import { PoolConnection, Pool, createPool } from 'mariadb';

type ConnectionConfig = {
    host: string,
    user: string,
    password: string,
    database: string,
    port: number,
};

export default class Database {
    private static instance: Database;
    private pool: Pool;

    private constructor(config: ConnectionConfig) {
        this.pool = createPool(config);
    }

    public static getInstance(): Database {
        if (!Database.instance) {
            Database.instance = new Database({
                host: process.env.DATABASE_HOST as string,
                user: process.env.DATABASE_USER as string,
                password: process.env.DATABASE_PASSWORD as string,
                database: process.env.DATABASE_SCHEMA as string,
                port: 3306
            });
        }

        return Database.instance;
    }

    public async getConnection(): Promise<PoolConnection> {
        return this.pool.getConnection();
    }
}