use sqlite_loadable::prelude::*;
use sqlite_loadable::{api, define_scalar_function, Result};

pub fn add(context: *mut sqlite3_context, values: &[*mut sqlite3_value]) -> Result<()> {
    let a = api::value_int(&values[0]);
    let b = api::value_int(&values[1]);
    api::result_int(context, a + b);
    Ok(())
}

#[sqlite_entrypoint]
pub fn sqlite3_manual_init(db: *mut sqlite3) -> Result<()> {
    define_scalar_function(db, "addx", 2, add, FunctionFlags::empty())?;
    Ok(())
}

#[cfg(feature = "static")]
#[cfg(test)]
mod tests {
    use super::*;

    use rusqlite::Connection;

    #[test]
    fn test_manual_load() {
        let db = Connection::open_in_memory().unwrap();
        // TODO when static linking is fixed, this should work
        unsafe {
            sqlite3_manual_init(
                std::mem::transmute(db.handle()),
                std::ptr::null_mut(),
                std::ptr::null_mut(),
            );
        }

        let result: i32 = db
            .query_row("select addx(?1, ?2)", [1, 2], |x| x.get(0))
            .unwrap();

        assert_eq!(result, 3);
    }
}