Initial split of the modules

NadekoBot.Core/Modules/Administration/Services/GuildTimezoneService.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
+using Discord.WebSocket;
+using NadekoBot.Extensions;
+using NadekoBot.Services;
+using NadekoBot.Services.Database.Models;
+
+namespace NadekoBot.Modules.Administration.Services
+{
+    public class GuildTimezoneService : INService
+    {
+        // todo 70 this is a hack >.<
+        public static ConcurrentDictionary<ulong, GuildTimezoneService> AllServices { get; } = new ConcurrentDictionary<ulong, GuildTimezoneService>();
+        private ConcurrentDictionary<ulong, TimeZoneInfo> _timezones;
+        private readonly DbService _db;
+
+        public GuildTimezoneService(DiscordSocketClient client, IEnumerable<GuildConfig> gcs, DbService db)
+        {
+            _timezones = gcs
+                .Select(x =>
+                {
+                    TimeZoneInfo tz;
+                    try
+                    {
+                        if (x.TimeZoneId == null)
+                            tz = null;
+                        else
+                            tz = TimeZoneInfo.FindSystemTimeZoneById(x.TimeZoneId);
+                    }
+                    catch
+                    {
+                        tz = null;
+                    }
+                    return (x.GuildId, tz);
+                })
+                .Where(x => x.Item2 != null)
+                .ToDictionary(x => x.Item1, x => x.Item2)
+                .ToConcurrent();
+
+            var curUser = client.CurrentUser;
+            if (curUser != null)
+                AllServices.TryAdd(curUser.Id, this);
+            _db = db;
+        }
+
+        public TimeZoneInfo GetTimeZoneOrDefault(ulong guildId)
+        {
+            if (_timezones.TryGetValue(guildId, out var tz))
+                return tz;
+            return null;
+        }
+
+        public void SetTimeZone(ulong guildId, TimeZoneInfo tz)
+        {
+            using (var uow = _db.UnitOfWork)
+            {
+                var gc = uow.GuildConfigs.For(guildId, set => set);
+
+                gc.TimeZoneId = tz?.Id;
+                uow.Complete();
+
+                if (tz == null)
+                    _timezones.TryRemove(guildId, out tz);
+                else
+                    _timezones.AddOrUpdate(guildId, tz, (key, old) => tz);
+            }
+        }
+
+        public TimeZoneInfo GetTimeZoneOrUtc(ulong guildId)
+            => GetTimeZoneOrDefault(guildId) ?? TimeZoneInfo.Utc;
+    }
+}