/**
	This file is a part of rexy's general purpose library
	Copyright (C) 2020 rexy712

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU 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 General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef REXY_CX_VECTOR_HPP
#define REXY_CX_VECTOR_HPP

#include <cstddef> //size_t
#include <utility> //move, forward

#include "detail/bool_specialize_base.hpp"
#include "../utility.hpp" //swap
#include "../compat/standard.hpp"

#include <type_traits>

namespace rexy::cx{

	template<class T, std::size_t N>
	class vector
	{
	public:
		using value_type = T;
		using size_type = std::size_t;
		using difference_type = ptrdiff_t;
		using iterator = T*;
		using const_iterator = const T*;
		using reference = T&;
		using const_reference = const T&;
		using pointer = T*;
		using const_pointer = const T*;

		static constexpr size_type max_elements = N;

	private:
		value_type m_elements[N] = {};
		size_type m_size = 0;

	public:
		constexpr vector(void)noexcept(std::is_nothrow_default_constructible<T>::value) = default;
		constexpr vector(const vector&)noexcept(std::is_nothrow_copy_constructible<T>::value) = default;
		constexpr vector(vector&&)noexcept(std::is_nothrow_move_constructible<T>::value) = default;

		constexpr vector(size_type count, const T& value)
			noexcept(std::is_nothrow_copy_assignable<T>::value)
		{
			for(size_type i = 0;i < min(count, max_elements);++i){
				m_elements[i] = value;
			}
			m_size = min(count, max_elements);
		}

		REXY_CPP20_CONSTEXPR ~vector(void)noexcept = default;

		constexpr vector& operator=(const vector&)noexcept(std::is_nothrow_copy_assignable<T>::value) = default;
		constexpr vector& operator=(vector&&)noexcept(std::is_nothrow_move_assignable<T>::value) = default;

		constexpr reference at(size_type pos)noexcept{
			return m_elements[pos];
		}
		constexpr const_reference at(size_type pos)const noexcept{
			return m_elements[pos];
		}
		constexpr reference operator[](size_type pos)noexcept{
			return m_elements[pos];
		}
		constexpr const_reference operator[](size_type pos)const noexcept{
			return m_elements[pos];
		}
		constexpr reference front(void)noexcept{
			return m_elements[0];
		}
		constexpr const_reference front(void)const noexcept{
			return m_elements[0];
		}
		constexpr reference back(void)noexcept{
			return m_elements[m_size-1];
		}
		constexpr const_reference back(void)const noexcept{
			return m_elements[m_size-1];
		}
		constexpr const_pointer data(void)const noexcept{
			return m_elements;
		}
		constexpr iterator begin(void)noexcept{
			return m_elements;
		}
		constexpr const_iterator begin(void)const noexcept{
			return m_elements;
		}
		constexpr const_iterator cbegin(void)const noexcept{
			return m_elements;
		}
		constexpr iterator end(void)noexcept{
			return m_elements+m_size;
		}
		constexpr const_iterator end(void)const noexcept{
			return m_elements+m_size;
		}
		constexpr const_iterator cend(void)const noexcept{
			return m_elements+m_size;
		}

		constexpr bool empty(void)const noexcept{
			return m_size == 0;
		}
		constexpr size_type size(void)const noexcept{
			return m_size;
		}
		constexpr size_type max_size(void)const noexcept{
			return max_elements;
		}
		constexpr size_type capacity(void)const noexcept{
			return max_elements;
		}
		constexpr void clear(void)noexcept{
			m_size = 0;
		}
		constexpr iterator insert(iterator pos, const T& value)
			noexcept(std::is_nothrow_move_assignable<T>::value &&
			         std::is_nothrow_copy_assignable<T>::value)
		{
			auto start = pos;
			if(start != end()){
				auto it = pos;
				++pos;
				for(;pos != end();++it,++pos){
					*pos = std::move(*it);
				}
			}
			++m_size;
			*start = value;
			return start;
		}
		constexpr iterator insert(const_iterator pos, T&& value)
			noexcept(std::is_nothrow_move_assignable<T>::value)
		{
			auto start = pos;
			if(start != end()){
				auto it = pos;
				++pos;
				for(;pos != end();++it,++pos){
					*pos = std::move(*it);
				}
			}
			++m_size;
			*start = std::move(value);
			return begin() + (pos - start);
		}
		template<class... Args>
		constexpr iterator emplace(const_iterator pos, Args&&... args)
			noexcept(std::is_nothrow_move_assignable<T>::value &&
			         std::is_nothrow_constructible<T,Args&&...>::value)
		{
			auto start = pos;
			if(start != end()){
				auto it = pos;
				++pos;
				for(;pos != end();++it,++pos){
					*pos = std::move(*it);
				}
			}
			++m_size;
			*start = T{std::forward<Args>(args)...};
			return begin() + (start - pos);
		}
		constexpr iterator erase(const_iterator pos)
			noexcept(std::is_nothrow_move_assignable<T>::value)
		{
			auto start = pos;
			if(start != end()){
				auto it = pos;
				++pos;
				for(;pos != end();++it,++pos){
					*it = std::move(*pos);
				}
			}
			--m_size;
			return begin() + (end() - start);
		}
		constexpr iterator push_back(const T& value)
			noexcept(std::is_nothrow_copy_assignable<T>::value)
		{
			m_elements[m_size] = value;
			return m_elements+(m_size++);
		}
		template<class... Args>
		constexpr iterator emplace_back(Args&&... args)
			noexcept(std::is_nothrow_constructible<T,Args&&...>::value)
		{
			m_elements[m_size++] = T{std::forward<Args>(args)...};
			return m_elements+(m_size++);
		}
		constexpr void pop_back(void)noexcept{
			--m_size;
		}
		constexpr void resize(size_type count)noexcept{
			if(count <= max_size())
				m_size = count;
		}
		constexpr void resize(size_type count, const value_type& value)noexcept{
			if(count > m_size){
				if(count <= max_size()){
					for(size_type i = m_size;i < count;++i){
						m_elements[i] = value;
					}
				}
			}else{
				m_size = count;
			}
		}
		constexpr void fill(const T& value)
			noexcept(std::is_nothrow_copy_assignable<T>::value)
		{
			for(auto it = begin();it != end();++it){
				*it = value;
			}
		}
		constexpr void swap(vector& other)
			noexcept(noexcept(swap(m_elements[0], other.m_elements[0])))
		{
			size_type i = 0;
			for(;i < m_size;++i){
				swap(m_elements[i], other.m_elements[i]);
			}
			for(;i < other.m_size;++i){
				swap(m_elements[i], other.m_elements[i]);
			}
			swap(m_size, other.m_size);
		}
	};

	template<std::size_t N>
	class vector<bool,N> : public detail::bool_specialize_base
	{
	public:
		using value_type = bool;
		using size_type = bool_specialize_base::size_type;
		using difference_type = bool_specialize_base::difference_type;
		using iterator = bool_iter;
		using const_iterator = const_bool_iter;
		using reference = boolean;
		using const_reference = bool;

		static constexpr size_type max_elements = N;

	private:
		static constexpr size_type arr_size = (N / bits_per_byte) + (N % bits_per_byte == 0 ? 0 : 1);
		size_type m_size = 0;
		booleans m_elements[arr_size] = {};


	public:
		constexpr vector(void)noexcept = default;
		constexpr vector(const vector&)noexcept = default;
		constexpr vector(vector&&)noexcept = default;

		constexpr vector(size_type count, const value_type& value)noexcept{
			auto [byte_count,bits_count] = convert_to_byte_bit_pair(count);

			size_type i = 0;
			for(;i < byte_count;++i){
				for(size_type j = 0;i < bits_per_byte;++i){
					m_elements[i][j] = value;
				}
			}
			for(size_type j = 0;j < bits_count;++j){
				m_elements[i][j] = value;
			}
			m_size = min(count, max_elements);
		}

		REXY_CPP20_CONSTEXPR ~vector(void)noexcept = default;

		constexpr vector& operator=(const vector&)noexcept = default;
		constexpr vector& operator=(vector&&)noexcept = default;

		constexpr reference at(size_type pos)noexcept{
			auto [byte_count,bits_count] = convert_to_byte_bit_pair(pos);
			return m_elements[byte_count][bits_count];
		}
		constexpr const_reference at(size_type pos)const noexcept{
			auto [byte_count,bits_count] = convert_to_byte_bit_pair(pos);
			return m_elements[byte_count][bits_count];
		}
		constexpr reference operator[](size_type pos)noexcept{
			auto [byte_count,bits_count] = convert_to_byte_bit_pair(pos);
			return m_elements[byte_count][bits_count];
		}
		constexpr const_reference operator[](size_type pos)const noexcept{
			auto [byte_count,bits_count] = convert_to_byte_bit_pair(pos);
			return m_elements[byte_count][bits_count];
		}
		constexpr reference front(void)noexcept{
			return m_elements[0][0];
		}
		constexpr const_reference front(void)const noexcept{
			return m_elements[0][0];
		}
		constexpr reference back(void)noexcept{
			if(!m_size)
				return m_elements[0][0];
			auto [byte_count,bits_count] = convert_to_byte_bit_pair(m_size);
			if(bits_count == 0){
				bits_count = bits_per_byte-1;
				byte_count -= 1;
			}
			return m_elements[byte_count][bits_count];
		}
		constexpr const_reference back(void)const noexcept{
			if(!m_size)
				return m_elements[0][0];
			auto [byte_count,bits_count] = convert_to_byte_bit_pair(m_size);
			if(bits_count == 0){
				bits_count = bits_per_byte-1;
				byte_count -= 1;
			}
			return m_elements[byte_count][bits_count];
		}
		constexpr iterator begin(void)noexcept{
			return bool_iter{m_elements[0], 0};
		}
		constexpr const_iterator begin(void)const noexcept{
			return const_bool_iter{m_elements[0], 0};
		}
		constexpr const_iterator cbegin(void)const noexcept{
			return const_bool_iter{m_elements[0], 0};
		}
		constexpr iterator end(void)noexcept{
			auto [byte_count,bits_count] = convert_to_byte_bit_pair(m_size);
			return bool_iter{m_elements[byte_count], bits_count};
		}
		constexpr const_iterator end(void)const noexcept{
			auto [byte_count,bits_count] = convert_to_byte_bit_pair(m_size);
			return const_bool_iter{m_elements[byte_count], bits_count};
		}
		constexpr const_iterator cend(void)const noexcept{
			auto [byte_count,bits_count] = convert_to_byte_bit_pair(m_size);
			return const_bool_iter{m_elements[byte_count], bits_count};
		}

		constexpr bool empty(void)const noexcept{
			return m_size == 0;
		}
		constexpr size_type size(void)const noexcept{
			return m_size;
		}
		constexpr size_type max_size(void)const noexcept{
			return max_elements;
		}
		constexpr size_type capacity(void)const noexcept{
			return max_elements;
		}
		constexpr void clear(void)noexcept{
			m_size = 0;
		}
		constexpr iterator insert(const_iterator pos, const value_type& value)noexcept{
			auto start = pos;
			if(pos != end()){
				auto it = pos;
				++pos;
				for(;pos != end();++it,++pos){
					*pos = std::move(*it);
				}
			}
			++m_size;
			*start = value;
			return begin() + (pos - start);
		}
		template<class... Args>
		constexpr iterator emplace(const_iterator pos, Args&&... args)noexcept{
			auto start = pos;
			if(pos != end()){
				auto it = pos;
				++pos;
				for(;pos != end();++it,++pos){
					*pos = std::move(*it);
				}
			}
			++m_size;
			*start = bool{std::forward<Args>(args)...};
			return begin() + (pos - start);
		}
		constexpr iterator erase(const_iterator pos)noexcept{
			auto start = pos;
			if(pos != end()){
				auto it = pos;
				++pos;
				for(;pos != end();++it,++pos){
					*it = std::move(*pos);
				}
			}
			--m_size;
			return begin() + (end() - start);
		}
		constexpr iterator push_back(const value_type& value)noexcept{
			return insert(end(), value);
		}
		template<class... Args>
		constexpr iterator emplace_back(Args&&... args)noexcept{
			return emplace(end(), std::forward<Args>(args)...);
		}
		constexpr void pop_back(void)noexcept{
			--m_size;
		}
		constexpr void resize(size_type count)noexcept{
			if(count <= max_size())
				m_size = count;
		}
		constexpr void resize(size_type count, const value_type& value)noexcept{
			if(count > m_size){
				auto actual_count = min(count, max_size());
				auto num = actual_count - m_size;
				auto it = end();
				for(size_type i = 0;i < num;++i){
					*it = value;
					++it;
				}
			}
			m_size = count;
		}
		constexpr void fill(const bool& value)noexcept{
			for(auto it = begin();it != end();++it){
				*it = value;
			}
		}
		constexpr void swap(vector& other)noexcept{
			auto [byte_count,bits_count] = convert_to_byte_bit_pair(m_size);
			auto [other_byte_count,other_bits_count] = convert_to_byte_bit_pair(other.m_size);
			if(bits_count)
				++byte_count;
			if(other_bits_count)
				++other_byte_count;
			size_type i = 0;
			for(;i < byte_count;++i){
				swap(m_elements[i], other.m_elements[i]);
			}
			for(;i < other_byte_count;++i){
				swap(m_elements[i], other.m_elements[i]);
			}
			swap(m_size, other.m_size);
		}
	};

}

#endif