Massive cleanup

- Removed GuildConfigs repository, moved to extensions
- Moved StreamSettings extension to GuildConfig extensions
- namespace NadekoBot.Core has been simplified to NadekoBot in many places (more to come)
- Replaced some raw delete queries with simple linqtodb queries

src/NadekoBot/Services/Database/Repositories/Impl/UserXpExtensions.cs

@@ -0,0 +1,86 @@
+using NadekoBot.Services.Database.Models;
+using System.Linq;
+using Microsoft.EntityFrameworkCore;
+using System.Collections.Generic;
+using LinqToDB;
+using NadekoBot.Core.Services.Database;
+using NadekoBot.Core.Services.Database.Models;
+using NadekoBot.Services.Database;
+
+namespace NadekoBot.Modules.Xp.Common
+{
+    public static class UserXpExtensions
+    {
+        public static UserXpStats GetOrCreateUserXpStats(this NadekoContext ctx, ulong guildId, ulong userId)
+        {
+            var usr = ctx.UserXpStats.FirstOrDefault(x => x.UserId == userId && x.GuildId == guildId);
+
+            if (usr == null)
+            {
+                ctx.Add(usr = new UserXpStats()
+                {
+                    Xp = 0,
+                    UserId = userId,
+                    NotifyOnLevelUp = XpNotificationLocation.None,
+                    GuildId = guildId,
+                });
+            }
+
+            return usr;
+        }
+
+        public static List<UserXpStats> GetUsersFor(this DbSet<UserXpStats> xps, ulong guildId, int page)
+        {
+            return xps
+                .AsQueryable()
+                .AsNoTracking()
+                .Where(x => x.GuildId == guildId)
+                .OrderByDescending(x => x.Xp + x.AwardedXp)
+                .Skip(page * 9)
+                .Take(9)
+                .ToList();
+        }
+
+        public static List<UserXpStats> GetTopUserXps(this DbSet<UserXpStats> xps, ulong guildId, int count)
+        {
+            return xps
+                .AsQueryable()
+                .AsNoTracking()
+                .Where(x => x.GuildId == guildId)
+                .OrderByDescending(x => x.Xp + x.AwardedXp)
+                .Take(count)
+                .ToList();
+        }
+
+        public static int GetUserGuildRanking(this DbSet<UserXpStats> xps, ulong userId, ulong guildId)
+        {
+            //            @"SELECT COUNT(*) + 1
+            //FROM UserXpStats
+            //WHERE GuildId = @p1 AND ((Xp + AwardedXp) > (SELECT Xp + AwardedXp
+            //	FROM UserXpStats
+            //	WHERE UserId = @p2 AND GuildId = @p1
+            //	LIMIT 1));";
+
+            return xps
+                .AsQueryable()
+                .AsNoTracking()
+                .Where(x => x.GuildId == guildId && ((x.Xp + x.AwardedXp) >
+                    (xps.AsQueryable()
+                        .Where(y => y.UserId == userId && y.GuildId == guildId)
+                        .Select(y => y.Xp + y.AwardedXp)
+                        .FirstOrDefault())
+                ))
+                .Count() + 1;
+        }
+
+        public static void ResetGuildUserXp(this DbSet<UserXpStats> xps, ulong userId, ulong guildId)
+        {
+            xps.Delete(x => x.UserId == userId && x.GuildId == guildId);
+        }
+
+        public static void ResetGuildXp(this DbSet<UserXpStats> xps, ulong guildId)
+        {
+            xps.Delete(x => x.GuildId == guildId);
+        }
+    }
+}