/*
    wearechat - generic multiplayer game with voip
    Copyright (C) 2025 metamuffin

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License as published by
    the Free Software Foundation, version 3 of the License only.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/
use egui::Widget;
use std::{
    collections::{HashMap, HashSet},
    hash::Hash,
    sync::RwLock,
};

pub struct DemandMap<K, V> {
    inner: RwLock<DemandMapState<K, V>>,
}
struct DemandMapState<K, V> {
    values: HashMap<K, V>,
    needed: HashSet<K>,
    size_metric: usize,
}
impl<K: Hash + Eq + Clone, V: Clone> DemandMap<K, V> {
    pub fn new() -> Self {
        Self {
            inner: DemandMapState {
                needed: HashSet::new(),
                values: HashMap::new(),
                size_metric: 0,
            }
            .into(),
        }
    }
    pub fn needed(&self) -> Vec<K> {
        self.inner.read().unwrap().needed.iter().cloned().collect()
    }
    pub fn insert(&self, key: K, value: V, size: usize) {
        let mut s = self.inner.write().unwrap();
        s.needed.remove(&key);
        s.values.insert(key, value);
        s.size_metric += size;
    }
    pub fn try_get(&self, key: K) -> Option<V> {
        let mut s = self.inner.write().unwrap();
        if let Some(k) = s.values.get(&key) {
            Some(k.to_owned())
        } else {
            s.needed.insert(key);
            None
        }
    }
}

impl<K, V> Widget for &DemandMap<K, V> {
    fn ui(self, ui: &mut egui::Ui) -> egui::Response {
        let state = self.inner.read().unwrap();
        ui.label(state.needed.len().to_string());
        ui.label(state.values.len().to_string());
        ui.label(humansize::format_size(
            state.size_metric,
            humansize::DECIMAL,
        ));
        ui.end_row();
        ui.response()
    }
}