#ifndef CEPIS_TESTS_TEST_SERVER_HPP
#define CEPIS_TESTS_TEST_SERVER_HPP

#include <atomic>
#include <functional>
#include <map>
#include <mutex>
#include <string>
#include <string_view>
#include <thread>
#include <utility>
#include <vector>

namespace cepis::testing {

/// One canned HTTP response.
struct Reply {
  int status = 200;
  std::string body;
  std::vector<std::pair<std::string, std::string>> headers;
};

/// A throwaway HTTP/1.1 server on a random loopback port.
///
/// The tests point `Config::base_url` at it, so the code path they exercise is
/// the one that runs in production — request construction, header reading and
/// error-body reading included. Nothing is mocked below the socket, and it
/// doubles as the test that `base_url` works: without it none of this runs.
class Server {
 public:
  Server();
  ~Server();

  Server(const Server&) = delete;
  Server& operator=(const Server&) = delete;
  Server(Server&&) = delete;
  Server& operator=(Server&&) = delete;

  /// `http://127.0.0.1:<port>`, ready to hand to `Config::base_url`.
  [[nodiscard]] std::string url() const;

  /// Registers the response for a path. The last entry of a queue repeats once
  /// the earlier ones are consumed, which is how retrying is tested.
  void respond(std::string path, Reply reply);
  void respond(std::string path, std::vector<Reply> replies);

  /// Installs a catch-all that sees every request. Takes precedence over the
  /// registered paths.
  void handle(std::function<Reply(const std::string& path)> handler);

  /// How many requests so far began with `prefix`.
  [[nodiscard]] int count(std::string_view prefix) const;

  /// Every path requested so far, in order.
  [[nodiscard]] std::vector<std::string> calls() const;

 private:
  void serve();
  Reply next(const std::string& path);

  int listen_fd_ = -1;
  int port_ = 0;
  std::atomic<bool> stopping_{false};
  std::thread thread_;

  mutable std::mutex mutex_;
  std::map<std::string, std::vector<Reply>> routes_;
  std::function<Reply(const std::string&)> handler_;
  std::vector<std::string> calls_;
};

}  // namespace cepis::testing

#endif  // CEPIS_TESTS_TEST_SERVER_HPP