#pragma once
#include "file_manager/file.hpp"

namespace big
{
	class cache_header final
	{
	public:
		std::uint32_t m_cache_version;
		std::uint32_t m_game_version;
		float m_online_version;
		std::uint64_t m_data_size;
	};

	using cache_data = std::unique_ptr<std::uint8_t[]>;
	class cache_file final
	{
	public:
		/// <summary>
		/// 
		/// </summary>
		/// <param name="cache_file">FileMgr file object</param>
		/// <param name="cache_version">Internal version, use this to invalidate the cache when changing the structure of the data</param>
		cache_file(file cache_file, std::uint32_t cache_version);

		/// <summary>
		/// Frees any memory used to hold the cached data.
		/// </summary>
		void free();

		/// <summary>
		/// Attempts to load the cache from disk
		/// </summary>
		/// <returns>True after successfully loading the data, false if the file didn't exist.</returns>
		bool load();

		/// <summary>
		/// Writes the cache to disk
		/// </summary>
		/// <returns></returns>
		bool write() const;

		std::uint8_t* data() const;
		std::uint64_t data_size() const;

		/// <summary>
		/// Check if the cache file is up to date with the expected versions
		/// </summary>
		/// <param name="game_version">Current Game version</param>
		/// <param name="online_version">Current Online version</param>
		/// <returns>True if cache is up to date, false otherwise.</returns>
		bool up_to_date(std::uint32_t game_version, float online_version) const;


		void set_data(cache_data&& data, std::uint64_t data_size);
		/// <summary>
		/// Sets the version information of the cache header.
		/// </summary>
		/// <param name="game_version">Game Build</param>
		/// <param name="online_version">Online Version</param>
		void set_header_version(std::uint32_t game_version, float online_version);

	private:
		file m_cache_file;

		std::uint32_t m_cache_version;

		cache_header m_cache_header;
		cache_data m_data;
	};
}