/*
 * Copyright 2000-2012 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 org.jetbrains.idea.devkit.actions;

import com.intellij.openapi.actionSystem.*;
import com.intellij.openapi.application.ApplicationManager;
import com.intellij.openapi.command.CommandProcessor;
import com.intellij.openapi.components.StoragePathMacros;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.openapi.editor.Editor;
import com.intellij.openapi.project.Project;
import com.intellij.psi.*;
import com.intellij.psi.codeStyle.CodeStyleManager;
import com.intellij.psi.codeStyle.JavaCodeStyleManager;
import com.intellij.psi.util.PsiTreeUtil;
import com.intellij.util.IncorrectOperationException;
import org.jetbrains.annotations.NonNls;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.idea.devkit.DevKitBundle;

/**
 * @author max
 */
public class GenerateComponentExternalizationAction extends AnAction {
  private static final Logger LOG = Logger.getInstance("#org.jetbrains.idea.devkit.actions.GenerateComponentExternalizationAction");

  @NonNls private final static String BASE_COMPONENT = "com.intellij.openapi.components.BaseComponent";
  @NonNls private final static String PERSISTENCE_STATE_COMPONENT = "com.intellij.openapi.components.PersistentStateComponent";
  @NonNls private final static String STATE = "com.intellij.openapi.components.State";
  @NonNls private final static String STORAGE = "com.intellij.openapi.components.Storage";

  public void actionPerformed(AnActionEvent e) {
    final PsiClass target = getComponentInContext(e.getDataContext());
    assert target != null;

    final PsiElementFactory factory = JavaPsiFacade.getInstance(target.getProject()).getElementFactory();
    final CodeStyleManager formatter = CodeStyleManager.getInstance(target.getManager().getProject());
    final JavaCodeStyleManager styler = JavaCodeStyleManager.getInstance(target.getProject());
    final String qualifiedName = target.getQualifiedName();
    Runnable runnable = new Runnable() {
      public void run() {
        ApplicationManager.getApplication().runWriteAction(new Runnable() {
          public void run() {
            try {
              final PsiReferenceList implList = target.getImplementsList();
              assert implList != null;
              final PsiJavaCodeReferenceElement referenceElement =
                factory.createReferenceFromText(PERSISTENCE_STATE_COMPONENT + "<" + qualifiedName + ">", target);
              implList.add(styler.shortenClassReferences(referenceElement.copy()));
              PsiMethod read = factory.createMethodFromText(
                "public void loadState(" + qualifiedName + " state) {\n" +
                "    com.intellij.util.xmlb.XmlSerializerUtil.copyBean(state, this);\n" +
                "}",
                target
              );

              read = (PsiMethod)formatter.reformat(target.add(read));
              styler.shortenClassReferences(read);

              PsiMethod write = factory.createMethodFromText(
                "public " + qualifiedName + " getState() {\n" +
                "    return this;\n" +
                "}\n",
                target
              );
              write = (PsiMethod)formatter.reformat(target.add(write));
              styler.shortenClassReferences(write);

              PsiAnnotation annotation = target.getModifierList().addAnnotation(STATE);

              annotation = (PsiAnnotation)formatter.reformat(annotation.replace(
                factory.createAnnotationFromText("@" + STATE +
                                                 "(name = \"" + qualifiedName + "\", " +
                                                 "storages = {@" + STORAGE + "(file = \"" + StoragePathMacros.WORKSPACE_FILE + "\"\n )})",
                                                 target)));
              styler.shortenClassReferences(annotation);
            }
            catch (IncorrectOperationException e1) {
              LOG.error(e1);
            }
          }
        });
      }
    };

    CommandProcessor.getInstance().executeCommand(target.getProject(), runnable,
                                                  DevKitBundle.message("command.implement.externalizable"), null);
  }

  @Nullable
  private PsiClass getComponentInContext(DataContext context) {
    Editor editor = CommonDataKeys.EDITOR.getData(context);
    Project project = CommonDataKeys.PROJECT.getData(context);
    if (editor == null || project == null) return null;

    PsiDocumentManager.getInstance(project).commitDocument(editor.getDocument());

    PsiFile file = CommonDataKeys.PSI_FILE.getData(context);
    if (file == null) return null;

    PsiClass contextClass = PsiTreeUtil.findElementOfClassAtOffset(file, editor.getCaretModel().getOffset(), PsiClass.class, false);
    if (contextClass == null || contextClass.isEnum() || contextClass.isInterface() || contextClass instanceof PsiAnonymousClass) {
      return null;
    }

    PsiClass componentClass = JavaPsiFacade.getInstance(file.getProject()).findClass(BASE_COMPONENT, file.getResolveScope());
    if (componentClass == null || !contextClass.isInheritor(componentClass, true)) return null;

    PsiClass externClass = JavaPsiFacade.getInstance(file.getProject()).findClass(PERSISTENCE_STATE_COMPONENT, file.getResolveScope());
    if (externClass == null || contextClass.isInheritor(externClass, true)) return null;


    return contextClass;
  }

  public void update(AnActionEvent e) {
    super.update(e);
    final PsiClass target = getComponentInContext(e.getDataContext());

    final Presentation presentation = e.getPresentation();
    presentation.setEnabled(target != null);
    presentation.setVisible(target != null);
  }
}