{ lib
, stdenv
, fetchurl
, fetchpatch
, autoreconfHook
, libgpg-error
, gnupg
, pkg-config
, glib
, pth
, libassuan
, file
, which
, ncurses
, texinfo
, buildPackages
, qtbase ? null
, pythonSupport ? false
, swig2 ? null
, python ? null
# only for passthru.tests
, libsForQt5
, python3
}:
let
  inherit (stdenv.hostPlatform) system;
in
stdenv.mkDerivation rec {
  pname = "gpgme";
  version = "1.18.0";

  src = fetchurl {
    url = "mirror://gnupg/gpgme/${pname}-${version}.tar.bz2";
    hash = "sha256-Nh1OrkfOkl26DqVpr0DntSxkXEri5l5WIb8bbN2LDp4=";
  };

  patches = [
    # Fix compilation on i686, would not be needed after 1.18.1 releases, https://dev.gnupg.org/T5522
    ./t-addexistingsubkey-i686.patch
    # https://dev.gnupg.org/rMc4cf527ea227edb468a84bf9b8ce996807bd6992
    ./fix_gpg_list_keys.diff
    # https://lists.gnupg.org/pipermail/gnupg-devel/2020-April/034591.html
    (fetchpatch {
      name = "0001-Fix-python-tests-on-non-Linux.patch";
      url = "https://lists.gnupg.org/pipermail/gnupg-devel/attachments/20200415/f7be62d1/attachment.obj";
      sha256 = "00d4sxq63601lzdp2ha1i8fvybh7dzih4531jh8bx07fab3sw65g";
    })
    # Support Python 3.10 version detection without distutils, https://dev.gnupg.org/D545
    ./python-310-detection-without-distutils.patch
    # Find correct version string for Python >= 3.10, https://dev.gnupg.org/D546
    ./python-find-version-string-above-310.patch
    # Fix a test after disallowing compressed signatures in gpg (PR #180336)
    ./test_t-verify_double-plaintext.patch

    # Disable python tests on Darwin as they use gpg (see configureFlags below)
  ] ++ lib.optional stdenv.isDarwin ./disable-python-tests.patch
  # Fix _AC_UNDECLARED_WARNING for autoconf>=2.70
  # See https://lists.gnupg.org/pipermail/gnupg-devel/2020-November/034643.html
  ++ lib.optional stdenv.cc.isClang ./fix-clang-autoconf-undeclared-warning.patch;

  outputs = [ "out" "dev" "info" ];

  outputBin = "dev"; # gpgme-config; not so sure about gpgme-tool

  nativeBuildInputs = [
    autoreconfHook
    gnupg
    pkg-config
    texinfo
  ] ++ lib.optionals pythonSupport [
    ncurses
    python
    swig2
    which
  ];

  propagatedBuildInputs = [
    glib
    libassuan
    libgpg-error
    pth
  ] ++ lib.optionals (qtbase != null) [
    qtbase
  ];

  nativeCheckInputs = [
    which
  ];

  depsBuildBuild = [
    buildPackages.stdenv.cc
  ];

  dontWrapQtApps = true;

  configureFlags = [
    "--enable-fixed-path=${gnupg}/bin"
    "--with-libgpg-error-prefix=${libgpg-error.dev}"
    "--with-libassuan-prefix=${libassuan.dev}"
  ] ++ lib.optional pythonSupport "--enable-languages=python"
  # Tests will try to communicate with gpg-agent instance via a UNIX socket
  # which has a path length limit. Nix on darwin is using a build directory
  # that already has quite a long path and the resulting socket path doesn't
  # fit in the limit. https://github.com/NixOS/nix/pull/1085
  ++ lib.optionals stdenv.isDarwin [ "--disable-gpg-test" ];

  env.NIX_CFLAGS_COMPILE = toString (
    # qgpgme uses Q_ASSERT which retains build inputs at runtime unless
    # debugging is disabled
    lib.optional (qtbase != null) "-DQT_NO_DEBUG"
    # https://www.gnupg.org/documentation/manuals/gpgme/Largefile-Support-_0028LFS_0029.html
    ++ lib.optional stdenv.hostPlatform.is32bit "-D_FILE_OFFSET_BITS=64"
  );

  # prevent tests from being run during the buildPhase
  makeFlags = [ "tests=" ];

  doCheck = true;

  checkFlags = [ "-C" "tests" ];

  passthru.tests = {
    python = python3.pkgs.gpgme;
    qt = libsForQt5.qgpgme;
  };

  meta = with lib; {
    homepage = "https://gnupg.org/software/gpgme/index.html";
    changelog = "https://git.gnupg.org/cgi-bin/gitweb.cgi?p=gpgme.git;f=NEWS;hb=gpgme-${version}";
    description = "Library for making GnuPG easier to use";
    longDescription = ''
      GnuPG Made Easy (GPGME) is a library designed to make access to GnuPG
      easier for applications. It provides a High-Level Crypto API for
      encryption, decryption, signing, signature verification and key
      management.
    '';
    license = with licenses; [ lgpl21Plus gpl3Plus ];
    platforms = platforms.unix;
    maintainers = with maintainers; [ dotlambda ];
  };
}