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

import java.util.ArrayList;

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.Templates;
import net.sourceforge.phpdt.internal.corext.template.php.CompilationUnitContextType;
import net.sourceforge.phpdt.internal.ui.PHPUiImages;
import net.sourceforge.phpdt.internal.ui.text.java.IPHPCompletionProposal;
import net.sourceforge.phpeclipse.PHPeclipsePlugin;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.Region;
import org.eclipse.swt.graphics.Point;
//import org.eclipse.jdt.internal.ui.text.link.LinkedPositionManager;

public class TemplateEngine {

  /** The context type. */
  private ContextType fContextType;
  /** The result proposals. */
  private ArrayList fProposals = new ArrayList();

  /**
   * Creates the template engine for a particular context type.
   * See <code>TemplateContext</code> for supported context types.
   */
  public TemplateEngine(ContextType contextType) {
    //	Assert.isNotNull(contextType);
    fContextType = contextType;
  }

  /**
   * Empties the collector.
   * 
   * @param viewer the text viewer  
   * @param unit   the compilation unit (may be <code>null</code>)
   */
  public void reset() {
    fProposals.clear();
  }

  /**
   * Returns the array of matching templates.
   */
  public IPHPCompletionProposal[] getResults() {
    return (IPHPCompletionProposal[]) fProposals.toArray(new IPHPCompletionProposal[fProposals.size()]);
  }

  /**
   * Inspects the context of the compilation unit around <code>completionPosition</code>
   * and feeds the collector with proposals.
   * @param viewer the text viewer
   * @param completionPosition the context position in the document of the text viewer
   * @param compilationUnit the compilation unit (may be <code>null</code>)
   */
  public void complete(ITextViewer viewer, int completionPosition)
  //,ICompilationUnit compilationUnit)
  //hrows JavaModelException
  {
    IDocument document = viewer.getDocument();

    if (!(fContextType instanceof CompilationUnitContextType))
      return;

    Point selection = viewer.getSelectedRange();
    // remember selected text
    String selectedText = null;
    if (selection.y != 0) {
      try {
        selectedText = document.get(selection.x, selection.y);
      } catch (BadLocationException e) {
      }
    }

    ((CompilationUnitContextType) fContextType).setContextParameters(document, completionPosition, selection.y); //mpilationUnit);
    DocumentTemplateContext context = (DocumentTemplateContext) fContextType.createContext();
    int start = context.getStart();
    int end = context.getEnd();
    IRegion region = new Region(start, end - start);

    Template[] templates = Templates.getInstance().getTemplates();
    int maxProposals = PHPeclipsePlugin.MAX_PROPOSALS;

    for (int i = 0; i != templates.length; i++)
      if (context.canEvaluate(templates[i])) {
        if (maxProposals-- < 0) {
          return;
        }
        fProposals.add(new TemplateProposal(templates[i], context, region, viewer, PHPUiImages.get(PHPUiImages.IMG_OBJS_TEMPLATE)));
      }
  }

}