/*
 * Copyright 2000-2014 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.jetbrains.python.inspections;

import com.intellij.codeInspection.LocalInspectionToolSession;
import com.intellij.codeInspection.ProblemsHolder;
import com.intellij.psi.PsiElement;
import com.intellij.psi.PsiElementVisitor;
import com.jetbrains.python.PyPsiBundle;
import com.jetbrains.python.inspections.quickfix.PyMoveExceptQuickFix;
import com.jetbrains.python.psi.*;
import com.jetbrains.python.psi.types.TypeEvalContext;
import org.jetbrains.annotations.NotNull;

import java.util.HashSet;
import java.util.Set;

public final class PyExceptClausesOrderInspection extends PyInspection {

  @Override
  public @NotNull PsiElementVisitor buildVisitor(@NotNull ProblemsHolder holder,
                                                 boolean isOnTheFly,
                                                 @NotNull LocalInspectionToolSession session) {
    return new Visitor(holder, PyInspectionVisitor.getContext(session));
  }

  private static class Visitor extends PyInspectionVisitor {

    Visitor(final ProblemsHolder holder, @NotNull TypeEvalContext context) {
      super(holder, context);
    }

    @Override
    public void visitPyTryExceptStatement(@NotNull PyTryExceptStatement node) {
      PyExceptPart[] exceptParts = node.getExceptParts();
      if (exceptParts.length > 1) {
        Set<PyClass> exceptClasses = new HashSet<>();
        for (PyExceptPart exceptPart : exceptParts) {
          PyExpression exceptClass = exceptPart.getExceptClass();
          if (exceptClass instanceof PyReferenceExpression) {
            PsiElement element = ((PyReferenceExpression)exceptClass).followAssignmentsChain(getResolveContext()).getElement();
            if (element instanceof PyClass pyClass) {
              if (exceptClasses.contains(pyClass)) {
                registerProblem(exceptClass, PyPsiBundle.message("INSP.bad.except.exception.class.already.caught", pyClass.getName()));
              }
              else {
                for (PyClass superClass : pyClass.getSuperClasses(null)) {
                  if (exceptClasses.contains(superClass)) {
                    registerProblem(exceptClass, PyPsiBundle
                                      .message("INSP.bad.except.superclass.of.exception.class.already.caught", superClass.getName(), pyClass.getName()),
                                    new PyMoveExceptQuickFix());
                  }
                }
              }
              exceptClasses.add(pyClass);
            }
          }
        }
      }
    }
  }
}
