module pg

pub struct ConnectionPool {
mut:
    connections chan DB
    config      Config
}

// new_connection_pool creates a new connection pool with the given size and configuration.
pub fn new_connection_pool(config Config, size int) !ConnectionPool {
    mut connections := chan DB{cap: size}
    for _ in 0 .. size {
        conn := connect(config)!
        connections <- conn
    }
    return ConnectionPool{
        connections: connections
        config:      config
    }
}

// acquire gets a connection from the pool
pub fn (mut pool ConnectionPool) acquire() !DB {
    return <-pool.connections or { return error('Failed to acquire a connection from the pool') }
}

// release returns a connection back to the pool.
pub fn (mut pool ConnectionPool) release(conn DB) {
    pool.connections <- conn
}

// close closes all connections in the pool.
pub fn (mut pool ConnectionPool) close() {
    for _ in 0 .. pool.connections.len {
        conn := <-pool.connections or { break }
        conn.close() or { break }
    }
}