/*  OpenTally: Open-source election vote counting
 *  Copyright © 2021–2022 Lee Yingtong Li (RunasSudo)
 *
 *  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, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  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 crate::election::Candidate;

use nohash_hasher::BuildNoHashHasher;

use std::{collections::{HashMap, hash_map}, ops::Index};

/// Newtype for [HashMap] on [Candidate]s
#[derive(Clone)]
pub struct CandidateMap<'e, V> {
	// TODO: Can we implement this more efficiently as a Vec?
	map: HashMap<&'e Candidate, V, BuildNoHashHasher<Candidate>>
}

impl<'e, V> CandidateMap<'e, V> {
	/// See [HashMap::new]
	pub fn new() -> Self {
		Self {
			map: HashMap::with_hasher(BuildNoHashHasher::default())
		}
	}
	
	/// See [HashMap::with_capacity]
	pub fn with_capacity(capacity: usize) -> Self {
		Self {
			map: HashMap::with_capacity_and_hasher(capacity, BuildNoHashHasher::default())
		}
	}
	
	/// See [HashMap::len]
	#[inline]
	pub fn len(&self) -> usize {
		return self.map.len();
	}
	
	/// See [HashMap::insert]
	#[inline]
	pub fn insert(&mut self, candidate: &'e Candidate, value: V) {
		self.map.insert(candidate, value);
	}
	
	/// See [HashMap::get]
	#[inline]
	pub fn get(&self, candidate: &'e Candidate) -> Option<&V> {
		return self.map.get(candidate);
	}
	
	/// See [HashMap::get_mut]
	#[inline]
	pub fn get_mut(&mut self, candidate: &'e Candidate) -> Option<&mut V> {
		return self.map.get_mut(candidate);
	}
	
	/// See [HashMap::iter]
	#[inline]
	pub fn iter(&self) -> hash_map::Iter<&'e Candidate, V> {
		return self.map.iter();
	}
	
	/// See [HashMap::iter_mut]
	#[inline]
	pub fn iter_mut(&mut self) -> hash_map::IterMut<&'e Candidate, V> {
		return self.map.iter_mut();
	}
	
	/// See [HashMap::values]
	#[inline]
	pub fn values(&self) -> hash_map::Values<&'e Candidate, V> {
		return self.map.values();
	}
}

impl<'e, V> Index<&Candidate> for CandidateMap<'e, V> {
	type Output = V;
	
	fn index(&self, candidate: &Candidate) -> &Self::Output {
		return &self.map[candidate];
	}
}

impl<'e, V> IntoIterator for CandidateMap<'e, V> {
	type Item = (&'e Candidate, V);
	
	type IntoIter = hash_map::IntoIter<&'e Candidate, V>;
	
	fn into_iter(self) -> Self::IntoIter {
		return self.map.into_iter();
	}
}