Added database configuration

ConfigItem/DatabaseConfig.cs

@@ -0,0 +1,68 @@
+using Newtonsoft.Json.Linq;
+using Npgsql;
+using System.Threading.Tasks;
+
+namespace Noikoio.RegexBot.ConfigItem
+{
+    class DatabaseConfig
+    {
+        private readonly bool _enabled;
+        private readonly string _host;
+        private readonly string _user;
+        private readonly string _pass;
+        private readonly string _dbname;
+        private readonly string _parsemsg;
+
+        /// <summary>
+        /// Gets whether database features are enabled.
+        /// </summary>
+        public bool Enabled => _enabled;
+        /// <summary>
+        /// Constructor error message (only if not enabled)
+        /// </summary>
+        public string ParseMsg => _parsemsg;
+
+        public DatabaseConfig(JToken ctok)
+        {
+            if (ctok == null || ctok.Type != JTokenType.Object)
+            {
+                _enabled = false;
+                _parsemsg = "Database configuration not defined.";
+                return;
+            }
+            var conf = (JObject)ctok;
+
+            _host = conf["hostname"]?.Value<string>() ?? "localhost"; // default to localhost
+            _user = conf["username"]?.Value<string>();
+            _pass = conf["password"]?.Value<string>();
+            _dbname = conf["database"]?.Value<string>();
+
+            if (string.IsNullOrWhiteSpace(_user) || string.IsNullOrWhiteSpace(_pass) || string.IsNullOrWhiteSpace(_dbname))
+            {
+                _parsemsg = "One or more required values are invalid or not defined.";
+                _enabled = false;
+            }
+
+            _parsemsg = null;
+            _enabled = true;
+        }
+
+        public async Task<NpgsqlConnection> OpenConnectionAsync(ulong? guildId)
+        {
+            if (!Enabled) return null;
+
+            var cs = new NpgsqlConnectionStringBuilder()
+            {
+                Host = _host,
+                Username = _user,
+                Password = _pass,
+                Database = _dbname
+            };
+            if (guildId.HasValue) cs.SearchPath = "g_" + guildId.Value.ToString();
+            
+            var db = new NpgsqlConnection(cs.ToString());
+            await db.OpenAsync();
+            return db;
+        }
+    }
+}

Configuration.cs

@@ -20,6 +20,7 @@ namespace Noikoio.RegexBot
 
         private readonly RegexBot _bot;
         private readonly string _configPath;
+        private DatabaseConfig _dbConfig;
         private ServerConfig[] _servers;
 
         // The following values do not change on reload:
@@ -28,6 +29,8 @@ namespace Noikoio.RegexBot
 
         public string BotUserToken => _botToken;
         public string CurrentGame => _currentGame;
+        public DatabaseConfig Database => _dbConfig;
+
         public ServerConfig[] Servers => _servers;
 
         public Configuration(RegexBot bot)
@@ -84,6 +87,8 @@ namespace Noikoio.RegexBot
             }
             _currentGame = conf["playing"]?.Value<string>();
 
+            _dbConfig = new DatabaseConfig(conf["database"]);
+
             return true;
         }