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use std::{any::type_name, collections::HashMap, fmt::Debug};

/// HashMap wrapper with incremental ID (u64) assignment.
pub struct HashMapId<T> {
    id_seed: u64,
    store: HashMap<u64, T>,
}

impl<T> HashMapId<T>
where
    T: Send + Sync,
{
    pub fn new() -> Self {
        Self {
            id_seed: 0,
            store: HashMap::new(),
        }
    }

    pub fn add(&mut self, item: T) -> u64 {
        let id = self.id_seed;
        self.store.insert(id, item);
        self.id_seed += 1;
        id
    }

    pub fn remove(&mut self, id: u64) -> Option<T> {
        self.store.remove(&id)
    }

    pub fn get_mut(&mut self, id: u64) -> Option<&mut T> {
        self.store.get_mut(&id)
    }

    pub fn get(&self, id: u64) -> Option<&T> {
        self.store.get(&id)
    }
}

impl<T> Default for HashMapId<T>
where
    T: Send + Sync,
{
    fn default() -> Self {
        Self::new()
    }
}

impl<T> Debug for HashMapId<T> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("HashMapId")
            .field("id_seed", &self.id_seed)
            .field("type", &type_name::<T>())
            .finish()
    }
}