//
// Copyright (c) 2025 Marcelo Zimbres Silva (mzimbres@gmail.com),
// Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef BOOST_REDIS_SENTINEL_RESOLVE_FSM_HPP
#define BOOST_REDIS_SENTINEL_RESOLVE_FSM_HPP

#include <boost/redis/adapter/any_adapter.hpp>
#include <boost/redis/config.hpp>
#include <boost/redis/detail/connect_params.hpp>

#include <boost/asio/cancellation_type.hpp>
#include <boost/assert.hpp>
#include <boost/system/error_code.hpp>

// Sans-io algorithm for async_sentinel_resolve, as a finite state machine

namespace boost::redis::detail {

// Forward decls
struct connection_state;

class sentinel_action {
public:
   enum class type
   {
      done,     // Call the final handler
      connect,  // Transport connection establishment
      request,  // Send the Sentinel request
   };

   sentinel_action(system::error_code ec) noexcept
   : type_(type::done)
   , ec_(ec)
   { }

   sentinel_action(const address& addr) noexcept
   : type_(type::connect)
   , connect_(&addr)
   { }

   static sentinel_action request() { return {type::request}; }

   type get_type() const { return type_; }

   [[nodiscard]]
   system::error_code error() const
   {
      BOOST_ASSERT(type_ == type::done);
      return ec_;
   }

   const address& connect_addr() const
   {
      BOOST_ASSERT(type_ == type::connect);
      return *connect_;
   }

private:
   type type_;
   union {
      system::error_code ec_;
      const address* connect_;
   };

   sentinel_action(type type) noexcept
   : type_(type)
   { }
};

class sentinel_resolve_fsm {
   int resume_point_{0};
   std::size_t idx_{0u};

public:
   sentinel_resolve_fsm() = default;

   sentinel_action resume(
      connection_state& st,
      system::error_code ec,
      asio::cancellation_type_t cancel_state);
};

connect_params make_sentinel_connect_params(const config& cfg, const address& sentinel_addr);
any_adapter make_sentinel_adapter(connection_state& st);

}  // namespace boost::redis::detail

#endif  // BOOST_REDIS_CONNECTOR_HPP