/*!
This is not really an example :-) This is a variant of the `pooled_sessions` example
that, unlike its progenitor, runs forever. This is used as a regression test for
[issue #3](https://github.com/quietboil/sibyl/issues/3).
*/

#[cfg(feature="blocking")]
fn main() -> sibyl::Result<()> {
    use std::{env, thread};
    use std::sync::Arc;
    use once_cell::sync::OnceCell;

    use sibyl::*;

    static ORACLE : OnceCell<Environment> = OnceCell::new();
    let oracle = ORACLE.get_or_try_init(|| {
        Environment::new()
    })?;

    let dbname = env::var("DBNAME").expect("database name");
    let dbuser = env::var("DBUSER").expect("user name");
    let dbpass = env::var("DBPASS").expect("password");

    let pool = oracle.create_session_pool(&dbname, &dbuser, &dbpass, 0, 1, 10)?;
    let pool = Arc::new(pool);

    let mut workers = Vec::with_capacity(10);
    for i in 0..workers.capacity() {
        let pool = pool.clone();
        let handle = thread::spawn(move || -> Result<()> {
            for n in 1..10_000 {
                for _ in 0..1000 {
                    let report = select_latest_hire(&pool)?;
                    assert_eq!(report, "Amit Banda was hired on April 21, 2008");
                }
                println!("{}:{}", i, n);
            }
            Ok(())
        });
        workers.push(handle);
    }
    for handle in workers {
        handle.join().expect("finished worker")?;
    }
    Ok(())
}

#[cfg(feature="blocking")]
fn select_latest_hire(pool: &sibyl::SessionPool) -> sibyl::Result<String> {
    let session = pool.get_session()?;
    let stmt = session.prepare("
        SELECT first_name, last_name, hire_date
        FROM (
              SELECT first_name, last_name, hire_date
                   , Row_Number() OVER (ORDER BY hire_date DESC, last_name) AS hire_date_rank
                FROM hr.employees
             )
         WHERE hire_date_rank = 1
    ")?;
    if let Some( row ) = stmt.query_single(())? {
        let first_name : Option<&str> = row.get(0)?;
        let last_name : &str = row.get(1)?;
        let name = first_name.map_or(last_name.to_string(), |first_name| format!("{} {}", first_name, last_name));
        let hire_date : sibyl::Date = row.get(2)?;
        let hire_date = hire_date.to_string("FMMonth DD, YYYY")?;

        Ok(format!("{} was hired on {}", name, hire_date))
    } else {
        Ok("Not found".to_string())
    }
}

#[cfg(feature="nonblocking")]
fn main() {}