/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved.
 */
package net.sourceforge.phpdt.internal.corext.template.php;

import net.sourceforge.phpdt.internal.corext.template.ContextType;
import net.sourceforge.phpdt.internal.corext.template.DocumentTemplateContext;
import net.sourceforge.phpdt.internal.corext.template.Template;
import net.sourceforge.phpdt.internal.corext.template.TemplateBuffer;
import net.sourceforge.phpdt.internal.corext.template.TemplateTranslator;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;

/**
 * A context for phpdoc.
 */
public class PHPDocContext extends DocumentTemplateContext  {

	// tags
	private static final char HTML_TAG_BEGIN= '<';
	private static final char HTML_TAG_END= '>';
	private static final char JAVADOC_TAG_BEGIN= '@';	

	/**
	 * Creates a phpdoc template context.
	 * 
	 * @param type   the context type.
	 * @param document the document.
	 * @param completionPosition the completion position within the document.
	 * @param unit the compilation unit (may be <code>null</code>).
	 */
	public PHPDocContext(ContextType type, IDocument document, int completionOffset, int completionLength)
	//, int completionOffset, int completionLength, ICompilationUnit compilationUnit)
	{
    super(type, document, completionOffset, completionLength);
//		super(type, document, completionOffset, completionLength, compilationUnit);
	}

	/*
	 * @see TemplateContext#canEvaluate(Template templates)
	 */
	public boolean canEvaluate(Template template) {
		String key= getKey();
		
//		if (fForceEvaluation)
//			return true;
    return template.matches(getKey(), getContextType().getName());
//		return
//			template.matches(key, getContextType().getName()) &&
//			(key.length() != 0) && template.getName().toLowerCase().startsWith(key.toLowerCase());
	}

	/*
	 * @see DocumentTemplateContext#getStart()
	 */ 
	public int getStart() {
		try {
			IDocument document= getDocument();

			if (getCompletionLength() == 0) {
				int start= getCompletionOffset();
		
				if ((start != 0) && (document.getChar(start - 1) == HTML_TAG_END))
					start--;
		
				while ((start != 0) && Character.isUnicodeIdentifierPart(document.getChar(start - 1)))
					start--;
				
				if ((start != 0) && Character.isUnicodeIdentifierStart(document.getChar(start - 1)))
					start--;
		
				// include html and phpdoc tags
				if ((start != 0) && (
					(document.getChar(start - 1) == HTML_TAG_BEGIN) ||
					(document.getChar(start - 1) == JAVADOC_TAG_BEGIN)))
				{
					start--;
				}	
		
				return start;
				
			} else {

				int start= getCompletionOffset();
				int end= getCompletionOffset() + getCompletionLength();

				while (start != 0 && Character.isUnicodeIdentifierPart(document.getChar(start - 1)))
					start--;
				
				while (start != end && Character.isWhitespace(document.getChar(start)))
					start++;
				
				if (start == end)
					start= getCompletionOffset();	
				
				return start;					
			}

		} catch (BadLocationException e) {
			return getCompletionOffset();	
		}
	}

	/*
	 * @see net.sourceforge.phpdt.internal.corext.template.DocumentTemplateContext#getEnd()
	 */
	public int getEnd() {
		
		if (getCompletionLength() == 0)		
			return super.getEnd();

		try {			
			IDocument document= getDocument();

			int start= getCompletionOffset();
			int end= getCompletionOffset() + getCompletionLength();
			
			while (start != end && Character.isWhitespace(document.getChar(end - 1)))
				end--;
			
			return end;	

		} catch (BadLocationException e) {
			return super.getEnd();
		}		
	}

	/*
	 * @see net.sourceforge.phpdt.internal.corext.template.DocumentTemplateContext#getKey()
	 */
	public String getKey() {

		if (getCompletionLength() == 0)		
			return super.getKey();

		try {
			IDocument document= getDocument();

			int start= getStart();
			int end= getCompletionOffset();
			return start <= end
				? document.get(start, end - start)
				: ""; //$NON-NLS-1$
			
		} catch (BadLocationException e) {
			return super.getKey();			
		}
	}

	/*
	 * @see TemplateContext#evaluate(Template)
	 */
	public TemplateBuffer evaluate(Template template) throws CoreException {
		TemplateTranslator translator= new TemplateTranslator();
		TemplateBuffer buffer= translator.translate(template.getPattern());

		getContextType().edit(buffer, this);
			
		return buffer;
	}

}