open Pdfutil

(* These may move into CamlPDF at some point *)
let process_xobject f pdf resources i =
  let xobj = Pdf.lookup_obj pdf i in
    match Pdf.lookup_direct pdf "/Subtype" xobj with
    | None -> raise (Pdf.PDFError "No /Subtype in Xobject") 
    | Some (Pdf.Name "/Form") ->
        Pdf.getstream xobj;
        begin match xobj with
        | Pdf.Stream ({contents = Pdf.Dictionary dict, Pdf.Got bytes} as rf) ->
            begin match f pdf resources [Pdf.Stream rf] with
            | [Pdf.Stream {contents = (Pdf.Dictionary dict', data)}] ->
                let dict' =
                  Pdf.remove_dict_entry
                    (Pdf.Dictionary (mergedict dict dict'))
                    "/Filter"
                in
                  rf := (dict', data)
            | _ -> assert false
            end
        | _ -> assert false (* getstream would have complained already *)
        end
    | Some _ -> ()

let process_xobjects pdf page f =
  match Pdf.lookup_direct pdf "/XObject" page.Pdfpage.resources with
  | Some (Pdf.Dictionary elts) ->
      iter
        (fun (k, v) ->
          match v with
          | Pdf.Indirect i -> process_xobject f pdf page.Pdfpage.resources i
          | _ -> raise (Pdf.PDFError "process_xobject"))
        elts
  | _ -> ()