(Feat): Initial Commit

backend-deno/config/database.ts

@@ -0,0 +1,79 @@
+import { createPool, Pool } from "mysql2/promise";
+import { load } from "@std/dotenv";
+
+// Load environment variables
+await load({ export: true });
+
+const config = {
+  host: Deno.env.get("DB_HOST") || "localhost",
+  user: Deno.env.get("DB_USER") || "root",
+  password: Deno.env.get("DB_PASSWORD") || "admin123",
+  database: Deno.env.get("DB_NAME") || "work_allocation",
+  port: parseInt(Deno.env.get("DB_PORT") || "3306"),
+  waitForConnections: true,
+  connectionLimit: 10,
+  queueLimit: 0,
+  enableKeepAlive: true,
+  keepAliveInitialDelay: 0,
+};
+
+class Database {
+  private pool: Pool | null = null;
+  private static instance: Database;
+
+  private constructor() {}
+
+  static getInstance(): Database {
+    if (!Database.instance) {
+      Database.instance = new Database();
+    }
+    return Database.instance;
+  }
+
+  async connect(): Promise<Pool> {
+    if (!this.pool) {
+      this.pool = createPool(config);
+      
+      // Test connection
+      try {
+        const connection = await this.pool.getConnection();
+        console.log("✅ Database connected successfully");
+        connection.release();
+      } catch (error) {
+        console.error("❌ Database connection failed:", (error as Error).message);
+        throw error;
+      }
+    }
+    return this.pool;
+  }
+
+  async getPool(): Promise<Pool> {
+    if (!this.pool) {
+      return await this.connect();
+    }
+    return this.pool;
+  }
+
+  async query<T>(sql: string, params?: unknown[]): Promise<T> {
+    const pool = await this.getPool();
+    const [rows] = await pool.query(sql, params);
+    return rows as T;
+  }
+
+  async execute(sql: string, params?: unknown[]): Promise<{ insertId: number; affectedRows: number }> {
+    const pool = await this.getPool();
+    const [result] = await pool.execute(sql, params);
+    return result as { insertId: number; affectedRows: number };
+  }
+
+  async close(): Promise<void> {
+    if (this.pool) {
+      await this.pool.end();
+      this.pool = null;
+      console.log("Database connection closed");
+    }
+  }
+}
+
+export const db = Database.getInstance();
+export default db;