Biokepi API : Biokepi_pipeline_edsl.Pipeline

struct
  type t =
    | Fastq of fastq
    | Bam of bam
  and fastq = {
    fastq_sample_name : string;
    files : fastq_fragment list;
  }
  and bam = {
    bam_sample_name: string;
    path: string;
    how: how;
    sorting: sorting option;
    reference_build: string;
  }
  and fastq_fragment = (string option * fastq_data)
  and fastq_data =
    | PE of string * string
    | SE of string
    | Of_bam of how * sorting option * string * string
  and sorting = [ `Coordinate | `Read_name ]
  and how = [ `PE | `SE ]
    [@@deriving show,yojson]

  let pe ?fragment_id a b = (fragment_id, PE (a, b))
  let se ?fragment_id a = (fragment_id, SE a)
  let fastq_of_bam ?fragment_id ?sorted ~reference_build how s =
    (fragment_id, Of_bam (how, sorted, reference_build,  s))
  let fastq_sample ~sample_name files = Fastq {fastq_sample_name = sample_name; files}
  let bam_sample ~sample_name ?sorting ~reference_build ~how path =
    Bam {bam_sample_name = sample_name; path; how; reference_build; sorting }

  let tag_v0 = "biokepi-input-v0"
  let current_version_tag = tag_v0

  let to_yojson =
    let string s = `String s in
    let option f o : Yojson.Safe.json = Option.value_map o ~default:`Null ~f in
    let data_to_yojson =
      function
      | PE (r1, r2) ->
        `Assoc ["paired-end", `Assoc ["r1", string r1; "r2", string r2]]
      | SE f -> `Assoc ["single-end", string f]
      | Of_bam (how, sorto, refb, fil) ->
        `Assoc ["bam",
                `Assoc ["kind",
                        string (match how with
                          | `PE -> "paired-end"
                          | `SE -> "single-end");
                        "sorting",
                        (match sorto with
                        | None  -> `Null
                        | Some `Read_name -> `String "read-name"
                        | Some `Coordinate -> `String "coordinate");
                        "reference-genome", string refb;
                        "path", string fil]]
    in
    let file_to_yojson (fragment_option, data) =
      `Assoc [
        "fragment-id", option string fragment_option;
        "data", data_to_yojson data;
    ] in
    let files_to_yojson files = `List (List.map ~f:file_to_yojson files) in
    function
    | Fastq {fastq_sample_name; files} ->
      `Assoc [current_version_tag,
              `Assoc ["fastq", `Assoc [
                  "sample-name", string fastq_sample_name;
                  "fragments", files_to_yojson files;
                ]]]
    | Bam bam ->
      `Assoc [current_version_tag,
              `Assoc ["bam", bam_to_yojson bam]]

  let of_yojson j =
    let open Pvem.Result in
    let error ?json fmt =
      ksprintf (fun s ->
          fail (sprintf "%s%s" s
                  (Option.value_map ~default:"" json
                     ~f:(fun j ->
                         sprintf " but got %s" @@
                         Yojson.Safe.pretty_to_string ~std:true j)))
        ) fmt in
    let data_of_yojson =
      function
      | `Assoc ["paired-end", `Assoc ["r1", `String r1; "r2", `String r2]] ->
        return (PE (r1, r2))
      | `Assoc ["single-end", `String file] -> SE file |> return
      | `Assoc ["bam", `Assoc ["kind", `String kind;
                               "sorting", sorting;
                               "reference-genome", `String refb;
                               "path", `String path;]] ->
        begin match sorting with
        | `Null -> return None
        | `String "coordinate" -> Some `Coordinate |> return
        | `String "read-name" -> Some `Read_name |> return
        | other ->
          error ~json:other "Expecting %S, %S or null (in \"sorting\": ...)"
            "coordinate" "read-name"
        end
        >>= fun sorting ->
        begin match kind with
        | "single-end" -> return `SE
        | "paired-end" -> return `PE
        | other -> error "Kind in bam must be \"SE\" or \"PE\""
        end
        >>= fun kind ->
        return (Of_bam (kind, sorting, refb, path))
      | other ->
        error ~json:other "Expecting string or null (in \"fragment\": ...)"
    in
    let fragment_of_yojson =
      function
      | `Assoc ["fragment-id", frag; "data", data] ->
        begin match frag with
        | `String s -> return (Some s)
        | `Null -> return (None)
        | other ->
          error ~json:other "Expecting string or null (in \"fragment\": ...)"
        end
        >>= fun fragment_id ->
        data_of_yojson data
        >>= fun data_parsed ->
        return (fragment_id, data_parsed)
      | other -> error ~json:other "Expecting {\"fragment\": ... , \"data\": ...}"
    in
    match j with
    | `Assoc [vtag, more] when vtag = current_version_tag ->
      begin match more with
      | `Assoc ["fastq",
                `Assoc ["sample-name", `String sample; "fragments", `List frgs]] ->
        List.fold ~init:(return []) frgs ~f:(fun prev frag ->
            prev >>= fun p ->
            fragment_of_yojson frag
            >>= fun more ->
            return (more :: p))
        >>= fun l ->
        return (Fastq { fastq_sample_name = sample; files = List.rev l })
      | `Assoc ["bam", bam] ->
        begin match bam_of_yojson bam with
        | Result.Ok ok -> return ok
        | Result.Error err -> fail err
        end
        >>= fun bam ->
        return (Bam bam)
      | other ->
        error ~json:other "Expecting Fastq or Bam"
      end
    | other ->
      error ~json:other "Expecting Biokepi_input_v0"

  module Derive = struct

    let ensure_one_flowcell_max files =
      let open Pvem_lwt_unix.Deferred_result in
      let flowcell_re = Re.compile (Re_posix.re {re|.*(\..+)?\.fastq\.gz|re}) in
      let flowcells =
        Pvem_lwt_unix.Deferred_list.while_sequential files
          ~f:(fun f -> match Re.Group.all (Re.exec flowcell_re f) with
            | [|_; flowcell|] -> return flowcell
            | _ -> fail (`Re_group_error
                           "Re.Group.all returned an unexpected number of groups."))
      in
      flowcells >>| List.dedup >>= fun flowcells ->
      if List.length flowcells > 1
      then fail (`Multiple_flowcells flowcells)
      else return files

    let fastqs ?(paired_end=true) ~host dir =
      let open Pvem_lwt_unix.Deferred_result in
      (* We only want to select fastq.gzs in the directory: *)
      let fastq_re = Re.compile (Re_posix.re {re|.*\.fastq\.gz|re}) in
      let fastq_p = Re.execp fastq_re in
      let r1_to_r2 s =
        let r1_re = Re.compile (Re_posix.re "_R1_") in
        Re.replace_string r1_re ~by:"_R2_" s
      in
      (* If we're expecting paired_end reads, make sure we have a R2 in the
         directory for each R1 fragment. Returns the list of R1 fragments. *)
      let ensure_matching_r2s files =
        if paired_end then
          (List.fold ~init:(return []) files ~f:(fun acc r1 ->
               acc >>= fun r1s ->
               match String.index_of_string r1 ~sub:"_R1_" with
               | None -> acc
               | Some _ ->
                 if List.mem (r1_to_r2 r1) ~set:files
                 then return (r1 :: r1s)
                 else fail (`R2_expected_for_r1 r1)))
        else return files
      in
      let as_fragments read1s_filenames =
        List.mapi read1s_filenames
          ~f:(fun i r1 ->
              if paired_end then
                let r2 = dir // (r1_to_r2 r1) in
                let r1 = dir // r1 in
                let fragment_id = sprintf "fragment-%d" i in
                pe ~fragment_id r1 r2
              else
                let r1 = dir // r1 in
                let fragment_id = sprintf "fragment-%d" i in
                se ~fragment_id r1)
        |> return
      in
      let cmd = (sprintf "ls '%s' | sort" dir) in
      Ketrew.Host_io.(get_shell_command_output (create ()) ~host:host cmd)
      >>= fun (out, err) ->
      String.split ~on:(`Character '\n') out |> List.filter ~f:fastq_p |> return
      >>= ensure_matching_r2s
      >>= ensure_one_flowcell_max
      >>= as_fragments

  end
end