Add new extension methods for retrieving data

Data/Extensions.cs

@@ -0,0 +1,19 @@
+namespace BirthdayBot.Data;
+
+internal static class Extensions {
+    /// <summary>
+    /// Gets the corresponding <see cref="GuildConfig"/> for this guild, or a new one if one does not exist.
+    /// If it doesn't exist in the database, <see cref="GuildConfig.IsNew"/> returns true.
+    /// </summary>
+    public static GuildConfig GetConfigOrNew(this SocketGuild guild, BotDatabaseContext db)
+        => db.GuildConfigurations.Where(g => g.GuildId == (long)guild.Id).FirstOrDefault() 
+            ?? new GuildConfig() { IsNew = true, GuildId = (long)guild.Id };
+
+    /// <summary>
+    /// Gets the corresponding <see cref="UserEntry"/> for this user in this guild, or a new one if one does not exist.
+    /// If it doesn't exist in the database, <see cref="UserEntry.IsNew"/> returns true.
+    /// </summary>
+    public static UserEntry GetUserEntryOrNew(this SocketGuildUser user, BotDatabaseContext db)
+        => db.UserEntries.Where(u => u.GuildId == (long)user.Guild.Id && u.UserId == (long)user.Id).FirstOrDefault()
+            ?? new UserEntry() { IsNew = true, GuildId = (long)user.Guild.Id, UserId = (long)user.Id };
+}

Data/GuildConfig.cs

@@ -36,4 +36,10 @@ public class GuildConfig {
     public ICollection<BlocklistEntry> BlockedUsers { get; set; }
     [InverseProperty(nameof(UserEntry.Guild))]
     public ICollection<UserEntry> UserEntries { get; set; }
+
+    /// <summary>
+    /// Gets if this instance is new and does not (yet) exist in the database.
+    /// </summary>
+    [NotMapped]
+    public bool IsNew { get; set; }
 }

Data/UserEntry.cs

@@ -23,4 +23,10 @@ public class UserEntry {
     [ForeignKey(nameof(GuildConfig.GuildId))]
     [InverseProperty(nameof(GuildConfig.UserEntries))]
     public GuildConfig Guild { get; set; } = null!;
+
+    /// <summary>
+    /// Gets if this instance is new and does not (yet) exist in the database.
+    /// </summary>
+    [NotMapped]
+    public bool IsNew { get; set; }
 }