//! Some ORM helpers
//!
//! The macros, types and traits in this module are used to create a simple GraphQL API on top of
//! models that are in the database.

#![allow(unused_macros)]

macro_rules! all {
    ($model_name:ident, $conn:expr) => {{
        use diesel::associations::HasTable;

        let table = $crate::models::$model_name::table();
        table.load(&$conn)
    }};
}

macro_rules! retrieve {
    ($model_name:ident, $primary_key:expr, $conn:expr) => {{
        use diesel::associations::HasTable;

        let table = $crate::models::$model_name::table();
        table.find($primary_key).first(&$conn)
    }};
}

macro_rules! create {
    ($model_name:ident, $object:expr, $conn:expr) => {{
        use diesel::associations::HasTable;
        use diesel::{ExpressionMethods, QueryDsl, RunQueryDsl, Table};

        let table = $crate::models::$model_name::table();
        let primary_key = table.primary_key();
        $conn.transaction::<$model_name, diesel::result::Error, _>(|| {
            diesel::insert_into(table).values($object).execute(&$conn)?;
            table.order(primary_key.desc()).first(&$conn)
        })
    }};
}

macro_rules! update {
    ($model_name:ident, $primary_key:expr, $object:expr, $conn:expr) => {{
        use diesel::associations::HasTable;

        let table = $crate::models::$model_name::table();
        $conn.transaction::<_, diesel::result::Error, _>(|| {
            diesel::update(table.find($primary_key))
                .set($object)
                .execute(&$conn)?;
            table.find($primary_key).first(&$conn)
        })
    }};
}

macro_rules! destroy {
    ($model_name:ident, $primary_key:expr, $conn:expr) => {{
        use diesel::associations::HasTable;

        let table = $crate::models::$model_name::table();
        let result: Result<$model_name, _> = get!($model_name, $primary_key, $conn);
        match result {
            Ok(_) => diesel::delete(table.find($primary_key)).execute(&$conn),
            Err(e) => Err(e),
        }
    }};
}

macro_rules! destroy_all {
    ($model_name:ident, $conn:expr) => {{
        use diesel::associations::HasTable;
        use diesel::RunQueryDsl;

        let table = $crate::models::$model_name::table();
        diesel::delete(table).execute(&$conn)
    }};
}