Fix several database issues

- Specify default value
- Cache all guild users on initial download
- Fix foreign key constraint issues

RegexBot/Data/BotDatabaseContext.cs

@@ -33,6 +33,7 @@ public class BotDatabaseContext : DbContext {
         modelBuilder.Entity<CachedGuildUser>(entity => {
             entity.Navigation(e => e.User).AutoInclude();
             entity.HasKey(e => new { e.UserId, e.GuildId });
+            entity.Property(e => e.FirstSeenTime).HasDefaultValueSql("now()");
         });
         modelBuilder.Entity<CachedGuildMessage>(entity => entity.Property(e => e.CreatedAt).HasDefaultValueSql("now()"));
     }

RegexBot/Data/Migrations/20220610210059_InitialMigration.Designer.cs

@@ -13,8 +13,8 @@ using RegexBot.Data;
 namespace RegexBot.Data.Migrations
 {
     [DbContext(typeof(BotDatabaseContext))]
-    [Migration("20220513061851_InitialEFSetup")]
+    [Migration("20220610210059_InitialMigration")]
-    partial class InitialEFSetup
+    partial class InitialMigration
     {
         protected override void BuildTargetModel(ModelBuilder modelBuilder)
         {
@@ -83,8 +83,10 @@ namespace RegexBot.Data.Migrations
                         .HasColumnName("guild_id");
 
                     b.Property<DateTimeOffset>("FirstSeenTime")
+                        .ValueGeneratedOnAdd()
                         .HasColumnType("timestamp with time zone")
-                        .HasColumnName("first_seen_time");
+                        .HasColumnName("first_seen_time")
+                        .HasDefaultValueSql("now()");
 
                     b.Property<DateTimeOffset>("GULastUpdateTime")
                         .HasColumnType("timestamp with time zone")

RegexBot/Data/Migrations/20220610210059_InitialMigration.cs

@@ -7,7 +7,7 @@ using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
 
 namespace RegexBot.Data.Migrations
 {
-    public partial class InitialEFSetup : Migration
+    public partial class InitialMigration : Migration
     {
         protected override void Up(MigrationBuilder migrationBuilder)
         {
@@ -73,7 +73,7 @@ namespace RegexBot.Data.Migrations
                     user_id = table.Column<long>(type: "bigint", nullable: false),
                     guild_id = table.Column<long>(type: "bigint", nullable: false),
                     gu_last_update_time = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false),
-                    first_seen_time = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false),
+                    first_seen_time = table.Column<DateTimeOffset>(type: "timestamp with time zone", nullable: false, defaultValueSql: "now()"),
                     nickname = table.Column<string>(type: "text", nullable: true)
                 },
                 constraints: table =>

RegexBot/Data/Migrations/BotDatabaseContextModelSnapshot.cs

@@ -81,8 +81,10 @@ namespace RegexBot.Data.Migrations
                         .HasColumnName("guild_id");
 
                     b.Property<DateTimeOffset>("FirstSeenTime")
+                        .ValueGeneratedOnAdd()
                         .HasColumnType("timestamp with time zone")
-                        .HasColumnName("first_seen_time");
+                        .HasColumnName("first_seen_time")
+                        .HasDefaultValueSql("now()");
 
                     b.Property<DateTimeOffset>("GULastUpdateTime")
                         .HasColumnType("timestamp with time zone")

RegexBot/Program.cs

@@ -29,7 +29,8 @@ class Program {
             MessageCacheSize = 0, // using our own
             LogLevel = LogSeverity.Info,
             GatewayIntents = GatewayIntents.All & ~GatewayIntents.GuildPresences,
-            LogGatewayIntentWarnings = false
+            LogGatewayIntentWarnings = false,
+            AlwaysDownloadUsers = true
         });
 
         // Kerobot class initialization - will set up services and modules

RegexBot/Services/EntityCache/UserCachingSubservice.cs

@@ -13,16 +13,35 @@ class UserCachingSubservice {
     private static Regex DiscriminatorSearch { get; } = new(@"(.+)#(\d{4}(?!\d))", RegexOptions.Compiled);
 
     internal UserCachingSubservice(RegexbotClient bot) {
+        bot.DiscordClient.GuildMembersDownloaded += DiscordClient_GuildMembersDownloaded;
         bot.DiscordClient.GuildMemberUpdated += DiscordClient_GuildMemberUpdated;
         bot.DiscordClient.UserUpdated += DiscordClient_UserUpdated;
     }
 
+    private async Task DiscordClient_GuildMembersDownloaded(SocketGuild arg) {
+        using var db = new BotDatabaseContext();
+        foreach (var user in arg.Users) {
+            UpdateUser(user, db);
+            UpdateGuildUser(user, db);
+        }
+        await db.SaveChangesAsync();
+    }
+
+    private async Task DiscordClient_GuildMemberUpdated(Discord.Cacheable<SocketGuildUser, ulong> old, SocketGuildUser current) {
+        using var db = new BotDatabaseContext();
+        UpdateUser(current, db); // Update user data first (avoid potential foreign key constraint violation)
+        UpdateGuildUser(current, db);
+
+        await db.SaveChangesAsync();
+    }
+
     private async Task DiscordClient_UserUpdated(SocketUser old, SocketUser current) {
         using var db = new BotDatabaseContext();
         UpdateUser(current, db);
         await db.SaveChangesAsync();
     }
 
+    // IMPORTANT: Do NOT forget to save changes in database after calling this!
     private static void UpdateUser(SocketUser user, BotDatabaseContext db) {
         CachedUser uinfo;
         try {
@@ -38,23 +57,18 @@ class UserCachingSubservice {
         uinfo.ULastUpdateTime = DateTimeOffset.UtcNow;
     }
 
-    private async Task DiscordClient_GuildMemberUpdated(Discord.Cacheable<SocketGuildUser, ulong> old, SocketGuildUser current) {
+    private static void UpdateGuildUser(SocketGuildUser user, BotDatabaseContext db) {
-        using var db = new BotDatabaseContext();
-        UpdateUser(current, db); // Update user data too (avoid potential foreign key constraint violation)
-
         CachedGuildUser guinfo;
         try {
-            guinfo = db.GuildUserCache.Where(c => c.GuildId == (long)current.Guild.Id && c.UserId == (long)current.Id).First();
+            guinfo = db.GuildUserCache.Where(c => c.GuildId == (long)user.Guild.Id && c.UserId == (long)user.Id).First();
         } catch (InvalidOperationException) {
-            guinfo = new() { GuildId = (long)current.Guild.Id, UserId = (long)current.Id };
+            guinfo = new() { GuildId = (long)user.Guild.Id, UserId = (long)user.Id };
             db.GuildUserCache.Add(guinfo);
         }
 
         guinfo.GULastUpdateTime = DateTimeOffset.UtcNow;
-        guinfo.Nickname = current.Nickname;
+        guinfo.Nickname = user.Nickname;
         // TODO guild-specific avatar, other details?
-
-        await db.SaveChangesAsync();
     }
 
     // Hooked