable WorkingContext getMode(final TSourceUnit su) {
		if (su instanceof WorkspaceSourceUnit) {
			return su.getWorkingContext();
		}
		return null;
	}
	
	protected final @Nullable WorkingContext getMode() {
		return this.mode;
	}
	
	
	public TSourceUnit getSourceUnit() {
		return this.unit;
	}
	
	public SourceContent getParseContent(final IProgressMonitor monitor) {
		return this.unit.getContent(monitor);
	}
	
	public @Nullable AstInfo getAstInfo(final boolean ensureSync, final IProgressMonitor monitor) {
		if (ensureSync) {
			try {
				getModelManager().reconcile(this, ModelManager.AST, monitor);
			}
			catch (final CancellationException e) {}
		}
		return this.astInfo;
	}
	
	public @Nullable TModelInfo getModelInfo(final int syncLevel, final IProgressMonitor monitor) {
		if ((syncLevel & ModelManager.REFRESH) != 0) {
			clear();
		}
		if ((syncLevel & 0xf) >= ModelManager.MODEL_FILE) {
			final @Nullable TModelInfo currentModel= this.modelInfo;
			if ((syncLevel & ModelManager.RECONCILE) != 0
					|| currentModel == null
					|| currentModel.getStamp().getContentStamp() == 0
					|| currentModel.getStamp().getContentStamp() != this.unit.getContentStamp(monitor) ) {
				try {
					getModelManager().reconcile(this, syncLevel, monitor);
				}
				catch (final CancellationException e) {}
			}
		}
		return this.modelInfo;
	}
	
	protected abstract ModelManager getModelManager();
	
	
	public void clear() {
		this.astInfo= null;
		this.modelInfo= null;
	}
	
	public @Nullable AstInfo getCurrentAst() {
		if (this.mode == Ltk.PERSISTENCE_CONTEXT) {
			final @Nullable TModelInfo model= getCurrentModel();
			if (model != null) {
				return model.getAst();
			}
			return null;
		}
		return this.astInfo;
	}
	
	public void setAst(final AstInfo ast) {
		if (this.mode == Ltk.PERSISTENCE_CONTEXT) {
			return;
		}
		this.astInfo= ast;
	}
	
	public @Nullable TModelInfo getCurrentModel() {
		return this.modelInfo;
	}
	
	public void setModel(final @Nullable TModelInfo modelInfo) {
		final AstInfo astInfo;
		if (modelInfo != null
				&& ((astInfo= this.astInfo) == null || astInfo.getStamp().equals(modelInfo.getAst().getStamp())) ) {
									// otherwise, the ast is probably newer
			setAst(modelInfo.getAst());
		}
		this.modelInfo= modelInfo;
	}
	
	
	public @Nullable ProblemRequestor createProblemRequestor() {
		return null;
	}
	
}