use super::*;
use std::collections::{HashMap, HashSet};
use std::sync::Arc;
use tokio::sync::RwLock;
use generational_arena::{
    Arena,Index,
};

use user::{User, UserID};
use post::{Post, PostID};

mod freeze;
pub use freeze::*;

#[derive(Debug)]
struct Oneesan
{
    users: Arena<Arc<RwLock<User>>>,
    posts: Arena<Arc<RwLock<Post>>>,

    /// Maps `UserID`s to indexes in the `users` arena.
    users_map: HashMap<UserID, Index>,
    /// Maps `PostID`s to indexies in the `posts` arena.
    posts_map: HashMap<PostID, Index>,

    /// Maps `UserID`s to the user's owned posts in the `posts` arena.
    posts_user_map: HashMap<UserID, MaybeVec<Index>>,
}

#[derive(Debug)]
struct Inner
{
    /// The posts and user state.
    oneesan: RwLock<Oneesan>,
}

/// Contains all posts and users
#[derive(Debug, Clone)]
pub struct State(Arc<Inner>);

impl State
{
    /// Create a new empty state
    pub fn new() -> Self
    {
	Self(Arc::new(
	    Inner {
		oneesan: RwLock::new(Oneesan {
		    users: Arena::new(),
		    posts: Arena::new(),

		    users_map: HashMap::new(),
		    posts_map: HashMap::new(),

		    posts_user_map: HashMap::new(),
		})
	    }
	))
    }
}