using System;
using System.Diagnostics;

namespace TwlBackupBlock
{
    public enum BkpType
    {
        NORMAL,
        WITH_PRIVATE_SAVE,
        LEGACY
    };

    /// <summary>
    /// ブロックの集合です。
    /// </summary>
    public class Blocks : ICloneable
    {
        private const int NUM_BLOCKS = 15;

        public Block banner;
        public Block header;
        public Block signature;
        public Block tmd;
        public Block[] content;
        public Block publicSave;
        public Block subBanner;
        public Block privateSave;

        /// <summary>
        /// Blocksクラスの新しいインスタンスを初期化します。
        /// </summary>
        public Blocks()
        {
            banner = new Block();
            header = new Block();
            signature = new Block();
            tmd = new Block();
            content = new Block[HeaderBody.MAX_CONTENTS];
            for (int i = 0; i < HeaderBody.MAX_CONTENTS; i++)
            {
                content[i] = new Block();
            }
            publicSave = new Block();
            subBanner = new Block();
            privateSave = new Block();
        }

        /// <summary>
        /// 指定したインデックスのブロックにアクセスします。
        /// </summary>
        /// <param name="index">インデックス。</param>
        /// <returns>指定したインデックスのブロック。</returns>
        public Block this[int index]
        {
            get
            {
                if (4 <= index && index < 4 + HeaderBody.MAX_CONTENTS)
                {
                    return content[index - 4];
                }
                else
                {
                    switch (index)
                    {
                        case 0: return banner;
                        case 1: return header;
                        case 2: return signature;
                        case 3: return tmd;
                        case 12: return publicSave;
                        case 13: return subBanner;
                        case 14: return privateSave;
                        default:
                            Debug.Assert(false);
                            return null; // never reach
                    }
                }
            }
        }

        /// <summary>
        /// ブロック数を取得します。
        /// </summary>
        public int Length
        {
            get
            {
                return NUM_BLOCKS;
            }
        }

        /// <summary>
        /// Blocksのディープコピーを作成します。
        /// </summary>
        /// <returns>Blocksのコピー</returns>
        public object Clone()
        {
            Blocks newBlocks = new Blocks();
            newBlocks.banner = (Block)banner.Clone();
            newBlocks.header = (Block)header.Clone();
            newBlocks.signature = (Block)signature.Clone();
            newBlocks.tmd = (Block)tmd.Clone();
            for (int i = 0; i < HeaderBody.MAX_CONTENTS; i++)
            {
                if (content[i].body != null)
                {
                    newBlocks.content[i] = (Block)content[i].Clone();
                }
            }
            newBlocks.publicSave = (Block)publicSave.Clone();
            newBlocks.subBanner = (Block)subBanner.Clone();
            if (privateSave.body != null)
            {
                newBlocks.privateSave = (Block)privateSave.Clone();
            }
            return newBlocks;
        }
    }
}