Load database config on initialization

Adapted from RegexBot.
This allows `dotnet ef` tools to make use of actual SQL credentials
rather than dummy ones.

Configuration.cs

@@ -1,56 +1,52 @@
 using CommandLine;
-using CommandLine.Text;
+using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
-using Npgsql;
 using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
 
 namespace WorldTime;
-
 /// <summary>
 /// Loads and holds configuration values.
 /// </summary>
 class Configuration {
-    const string KeySqlHost = "SqlHost";
-    const string KeySqlUsername = "SqlUsername";
-    const string KeySqlPassword = "SqlPassword";
-    const string KeySqlDatabase = "SqlDatabase";
-
-    public string DbConnectionString { get; }
     public string BotToken { get; }
     public string? DBotsToken { get; }
 
     public int ShardTotal { get; }
 
-    public Configuration(string[] args) {
-        var cmdline = CmdLineOpts.Parse(args);
+    public string? SqlHost { get; }
+    public string? SqlDatabase { get; }
+    public string SqlUsername { get; }
+    public string SqlPassword { get; }
+
+    public Configuration() {
+        var args = CommandLineParameters.Parse(Environment.GetCommandLineArgs());
+        var path = args?.ConfigFile ?? Path.GetDirectoryName(Assembly.GetEntryAssembly()!.Location)
+            + Path.DirectorySeparatorChar + "." + Path.DirectorySeparatorChar + "settings.json";
 
         // Looks for configuration file
-        var confPath = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location) + Path.DirectorySeparatorChar;
-        confPath += cmdline.Config!;
-        if (!File.Exists(confPath)) throw new Exception("Settings file not found in path: " + confPath);
+        JObject jc;
+        try {
+            var conftxt = File.ReadAllText(path);
+            jc = JObject.Parse(conftxt);
+        } catch (Exception ex) {
+            string pfx;
+            if (ex is JsonException) pfx = "Unable to parse configuration: ";
+            else pfx = "Unable to access configuration: ";
 
-        var jc = JObject.Parse(File.ReadAllText(confPath));
+            throw new Exception(pfx + ex.Message, ex);
+        }
 
         BotToken = ReadConfKey<string>(jc, nameof(BotToken), true);
         DBotsToken = ReadConfKey<string>(jc, nameof(DBotsToken), false);
 
-        ShardTotal = cmdline.ShardTotal ?? ReadConfKey<int?>(jc, nameof(ShardTotal), false) ?? 1;
+        ShardTotal = args.ShardTotal ?? ReadConfKey<int?>(jc, nameof(ShardTotal), false) ?? 1;
         if (ShardTotal < 1) throw new Exception($"'{nameof(ShardTotal)}' must be a positive integer.");
 
-        var sqlhost = ReadConfKey<string>(jc, KeySqlHost, false) ?? "localhost"; // Default to localhost
-        var sqluser = ReadConfKey<string>(jc, KeySqlUsername, false);
-        var sqlpass = ReadConfKey<string>(jc, KeySqlPassword, false);
-        if (string.IsNullOrWhiteSpace(sqluser) || string.IsNullOrWhiteSpace(sqlpass))
-            throw new Exception("'SqlUsername', 'SqlPassword' must be specified.");
-        var csb = new NpgsqlConnectionStringBuilder() {
-            Host = sqlhost,
-            Username = sqluser,
-            Password = sqlpass
-        };
-        var sqldb = ReadConfKey<string>(jc, KeySqlDatabase, false);
-        if (sqldb != null) csb.Database = sqldb; // Optional database setting
-        DbConnectionString = csb.ToString();
+        SqlHost = ReadConfKey<string>(jc, nameof(SqlHost), false);
+        SqlDatabase = ReadConfKey<string?>(jc, nameof(SqlDatabase), false);
+        SqlUsername = ReadConfKey<string>(jc, nameof(SqlUsername), true);
+        SqlPassword = ReadConfKey<string>(jc, nameof(SqlPassword), true);
     }
 
     private static T? ReadConfKey<T>(JObject jc, string key, [DoesNotReturnIf(true)] bool failOnEmpty) {
@@ -59,29 +55,24 @@ class Configuration {
         return default;
     }
 
-    private class CmdLineOpts {
-        [Option('c', "config", Default = "settings.json",
-            HelpText = "Custom path to instance configuration, relative from executable directory.")]
-        public string? Config { get; set; }
+    class CommandLineParameters {
+        [Option('c', "config")]
+        public string? ConfigFile { get; set; }
 
-        [Option("shardtotal",
-            HelpText = "Total number of shards online. MUST be the same for all instances.\n"
-            + "This value overrides the config file value.")]
+        [Option("shardtotal")]
         public int? ShardTotal { get; set; }
 
-        public static CmdLineOpts Parse(string[] args) {
-            // Do not automatically print help message
-            var clp = new Parser(c => c.HelpWriter = null);
+        public static CommandLineParameters? Parse(string[] args) {
+            CommandLineParameters? result = null;
 
-            CmdLineOpts? result = null;
-            var r = clp.ParseArguments<CmdLineOpts>(args);
-            r.WithParsed(parsed => result = parsed);
-            r.WithNotParsed(err => {
-                var ht = HelpText.AutoBuild(r);
-                Console.WriteLine(ht.ToString());
-                Environment.Exit((int)Program.ExitCodes.BadCommand);
-            });
-            return result!;
+            new Parser(settings => {
+                settings.IgnoreUnknownArguments = true;
+                settings.AutoHelp = false;
+                settings.AutoVersion = false;
+            }).ParseArguments<CommandLineParameters>(args)
+                .WithParsed(p => result = p)
+                .WithNotParsed(e => { /* ignore */ });
+            return result;
         }
     }
 }

Data/BotDatabaseContext.cs

@@ -1,29 +1,26 @@
 using Microsoft.EntityFrameworkCore;
+using Npgsql;
 
 namespace WorldTime.Data;
 public class BotDatabaseContext : DbContext {
-    private static string? _npgsqlConnectionString;
-    internal static string NpgsqlConnectionString {
-#if DEBUG
-        get {
-            if (_npgsqlConnectionString != null) return _npgsqlConnectionString;
-            Program.Log(nameof(BotDatabaseContext), "Using hardcoded connection string!");
-            return _npgsqlConnectionString ?? "Host=localhost;Username=worldtime;Password=wt";
-        }
-#else
-        get => _npgsqlConnectionString!;
-#endif
-        set => _npgsqlConnectionString ??= value;
+    private static readonly string _connectionString;
+
+    static BotDatabaseContext() {
+        // Get our own config loaded just for the SQL stuff
+        var conf = new Configuration();
+        _connectionString = new NpgsqlConnectionStringBuilder() {
+            Host = conf.SqlHost ?? "localhost", // default to localhost
+            Database = conf.SqlDatabase,
+            Username = conf.SqlUsername,
+            Password = conf.SqlPassword
+        }.ToString();
     }
 
     public DbSet<UserEntry> UserEntries { get; set; } = null!;
 
     protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
          => optionsBuilder
-            .UseNpgsql(NpgsqlConnectionString)
-#if DEBUG
-            .LogTo((string line) => Program.Log("EF", line), Microsoft.Extensions.Logging.LogLevel.Information)
-#endif
+            .UseNpgsql(_connectionString)
             .UseSnakeCaseNamingConvention();
 
     protected override void OnModelCreating(ModelBuilder modelBuilder) {

Program.cs

@@ -9,17 +9,15 @@ class Program {
     /// </summary>
     public static string BotUptime => (DateTimeOffset.UtcNow - _botStartTime).ToString("d' days, 'hh':'mm':'ss");
 
-    static async Task Main(string[] args) {
+    static async Task Main() {
         Configuration? cfg = null;
         try {
-            cfg = new Configuration(args);
+            cfg = new Configuration();
         } catch (Exception ex) {
             Console.WriteLine(ex);
             Environment.Exit((int)ExitCodes.ConfigError);
         }
 
-        Data.BotDatabaseContext.NpgsqlConnectionString = cfg.DbConnectionString;
-
         Console.CancelKeyPress += OnCancelKeyPressed;
         _bot = new WorldTime(cfg);
         await _bot.StartAsync().ConfigureAwait(false);

WorldTime.cs

@@ -31,6 +31,7 @@ internal class WorldTime : IDisposable {
     private readonly CancellationTokenSource _mainCancel;
     private readonly CommandsText _commandsTxt;
     private readonly IServiceProvider _services;
+    private readonly HashSet<ulong> _aotUserDownloadChecked = new();
 
     internal Configuration Config { get; }
     internal DiscordShardedClient DiscordClient => _services.GetRequiredService<DiscordShardedClient>();
@@ -186,7 +187,9 @@ internal class WorldTime : IDisposable {
         if (message.Channel is not SocketTextChannel channel) return;
 
         // Proactively fill guild user cache if the bot has any data for the respective guild
-        // Can skip an extra query if the last_seen update is known to have been successful, otherwise query for any users
+        lock (_aotUserDownloadChecked) {
+            if (!_aotUserDownloadChecked.Add(channel.Guild.Id)) return; // ...once. Just once. Not all the time.
+        }
         if (!channel.Guild.HasAllMembers) {
             using var db = _services.GetRequiredService<BotDatabaseContext>();
             if (db.HasAnyUsers(channel.Guild)) {