/*
   This file is part of Fennix Kernel.

   Fennix Kernel 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.

   Fennix Kernel 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 Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/

#pragma once

#include <types.h>

#include <type_trails>
#include <functional>
#include <algorithm>
#include <assert.h>
#include <cstring>
#include <utility>

// #define DEBUG_VECTOR_MESSAGES 1

#ifdef DEBUG_VECTOR_MESSAGES
#define vDebug(m, ...) debug(m, ##__VA_ARGS__)
#else
#define vDebug(m, ...)
#endif

namespace std
{
	template <class T>
	class vector
	{
	private:
		size_t VectorSize = 0;
		size_t VectorCapacity = 0;
		T *VectorBuffer = nullptr;

	public:
		typedef T *iterator;
		typedef const T *const_iterator;

		vector() { vDebug("%#lx: ( empty init )", this); }

		vector(size_t Size)
			: VectorSize(Size),
			  VectorCapacity(Size),
			  VectorBuffer(new T[Size])
		{
			vDebug("%#lx: ( init w/size: %lld )", this, Size);
		}

		vector(size_t Size, const T &Initial)
			: VectorSize(Size),
			  VectorCapacity(Size),
			  VectorBuffer(new T[Size])
		{
			vDebug("%#lx: ( init w/size: %lld, initial vector: %llx )", this,
				   Size, Initial);

			assert(Size > 0);
			for (size_t i = 0; i < Size; i++)
				VectorBuffer[i] = Initial;
		}

		vector(const vector<T> &v)
			: VectorSize(v.VectorSize),
			  VectorCapacity(v.VectorCapacity),
			  VectorBuffer(nullptr)
		{
			vDebug("%#lx: ( vector copy: %#lx )", this, &v);

			if (!v.VectorBuffer || VectorSize <= 0)
				return;

			VectorBuffer = new T[VectorSize];
			std::copy(v.VectorBuffer, v.VectorBuffer + VectorSize, VectorBuffer);
		}

		~vector()
		{
			vDebug("%#lx: ( deinit )", this);

			VectorSize = 0;
			VectorCapacity = 0;
			if (VectorBuffer != nullptr)
			{
				delete[] VectorBuffer;
				VectorBuffer = nullptr;
			}
		}

		void erase(iterator Position)
		{
			vDebug("%#lx: Erasing element at position %lld (v. size: %lld)", this,
				   Position - this->VectorBuffer, this->VectorSize);

			if (Position == this->end())
			{
				warn("%#lx: Cannot erase element at end of vector", this);
				return;
			}

			assert(Position >= this->VectorBuffer);
			assert(Position < this->VectorBuffer + this->VectorSize);

			size_t index = Position - this->VectorBuffer;

			if (std::is_trivially_copyable<T>::value)
			{
				this->VectorBuffer[index] = T();
				vDebug("%#lx: %#lx is trivially copyable", this,
					   &this->VectorBuffer[index]);
			}
			else
			{
				this->VectorBuffer[index].~T();
				vDebug("%#lx: %#lx is not trivially copyable", this,
					   &this->VectorBuffer[index]);
			}

			for (size_t i = index; i < this->VectorSize - 1; ++i)
			{
				this->VectorBuffer[i] = std::move(this->VectorBuffer[i + 1]);
			}
			this->VectorSize--;
		}

		T &next(size_t Position)
		{
			if (Position + 1 < this->VectorSize)
				return this->VectorBuffer[Position + 1];

			warn("%#lx: next( %lld ) is null (requested by %#lx)", this,
				 Position, __builtin_return_address(0));

			return {};
		}

		T &prev(size_t Position)
		{
			if (Position > 0)
				return this->VectorBuffer[Position - 1];

			warn("%#lx: prev( %lld ) is null (requested by %#lx)", this,
				 Position, __builtin_return_address(0));

			return {};
		}

		T &next(const T &Value)
		{
			for (size_t i = 0; i < this->VectorSize; i++)
			{
				if (std::equal_to<T>()(this->VectorBuffer[i], Value))
				{
					if (i + 1 < this->VectorSize)
						return this->VectorBuffer[i + 1];
					else
						break;
				}
			}

			warn("%#lx: next( %#lx ) is null (requested by %#lx)", this,
				 Value, __builtin_return_address(0));

			return {};
		}

		T &prev(const T &Value)
		{
			for (size_t i = 0; i < this->VectorSize; i++)
			{
				if (std::equal_to<T>()(this->VectorBuffer[i], Value))
				{
					if (i > 0)
						return this->VectorBuffer[i - 1];
					else
						break;
				}
			}

			warn("%#lx: prev( %#lx ) is null (requested by %#lx)", this,
				 Value, __builtin_return_address(0));

			return {};
		}

		void push_back(const T &Value)
		{
			vDebug("%#lx: push_back( %#lx )", this, Value);

			if (this->VectorSize >= this->VectorCapacity)
			{
				size_t newCapacity = this->VectorCapacity == 0
										 ? 1
										 : this->VectorCapacity * 2;
				reserve(newCapacity);
			}

			this->VectorBuffer[this->VectorSize++] = Value;
		}

		void reverse()
		{
			if (this->VectorSize <= 1)
				return;

			for (size_t i = 0, j = this->VectorSize - 1; i < j; i++, j--)
			{
				T &elem1 = this->VectorBuffer[i];
				T &elem2 = this->VectorBuffer[j];
				std::swap(elem1, elem2);
			}
		}

		void reserve(size_t Capacity)
		{
			assert(!(Capacity <= VectorCapacity));

			T *NewBuffer = new T[Capacity];
			size_t Size = std::min(Capacity, this->VectorSize);
			for (size_t i = 0; i < Size; i++)
				NewBuffer[i] = std::move(this->VectorBuffer[i]);

			vDebug("%#lx: reserve( %lld )->Buffer:~%#lx", this,
				   Capacity, this->VectorBuffer);

			delete[] this->VectorBuffer;
			this->VectorBuffer = NewBuffer;
			this->VectorCapacity = Capacity;
		}

		void resize(size_t Size)
		{
			reserve(Size);
			this->VectorSize = Size;
		}

		void clear()
		{
			this->VectorCapacity = 0;
			this->VectorSize = 0;
			if (VectorBuffer != nullptr)
			{
				delete[] this->VectorBuffer;
				this->VectorBuffer = nullptr;
			}
		}

		T &operator[](size_t Index)
		{
			if (Index >= this->VectorSize || !this->VectorBuffer)
			{
				warn("%#lx: operator[]( %lld ) is null (requested by %#lx)", this,
					 Index, __builtin_return_address(0));

				static T null_elem{};
				return null_elem;
			}
			return this->VectorBuffer[Index];
		}

		vector<T> &operator=(const vector<T> &v)
		{
			if (this == &v)
				return *this;

			delete[] this->VectorBuffer;
			this->VectorSize = v.VectorSize;
			this->VectorCapacity = v.VectorCapacity;

			vDebug("%#lx: operator=( <vector> )->Size:%lld", this,
				   this->VectorSize);

			this->VectorBuffer = new T[this->VectorSize];
			for (size_t i = 0; i < this->VectorSize; i++)
				this->VectorBuffer[i] = v.VectorBuffer[i];

			return *this;
		}

		void pop_back() { this->VectorSize--; }
		T &front() { return this->VectorBuffer[0]; }
		T &back() { return this->VectorBuffer[this->VectorSize - 1]; }
		T *data() { return this->VectorBuffer; }
		bool empty() const { return this->VectorSize == 0; }
		size_t capacity() const { return this->VectorCapacity; }
		size_t size() const { return this->VectorSize; }
		iterator begin() { return this->VectorBuffer; }
		iterator end() { return this->VectorBuffer + size(); }
		const_iterator begin() const { return this->VectorBuffer; }
		const_iterator end() const { return this->VectorBuffer + size(); }
	};
}