#pragma once
#include <map>
#include <set>
#include <mutex>
#include <chrono>
#include "Export.h"
#include "HTTPObjects.h"

namespace Json
{
	class Value;
}

class UNSWSC_DLL_EXPORT SessionManager
{
public:
	using systime = std::chrono::system_clock::time_point;

	class UNSWSC_DLL_EXPORT Session
	{
	private:
		int uid;
		std::string cookie;
		systime expiry_date;

		static const std::chrono::hours max_age;

	public:
		Session();
		Session(const Session& obj);
		Session(const std::string& cookie);		//构造仅用于比较的临时Session对象
		Session(const Json::Value& json_obj);	//从JSON反序列化
		Session(int uid, const std::string& cookie);

	public:
		int GetUID() const;
		bool Expired() const;
		std::string GetCookie() const;
		systime GetExpiryDate() const;
		bool NeedExpiryDateRefresh() const;		//使用超过一天且在活跃的cookie将被刷新。此处仅作时间判断

	public:
		void SetUID(int uid);
		void RefreshExpiryDate();
		void SetCookie(const std::string& cookie);
		void SetExpiryDate(const systime& expiry_time);

	public:
		bool operator<(const Session& obj) const;	//For std::map/std::set/...
		operator Json::Value() const;	//JSON序列化

		static int GetMaxAgeSeconds();
	};

private:
	std::mutex pool_mutex;
	//Key: Cookie Pair(oreo=xxxxx), Value: UID
	std::map<std::string, int> cookie_storage;
	//Key: UID, Value: Cookie Lists
	std::map<int, std::set<Session>> reverse_cookie_storage;

	const std::string prefix = "oreo=";
	//const std::string cookie_template = prefix + "{}; HttpOnly; Path=/; SameSite=Lax; Max-Age={}";
	const std::string cookie_template = prefix + "{}; HttpOnly; Secure; Path=/; SameSite=None; Max-Age={}";

public:
	SessionManager();
	SessionManager(const SessionManager& obj) = delete;

public:
	static std::string Random();
	static std::string ISO8601_TimeString();

public:
	void AutoCleanCookiePool();
	std::string GenerateCookieForUser(int uid, bool cookie_only = false);
	std::string DeleteCookie(const std::string& cookie);
	bool CheckRequestCookie(uns::RequestPtr request, int& uid);
	std::string DeleteAllCookieForUser(int uid, const std::string& current_cookie);

	bool HasDumpedCookie(const std::string& path);
	bool LoadDumpedCookie(const std::string& path);
	bool DumpAllValidCookies(const std::string& path);
};

extern UNSWSC_DLL_EXPORT SessionManager GlobalSessionManager;