Add basic PGSQL connection

dub.sdl

@@ -5,5 +5,7 @@ copyright "Copyright © 2024, Marisa"
 license "MIT"
 dependency "slf4d" version="~>3.0.0"
 dependency "handy-httpd" version="~>8.2.0"
-dependency "hibernated" version="~>0.4.0"
 dependency "requests" version="~>2.1.3"
+dependency "ddbc" version="~>0.6.0"
+
+subConfiguration "ddbc" "PGSQL"

dub.selections.json

@@ -2,14 +2,22 @@
 	"fileVersion": 1,
 	"versions": {
 		"automem": "0.6.9",
-		"cachetools": "0.4.1",
+		"cachetools": "0.3.1",
+		"d-unit": "0.10.2",
+		"ddbc": "0.6.0",
+		"derelict-pq": "2.2.0",
+		"derelict-util": "2.0.6",
 		"handy-httpd": "8.2.0",
+		"hibernated": "0.4.0",
 		"httparsed": "1.2.1",
+		"mysql-native": "3.1.0",
+		"odbc": "1.0.0",
 		"path-matcher": "1.1.3",
 		"requests": "2.1.3",
 		"slf4d": "3.0.0",
 		"streams": "3.5.0",
 		"test_allocator": "0.3.4",
+		"undead": "1.1.8",
 		"unit-threaded": "0.10.8"
 	}
 }

source/db/db.d

@@ -0,0 +1,50 @@
+module db.db;
+
+import slf4d;
+
+import ddbc.core;
+
+enum DBConnector {
+  DB_MYSQL,
+  DB_PGSQL,
+  DB_SQLITE,
+}
+
+struct DBSettings {
+  DBConnector connector;
+  string host;
+  ushort port;
+  string username;
+  string password;
+  string dbname;
+}
+
+class DB {
+  protected DBSettings m_settings;
+  protected DataSource m_ds;
+  protected Connection m_conn;
+
+  shared this(DBSettings settings) {
+    this.m_settings = settings;
+  }
+
+  static shared(DB) getDB(DBSettings settings) {
+    switch (settings.connector) {
+    case DBConnector.DB_PGSQL:
+      import db.pgsql;
+
+      debugF!"DB type is PostgreSQL";
+      return new shared PostgresDB(settings);
+
+    default:
+      throw new Exception("DB not supported");
+    }
+  }
+
+  protected abstract DataSource getDataSource();
+
+  void connect() {
+    this.m_ds = this.getDataSource();
+    this.m_conn = this.m_ds.getConnection();
+  }
+}

source/db/pgsql.d

@@ -0,0 +1,27 @@
+module db.pgsql;
+
+import db.db;
+
+import ddbc.core;
+import ddbc.common;
+
+class PostgresDB : DB {
+  shared this(Args...)(auto ref Args args) {
+    super(args);
+  }
+
+  protected override DataSource getDataSource() {
+    import ddbc.drivers.pgsqlddbc;
+
+    Driver driver = new PGSQLDriver();
+    string url;
+    string[string] params;
+
+    with (this.m_settings) {
+      url = PGSQLDriver.generateUrl(host, port, dbname);
+      params = PGSQLDriver.setUserAndPassword(username, password);
+    }
+
+    return new ConnectionPoolDataSourceImpl(driver, url, params);
+  }
+}