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

import java.util.ArrayList;
import java.util.Iterator;
import java.util.SortedMap;

import net.sourceforge.phpdt.core.compiler.ITerminalSymbols;
import net.sourceforge.phpdt.internal.corext.template.ContextType;
import net.sourceforge.phpdt.internal.corext.template.php.CompilationUnitContextType;
import net.sourceforge.phpdt.internal.corext.template.php.PHPUnitContext;
import net.sourceforge.phpdt.internal.ui.text.java.IPHPCompletionProposal;
import net.sourceforge.phpeclipse.PHPeclipsePlugin;
import net.sourceforge.phpeclipse.builder.PHPIdentifierLocation;

import org.eclipse.core.resources.IFile;
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 DeclarationEngine {

  /** The context type. */
  private ContextType fContextType;
  /** The result proposals. */
  private ArrayList fProposals = new ArrayList();
  /** Token determines last which declarations are allowed for proposal */
  private int fLastSignificantToken;

  private IFile fFile;
  private String fFileName;

  /**
   * Creates the template engine for a particular context type.
   * See <code>TemplateContext</code> for supported context types.
   */
  public DeclarationEngine(ContextType contextType, int lastSignificantToken, IFile file) {
    //	Assert.isNotNull(contextType);
    fContextType = contextType;

    fLastSignificantToken = lastSignificantToken;
    fFile = file;
    if (fFile != null) {
      fFileName = fFile.getFullPath().toString();
    } else {
      fFileName = "";
    }
  }

  /**
   * 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, SortedMap map) {
    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);

    PHPUnitContext context = (PHPUnitContext) fContextType.createContext();
    int start = context.getStart();
    int end = context.getEnd();
    String prefix = context.getKey();
    IRegion region = new Region(start, end - start);

    String identifier = null;

    SortedMap subMap = map.subMap(prefix, prefix + '\255');
    Iterator iter = subMap.keySet().iterator();
    PHPIdentifierLocation location;
    ArrayList list;
    int maxProposals = PHPeclipsePlugin.MAX_PROPOSALS;
    while (iter.hasNext()) {
      identifier = (String) iter.next();
      if (context.canEvaluate(identifier)) {
        list = (ArrayList) subMap.get(identifier);
        for (int i = 0; i < list.size(); i++) {
          location = (PHPIdentifierLocation) list.get(i);
          int type = location.getType();
          switch (fLastSignificantToken) {
            case ITerminalSymbols.TokenNameMINUS_GREATER :
              if (type != PHPIdentifierLocation.METHOD && type != PHPIdentifierLocation.VARIABLE) {
                continue; // for loop
              }
              break;
            case ITerminalSymbols.TokenNamethis :
              if (type != PHPIdentifierLocation.METHOD && type != PHPIdentifierLocation.VARIABLE) {
                continue; // for loop
              }
              if (!fFileName.equals(location.getFilename())) {
                continue; // for loop
              }
              break;
            case ITerminalSymbols.TokenNamenew :
              if (type != PHPIdentifierLocation.CLASS && type != PHPIdentifierLocation.CONSTRUCTOR) {
                continue; // for loop
              }
              break;
            default :
              if (type == PHPIdentifierLocation.METHOD || type == PHPIdentifierLocation.CONSTRUCTOR || type == PHPIdentifierLocation.VARIABLE) {
                continue; // for loop
              }
          }
          if (maxProposals-- < 0) {
            return;
          }
          fProposals.add(new DeclarationProposal(identifier, location, context, region, viewer));
        }
      }
    }

  }

}