/*
 * Copyright 2017 Google Inc. All Rights Reserved.
 *
 * 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.google.errorprone.bugpatterns;

import static com.google.errorprone.BugPattern.Category.JDK;
import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
import static com.google.errorprone.matchers.Description.NO_MATCH;
import static com.google.errorprone.util.ASTHelpers.findSuperMethods;
import static com.google.errorprone.util.ASTHelpers.hasAnnotation;

import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.annotations.DoNotCall;
import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
import com.google.errorprone.bugpatterns.BugChecker.MethodTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.fixes.SuggestedFixes;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.source.tree.MethodTree;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import javax.lang.model.element.Modifier;

/** @author cushon@google.com (Liam Miller-Cushon) */
// TODO(cushon): this should subsume ImmutableModification and LocalizableWrongToString
@BugPattern(
  name = "DoNotCall",
  category = JDK,
  summary = "This method should not be called.",
  severity = ERROR
)
public class DoNotCallChecker extends BugChecker
    implements MethodTreeMatcher, MethodInvocationTreeMatcher {
  @Override
  public Description matchMethod(MethodTree tree, VisitorState state) {
    MethodSymbol symbol = ASTHelpers.getSymbol(tree);
    if (symbol == null) {
      return NO_MATCH;
    }
    if (hasAnnotation(tree, DoNotCall.class, state)) {
      if (symbol.getModifiers().contains(Modifier.ABSTRACT)) {
        return NO_MATCH;
      }
      if (symbol.getModifiers().contains(Modifier.FINAL)) {
        return NO_MATCH;
      }
      if (symbol.owner.enclClass().getModifiers().contains(Modifier.FINAL)) {
        return NO_MATCH;
      }
        return buildDescription(tree)
            .setMessage("Methods annotated with @DoNotCall should be final.")
            .addFix(SuggestedFixes.addModifiers(tree, state, Modifier.FINAL))
            .build();
    }
    return findSuperMethods(symbol, state.getTypes())
        .stream()
        .filter(s -> hasAnnotation(s, DoNotCall.class, state))
        .findAny()
        .map(
            s -> {
              String message =
                  String.format(
                      "Method overrides %s in %s which is annotated @DoNotCall,"
                          + " it should also be annotated.",
                      s.getSimpleName(), s.owner.getSimpleName());
              return buildDescription(tree)
                  .setMessage(message)
                  .addFix(
                      SuggestedFix.builder()
                          .addImport(DoNotCall.class.getName())
                          .prefixWith(tree, "@DoNotCall ")
                          .build())
                  .build();
            })
        .orElse(NO_MATCH);
  }

  @Override
  public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
    DoNotCall doNotCall = ASTHelpers.getAnnotation(tree, DoNotCall.class);
    if (doNotCall == null) {
      return NO_MATCH;
    }
    StringBuilder message = new StringBuilder("This method should not be called");
    if (doNotCall.value().isEmpty()) {
      message.append(", see its documentation for details.");
    } else {
      message.append(": ").append(doNotCall.value());
    }
    return buildDescription(tree).setMessage(message.toString()).build();
  }
}