using System;
using System.Security.Cryptography;

namespace Models
{
    public class Block
    {
        public int Index { get; set; }
        public Int64 TimeStamp { get; set; }
        public byte[] PrevHash { get; set; }
        public byte[] Hash { get; set; }
        public byte[] Transaction { get; set; }

        public Block( byte[] prevHash, byte[] transaction)
        {
            Index = 0;
            PrevHash = prevHash;
            TimeStamp = DateTime.Now.Ticks;
            Transaction = transaction;
            Hash = GenerateHash();
        }

        public byte[] GenerateHash()
        {
            SHA256 sha256 = SHA256.Create();
            byte[] tStamp = BitConverter.GetBytes(TimeStamp);
            byte[] sumBytes = new byte[tStamp.Length + PrevHash.Length + Transaction.Length];

            System.Buffer.BlockCopy(tStamp, 0, sumBytes, 0, tStamp.Length);
            System.Buffer.BlockCopy(PrevHash, 0, sumBytes, tStamp.Length, PrevHash.Length);
            System.Buffer.BlockCopy(Transaction, 0, sumBytes, tStamp.Length + PrevHash.Length, Transaction.Length);

            byte[] hashBytes = sha256.ComputeHash(sumBytes);
            return hashBytes;
        }

    }
}