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

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 compilation unit context.
 */
public class CompilationUnitContext extends DocumentTemplateContext {

  /** The platform default line delimiter. */
  private static final String PLATFORM_LINE_DELIMITER= System.getProperty("line.separator"); //$NON-NLS-1$

	/** The compilation unit, may be <code>null</code>. */
//	private final ICompilationUnit fCompilationUnit;

	/**
	 * Creates a compilation unit context.
	 * 
	 * @param type   the context type.
	 * @param document the document.
	 * @param completionPosition the completion position within the document.
	 * @param compilationUnit the compilation unit (may be <code>null</code>).
	 */
	protected CompilationUnitContext(ContextType type, IDocument document, int completionPosition)
	//,ICompilationUnit compilationUnit)
	{
		super(type, document, completionPosition);
	//	fCompilationUnit= compilationUnit;
	}
	
    /*
   * @see TemplateContext#canEvaluate(Template templates)
   */
  public boolean canEvaluate(Template template) {
    // return fForceEvaluation || 
    return template.matches(getKey(), getContextType().getName());
  }
  
  /**
   * Returns <code>true</code> if template matches the prefix and context,
   * <code>false</code> otherwise.
   */
  public boolean canEvaluate(String identifier) {
    String prefix = getKey();
    return 
//      fEnabled &&
//      fContextTypeName.equals(contextTypeName) &&
      (prefix.length() != 0) &&
      identifier.toLowerCase().startsWith(prefix.toLowerCase());
  }
  
    /*
   * @see TemplateContext#evaluate(Template template)
   */
  public TemplateBuffer evaluate(Template template) throws CoreException {
    if (!canEvaluate(template))
      return null;
    
    TemplateTranslator translator= new TemplateTranslator();
    TemplateBuffer buffer= translator.translate(template.getPattern());

    getContextType().edit(buffer, this);
      
    String lineDelimiter= null;
    try {
      lineDelimiter= getDocument().getLineDelimiter(0);
    } catch (BadLocationException e) {
    }

    if (lineDelimiter == null)
      lineDelimiter= PLATFORM_LINE_DELIMITER;
    
//    ITemplateEditor formatter= new JavaFormatter(lineDelimiter);
//    formatter.edit(buffer, this);

    return buffer;
  }
  
  /*
   * @see DocumentTemplateContext#getCompletionPosition();
   */
  public int getStart() {
    IDocument document= getDocument();
    try {
      int start= getCompletionPosition();
  
      while ( ((start != 0) && Character.isUnicodeIdentifierPart(document.getChar(start - 1))) ||
               ((start != 0) && document.getChar(start - 1)=='$') ) {
        start--;
      }
        
      if ( ((start != 0) && Character.isUnicodeIdentifierStart(document.getChar(start - 1))) ||
           ((start != 0) && document.getChar(start - 1)=='$')) {
        start--;
      }
  
      return start;

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

  /**
   * Returns the character before start position of completion.
   */
  public char getCharacterBeforeStart() {
    int start= getStart();
    
    try {
      return start == 0
        ? ' '
        : getDocument().getChar(start - 1);

    } catch (BadLocationException e) {
      return ' ';
    }
  }
	/**
	 * Returns the compilation unit if one is associated with this context, <code>null</code> otherwise.
	 */
//	public final ICompilationUnit getCompilationUnit() {
//		return fCompilationUnit;
//	}

	/**
	 * Returns the enclosing element of a particular element type, <code>null</code>
	 * if no enclosing element of that type exists.
	 */
//	public IJavaElement findEnclosingElement(int elementType) {
//		if (fCompilationUnit == null)
//			return null;
//
//		try {
//			IJavaElement element= fCompilationUnit.getElementAt(getStart());
//			while (element != null && element.getElementType() != elementType)
//				element= element.getParent();
//			
//			return element;
//
//		} catch (JavaModelException e) {
//			return null;
//		}	
//	}

}