﻿/*
 * SonarAnalyzer for .NET
 * Copyright (C) 2015-2017 SonarSource SA
 * mailto: contact AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

using System;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Linq;
using Microsoft.CodeAnalysis;

namespace SonarAnalyzer.Helpers.FlowAnalysis.Common
{
    public class SimpleBlock : Block
    {
        internal SimpleBlock(Block successor)
        {
            if (successor == null)
            {
                throw new ArgumentNullException(nameof(successor));
            }

            SuccessorBlock = successor;
        }

        public Block SuccessorBlock { get; internal set; }

        public override IReadOnlyList<Block> SuccessorBlocks => ImmutableArray.Create(SuccessorBlock);

        internal override void ReplaceSuccessors(Dictionary<Block, Block> replacementMapping)
        {
            if (replacementMapping.ContainsKey(SuccessorBlock))
            {
                SuccessorBlock = replacementMapping[SuccessorBlock];
            }
        }

        internal override Block GetPossibleNonEmptySuccessorBlock()
        {
            if (ReversedInstructions.Any())
            {
                return this;
            }

            return SuccessorBlock.GetPossibleNonEmptySuccessorBlock();
        }
    }
}
