#pragma once

/**
 * \file DataBuffer.h
 * \brief File containing the sp::DataBuffer class
 */

#include <algorithm>
#include <array>
#include <cassert>
#include <cstdint>
#include <cstring>
#include <list>
#include <map>
#include <memory>
#include <sp/common/ByteSwapping.h>
#include <sp/common/VarInt.h>
#include <string>
#include <vector>

namespace sp {

/**
 * \class DataBuffer
 * \brief Class used to manipulate memory
 */
class DataBuffer {
  private:
	using Data = std::vector<std::uint8_t>;

  private:
	Data m_Buffer;
	std::size_t m_ReadOffset;

  public:
	using iterator = Data::iterator;
	using const_iterator = Data::const_iterator;
	using reference = Data::reference;
	using const_reference = Data::const_reference;
	using difference_type = Data::difference_type;

	DataBuffer();
	DataBuffer(std::size_t a_InitialSize);
	DataBuffer(const DataBuffer& other);
	DataBuffer(const DataBuffer& other, difference_type offset);
	DataBuffer(DataBuffer&& other);
	DataBuffer(const std::string& str);

	DataBuffer& operator=(const DataBuffer& other);
	DataBuffer& operator=(DataBuffer&& other);

	/**
	 * \brief Append data to the buffer
	 * \warning No endian checks
	 */
	template <typename T>
	void Append(const T& a_Data) {
		std::size_t size = sizeof(a_Data);
		std::size_t end_pos = m_Buffer.size();
		m_Buffer.resize(m_Buffer.size() + size);
		std::memcpy(&m_Buffer[end_pos], &a_Data, size);
	}

	/**
	 * \brief Read data into a_Data
	 * \warning No endian checks
	 */
	template <typename T>
	void Read(T& a_Data) {
		assert(m_ReadOffset + sizeof(T) <= GetSize());
		std::memcpy(&a_Data, m_Buffer.data() + m_ReadOffset, sizeof(T));
		m_ReadOffset += sizeof(T);
	}

	/**
	 * \brief Write some data to the buffer
	 * \param buffer The buffer to write
	 * \param amount The amount of data to write
	 */
	void WriteSome(const char* buffer, std::size_t amount);

	/**
	 * \brief Write some data to the buffer
	 * \param buffer The buffer to write
	 * \param amount The amount of data to write
	 */
	void WriteSome(const std::uint8_t* buffer, std::size_t amount);

	/**
	 * \brief Read some data from the buffer
	 * \param buffer The buffer to Read
	 * \param amount The amount of data from the buffer
	 */
	void ReadSome(char* buffer, std::size_t amount);

	/**
	 * \brief Read some data from the buffer
	 * \param buffer The buffer to Read
	 * \param amount The amount of data from the buffer
	 */
	void ReadSome(std::uint8_t* buffer, std::size_t amount);

	/**
	 * \brief Read some data from the buffer
	 * \param buffer The buffer to Read
	 * \param amount The amount of data from the buffer
	 */
	void ReadSome(DataBuffer& buffer, std::size_t amount);

	/**
	 * \brief Resize the buffer
	 * \param size The new size of the buffer
	 */
	void Resize(std::size_t size) {
		m_Buffer.resize(size);
	}

	/**
	 * \brief Reserve some space in the buffer
	 * \param amount The amount of space to reserve
	 */
	void Reserve(std::size_t amount) {
		m_Buffer.reserve(amount);
	}

	/**
	 * \brief Clear the buffer
	 */
	void Clear() {
		m_Buffer.clear();
		m_ReadOffset = 0;
	}

	/**
	 * \brief When the buffer has been read entirely
	 */
	bool IsFinished() const {
		return m_ReadOffset >= m_Buffer.size();
	}

	/**
	 * \brief Get the buffer data
	 */
	std::uint8_t* data() {
		return m_Buffer.data();
	}

	/**
	 * \brief Get the buffer data
	 */
	const std::uint8_t* data() const {
		return m_Buffer.data();
	}

	/**
	 * \brief Get the read offset
	 */
	std::size_t GetReadOffset() const {
		return m_ReadOffset;
	}

	/**
	 * \brief Set the read offset
	 * \param pos The new read offset
	 */
	void SetReadOffset(std::size_t pos);

	/**
	 * \brief Get the size of the buffer
	 */
	std::size_t GetSize() const;

	/**
	 * \brief Get the remaining size of the buffer
	 */
	std::size_t GetRemaining() const;

	/**
	 * \brief Read a file into the buffer
	 * \param fileName The name of the file to read
	 */
	void ReadFile(const std::string& fileName);

	/**
	 * \brief Write a file into the buffer
	 * \param fileName The name of the file to write to
	 */
	void WriteFile(const std::string& fileName) const;

	/**
	 * \brief Allocate the buffer on the heap
	 * \warning Don't forget to free the data !
	 */
	std::uint8_t* HeapAllocatedData() const {
		std::uint8_t* newBuffer = new std::uint8_t[GetSize()];
		std::memcpy(newBuffer, data(), GetSize());
		return newBuffer;
	}

	/**
	 * \brief Operator == to compare two DataBuffer
	 */
	bool operator==(const DataBuffer& other) const {
		return m_Buffer == other.m_Buffer;
	}

	iterator begin();
	iterator end();
	const_iterator begin() const;
	const_iterator end() const;
};

/**
 * \brief Append data to the buffer from another const buffer
 * \param data The buffer to append
 */
DataBuffer& operator<<(DataBuffer& a_Buffer, const DataBuffer& data);

}  // namespace sp