//=======================================================================
// Copyright Baptiste Wicht 2013-2016.
// Distributed under the terms of the MIT License.
// (See accompanying file LICENSE or copy at
//  http://www.opensource.org/licenses/MIT)
//=======================================================================

#ifndef VECTOR_H
#define VECTOR_H

#include <initializer_list.hpp>
#include <types.hpp>
#include <algorithms.hpp>
#include <new.hpp>
#include <iterator.hpp>

//TODO The vector does not call any destructor

namespace std {

template<typename T>
class vector {
public:
    typedef T value_type;
    typedef value_type* pointer_type;
    typedef size_t size_type;
    typedef value_type* iterator;
    typedef const value_type* const_iterator;

    using reverse_iterator       = std::reverse_iterator<iterator>;
    using const_reverse_iterator = std::reverse_iterator<const_iterator>;

private:
    T* data;
    uint64_t _size;
    uint64_t _capacity;

public:
    vector() : data(nullptr), _size(0), _capacity(0) {}

    explicit vector(uint64_t c) : data(new T[c]), _size(0), _capacity(c) {}

    vector(initializer_list<T> values) : data(new T[values.size()]), _size(values.size()), _capacity(values.size()) {
        std::copy(values.begin(), values.end(), begin());
    }

    vector(const vector& rhs) : data(nullptr), _size(rhs._size), _capacity(rhs._capacity) {
        if(!rhs.empty()){
            data = new T[_capacity];

            for(size_t i = 0; i < _size; ++i){
                data[i] = rhs.data[i];
            }
        }
    }

    vector& operator=(const vector& rhs){
        if(data && _capacity < rhs._capacity){
            delete[] data;
            data = nullptr;
        }

        if(_capacity < rhs._capacity){
            _capacity = rhs._capacity;
            data = new T[_capacity];
        }

        _size = rhs._size;

        for(size_t i = 0; i < _size; ++i){
            data[i] = rhs.data[i];
        }

        return *this;
    }

    //Move constructors

    vector(vector&& rhs) : data(rhs.data), _size(rhs._size), _capacity(rhs._capacity) {
        rhs.data = nullptr;
        rhs._size = 0;
        rhs._capacity = 0;
    };

    vector& operator=(vector&& rhs){
        if(data){
            delete[] data;
        }

        data = rhs.data;
        _size = rhs._size;
        _capacity = rhs._capacity;
        rhs.data = nullptr;
        rhs._size = 0;
        rhs._capacity = 0;

        return *this;
    }

    ~vector(){
        if(data){
            delete[] data;
        }
    }

    //Getters

    constexpr size_type size() const {
        return _size;
    }

    bool empty() const {
        return _size == 0;
    }

    constexpr size_type capacity() const {
        return _capacity;
    }

    constexpr const value_type& operator[](size_type pos) const {
        return data[pos];
    }

    value_type& operator[](size_type pos){
        return data[pos];
    }

    value_type& front(){
        return data[0];
    }

    const value_type& front() const  {
        return data[0];
    }

    value_type& back(){
        return data[size() - 1];
    }

    const value_type& back() const  {
        return data[size() - 1];
    }

    //Modifiers

    void reserve(size_t new_capacity){
        if(new_capacity > capacity()){
            ensure_capacity(new_capacity);
        }
    }

    void resize(size_t new_size){
        if(new_size > size()){
            ensure_capacity(new_size);

            //The elements will automatically be created to their defaults when
            //the array gets resized in ensure_capacity
            _size = new_size;
        } else if(new_size < _size){
            //By diminishing the size, the last elements become unreachable
            _size = new_size;
        }
    }

    void push_back(value_type&& element){
        ensure_capacity(_size + 1);

        data[_size++] = std::forward<value_type>(element);
    }

    void push_back(const value_type& element){
        ensure_capacity(_size + 1);

        data[_size++] = element;
    }

    void push_front(value_type&& element){
        ensure_capacity(_size + 1);

        for(size_t i = _size; i > 0; --i){
            data[i] = std::move(data[i-1]);
        }

        data[0] = std::forward<value_type>(element);
        ++_size;
    }

    void push_front(const value_type& element){
        ensure_capacity(_size + 1);

        for(size_t i = _size; i > 0; --i){
            data[i] = std::move(data[i-1]);
        }

        data[0] = element;
        ++_size;
    }

    value_type& emplace_back(){
        ensure_capacity(_size + 1);

        new (&data[_size++]) T();

        return back();
    }

    template<typename... Args>
    value_type& emplace_back(Args... args){
        ensure_capacity(_size + 1);

        new (&data[_size++]) T{std::forward<Args>(args)...};

        return back();
    }

    void pop_back(){
        --_size;
    }

    void clear(){
        _size = 0;
    }

    void erase(size_t position){
        for(size_t i = position; i < _size - 1; ++i){
            data[i] = std::move(data[i+1]);
        }

        --_size;
    }

    void erase(iterator position){
        for(size_t i = position - begin(); i < _size - 1; ++i){
            data[i] = std::move(data[i+1]);
        }

        --_size;
    }

    void erase(iterator first, iterator last){
        auto n = std::distance(first, last);

        for(size_t i = first - begin(); i < _size - n; ++i){
            data[i] = std::move(data[i+n]);
        }

        _size -= n;
    }

    //Iterators

    iterator begin(){
        return iterator(&data[0]);
    }

    constexpr const_iterator begin() const {
        return const_iterator(&data[0]);
    }

    iterator end(){
        return iterator(&data[_size]);
    }

    constexpr const_iterator end() const {
        return const_iterator(&data[_size]);
    }

    //Iterators

    reverse_iterator rbegin(){
        return reverse_iterator(&data[_size] - 1);
    }

    constexpr const_reverse_iterator rbegin() const {
        return const_iterator(&data[_size - 1]);
    }

    reverse_iterator rend(){
        return reverse_iterator(&data[-1]);
    }

    constexpr const_reverse_iterator rend() const {
        return const_reverse_iterator(&data[-1]);
    }

    // Relational operators

    bool operator==(const vector& rhs) const {
        if(size() != rhs.size()){
            return false;
        }

        for(size_t i = 0; i < size(); ++i){
            if((*this)[i] != rhs[i]){
                return false;
            }
        }

        return true;
    }

    bool operator!=(const vector& rhs) const {
        return !(*this == rhs);
    }

private:
    void ensure_capacity(size_t new_capacity){
        if(_capacity == 0){
            _capacity = new_capacity;
            data = new T[_capacity];
        } else if(_capacity < new_capacity){
            _capacity= _capacity * 2;
            if(new_capacity > _capacity){
                _capacity = new_capacity;
            }

            auto new_data = new T[_capacity];
            std::move_n(data, _size, new_data);

            delete[] data;
            data = new_data;
        }
    }
};

} //end of namespace std

#endif