Removed channel expiry data persistence

Some leftover references here and there.
Will remove soon.

Module/VoteTempChannel/ChannelManager.cs

@@ -1,7 +1,5 @@
 using Discord.Rest;
 using Discord.WebSocket;
-using Npgsql;
-using NpgsqlTypes;
 using System;
 using System.Collections.Generic;
 using System.Threading;
@@ -18,7 +16,7 @@ namespace Noikoio.RegexBot.Module.VoteTempChannel
         readonly DiscordSocketClient _client;
 
         /// <summary>
-        /// Key = guild, Value = expiry time, notify flag.
+        /// Key = guild, Value = expiry time
         /// Must lock!
         /// </summary>
         readonly Dictionary<ulong, (DateTimeOffset, bool)> _trackedChannels;
@@ -34,7 +32,6 @@ namespace Noikoio.RegexBot.Module.VoteTempChannel
             _bgTask = Task.Factory.StartNew(ChannelExpirationChecker, _token.Token,
                 TaskCreationOptions.LongRunning, TaskScheduler.Default);
             _trackedChannels = new Dictionary<ulong, (DateTimeOffset, bool)>();
-            SetUpPersistenceTableAsync().Wait();
         }
 
         public void Dispose()
@@ -42,92 +39,12 @@ namespace Noikoio.RegexBot.Module.VoteTempChannel
             _token.Cancel();
             _token.Dispose();
         }
-
+        
-        #region Data persistence
-        private const string PersistTable = "votetemp_persist";
-        private async Task SetUpPersistenceTableAsync()
-        {
-            using (var db = await RegexBot.Config.GetOpenDatabaseConnectionAsync())
-            {
-                using (var c = db.CreateCommand())
-                {
-                    c.CommandText = $"create table if not exists {PersistTable} (" +
-                        "guild_id bigint primary key, " +
-                        "expiration_time timestamptz not null" +
-                        ")";
-                    await c.ExecuteNonQueryAsync();
-                }
-            }
-        }
-
-        private async Task<DateTimeOffset?> GetPersistData(ulong guildId)
-        {
-            using (var db = await RegexBot.Config.GetOpenDatabaseConnectionAsync())
-            {
-                using (var c = db.CreateCommand())
-                {
-                    c.CommandText = $"select expiration_time from {PersistTable} where guild_id = @Gid";
-                    c.Parameters.Add("@Gid", NpgsqlDbType.Bigint).Value = guildId;
-                    c.Prepare();
-                    using (var r = await c.ExecuteReaderAsync())
-                    {
-                        if (await r.ReadAsync()) return r.GetDateTime(0);
-                        return null;
-                    }
-                }
-            }
-        }
-
-        private async Task InsertOrUpdatePersistData(ulong guildId, DateTimeOffset expiration)
-        {
-            using (var db = await RegexBot.Config.GetOpenDatabaseConnectionAsync())
-            {
-                using (var c = db.CreateCommand())
-                {
-                    c.CommandText = $"delete from {PersistTable} where guild_id = @Gid";
-                    c.Parameters.Add("@Gid", NpgsqlDbType.Bigint).Value = guildId;
-                    await c.ExecuteNonQueryAsync();
-                }
-
-                using (var c = db.CreateCommand())
-                {
-                    c.CommandText = $"insert into {PersistTable} values (@Gid, @Exp)";
-                    c.Parameters.Add("@Gid", NpgsqlDbType.Bigint).Value = guildId;
-                    c.Parameters.Add("@Exp", NpgsqlDbType.TimestampTZ).Value = expiration;
-                    c.Prepare();
-                    try
-                    {
-                        await c.ExecuteNonQueryAsync();
-                    }
-                    catch (NpgsqlException ex)
-                    {
-                        // TODO should log this instead of throwing an exception...
-                        throw new ApplicationException("A database error occurred. Internal error message: " + ex.Message);
-                    }
-                }
-            }
-        }
-
-        private async Task DeletePersistData(ulong guildId)
-        {
-            using (var db = await RegexBot.Config.GetOpenDatabaseConnectionAsync())
-            {
-                using (var c = db.CreateCommand())
-                {
-                    c.CommandText = $"delete from {PersistTable} where guild_id = @Gid";
-                    c.Parameters.Add("@Gid", NpgsqlDbType.Bigint).Value = guildId;
-                    c.Prepare();
-                    await c.ExecuteNonQueryAsync();
-                }
-            }
-        }
-        #endregion
-
         #region Querying
         /// <summary>
         /// Determines if the given guild has a temporary channel that is up for a renewal vote.
         /// </summary>
-        public bool IsUpForRenewal(SocketGuild guild, GuildConfiguration info)
+        public bool IsUpForRenewal(SocketGuild guild, Configuration info)
         {
             DateTimeOffset tcExp;
             lock (_trackedChannels)
@@ -139,14 +56,7 @@ namespace Noikoio.RegexBot.Module.VoteTempChannel
             var renewThreshold = tcExp - info.KeepaliveVoteDuration;
             return DateTimeOffset.UtcNow > renewThreshold;
         }
-
+        
-        private SocketTextChannel FindTemporaryChannel(SocketGuild guild, GuildConfiguration conf)
-            => System.Linq.Enumerable.SingleOrDefault(guild.TextChannels, c => c.Name == conf.TempChannelName);
-
-        public bool HasExistingTemporaryChannel(SocketGuild guild, GuildConfiguration info)
-        {
-            return FindTemporaryChannel(guild, info) != null;
-        }
         #endregion
 
         #region Channel entry manipulation
@@ -156,7 +66,7 @@ namespace Noikoio.RegexBot.Module.VoteTempChannel
         /// <exception cref="ApplicationException">
         /// Various causes. Send exception message to log and channel if thrown.
         /// </exception>
-        public async Task<RestTextChannel> CreateChannelAndEntryAsync(SocketGuild guild, GuildConfiguration info)
+        public async Task<RestTextChannel> CreateChannelAndEntryAsync(SocketGuild guild, Configuration info)
         {
             lock (_trackedChannels)
             {
@@ -164,8 +74,6 @@ namespace Noikoio.RegexBot.Module.VoteTempChannel
                 if (_trackedChannels.ContainsKey(guild.Id)) return null;
             }
 
-            var channelExpiryTime = DateTimeOffset.UtcNow + info.ChannelBaseDuration;
-
             RestTextChannel newCh = null;
             try
             {
@@ -179,19 +87,13 @@ namespace Noikoio.RegexBot.Module.VoteTempChannel
             // Channel creation succeeded. Regardless of persistent state, at least add it to in-memory cache.
             lock (_trackedChannels) _trackedChannels.Add(guild.Id, (channelExpiryTime, false));
 
-            // Create persistent entry.
-            await InsertOrUpdatePersistData(guild.Id, channelExpiryTime);
-
             return newCh;
         }
 
         /// <summary>
         /// For an existing temporary channel, extends its lifetime by a predetermined amount.
         /// </summary>
-        /// <exception cref="ApplicationException">
+        public async Task ExtendChannelExpirationAsync(SocketGuild guild, Configuration info)
-        /// SQL. Send exception message to log and channel if thrown.
-        /// </exception>
-        public async Task ExtendChannelExpirationAsync(SocketGuild guild, GuildConfiguration info)
         {
             DateTimeOffset newExpiration;
             lock (_trackedChannels)
@@ -202,52 +104,8 @@ namespace Noikoio.RegexBot.Module.VoteTempChannel
                 newExpiration+= info.ChannelExtendDuration;
                 _trackedChannels[guild.Id] = (newExpiration, false);
             }
-
-            await InsertOrUpdatePersistData(guild.Id, newExpiration);
         }
-
+        
-        /// <summary>
-        /// Called when becoming aware of a new guild. Checks and acts on persistence data.
-        /// </summary>
-        public async Task RecheckExpiryInformation(SocketGuild guild, GuildConfiguration info)
-        {
-            var ch = FindTemporaryChannel(guild, info);
-            var persist = await GetPersistData(guild.Id);
-
-            if (persist.HasValue)
-            {
-                // Found persistence data and...
-                if (ch == null)
-                {
-                    // ...there is no existing corresponding channel. Delete persistence data.
-                    await DeletePersistData(guild.Id);
-                }
-                else
-                {
-                    // ...the channel exists. Add to in-memory cache.
-                    // Cached persistence should extend to at least 5 minutes if needed.
-                    // Should allow for enough time for users to vote for an extension.
-                    DateTimeOffset toCache;
-                    if ((DateTimeOffset.UtcNow - persist.Value).Duration().TotalMinutes > 5)
-                        toCache = persist.Value;
-                    else
-                        toCache = DateTimeOffset.UtcNow.AddMinutes(5);
-                    lock (_trackedChannels) { _trackedChannels.Add(guild.Id, (toCache, false)); }
-                }
-            }
-            else
-            {
-                // No persistence data.
-                if (ch != null)
-                {
-                    // But we have a channel. Add new value to cache.
-                    var exp = DateTimeOffset.UtcNow + info.ChannelBaseDuration;
-                    lock (_trackedChannels) { _trackedChannels.Add(guild.Id, (exp, false)); }
-                    await InsertOrUpdatePersistData(guild.Id, exp);
-                }
-            }
-        }
-
         /// <summary>
         /// Sets the given guild's temporary channel as up for immediate expiration.
         /// Use this to properly remove a temporary channel.
@@ -259,11 +117,10 @@ namespace Noikoio.RegexBot.Module.VoteTempChannel
                 if (!_trackedChannels.ContainsKey(guild.Id)) return; // how did we even get here?
                 _trackedChannels[guild.Id] = (DateTimeOffset.UtcNow, true);
             }
-            await DeletePersistData(guild.Id);
         }
 
         /// <summary>
-        /// Removes the given guild from the cache. Does not alter persistence data.
+        /// Removes the given guild from the cache.
         /// </summary>
         public void DropCacheEntry(SocketGuild guild)
         {
@@ -329,7 +186,6 @@ namespace Noikoio.RegexBot.Module.VoteTempChannel
                                 cachePostRemove.Add(item.Key);
                                 continue;
                             }
-                            DeletePersistData(item.Key).Wait();
                             cachePostRemove.Add(item.Key);
                         }
                         else if (item.Value.Item2 == false && IsUpForRenewal(ch.Guild, conf))