/*******************************************************************************
 * Copyright (c) 2007, 2010 Oracle. 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:
 *     Oracle - initial API and implementation
 ******************************************************************************/
package org.eclipse.jpt.jpa.core.internal.resource.java.source;

import java.util.Iterator;
import java.util.List;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.dom.ASTNode;
import org.eclipse.jdt.core.dom.AbstractTypeDeclaration;
import org.eclipse.jdt.core.dom.CompilationUnit;
import org.eclipse.jdt.core.dom.TypeDeclaration;
import org.eclipse.jpt.common.core.JptCommonCorePlugin;
import org.eclipse.jpt.common.core.JptResourceType;
import org.eclipse.jpt.common.core.utility.jdt.AnnotationEditFormatter;
import org.eclipse.jpt.common.utility.CommandExecutor;
import org.eclipse.jpt.common.utility.internal.iterators.EmptyIterator;
import org.eclipse.jpt.jpa.core.JpaAnnotationProvider;
import org.eclipse.jpt.jpa.core.resource.java.JavaResourcePersistentType;

/**
 * Java compilation unit (source file)
 * non package-info.java file
 */
public final class SourceTypeCompilationUnit
	extends SourceCompilationUnit
{

	/**
	 * The primary type of the AST compilation unit. We are not going to handle
	 * multiple types defined in a single compilation unit. Entities must have
	 * a public/protected no-arg constructor, and there is no way to access
	 * the constructor in a package class (which is what all top-level,
	 * non-primary classes must be).
	 */
	private JavaResourcePersistentType persistentType;	


	// ********** construction **********

	public SourceTypeCompilationUnit(
			ICompilationUnit compilationUnit,
			JpaAnnotationProvider annotationProvider, 
			AnnotationEditFormatter annotationEditFormatter,
			CommandExecutor modifySharedDocumentCommandExecutor) {
		super(compilationUnit, annotationProvider, annotationEditFormatter, modifySharedDocumentCommandExecutor);  // the JPA compilation unit is the root of its sub-tree
		this.persistentType = this.buildPersistentType();
	}

	private JavaResourcePersistentType buildPersistentType() {
		this.openCompilationUnit();
		CompilationUnit astRoot = this.buildASTRoot();
		this.closeCompilationUnit();
		return this.buildPersistentType(astRoot);
	}


	// ********** JavaResourceNode implementation **********

	public void synchronizeWith(CompilationUnit astRoot) {
		this.syncPersistentType(astRoot);
	}


	// ********** JavaResourceNode.Root implementation **********

	/**
	 * NB: return *all* the persistent types since we build them all
	 */
	public Iterator<JavaResourcePersistentType> persistentTypes() {
		return (this.persistentType == null) ?
				EmptyIterator.<JavaResourcePersistentType>instance() :
				this.persistentType.allTypes();
	}


	// ********** JptResourceModel implementation **********
	
	public JptResourceType getResourceType() {
		return JptCommonCorePlugin.JAVA_SOURCE_RESOURCE_TYPE;
	}


	// ********** JavaResourceCompilationUnit implementation **********

	public void resolveTypes() {
		if (this.persistentType != null) {
			this.persistentType.resolveTypes(this.buildASTRoot());
		}
	}


	// ********** persistent type **********

	private JavaResourcePersistentType buildPersistentType(CompilationUnit astRoot) {
		TypeDeclaration td = this.getPrimaryTypeDeclaration(astRoot);
		return (td == null) ? null : this.buildPersistentType(astRoot, td);
	}


	private void syncPersistentType(CompilationUnit astRoot) {
		TypeDeclaration td = this.getPrimaryTypeDeclaration(astRoot);
		if (td == null) {
			this.syncPersistentType_(null);
		} else {
			if (this.persistentType == null) {
				this.syncPersistentType_(this.buildPersistentType(astRoot, td));
			} else {
				this.persistentType.synchronizeWith(astRoot);
			}
		}
	}

	private void syncPersistentType_(JavaResourcePersistentType astPersistentType) {
		JavaResourcePersistentType old = this.persistentType;
		this.persistentType = astPersistentType;
		this.firePropertyChanged(PERSISTENT_TYPES_COLLECTION, old, astPersistentType);
	}


	// ********** internal **********

	private JavaResourcePersistentType buildPersistentType(CompilationUnit astRoot, TypeDeclaration typeDeclaration) {
		return SourcePersistentType.newInstance(this, typeDeclaration, astRoot);
	}

	/**
	 * i.e. the type with the same name as the compilation unit;
	 * return the first class or interface (ignore annotations and enums) with
	 * the same name as the compilation unit (file);
	 * NB: this type could be in error if there is an annotation or enum
	 * with the same name preceding it in the compilation unit
	 * 
	 * Return null if the parser did not resolve the type declaration's binding.
	 * This can occur if the project JRE is removed (bug 225332).
	 */
	private TypeDeclaration getPrimaryTypeDeclaration(CompilationUnit astRoot) {
		String primaryTypeName = this.getPrimaryTypeName();
		for (AbstractTypeDeclaration atd : this.types(astRoot)) {
			if (this.nodeIsPrimaryTypeDeclaration(atd, primaryTypeName)) {
				return (atd.resolveBinding() == null) ? null : (TypeDeclaration) atd;
			}
		}
		return null;
	}

	private boolean nodeIsPrimaryTypeDeclaration(AbstractTypeDeclaration atd, String primaryTypeName) {
		return (atd.getNodeType() == ASTNode.TYPE_DECLARATION) &&
					atd.getName().getFullyQualifiedName().equals(primaryTypeName);
	}

	private String getPrimaryTypeName() {
		return this.getCompilationUnitName();
	}

	// minimize scope of suppressed warnings
	@SuppressWarnings("unchecked")
	private List<AbstractTypeDeclaration> types(CompilationUnit astRoot) {
		return astRoot.types();
	}
}