/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   FileDescriptor.hpp                                 :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: acossari <acossari@student.codam.nl>       +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2026/08/24 16:24:03 by acossari          #+#    #+#             */
/*   Updated: 2026/08/24 20:05:59 by acossari         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#pragma once

#include <exception>
#include <string>

namespace webserv {

// Sole owner of one file descriptor, move-only. Copying would give two owners
// the same number, and the second close would land on whatever the kernel had
// handed out in the meantime, killing an unrelated connection.
class FileDescriptor final {
  public:
    class Error : public std::exception {
      public:
        explicit Error(std::string message);
        const char* what() const noexcept override;

      private:
        std::string msg_;
    };

    FileDescriptor() = default;

    // Takes ownership and sets FD_CLOEXEC, so a successful execve() in a
    // forked child closes the descriptor before the new program starts. A
    // negative fd is accepted and gives an invalid object instead of throwing,
    // so the result of socket() can be passed in and checked with valid().
    explicit FileDescriptor(int fd);

    ~FileDescriptor();

    FileDescriptor(const FileDescriptor&) = delete;
    FileDescriptor& operator=(const FileDescriptor&) = delete;
    FileDescriptor(FileDescriptor&& other) noexcept;
    FileDescriptor& operator=(FileDescriptor&& other) noexcept;

    int get() const noexcept { return fd_; }
    bool valid() const noexcept { return fd_ >= 0; }

    void setNonBlocking();

    // Closes now instead of at destruction. Idempotent.
    void reset() noexcept;

  private:
    int fd_ = -1;
};

}  // namespace webserv