/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package net.sourceforge.phpdt.internal.core.jdom;

import net.sourceforge.phpdt.core.Flags;
import net.sourceforge.phpdt.core.IJavaElement;
import net.sourceforge.phpdt.core.IPackageFragment;
import net.sourceforge.phpdt.core.jdom.IDOMCompilationUnit;
import net.sourceforge.phpdt.core.jdom.IDOMNode;
import net.sourceforge.phpdt.core.jdom.IDOMType;
import net.sourceforge.phpdt.internal.compiler.util.Util;
import net.sourceforge.phpdt.internal.core.util.CharArrayBuffer;
import net.sourceforge.phpdt.internal.core.util.CharArrayOps;

/**
 * DOMCompilation unit provides an implementation of IDOMCompilationUnit.
 * 
 * @see IDOMCompilationUnit
 * @see DOMNode
 */
class DOMCompilationUnit extends DOMNode implements IDOMCompilationUnit {

	/**
	 * The comment and/or whitespace preceding the first document fragment in
	 * this compilation unit.
	 */
	protected String fHeader;

	/**
	 * Creates a new empty COMPILATION_UNIT document fragment.
	 */
	DOMCompilationUnit() {
		fHeader = ""; //$NON-NLS-1$
	}

	/**
	 * Creates a new COMPILATION_UNIT on the given range of the document.
	 * 
	 * @param document -
	 *            the document containing this node's original contents
	 * @param sourceRange -
	 *            a two element array of integers describing the entire
	 *            inclusive source range of this node within its document. A
	 *            compilation unit's source range is the entire document - the
	 *            first integer is zero, and the second integer is the position
	 *            of the last character in the document.
	 */
	DOMCompilationUnit(char[] document, int[] sourceRange) {
		super(document, sourceRange, null, new int[] { -1, -1 });
		fHeader = ""; //$NON-NLS-1$
	}

	/**
	 * @see DOMNode#appendContents(CharArrayBuffer)
	 */
	protected void appendFragmentedContents(CharArrayBuffer buffer) {
		buffer.append(getHeader());
		appendContentsOfChildren(buffer);
	}

	/**
	 * @see IDOMNode#canHaveChildren()
	 */
	public boolean canHaveChildren() {
		return true;
	}

	/**
	 * @see IDOMCompilationUnit#getHeader()
	 */
	public String getHeader() {
		return fHeader;
	}

	/**
	 * @see IDOMNode#getJavaElement
	 */
	public IJavaElement getJavaElement(IJavaElement parent)
			throws IllegalArgumentException {
		if (parent.getElementType() == IJavaElement.PACKAGE_FRAGMENT) {
			return ((IPackageFragment) parent).getCompilationUnit(getName());
		} else {
			throw new IllegalArgumentException(Util
					.bind("element.illegalParent")); //$NON-NLS-1$
		}
	}

	/**
	 * @see IDOMCompilationUnit#getName()
	 */
	public String getName() {
		IDOMType topLevelType = null;
		IDOMType firstType = null;
		IDOMNode child = fFirstChild;
		while (child != null) {
			if (child.getNodeType() == IDOMNode.TYPE) {
				IDOMType type = (IDOMType) child;
				if (firstType == null) {
					firstType = type;
				}
				if (Flags.isPublic(type.getFlags())) {
					topLevelType = type;
					break;
				}
			}
			child = child.getNextNode();
		}
		if (topLevelType == null) {
			topLevelType = firstType;
		}
		if (topLevelType != null) {
			return topLevelType.getName() + ".java"; //$NON-NLS-1$
		} else {
			return null;
		}
	}

	/**
	 * @see IDOMNode#getNodeType()
	 */
	public int getNodeType() {
		return IDOMNode.COMPILATION_UNIT;
	}

	/**
	 * Sets the header
	 */
	protected void initalizeHeader() {
		DOMNode child = (DOMNode) getFirstChild();
		if (child != null) {
			int childStart = child.getStartPosition();
			if (childStart > 1) {
				setHeader(CharArrayOps.substring(fDocument, 0, childStart));
			}
		}
	}

	/**
	 * @see IDOMNode#isAllowableChild(IDOMNode)
	 */
	public boolean isAllowableChild(IDOMNode node) {
		if (node != null) {
			int type = node.getNodeType();
			return type == IDOMNode.PACKAGE || type == IDOMNode.IMPORT
					|| type == IDOMNode.TYPE;
		} else {
			return false;
		}

	}

	/**
	 * @see DOMNode
	 */
	protected DOMNode newDOMNode() {
		return new DOMCompilationUnit();
	}

	/**
	 * Normalizes this <code>DOMNode</code>'s source positions to include
	 * whitespace preceeding the node on the line on which the node starts, and
	 * all whitespace after the node up to the next node's start
	 */
	void normalize(ILineStartFinder finder) {
		super.normalize(finder);
		initalizeHeader();
	}

	/**
	 * @see IDOMCompilationUnit@setHeader(String)
	 */
	public void setHeader(String comment) {
		fHeader = comment;
		fragment();
	}

	/**
	 * @see IDOMCompilationUnit#setName(String)
	 */
	public void setName(String name) {
	}

	/**
	 * @see DOMNode#shareContents(DOMNode)
	 */
	protected void shareContents(DOMNode node) {
		super.shareContents(node);
		fHeader = ((DOMCompilationUnit) node).fHeader;
	}

	/**
	 * @see IDOMNode#toString()
	 */
	public String toString() {
		return "COMPILATION_UNIT: " + getName(); //$NON-NLS-1$
	}
}