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open Alpha_context
open Script_typed_ir

let compare_address (x, ex) (y, ey) =
  let lres = Contract.compare x y in
  if Compare.Int.(lres = 0) then Compare.String.compare ex ey else lres

type compare_comparable_cont =
  | Compare_comparable :
      'a comparable_ty * 'a * 'a * compare_comparable_cont
      -> compare_comparable_cont
  | Compare_comparable_return : compare_comparable_cont

let compare_comparable : type a. a comparable_ty -> a -> a -> int =
  let rec compare_comparable :
      type a. a comparable_ty -> compare_comparable_cont -> a -> a -> int =
   fun kind k x y ->
    match (kind, x, y) with
    | (Unit_key _, (), ()) -> (apply [@tailcall]) 0 k
    | (Never_key _, _, _) -> .
    | (Signature_key _, x, y) -> (apply [@tailcall]) (Signature.compare x y) k
    | (String_key _, x, y) -> (apply [@tailcall]) (Script_string.compare x y) k
    | (Bool_key _, x, y) -> (apply [@tailcall]) (Compare.Bool.compare x y) k
    | (Mutez_key _, x, y) -> (apply [@tailcall]) (Tez.compare x y) k
    | (Key_hash_key _, x, y) ->
        (apply [@tailcall]) (Signature.Public_key_hash.compare x y) k
    | (Key_key _, x, y) ->
        (apply [@tailcall]) (Signature.Public_key.compare x y) k
    | (Int_key _, x, y) -> (apply [@tailcall]) (Script_int.compare x y) k
    | (Nat_key _, x, y) -> (apply [@tailcall]) (Script_int.compare x y) k
    | (Timestamp_key _, x, y) ->
        (apply [@tailcall]) (Script_timestamp.compare x y) k
    | (Address_key _, x, y) -> (apply [@tailcall]) (compare_address x y) k
    | (Bytes_key _, x, y) -> (apply [@tailcall]) (Compare.Bytes.compare x y) k
    | (Chain_id_key _, x, y) -> (apply [@tailcall]) (Chain_id.compare x y) k
    | (Pair_key ((tl, _), (tr, _), _), (lx, rx), (ly, ry)) ->
        (compare_comparable [@tailcall])
          tl
          (Compare_comparable (tr, rx, ry, k))
          lx
          ly
    | (Union_key ((tl, _), _, _), L x, L y) ->
        (compare_comparable [@tailcall]) tl k x y
    | (Union_key _, L _, R _) -> -1
    | (Union_key _, R _, L _) -> 1
    | (Union_key (_, (tr, _), _), R x, R y) ->
        (compare_comparable [@tailcall]) tr k x y
    | (Option_key _, None, None) -> (apply [@tailcall]) 0 k
    | (Option_key _, None, Some _) -> -1
    | (Option_key _, Some _, None) -> 1
    | (Option_key (t, _), Some x, Some y) ->
        (compare_comparable [@tailcall]) t k x y
  and apply ret k =
    match (ret, k) with
    | (0, Compare_comparable (ty, x, y, k)) ->
        (compare_comparable [@tailcall]) ty k x y
    | (0, Compare_comparable_return) -> 0
    | (ret, _) ->
        (* ret <> 0, we perform an early exit *)
        if Compare.Int.(ret > 0) then 1 else -1
  in
  fun t -> compare_comparable t Compare_comparable_return
  [@@coq_axiom_with_reason "non top-level mutually recursive function"]