use diesel::r2d2::{self, ConnectionManager};
use diesel::PgConnection;
use std::env;
use dotenvy::dotenv;

pub type DbPool = r2d2::Pool<ConnectionManager<PgConnection>>;
pub type DbConn = r2d2::PooledConnection<ConnectionManager<PgConnection>>;

pub fn establish_connection() -> Result<DbPool, Box<dyn std::error::Error>> {
    dotenv().ok();
    
    let database_url = env::var("DATABASE_URL")
        .map_err(|_| "DATABASE_URL must be set")?;
        
    let manager = ConnectionManager::<PgConnection>::new(database_url);
    let pool = r2d2::Pool::builder()
        .build(manager)
        .map_err(|e| format!("Failed to create pool: {}", e))?;
        
    Ok(pool)
}

pub fn get_connection() -> Result<DbConn, Box<dyn std::error::Error>> {
    let pool = establish_connection()?;
    pool.get().map_err(|e| -> Box<dyn std::error::Error> { Box::new(e) })
}