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

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Vector;

import net.sourceforge.phpdt.internal.corext.textmanipulation.MultiTextEdit;
import net.sourceforge.phpdt.internal.corext.textmanipulation.NopTextEdit;
import net.sourceforge.phpdt.internal.corext.textmanipulation.SimpleTextEdit;
import net.sourceforge.phpdt.internal.corext.textmanipulation.TextBuffer;
import net.sourceforge.phpdt.internal.corext.textmanipulation.TextBufferEditor;
import net.sourceforge.phpdt.internal.corext.textmanipulation.TextEdit;
import org.eclipse.core.runtime.CoreException;

 

/**
 * A context type is a context factory.
 */
public abstract class ContextType implements ITemplateEditor {

  /** name of the context type */
  private final String fName;

  /** variables used by this content type */
  private final Map fVariables = new HashMap();

  /**
   * Creates a context type with a name.
   * 
   * @param name the name of the context. It has to be unique wrt to other context names.
   */
  public ContextType(String name) {
    fName = name;
  }

  /**
   * Returns the name of the context type.
   */
  public String getName() {
    return fName;
  }

  /**
   * Adds a template variable to the context type.
   */
  public void addVariable(TemplateVariable variable) {
    fVariables.put(variable.getName(), variable);
  }

  /**
   * Removes a template variable from the context type.
   */
  public void removeVariable(TemplateVariable variable) {
    fVariables.remove(variable.getName());
  }

  /**
   * Removes all template variables from the context type.
   */
  public void removeAllVariables() {
    fVariables.clear();
  }

  /**
   * Returns an iterator for the variables known to the context type.
   */
  public Iterator variableIterator() {
    return fVariables.values().iterator();
  }

  /**
   * Creates a template context.
   */
  public abstract TemplateContext createContext();

  /*
   * @see ITemplateEditor#edit(TemplateBuffer)
   */
  public void edit(TemplateBuffer templateBuffer, TemplateContext context) throws CoreException {
    TextBuffer textBuffer = TextBuffer.create(templateBuffer.getString());
    TemplatePosition[] variables = templateBuffer.getVariables();

    MultiTextEdit positions = variablesToPositions(variables);
    MultiTextEdit multiEdit = new MultiTextEdit();

    // iterate over all variables and try to resolve them
    for (int i = 0; i != variables.length; i++) {
      TemplatePosition variable = variables[i];

      if (variable.isResolved())
        continue;

      String name = variable.getName();
      int[] offsets = variable.getOffsets();
      int length = variable.getLength();

      TemplateVariable evaluator = (TemplateVariable) fVariables.get(name);
      String value = (evaluator == null) ? null : evaluator.evaluate(context);

      if (value == null)
        continue;

      variable.setLength(value.length());
      variable.setResolved(evaluator.isResolved(context));

      for (int k = 0; k != offsets.length; k++)
        multiEdit.add(SimpleTextEdit.createReplace(offsets[k], length, value));
    }

    TextBufferEditor editor = new TextBufferEditor(textBuffer);
    editor.add(positions);
    editor.add(multiEdit);
    editor.performEdits(null);

    positionsToVariables(positions, variables);

    templateBuffer.setContent(textBuffer.getContent(), variables);
  }

  private static MultiTextEdit variablesToPositions(TemplatePosition[] variables) {
    MultiTextEdit positions = new MultiTextEdit();
    for (int i = 0; i != variables.length; i++) {
      int[] offsets = variables[i].getOffsets();
      for (int j = 0; j != offsets.length; j++)
        positions.add(new NopTextEdit(offsets[j], 0));
    }

    return positions;
  }

  private static void positionsToVariables(MultiTextEdit positions, TemplatePosition[] variables) {
    Iterator iterator = positions.iterator();

    for (int i = 0; i != variables.length; i++) {
      TemplatePosition variable = variables[i];

      int[] offsets = new int[variable.getOffsets().length];
      for (int j = 0; j != offsets.length; j++)
        offsets[j] = ((TextEdit) iterator.next()).getTextRange().getOffset();

      variable.setOffsets(offsets);
    }
  }

  /**
   * Returns the templates associated with this context type.
   */
  public Template[] getTemplates() {
    Template[] templates = Templates.getInstance().getTemplates();

    Vector vector = new Vector();
    for (int i = 0; i != templates.length; i++)
      if (templates[i].getContextTypeName().equals(fName))
        vector.add(templates[i]);

    return (Template[]) vector.toArray(new Template[vector.size()]);
  }

}