# Contributor: Mitch Tishmack <mitch.tishmack@gmail.com>
# Contributor: Jakub Jirutka <jakub@jirutka.cz>
# Maintainer: Mitch Tishmack <mitch.tishmack@gmail.com>
pkgname=idris
pkgver=1.0
pkgrel=1
pkgdesc="A Language with Dependent Types"
url="http://www.idris-lang.org"
# Note: same as ghc, if it gets ported elsewhere this should run too.
# armhf: disabled due to build failure
arch="x86_64"
license="BSD-3-Clause"
depends="gmp-dev gcc"
makedepends="ghc cabal libffi-dev ncurses-dev zlib-dev"
subpackages="$pkgname-doc"
source="$pkgname-$pkgver.tar.gz::https://github.com/idris-lang/Idris-dev/archive/v$pkgver.tar.gz
	cabal.config"
builddir="$srcdir/Idris-dev-$pkgver"

_cabal_home="$srcdir/cabal"

# Prevent cabal setup from using unbounded memory
_cabal_install_opts=" --max-backjumps=10000"

cabal_update() {
	msg "Updating constraints"

	cd "$builddir"

	# Create cabal config and fetch index.
	HOME="$_cabal_home" cabal update

	# Resolve deps and generate fresh cabal.config with version constraints.
	rm -f cabal.config
	HOME="$_cabal_home" cabal freeze --shadow-installed-packages

	# Add version tag at the first line.
	sed -i "1i--$pkgver" cabal.config

	mv cabal.config "$startdir"/

	cd "$startdir"
	abuild checksum
}


# Used by the subsequent two functions.
# This barf of a pipeline converts the cabal freeze config file lines from:
# constraints: foo ==VERSION,
#              bar ==VERSION
# etc...
# To something we can more easily munge into what we need for other purposes
# aka we end up with:
# foo==VERSION bar==VERSION ...
_cabal_constraints_prime() {
	printf "$(grep '==' cabal.config | \
		sed -e 's/constraints[:]//g' | \
		tr -d '[:space:]' | \
		sed -e 's/[,]/ /g')"
}

# Take the output from above and replace =='s to -'s so we can cabal fetch
# the specific package-version's via cabal
_cabal_pkgs() {
	printf "$(_cabal_constraints_prime)" | sed -e 's/==/-/g'
}

# Similar to the above, but convert to --constraint args used for cabal install
# so that our cabal install line can use the same constraints for idris in cabal.config.
#
# This works around us running against a newer hackage index where one of the packages
# in the freeze file has a newer version that cabal install libffi could end up
# selecting due to libffi having more relaxed constraints than idris.
#
# That is:
# --constraint=foo==VERSION --constraint=bar==VERSION
_cabal_constraints() {
	printf " $(_cabal_constraints_prime)" | sed -e 's/ / --constraint=/g'
}

prepare() {
	default_prepare

	if [ "$(head -n 1 "$srcdir"/cabal.config)" != "--$pkgver" ]; then
		die "Requirements file is outdated, run 'abuild cabal_update'"
	fi

	cd "$builddir"

	# Create cabal config and fetch index.
	HOME="$_cabal_home" cabal update

	# Cabal implicitly loads cabal.config from the project's directory.
	ln -sf "$srcdir"/cabal.config .

	# Create Cabal sandbox that will be used for all subsequent cabal
	# invocations. This is something like Python virtual env.
	HOME="$_cabal_home" cabal sandbox init

	# Fetch all dependencies.
	# Note: cabal-doctest is a transitive dependency for libffi-0.1 not idris
	HOME="$_cabal_home" cabal fetch --no-dependencies $(_cabal_pkgs) \
		 cabal-doctest-1.0.2 libffi-0.1
}

build() {
	cd "$builddir"

	# Build dependencies
	# Note: for libffi force constraints manually via the freeze file to prevent
	# cabal from possibly using newer constraints for libffi that might intersect
	# with those idris uses.
	HOME="$_cabal_home" cabal install $_cabal_install_opts --offline --constraint=cabal-doctest==1.0.2 \
		$(_cabal_constraints) -v libffi-0.1
	HOME="$_cabal_home" cabal install $_cabal_install_opts --offline --only-dependencies -v

	# Note: ordering of prefixes is important!
	HOME="$_cabal_home" cabal configure \
		--prefix='/usr' \
		--docdir='$prefix/share/doc' \
		--datadir='$prefix/share' \
		--htmldir='$docdir/html' \
		--libdir='$prefix/lib' \
		--libsubdir="$pkgname" \
		--datasubdir="$pkgname" \
		--dynlibdir="$pkgname" \
		--disable-shared \
		--disable-profiling \
		--disable-library-profiling \
		--flags='GMP FFI standalone'
	HOME="$_cabal_home" cabal build
}

# TODO: Run upstream tests and/or figure out how to set paths to be able
# to compile hello_world for check.
check() {
	cd "$builddir"

	./dist/build/idris/idris --version
}

package() {
	cd "$builddir"

	HOME="$_cabal_home" cabal copy --destdir="$pkgdir"

	cd "$pkgdir"

	# We don't need the haskell shared libraries or interface files.
	rm -r usr/lib/idris

	mkdir -p usr/share/doc/idris/ \
		usr/share/licenses/$pkgname/
	mv usr/share/idris/docs usr/share/doc/idris
	mv usr/share/doc/LICENSE usr/share/licenses/$pkgname/
}

sha512sums="a350004a8510f01d1cc8f965a9a4e2dab219f003980b98354ebb5ae42f73b32c90c98dce193943e9709d994cb92ad35814a46b79412a1afc85d42e1018c6ba10  idris-1.0.tar.gz
adce625aed6ab6f36adf6d91e5671c85c91a1009e17419a88071e3cd500962c1c545406b2eb431cd3efa45d3dacadac913a9a27a5956e8233bd13b4630ff2ab4  cabal.config"
