/**
	This file is a part of rexy's matrix client
	Copyright (C) 2019-2020 rexy712

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Affero General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	This program 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 Affero General Public License for more details.

	You should have received a copy of the GNU Affero General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef MATRIX_SESSION_HPP
#define MATRIX_SESSION_HPP

#include "matrix/client.hpp"
#include "matrix/session_info.hpp"
#include "matrix/auth.hpp"
#include "raii/curler.hpp"
#include "raii/string.hpp"
#include "matrix/connection.hpp"
#include <utility> //pair

namespace matrix{
	//Manages connection to homeserver and user login.
	//Shares states with any spawned clients and syncers.
	class session : public connection
	{
	private:
		bool m_valid = false;
	public:
		/*
			* Create a session object that does not initialize a connection to a homeserver
			* User will need to create a connection manually through the local setter interface, then call login()
		*/
		session(void);
		/*
			* Create a session object that will attempt to initialize a connection to a homeserver
			* using the details in the auth_data structure. If the access token given is invalid, a
			* new one will be retrieved. Use valid() to check if the session is successfully created.
		*/
		session(const auth_data&);
		//Copy and move constructors
		session(const session&) = default;
		session(session&&) = default;

		/*
			* NOT thread safe.
			* Invalidates the session. All spawned clients and syncers will be invalidated as well.
		*/
		~session(void);

		//Copy and move assignment
		session& operator=(const session&) = default;
		session& operator=(session&&) = default;

		/*
			* NOT thread safe.
			* Set the useragent for the session and all spawned clients and syncers.
		*/
		void set_useragent(const raii::string_base&);
		void set_useragent(raii::string&&);


		/*
			* NOT thread safe.
			* Set the access token for the session and all spawned clients and syncers.
			* Note this will not check if the access token is valid or not, nor will urls be updated.
		*/
		void set_access_token(const raii::string_base&);
		void set_access_token(raii::string&&);
		/*
			* NOT thread safe.
			* Set the homeserver for the session and all spawned clients and syncers.
			* Note this will not check if the homeserver is valid or not, nor will urs be updated.
		*/
		void set_homeserver(const raii::string_base&);
		void set_homeserver(raii::string&&);

		/*
			* NOT thread safe.
			* Manually log in to a homeserver using the current access token.
			* This will regenerate the urls and ensure access token and homeserver are valid.
			* Returns: true if success, false otherwise.
		*/
		netreturn<void> login(void);
		/*
			* NOT thread safe.
			* Manually log in to a homeserver first using the current access token, then trying the
			* username and password as a backup. This will regenerate the urls and ensure access token and
			* homeserver are valid.
			* Returns: true if success, false otherwise.
		*/
		netreturn<void> login(const raii::string_base& username, const raii::string_base& pass);

		/*
			* Logout of the current connection to the homeserver. Will invalidate the access token on the server side.
			* Returns: true if the logout was successful, false otherwise.
		*/
		netreturn<void> logout(void);
		/*
			* Returns: true if the session is successfully connected to the homeserver.
		*/
		bool valid(void)const;


		netreturn<void> change_password(const raii::string_base& oldpass, const raii::string_base& newpass);
		/*
			* Create a matrix::client which shares login details with this session.
			* Note the client and session will share memory for generated urls, homeserver, access_token, and
			* useragent. Changing any of these fields after spawning a client MUST be synchronized across threads.
			* Returns: a new matrix::client.
		*/
		client spawn_client(void)const;

		/*
			* NOT thread safe.
			* Invalidates the session and all spawned clients and syncers.
			* All generated urls will be discarded; homeserver, access token, and useragent will be discarded;
			* and valid() will return false.
		*/
		void invalidate(void);
	private:
		netreturn<void> _do_login(const raii::string_base& username, const raii::string_base& pass);
		void _populate_session_info(const auth_data& a);
		netreturn<raii::rjp_string> _get_userid(void);
		raii::string _request_access_token(const raii::string_base& name, const raii::string_base& pass, const raii::string_base& loginurl)const;
		netreturn<std::pair<raii::rjp_string,raii::rjp_string>> _get_new_access_token(const raii::string_base& name, const raii::string_base& pass, const raii::string_base& loginurl);
	};
}

#endif