/*
    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) 2025 metamuffin <metamuffin.org>
*/

use crate::backends::KV;
use anyhow::Result;
use std::{collections::BTreeMap, sync::RwLock};

pub struct Memory(RwLock<BTreeMap<Vec<u8>, Vec<u8>>>);

impl Memory {
    pub fn new() -> Self {
        Self(RwLock::new(BTreeMap::new()))
    }
}
impl KV for Memory {
    fn set(&self, key: &[u8], value: &[u8]) -> Result<()> {
        self.0.write().unwrap().insert(key.to_vec(), value.to_vec());
        Ok(())
    }
    fn get<'a>(&'a self, key: &[u8]) -> Result<Option<Vec<u8>>> {
        Ok(self.0.read().unwrap().get(key).cloned())
    }
    fn del(&self, key: &[u8]) -> Result<()> {
        self.0.write().unwrap().remove(key);
        Ok(())
    }
    fn next(&self, key: &[u8]) -> Result<Option<Vec<u8>>> {
        let r = self.0.read().unwrap();
        Ok(r.range(key.to_vec()..).next().map(|(k, _)| k.to_owned()))
    }
    fn prev(&self, key: &[u8]) -> Result<Option<Vec<u8>>> {
        let r = self.0.read().unwrap();
        Ok(r.range(..key.to_vec())
            .next_back()
            .map(|(k, _)| k.to_owned()))
    }
}