using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.Threading.Tasks;
using System.Text.Json.Serialization;

namespace WpfBlockChanApp
{
    internal class Block
    {
        public int Index { get; set; }
        public string PreviousHash { get; set; }
        public string Hash { get; set; }
        public string Data { get; set; }
        public long Timestamp { get; set; }
        public int Nonce { get; set; }
        public int Difficulty { get; set; }
        public int LastAdjustBlock { get; set; }

        [JsonIgnore]
        public string GetString 
        { 
            get { return $"{Index}\n{Data}\n{PreviousHash}\n{Hash}"; }
        }

        public Block(int index, string previousHash, string data, int difficulty, int lastAdjustBlock)
        {
            Index = index;
            PreviousHash = previousHash;
            Data = data;
            Timestamp = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();
            Nonce = 0;
            Difficulty = difficulty;
            LastAdjustBlock = lastAdjustBlock;
            Hash = CalculateHash();
        }

        public string CalculateHash()
        {
            using (SHA256 sha256 = SHA256.Create())
            {
                byte[] inputBytes = Encoding.UTF8.GetBytes($"{Index}{PreviousHash}{Timestamp}{Data}{Difficulty}{Nonce}");
                byte[] outputBytes = sha256.ComputeHash(inputBytes);
                return Convert.ToBase64String(outputBytes);
            }
        }

        public bool MatchDifficulty()
        {
            return Hash[..Difficulty] != new string('0', Difficulty);
        }


    }
}