/*
 * (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 compilation unit context.
 */
public class HTMLUnitContext extends DocumentTemplateContext {

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

  private static final String specialChars = "&<#";
  /** 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 HTMLUnitContext(ContextType type, IDocument document, int completionPosition)
  //,ICompilationUnit compilationUnit)
  {
    super(type, document, completionPosition, 0);
    //	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 = getCompletionOffset();
      char ch = ' ';
      while (start != 0) {
        ch = document.getChar(start - 1);
        if (specialChars.indexOf(ch) != (-1)) {
          return --start;
        }
        if (Character.isUnicodeIdentifierPart(ch)) {
          start--;
        } else {
          break;
        }
      }
      if ((start != 0) && Character.isUnicodeIdentifierStart(document.getChar(start - 1))) {
        start--;
        if ((start != 0) && specialChars.indexOf(document.getChar(start - 1)) != (-1)) {
          start--;
        }
      }

      //      while (((start != 0)
      //        && Character.isUnicodeIdentifierPart(document.getChar(start - 1)))
      //        || ((start != 0)
      //          && specialChars.indexOf(document.getChar(start - 1)) != (-1))) {
      //        start--;
      //      }
      //
      //if (((start != 0)
      //	&& Character.isUnicodeIdentifierStart(document.getChar(start - 1)))
      //	|| ((start != 0)
      //		&& specialChars.indexOf(document.getChar(start - 1)) != (-1))) {
      //	start--;
      //}

      return start;

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

  /**
   * 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;
  //		}	
  //	}

}