type opam_diff = {
    pkg: OpamPackage.t
  ; build: (OpamTypes.command list * OpamTypes.command list) option
  ; install: (OpamTypes.command list * OpamTypes.command list) option
  ; url: (OpamFile.URL.t option * OpamFile.URL.t option) option
  ; otherwise_equal: bool
}

type version_diff = {
    name: OpamPackage.Name.t
  ; version_left: OpamPackage.Version.t
  ; version_right: OpamPackage.Version.t
}

type duniverse_diff = {
    name: string
  ; urls: string * string option
  ; hash: (OpamHash.kind * string option * string option) list
}

val pp_opampackage : Format.formatter -> OpamPackage.t -> unit
val pp_version_diff : Format.formatter -> version_diff -> unit
val pp_duniverse_diff : Format.formatter -> duniverse_diff -> unit
val pp_duniverse_dir : Format.formatter -> string * string -> unit
val pp_opam_diff : Format.formatter -> opam_diff -> unit

val commands_to_strings :
  OpamTypes.command list * OpamTypes.command list -> string list * string list

val opt_url_to_string :
  OpamFile.URL.t option * OpamFile.URL.t option -> string * string

val compare :
     OpamFile.SwitchExport.t
  -> OpamFile.SwitchExport.t
  -> opam_diff list
     * version_diff list
     * OpamPackage.Set.t
     * OpamPackage.Set.t
     * ( (string * string) list * (string * string) list * duniverse_diff list
       , [> `Msg of string ] )
       result

val compare_to_json :
     opam_diff list
     * version_diff list
     * OpamPackage.Set.t
     * OpamPackage.Set.t
     * ( (string * string) list * (string * string) list * duniverse_diff list
       , [< `Msg of string ] )
       result
  -> Yojson.Basic.t