//-----------------------------------------------------------------------------
//     ___                      __ _       _
//    / _ \__ _ _ __ ___  ___  / /(_)_ __ | | __
//   / /_)/ _` | '__/ __|/ _ \/ / | | '_ \| |/ /
//  / ___/ (_| | |  \__ \  __/ /__| | | | |   <
//  \/    \__,_|_|  |___/\___\____/_|_| |_|_|\_\ .
//
//-----------------------------------------------------------------------------
// Author: Kurt Sassenrath
// Module: Server
//
// Simple in-memory session manager.
//
// Copyright (c) 2023 Kurt Sassenrath.
//
// License TBD.
//-----------------------------------------------------------------------------
#ifndef memory_session_manager_b3851872babe001d
#define memory_session_manager_b3851872babe001d

#include <boost/asio/io_context.hpp>
#include <boost/asio/strand.hpp>
#include <parselink/server/session_manager.h>
#include <unordered_set>

namespace parselink {

class memory_session_manager {
public:
    memory_session_manager(boost::asio::io_context& ctx);
    ~memory_session_manager();

    // Allocate a new session.
    tl::expected<proto::session*, proto::error> create_session(
            std::string_view user_id);

    // Destroy an existing session.
    tl::expected<tl::monostate, proto::error> destroy_session(
            proto::session* session);

    // Find a session by its user id.
    tl::expected<proto::session*, proto::error> find(std::string_view user_id);

    // Find a session by its ID.
    tl::expected<proto::session*, proto::error> find(
            proto::session_id const& session);

private:
    std::unordered_map<std::string, proto::session,
            proto::transparent_hash<std::string>, std::equal_to<>>
            sessions_;

    std::unordered_map<proto::session_id, proto::session*,
            proto::transparent_hash<proto::session_id>, std::equal_to<>>
            lookup_by_sid_;

    boost::asio::io_context& ctx_;
    boost::asio::io_context::strand strand_;
};

// Sanity check
static_assert(session_manager<memory_session_manager>);
static_assert(sync_session_manager<memory_session_manager>);
static_assert(!async_session_manager<memory_session_manager>);

} // namespace parselink

#endif // memory_session_manager_b3851872babe001d