/*
 * Copyright 2000-2010 JetBrains s.r.o.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.intellij.refactoring.changeSignature;

import consulo.ide.IconDescriptorUpdaters;
import com.intellij.openapi.progress.ProgressManager;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.util.Iconable;
import com.intellij.openapi.util.Ref;
import com.intellij.psi.PsiElement;
import com.intellij.refactoring.RefactoringBundle;
import com.intellij.ui.CheckedTreeNode;
import com.intellij.ui.ColoredTreeCellRenderer;

import javax.swing.tree.TreeNode;
import java.util.*;

public abstract class MethodNodeBase<M extends PsiElement> extends CheckedTreeNode {
  protected final M myMethod;
  protected final Set<M> myCalled;
  protected final Project myProject;
  protected final Runnable myCancelCallback;
  private boolean myOldChecked;

  protected abstract MethodNodeBase<M> createNode(M caller, HashSet<M> called);

  protected abstract List<M> computeCallers();

  protected abstract void customizeRendererText(ColoredTreeCellRenderer renderer);

  protected MethodNodeBase(final M method, Set<M> called, Project project, Runnable cancelCallback) {
    super(method);
    myMethod = method;
    myCalled = called;
    myProject = project;
    myCancelCallback = cancelCallback;
    isChecked = false;
  }

  //IMPORTANT: do not build children in children()
  private void buildChildren() {
    if (children == null) {
      final List<M> callers = findCallers();
      children = new Vector(callers.size());
      for (M caller : callers) {
        final HashSet<M> called = new HashSet<M>(myCalled);
        called.add(myMethod);
        final MethodNodeBase<M> child = createNode(caller, called);
        children.add(child);
        child.parent = this;
      }
    }
  }

  @Override
  public TreeNode getChildAt(int index) {
    buildChildren();
    return super.getChildAt(index);
  }

  @Override
  public int getChildCount() {
    buildChildren();
    return super.getChildCount();
  }

  @Override
  public int getIndex(TreeNode aChild) {
    buildChildren();
    return super.getIndex(aChild);
  }

  private List<M> findCallers() {
    if (myMethod == null) return Collections.emptyList();
    final Ref<List<M>> callers = new Ref<List<M>>();
    if (!ProgressManager.getInstance().runProcessWithProgressSynchronously(new Runnable() {
      @Override
      public void run() {
        callers.set(computeCallers());
      }
    }, RefactoringBundle.message("caller.chooser.looking.for.callers"), true, myProject)) {
      myCancelCallback.run();
      return Collections.emptyList();
    }
    return callers.get();
  }

  public void customizeRenderer(ColoredTreeCellRenderer renderer) {
    if (myMethod == null) return;
    int flags = Iconable.ICON_FLAG_VISIBILITY | Iconable.ICON_FLAG_READ_STATUS;
    renderer.setIcon(IconDescriptorUpdaters.getIcon(myMethod, flags));

    customizeRendererText(renderer);
  }

  @Override
  public void setEnabled(final boolean enabled) {
    super.setEnabled(enabled);
    if (!enabled) {
      myOldChecked = isChecked();
      setChecked(false);
    }
    else {
      setChecked(myOldChecked);
    }
  }

  public M getMethod() {
    return myMethod;
  }

  public PsiElement getElementToSearch() {
    return getMethod();
  }

}