use async_trait::async_trait;
use chrono::prelude::*;
use dataloader::non_cached::Loader;
use dataloader::BatchFn;
use diesel::prelude::*;
use std::collections::HashMap;
use uuidv7::Uuid;

use crate::{api::models, db};

pub struct DirectoryBatcher;

#[async_trait]
impl BatchFn<Uuid, models::directory::Directory> for DirectoryBatcher {
    async fn load(&mut self, keys: &[Uuid]) -> HashMap<Uuid, models::directory::Directory> {
        let db_conn = &mut db::POOL.get().unwrap();
        let mut map = HashMap::new();
        for row in db::schema::directories::table
            .select((
                db::schema::directories::id,
                db::schema::directories::created_at,
                db::schema::directories::updated_at,
            ))
            .filter(db::schema::directories::id.eq_any(keys))
            .load::<(Uuid, DateTime<Utc>, Option<DateTime<Utc>>)>(db_conn)
            .unwrap()
        {
            let row: (Uuid, DateTime<Utc>, Option<DateTime<Utc>>) = row;
            let data = models::directory::Directory {
                id: row.0,
                created_at: row.1,
                updated_at: row.2,
            };
            map.insert(data.id, data);
        }

        map
    }
}

pub type DirectoryLoader = Loader<Uuid, models::directory::Directory, DirectoryBatcher>;

pub const YIELD_COUNT: usize = 100;