use r2d2;

use diesel::pg::PgConnection;
use diesel::r2d2::ConnectionManager;
use lazy_static::lazy_static;

type Pool = r2d2::Pool<ConnectionManager<PgConnection>>;

#[allow(dead_code)]
pub type DbConnection = r2d2::PooledConnection<ConnectionManager<PgConnection>>;

lazy_static! {
    static ref POOL: Pool = {
        let database_url = "postgres://rust:rust@localhost:5433/dispatcher";
        let manager = ConnectionManager::<PgConnection>::new(database_url);
        Pool::new(manager).expect("failed to create db pool")
    };
}

pub fn init_database_pool() {
    lazy_static::initialize(&POOL);
}

#[allow(dead_code)]
pub fn get_connection() -> Result<DbConnection, String> {
    match POOL.get() {
        Ok(conn) => Ok(conn),
        Err(e) => Err(format!("unable to get pool connection: {}", e)),
    }
}