core/pkgs/build-support/fetchgitlab/default.nix

{ lib, fetchgit, fetchzip }:

lib.makeOverridable (
  # gitlab example
  { owner, repo, rev, protocol ? "https", domain ? "gitlab.com", name ? "source"
  , group ? null, fetchSubmodules ? false, leaveDotGit ? false
  , deepClone ? false, forceFetchGit ? false, sparseCheckout ? [ ]
  , ... # For hash agility
  }@args:

  let
    slug = lib.concatStringsSep "/"
      ((lib.optional (group != null) group) ++ [ owner repo ]);
    escapedSlug = lib.replaceStrings [ "." "/" ] [ "%2E" "%2F" ] slug;
    escapedRev = lib.replaceStrings [ "+" "%" "/" ] [ "%2B" "%25" "%2F" ] rev;
    passthruAttrs = removeAttrs args [
      "protocol"
      "domain"
      "owner"
      "group"
      "repo"
      "rev"
      "fetchSubmodules"
      "forceFetchGit"
      "leaveDotGit"
      "deepClone"
    ];

    useFetchGit = fetchSubmodules || leaveDotGit || deepClone || forceFetchGit
      || (sparseCheckout != [ ]);
    fetcher = if useFetchGit then fetchgit else fetchzip;

    gitRepoUrl = "${protocol}://${domain}/${slug}.git";

    fetcherArgs = (if useFetchGit then {
      inherit rev deepClone fetchSubmodules sparseCheckout leaveDotGit;
      url = gitRepoUrl;
    } else {
      url =
        "${protocol}://${domain}/api/v4/projects/${escapedSlug}/repository/archive.tar.gz?sha=${escapedRev}";

      passthru = { inherit gitRepoUrl; };
    }) // passthruAttrs // {
      inherit name;
    };

  in fetcher fetcherArgs // {
    meta.homepage = "${protocol}://${domain}/${slug}/";
    inherit rev owner repo;
  })