using System.Linq;
using System.Threading.Tasks;
using Content.Server.Administration;
using Content.Server.Database;
using Content.Server.GameTicking;
using Content.Shared.GameTicking;
using Content.Shared._White.Reputation;
using Robust.Server.Player;
using Robust.Shared.Network;
using Robust.Shared.Player;
using Robust.Shared.Random;

namespace Content.Server._White.Reputation;

public sealed class ReputationManager : EntitySystem
{
    [Dependency] private readonly IServerDbManager _db = default!;
    [Dependency] private readonly IServerNetManager _netMgr = default!;
    [Dependency] private readonly IRobustRandom _random = default!;
    [Dependency] private readonly ILogManager _logManager = default!;
    [Dependency] private readonly IPlayerLocator _locator = default!;

    private readonly Dictionary<NetUserId, ReputationInfo> _cacheReputation = new();
    private readonly Dictionary<NetUserId, DateTime> _playerConnectionTime = new();

    private ISawmill _sawmill = default!;
    private const string SawmillId = "reputation.logs";

    public override void Initialize()
    {
        base.Initialize();

        _netMgr.RegisterNetMessage<ReputationNetMsg>();

        _netMgr.Connecting += OnConnecting;
        _netMgr.Connected += OnConnected;

        SubscribeLocalEvent<RoundRestartCleanupEvent>(OnRoundRestartCleanup);
        SubscribeLocalEvent<UpdateCachedReputationEvent>(UpdateCachedReputation);
        SubscribeLocalEvent<PlayerBeforeSpawnEvent>(OnPlayerSpawn);
    }

    #region Cache

        private void OnPlayerSpawn(PlayerBeforeSpawnEvent ev)
        {
            _playerConnectionTime[ev.Player.UserId] = DateTime.UtcNow;
        }

        private void OnConnected(object? sender, NetChannelArgs e)
        {
            _cacheReputation.TryGetValue(e.Channel.UserId, out var info);
            var msg = new ReputationNetMsg() { Info = info };
            _netMgr.ServerSendMessage(msg, e.Channel);
        }

        private async Task OnConnecting(NetConnectingArgs e)
        {
            var uid = e.UserId;
            var value = await GetPlayerReputation(uid);

            if (value == null)
                return;

            var info = new ReputationInfo() { Value = value.Value };
            _cacheReputation[e.UserId] = info;
        }

        private async void UpdateCachedReputation(UpdateCachedReputationEvent ev)
        {
            var player = ev.Player;
            if (!_cacheReputation.TryGetValue(player, out _))
                return;

            var value = await GetPlayerReputation(player);

            if (value == null)
                return;

            var info = new ReputationInfo() { Value = value.Value };
            _cacheReputation[player] = info;
        }

        private void OnRoundRestartCleanup(RoundRestartCleanupEvent ev)
        {
            var connectedPlayers = _netMgr.Channels.Select(channel => channel.UserId).ToList();
            var newDictionary = _cacheReputation
                .Where(player => connectedPlayers.Contains(player.Key))
                .ToDictionary(player => player.Key, player => player.Value);

            _cacheReputation.Clear();
            _playerConnectionTime.Clear();

            foreach (var kvp in newDictionary)
            {
                _cacheReputation.Add(kvp.Key, kvp.Value);
            }
        }

    #endregion

    #region PublicApi

    public async void SetPlayerReputation(NetUserId player, float value, string? admin = null)
    {
        var preValue = await GetPlayerReputation(player);
        if (preValue == null)
            return;

        var guid = player.UserId;
        await SetPlayerReputationTask(guid, value);

        RaiseLocalEvent(new UpdateCachedReputationEvent(player));
        await LogReputationChange(player, preValue.Value, false, admin);
    }

    public async void ModifyPlayerReputation(NetUserId player, float value, string? admin = null)
    {
        var preValue = await GetPlayerReputation(player);
        if (preValue == null)
            return;

        var guid = player.UserId;
        await ModifyPlayerReputationTask(guid, value);

        RaiseLocalEvent(new UpdateCachedReputationEvent(player));
        await LogReputationChange(player, preValue.Value, true, admin);
    }

    public async Task<float?> GetPlayerReputation(NetUserId player)
    {
        var guid = player.UserId;
        return await GetPlayerReputationTask(guid);
    }

    public bool GetCachedPlayerReputation(NetUserId player, out float? value)
    {
        var success = _cacheReputation.TryGetValue(player, out var info);
        value = info?.Value;
        return success;
    }

    public bool GetCachedPlayerConnection(NetUserId player, out DateTime date)
    {
        var success = _playerConnectionTime.TryGetValue(player, out var dateTime);
        date = dateTime;
        return success;
    }

    public int GetPlayerWeight(float rep)
    {
        // Min-max return values
        const int minValue = 30;
        const int maxValue = 50;

        // Min-max reputation values
        const float minReputation = 0f;
        const float maxReputation = 1000f;

        if (rep < minReputation)
            return 20;

        var normalizedReputation = (rep - minReputation) / (maxReputation - minReputation);
        var result = (int)(minValue + (normalizedReputation * (maxValue - minValue)));

        result = Math.Max(minValue, Math.Min(maxValue, result));

        return result;
    }

    public ICommonSession PickPlayerBasedOnReputation(List<ICommonSession> prefList)
    {
        var list = new List<ICommonSession>();

        foreach (var session in prefList)
        {
            if (!GetCachedPlayerReputation(session.UserId, out var value))
                continue;

            if (value == null)
                continue;

            var weight = GetPlayerWeight(value.Value);

            for (var i = 0; i < weight; i++)
            {
                list.Add(session);
            }
        }

        if (list.Count == 0)
            return _random.Pick(prefList);

        var number = _random.Next(list.Count - 1);
        return list[number];
    }

    #endregion

    #region Private

    private async Task SetPlayerReputationTask(Guid player, float value)
    {
        try
        {
            await _db.SetPlayerReputation(player, value);
        }
        catch (Exception)
        {
            // Nope
        }
    }

    private async Task ModifyPlayerReputationTask(Guid player, float value)
    {
        try
        {
            await _db.ModifyPlayerReputation(player, value);
        }
        catch (Exception)
        {
            // Nope
        }
    }

    private async Task<float?> GetPlayerReputationTask(Guid player)
    {
        try
        {
            return await _db.GetPlayerReputation(player);
        }
        catch (Exception)
        {
            return null;
        }
    }

    private async Task LogReputationChange(NetUserId user, float preValue, bool modify, string? admin = null)
    {
        var located = await _locator.LookupIdAsync(user);
        if (located == null)
            return;

        var newValue = await GetPlayerReputation(user);
        if (newValue == null)
            return;

        var adminName = admin != null ? $" by {admin}" : "";

        var msg = modify
            ? $"Reputation of {located.Username} was modified from {preValue} to {newValue.Value}{adminName}."
            : $"Reputation of {located.Username} was set from {preValue} to {newValue.Value}{adminName}.";

        _sawmill = _logManager.GetSawmill(SawmillId);
        _sawmill.Info(msg);
    }

    #endregion
}