/*
    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
    Copyright (C) 2023 metamuffin <metamuffin.org>
*/
#![feature(lazy_cell)]
use base64::Engine;
use jellycommon::config::GlobalConfig;
use std::{fs::File, path::PathBuf, str::FromStr, sync::LazyLock};

pub static CONF: LazyLock<GlobalConfig> = LazyLock::new(|| {
    serde_json::from_reader(
        File::open(
            std::env::args()
                .nth(1)
                .expect("First argument must specify the config.json to use."),
        )
        .unwrap(),
    )
    .unwrap()
});

pub fn cache_file(seed: &[&str]) -> (PathBuf, Option<File>) {
    use sha2::Digest;
    let mut d = sha2::Sha512::new();
    for s in seed {
        d.update(s.as_bytes());
        d.update(b"\0");
    }
    let d = d.finalize();
    let fname = base64::engine::general_purpose::URL_SAFE.encode(d);
    let fname = &fname[..22]; // about 128 bits
    let fullpath = CONF.cache_path.join(fname);
    let cachepath = PathBuf::from_str(fname).unwrap();

    let f = if !fullpath.exists() {
        Some(File::create(&fullpath).unwrap())
    } else {
        None
    };
    (cachepath, f)
}