#pragma once

#include <array>
#include <cstddef>
#include <cstdint>
#include <optional>

#include <vamp_protocol/gesture.hpp>


namespace vamp_pico {

enum class request_kind {
  DISPLAY,
  COMMAND,
  HEARTBEAT,
  TITLE,
};

struct remote_request {
  request_kind kind{request_kind::DISPLAY};
  vamp_protocol::page_command command{vamp_protocol::page_command::NEXT};
  std::array<std::char_t, vamp_protocol::title_id_size + 1U> title_id{};
};

enum class enqueue_result {
  QUEUED,
  BUSY,
};

class request_scheduler {
public:
  static constexpr auto command_capacity = std::size_t{16};
  auto enqueue(vamp_protocol::page_command command) -> enqueue_result;
  auto next(std::uint64_t now_ms) -> std::optional<remote_request>;
  auto complete(std::uint64_t now_ms) -> void;
  auto queued() const -> std::size_t;
  auto want_title(std::string_view identifier) -> void;
  auto cancel_title() -> void;
private:
  std::array<vamp_protocol::page_command, command_capacity> commands_{};
  std::size_t head_{};
  std::size_t size_{};
  std::bool_t in_flight_{};
  std::bool_t completed_{};
  std::uint64_t completed_ms_{};
  std::array<std::char_t, vamp_protocol::title_id_size + 1U> title_id_{};
  std::bool_t title_pending_{};
  request_kind active_kind_{request_kind::DISPLAY};
};

}