(* Helper functions for handling libguestfs. *)

open Goaljobs

open Printf

open Config
open Utils

let package = "libguestfs"

(* Helper object which stores everything about a version. *)
type info = {
  version : string;              (* The version as a normal string. *)
  major : int;                   (* Broken-out version fields. *)
  minor : int;
  release: int;
  is_stable : bool;              (* is a stable version of libguestfs? *)
  branch : string;               (* 'master' or 'stable-1.xx' *)
  package_version : string;      (* package-version *)
  tarball : string;              (* package-version.tar.gz *)
  python_tarball : string;       (* guestfs-version.tar.gz *)
  urlpath : string;              (* download/1.X-(stable|development)/tarball *)
  python_urlpath : string;       (* download/python/python_tarball *)
  url : string;                  (* full download URL of tarball *)
  python_url : string;           (* python sdist *)
}

let compare_versions { major = major1; minor = minor1; release = release1 }
    { major = major2; minor = minor2; release = release2 } =
  compare (major1, minor1, release1) (major2, minor2, release2)

let string_of_libguestfs_version { version = version } = version

(* Helper function to make a full 'info' object from a version
 * number.
 *)
let vernames version =
  Scanf.sscanf version "%d.%d.%d" (
    fun major minor release ->
      let is_stable = minor mod 2 = 0 in
      let branch =
        if is_stable then
          sprintf "stable-%d.%d" major minor
        else
          sprintf "master" in
      let package_version = sprintf "%s-%d.%d.%d" package major minor release in
      let tarball = sprintf "%s.tar.gz" package_version in
      let urlpath =
        if is_stable then
          sprintf "download/%d.%d-stable/%s" major minor tarball
        else
          sprintf "download/%d.%d-development/%s" major minor tarball in
      let url = "http://libguestfs.org/" ^ urlpath in
      let python_tarball =
        sprintf "guestfs-%d.%d.%d.tar.gz" major minor release in
      let python_urlpath = sprintf "download/python/" ^ python_tarball in
      let python_url = "http://libguestfs.org/" ^ python_urlpath in

      { version = version;
        major = major; minor = minor; release = release;
        is_stable = is_stable;
        branch = branch;
        package_version = package_version;
        tarball = tarball;
        python_tarball = python_tarball;
        urlpath = urlpath;
        python_urlpath = python_urlpath;
        url = url;
        python_url = python_url }
  )

(* For libguestfs <= 1.24, we need an old supermin 4 binary. *)
let supermin = function
  | { major = 1; minor = i } when i <= 24 ->
    let home = Sys.getenv "HOME" in
    Some ( home // "d/supermin4/src/supermin",
           home // "d/supermin4/helper/supermin-helper" )
  | _ -> None

(* Clone or update a repo to the latest version on a branch, by force.
 * It is cached in name = $buildtmp/repos/<package>-<branch>
 *)
let git_force branch =
  let url = "https://github.com/libguestfs/libguestfs.git"  in
  sh "
    cd %s/repos
    if [ ! -d %s-%s ]; then git clone %s %s-%s; fi
    cd %s-%s
    git checkout --force %s
    git pull
    # Copy or update gnulib
    git submodule init
    git submodule update
  " buildtmp
    package (quote branch) (quote url) package (quote branch)
    package (quote branch)
    (quote branch)

(* Helper function to read the latest version in a repo and return
 * the version.
 *)
let git_latest_version branch =
  let v = shout "
    cd %s/repos/%s-%s
    git describe --tags --abbrev=0
  " buildtmp package (quote branch) in
  (* Branches <= 1.32 are tagged with "1.32.11",
   * branches >= 1.33 are tagged with "v1.33.11".
   *)
  let len = String.length v in
  let v =
    if len > 0 && v.[0] = 'v' then
      String.sub v 1 (len-1)
    else
      v in
  vernames v

(* Get the latest commit. *)
let git_latest_commit branch =
  shout "
    cd %s/repos/%s-%s
    git rev-parse HEAD
  " buildtmp package (quote branch)

(* Find the latest website tarball version.  Actually we use our local
 * CVS copy of the website rather than downloading from
 * http://libguestfs.org
 *)
let website_latest_version =
  let rex = Str.regexp "libguestfs-\\(.*\\)\\.tar\\.gz" in
  fun branch ->
    let wdir = libguestfs_website_repo // "download" // branch in
    let files = Sys.readdir wdir in
    let files = Array.to_list files in
    if files = [] then None
    else (
      let versions = filter_map (
        fun name ->
          if not (Str.string_match rex name 0) then None
          else Some (vernames (Str.matched_group 1 name))
      ) files in
      let versions = List.sort compare_versions versions in
      let versions = List.rev versions in
      Some (List.hd versions)
    )