type t =
  | Int
  | Term
  | Abrt
  | Alrm
  | Fpe
  | Hup
  | Ill
  | Kill
  | Pipe
  | Quit
  | Segv
  | Usr1
  | Usr2
  | Chld
  | Cont
  | Stop
  | Tstp
  | Ttin
  | Ttou
  | Vtalrm
  | Prof
  | Bus
  | Poll
  | Sys
  | Trap
  | Urg
  | Xcpu
  | Xfsz
  | Unknown of int

let all =
  let open Sys in
  [ (Abrt, sigabrt)
  ; (Alrm, sigalrm)
  ; (Fpe, sigfpe)
  ; (Hup, sighup)
  ; (Ill, sigill)
  ; (Int, sigint)
  ; (Kill, sigkill)
  ; (Pipe, sigpipe)
  ; (Quit, sigquit)
  ; (Segv, sigsegv)
  ; (Term, sigterm)
  ; (Usr1, sigusr1)
  ; (Usr2, sigusr2)
  ; (Chld, sigchld)
  ; (Cont, sigcont)
  ; (Stop, sigstop)
  ; (Tstp, sigtstp)
  ; (Ttin, sigttin)
  ; (Ttou, sigttou)
  ; (Vtalrm, sigvtalrm)
  ; (Prof, sigprof)
  ; (Bus, sigbus)
  ; (Poll, sigpoll)
  ; (Sys, sigsys)
  ; (Trap, sigtrap)
  ; (Urg, sigurg)
  ; (Xcpu, sigxcpu)
  ; (Xfsz, sigxfsz)
  ]

let name = function
  | Abrt -> "ABRT"
  | Alrm -> "ALRM"
  | Fpe -> "FPE"
  | Hup -> "HUP"
  | Ill -> "ILL"
  | Int -> "INT"
  | Kill -> "KILL"
  | Pipe -> "PIPE"
  | Quit -> "QUIT"
  | Segv -> "SEGV"
  | Term -> "TERM"
  | Usr1 -> "USR1"
  | Usr2 -> "USR2"
  | Chld -> "CHLD"
  | Cont -> "CONT"
  | Stop -> "STOP"
  | Tstp -> "TSTP"
  | Ttin -> "TTIN"
  | Ttou -> "TTOU"
  | Vtalrm -> "VTALRM"
  | Prof -> "PROF"
  | Bus -> "BUS"
  | Poll -> "POLL"
  | Sys -> "SYS"
  | Trap -> "TRAP"
  | Urg -> "URG"
  | Xcpu -> "XCPU"
  | Xfsz -> "XFSZ"
  | Unknown n -> Int.to_string n

let compare (x : t) (y : t) = Poly.compare x y

let to_dyn =
  let open Dyn in
  function
  | Unknown n -> variant "Unknown" [ int n ]
  | t -> variant (name t) []

include Comparable.Make (struct
  type nonrec t = t

  let compare = compare

  let to_dyn = to_dyn
end)

let to_int =
  let table = Map.of_list_exn all in
  function
  | Unknown n -> n
  | t -> Map.find_exn table t

let of_int i =
  let table = Int.Map.of_list_exn (List.map all ~f:(fun (t, i) -> (i, t))) in
  match Int.Map.find table i with
  | None -> Unknown i
  | Some s -> s
