refactor: database class singleton to use existing connection (#32)

This is a half-way fix for #31 so it does not close it. But it does solve the issue of `Too many connections` if the `Database` class when the `Database` class is instanced a lot. The issue of credentials still remain.

Reviewed-on: https://codeberg.org/vlw/scaffold/pulls/32

README.md

@@ -1,5 +1,5 @@
 # Scaffold
-This composer package contains my project boilerplate code for working with [Vegvisir](https://vegvisir.vlw.se) and [Reflect](https://reflect.vlw.se) projects. It contains my most commonly used classes and functions which I use to make development of new project in these frameworks easier.
+This composer package (primarily) contains my project boilerplate code for working with [Vegvisir](https://vegvisir.vlw.se) and [Reflect](https://reflect.vlw.se) projects. It contains my most commonly used classes and functions which I use to make development of new project in these frameworks easier.
 
 Refer to the documentation in each source file for more information about its function.
 

composer.json

@@ -1,6 +1,6 @@
 {
     "name": "vlw/scaffold",
-    "description": "Project scaffolding for Reflect and Vegvisir projects",
+    "description": "Project scaffolding (primarily) for Reflect and Vegvisir projects",
     "type": "library",
     "license": "GPL-3.0-or-later",
     "authors": [

src/Database/Database.php

@@ -15,6 +15,49 @@
 		public const DATE_FORMAT     = "Y-m-d";
 		public const DATETIME_FORMAT = "Y-m-d H:i:s";
 
+		private const DEFAULT_HOSTNAME = "localhost";
+		private const DEFAULT_USERNAME = "www-data";
+		private const DEFAULT_PASSWORD = "";
+
+		private static ?Database $instance = null;
+
+		/**
+		 * Create a new Database instance from credentials
+		 *
+		 * @param string $host
+		 * @param string $username
+		 * @param string $password
+		 * @param string $database
+		 * @return void
+		 */
+		public static function set_credentials(
+			?string $host = self::DEFAULT_HOSTNAME,
+			?string $username = self::DEFAULT_USERNAME,
+			?string $password = self::DEFAULT_PASSWORD,
+			?string $database = ""
+		) {
+			// Create key if it does not exist
+			if (!array_key_exists("mariadb", $_ENV)) {
+				$_ENV["mariadb"] = [];
+			}
+
+			// Set environment variables from credentials
+			$_ENV["mariadb"]["host"] = $host;
+			$_ENV["mariadb"]["user"] = $username;
+			$_ENV["mariadb"]["pass"] = $password;
+			$_ENV["mariadb"]["db"] = $database;
+
+			self::$instance = null;
+		}
+
+		public static function instance(): static {
+			if (self::$instance) {
+				return self::$instance;
+			}
+
+			return new static();
+		}
+
 		/**
 		 * Wrap a new vlw/MySQL instance with credentials from project .env.ini
 		 */
@@ -25,6 +68,8 @@
 				$_ENV["mariadb"]["pass"],
 				$_ENV["mariadb"]["db"],
 			);
+
+			self::$instance = $this;
 		}
 
 		/**

src/Database/Model.php

@@ -13,9 +13,10 @@
 		public const DATE_FORMAT     = Database::DATE_FORMAT;
 		public const DATETIME_FORMAT = Database::DATETIME_FORMAT;
 
-		abstract public string $id { get; }
+		abstract public int|string $id { get; }
+
+		public readonly Database $db;
 
-		protected readonly Database $db;
 		private bool $_resolved = false;
 		private bool $_isset;
 		private ?array $_row;
@@ -26,7 +27,7 @@
 		 * @param string $table The target database table
 		 */
 		protected static function create(string $table, array $values): bool {
-			return new Database()->from($table)->insert($values);
+			return Database::instance()->from($table)->insert($values);
 		}
 
 		/**
@@ -41,7 +42,7 @@
 			public readonly array $columns,
 			public readonly array $where
 		) {
-			$this->db = new Database();
+			$this->db = Database::instance();
 		}
 
 		/**
@@ -74,7 +75,7 @@
 		 * @return bool Entity exists
 		 */
 		public function isset(): bool {
-			return $this->_isset ??= new Database()
+			return $this->_isset ??= Database::instance()
 				->from($this->table)
 				->where($this->where)
 				->limit(1)
@@ -97,9 +98,10 @@
 		 *
 		 * @param string $key Target column to update
 		 * @param mixed $value New value of target column
+		 * @param return $return (optional) Return this instead of $value when set
 		 * @return mixed The value that was sent to $value
 		 */
-		public function set(string $key, mixed $value): mixed {
+		public function set(string $key, mixed $value, mixed $return = null): mixed {
 			$this->_row[$key] = $value;
 
 			$this->db
@@ -107,6 +109,6 @@
 				->where($this->where)
 				->update([$key => $value]);
 
-			return $value;
+			return func_num_args() === 2 ? $value : $return;
 		}
 	}