using AnotherReplayReader.Utils;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Security.Cryptography;
using System.Text;
using System.Text.Json;
using System.Text.Json.Serialization;
using System.Threading.Tasks;
using System.Web;
using static System.Text.Json.JsonSerializer;

namespace AnotherReplayReader
{
    internal sealed class IpAndPlayer
    {
        public static string SimpleIPToString(uint ip)
        {
            return $"{ip / 256 / 256 / 256}.{ip / 256 / 256 % 256}.{ip / 256 % 256}.{ip % 256}";
        }

        [JsonNumberHandling(JsonNumberHandling.AllowReadingFromString)]
        public uint Ip
        {
            get => _ip;
            set
            {
                _ip = value;
                IpString = SimpleIPToString(_ip);
            }
        }
        public string IpString { get; private set; } = "0.0.0.0";
        public string Id
        {
            get => _id;
            set
            {
                _id = value;
                _pinyin = _id.ToPinyin();
            }
        }
        public string? PinyinId => _pinyin;

        private uint _ip;
        private string _id = string.Empty;
        private string? _pinyin;
    }

    internal class PlayerIdentity
    {
        private const string StoredKey = "pt";
        private const string IvKey = "jw";
        private static readonly JsonSerializerOptions _jsonOptions = new()
        {
            PropertyNameCaseInsensitive = true
        };
        private readonly object _lock = new();
        private readonly Cache _cache;
        private IReadOnlyDictionary<uint, string>? _list;

        public bool IsUsable => Lock.Run(_lock, () => _list is not null);

        public PlayerIdentity(Cache cache)
        {
            _cache = cache;
            Task.Run(FetchLocal);
            Fetch();
        }

        public Task Fetch()
        {
            return Task.Run(async () =>
            {
                try
                {
                    var key = HttpUtility.UrlEncode(Auth.GetKey());
                    var request = WebRequest.Create($"https://lanyi.altervista.org/playertable/playertable.php?do=getTable&key={key}");
                    using var response = await request.GetResponseAsync().ConfigureAwait(false);
                    using var stream = response.GetResponseStream();
                    var list = await DeserializeAsync<List<IpAndPlayer>>(stream, _jsonOptions).ConfigureAwait(false);
                    var converted = list?.ToDictionary(x => x.Ip, x => x.Id);
                    lock (_lock)
                    {
                        _list = converted;
                    }

                    if (list is null || Auth.IdAsKey() is not { } encryptKey)
                    {
                        _cache.Set<string?>(StoredKey, null);
                        return;
                    }

                    using var memory = new MemoryStream();
                    using var aes = Aes.Create();
                    using (var encryptor = aes.CreateEncryptor(encryptKey, aes.IV))
                    using (var decryptorStream = new CryptoStream(memory, encryptor, CryptoStreamMode.Write))
                    {
                        await SerializeAsync(decryptorStream, list, _jsonOptions).ConfigureAwait(false);
                    }
                    memory.Flush();
                    _cache.SetValues((StoredKey, Convert.ToBase64String(memory.ToArray())), (IvKey, Convert.ToBase64String(aes.IV)));
                }
                catch { }
            });
        }

        public List<IpAndPlayer> AsSortedList()
        {
            using var locker = new Lock(_lock);

            return _list?
                .Select((kv) => new IpAndPlayer { Ip = kv.Key, Id = kv.Value })
                .OrderBy(x => x.Ip)
                .ToList() ?? new(0);
        }

        public string GetRealName(uint ip)
        {
            if (ip == 0)
            {
                return string.Empty;
            }

            using var locker = new Lock(_lock);
            if (_list is null || !_list.TryGetValue(ip, out var name))
            {
                return string.Empty;
            }

            return name;
        }

        public string FormatRealName(uint ip)
        {
            var name = GetRealName(ip);
            if (string.IsNullOrEmpty(name))
            {
                name = IpAndPlayer.SimpleIPToString(ip);
            }
            return $"（{name}）";
        }

        public string QueryRealNameAndIP(uint ip)
        {
            var ipText = IpAndPlayer.SimpleIPToString(ip);
            var name = GetRealName(ip);
            if (string.IsNullOrEmpty(name))
            {
                return ipText;
            }
            return $"{name}，{ipText}";
        }

        private async Task FetchLocal()
        {
            try
            {
                await _cache.Initialization;
                var stored = _cache.GetOrDefault(StoredKey, string.Empty);
                var iv = Convert.FromBase64String(_cache.GetOrDefault(IvKey, string.Empty));
                if (string.IsNullOrWhiteSpace(stored) || Auth.IdAsKey() is not { } key)
                {
                    return;
                }

                using var aes = Aes.Create();
                using var decryptor = aes.CreateDecryptor(key, iv);
                using var memory = new MemoryStream(Convert.FromBase64String(stored));
                using var decryptorStream = new CryptoStream(memory, decryptor, CryptoStreamMode.Read);
                var cachedTable = await DeserializeAsync<List<IpAndPlayer>>(decryptorStream, _jsonOptions).ConfigureAwait(false);
                if (cachedTable is null)
                {
                    return;
                }
                var converted = cachedTable.ToDictionary(x => x.Ip, x => x.Id);
                converted[0] = "【没有网络连接，正在使用上次保存的数据】";
                lock (_lock)
                {
                    _list ??= converted;
                }
            }
            catch { }
        }
    }
}