Add PDO connection config

src/Configuration.php

@@ -2,31 +2,44 @@
 
 namespace BitBadger\PDODocument;
 
+use PDO;
+
 /**
  * Common configuration for the document library
  */
 class Configuration
 {
     /** @var string The name of the ID field used in the database (will be treated as the primary key) */
-    private static string $_idField = 'id';
+    public static string $idField = 'id';
+
+    /** @var string The data source name (DSN) of the connection string */
+    public static string $pdoDSN = '';
+
+    /** @var string|null The username to use to establish a data connection (use env PDO_DOC_USERNAME if possible) */
+    public static ?string $username = null;
+
+    /** @var string|null The password to use to establish a data connection (use env PDO_DOC_PASSWORD if possible) */
+    public static ?string $password = null;
+
+    /** @var array|null Options to use for connections (driver-specific) */
+    public static ?array $options = null;
 
     /**
-     * Configure the ID field used by the library
+     * Retrieve a new connection to the database
      *
-     * @param string $name The name of the ID field within each document
+     * @return PDO A new connection to the SQLite database with foreign key support enabled
+     * @throws DocumentException If this is called before a connection string is set
      */
-    public static function useIdField(string $name): void
+    public static function dbConn(): PDO
     {
-        self::$_idField = $name;
-    }
+        if (empty(self::$pdoDSN)) {
+            throw new DocumentException('Please provide a data source name (DSN) before attempting data access');
+        }
+        $db = new PDO(self::$pdoDSN, $_ENV['PDO_DOC_USERNAME'] ?? self::$username,
+            $_ENV['PDO_DOC_PASSWORD'] ?? self::$password, self::$options);
 
-    /**
-     * Retrieve the ID field for documents within this library
-     *
-     * @return string The configured ID field
-     */
-    public static function idField(): string
-    {
-        return self::$_idField;
+        // TODO: determine driver, set mode for other queries
+        echo $db->getAttribute(PDO::ATTR_DRIVER_NAME);
+        return $db;
     }
 }