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use alienfile;
use Path::Tiny;

# Prefer the system libssh if pkg-config can find it.
# Falls back to building from the bundled source tarball.
#
# PkgConfig does probe and gather in one, for both paths: against the system
# library on the sys path, and against the libssh.pc the share build installs
# into the prefix on the share path. The hand-rolled `probe` plus a `sys`-only
# gather covered just the first of those, so a share install finished with no
# cflags, no libs and no version -- Alien::libssh->cflags came back empty and
# anything compiling against it could not find libssh/libssh.h.

# Author release only: force the bundled share build so the shipped offline
# fallback is exercised on every `dzil release` (TestRelease), even on a host
# that has a system libssh. RELEASE_TESTING marks the author release;
# !AUTOMATED_TESTING excludes thorough CPAN smokers, which set BOTH flags --
# they must keep probing for their own system libssh, not build share.
#
# This is the `override` hook (what ALIEN_INSTALL_TYPE drives), NOT a `probe`
# hook, on purpose: Alien::Build runs override before the probe hooks and lets
# 'share' win outright, whereas a probe returning 'share' only defers to the
# next probe -- PkgConfig would then still pick a present system lib, and the
# fallback would go untested at release. Registering override replaces
# Core::Override's default, so ALIEN_INSTALL_TYPE is re-checked here first to
# keep the forced-path runs (share/system) and any user override working.
meta->register_hook( override => sub {
  return $ENV{ALIEN_INSTALL_TYPE} if $ENV{ALIEN_INSTALL_TYPE};
  return 'share' if $ENV{RELEASE_TESTING} && !$ENV{AUTOMATED_TESTING};
  return '';
});

plugin 'PkgConfig' => (
  pkg_name => 'libssh',
);

share {
  start_url 'file://' . Path::Tiny->cwd->child('share/libssh-0.10.6.tar.xz')->stringify;

  # start_url alone does nothing: without a fetch hook Alien::Build reaches the
  # download phase with no way to act on it and dies with "No hooks registered
  # for fetch", so the advertised fallback never existed on a box without a
  # system libssh.
  plugin 'Fetch::Local';
  plugin 'Extract' => 'tar.xz';
  plugin 'Build::CMake';

  # libssh refuses to configure in its own source tree
  # (cmake/Modules/MacroEnsureOutOfSourceBuild.cmake compares CMAKE_SOURCE_DIR
  # against CMAKE_BINARY_DIR). Build::CMake builds in the extracted directory
  # itself unless told otherwise, which is why the source path used to be '..'
  # -- a directory nothing ever created or changed into.
  meta->prop->{out_of_source} = 1;

  # One command. A flat list is a sequence of separate commands to
  # Alien::Build, so the arguments were each exec'd as a program of their own;
  # and the make steps were absent, leaving a configure that built nothing.
  # plugin_build_cmake.args carries the generator, PIC, install prefix and
  # libdir, so only the libssh-specific switches are spelled out here.
  build [
    [ '%{cmake}',
      @{ meta->prop->{plugin_build_cmake}->{args} },
      '-DCMAKE_BUILD_TYPE=Release',
      # Static, because a share install puts libssh.so where the runtime
      # linker does not look: the XS test compiled fine against the prefix and
      # then died on `libssh.so.4: cannot open shared object file`, which is
      # exactly what Net::LibSSH (also XS) would do at use time.
      '-DBUILD_SHARED_LIBS=OFF',
      '-DWITH_EXAMPLES=OFF',
      '-DWITH_PCAP=OFF',
      '-DWITH_GSSAPI=OFF',
      '%{.install.extract}',
    ],
    '%{make}',
    '%{make} install',
  ];

  # libssh generates its libssh.pc with a bare `Libs: -L${libdir} -lssh` and no
  # Libs.private, so a static build hands the consumer a link line that omits
  # everything libssh itself pulls in: linking with just -lssh compiles and then
  # dies on `undefined symbol: EVP_PKEY_CTX_new`. libssh is built against
  # OpenSSL here (WITH_GCRYPT and WITH_MBEDTLS both default off) and with zlib
  # (WITH_ZLIB defaults on), so those are the two to declare. This hooks after
  # gather rather than being a plain gather, because PkgConfig registers its
  # own and would otherwise run last and put the bare .pc line back.
  after 'gather' => sub {
    my ($build) = @_;
    for my $key (qw( libs libs_static )) {
      my $v = $build->runtime_prop->{$key} // '';
      next if $v =~ /-lcrypto\b/;
      $build->runtime_prop->{$key} = join ' ', grep { length } $v, '-lcrypto', '-lz';
    }
  };
};