# Copyright 1999-2016 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id$

EAPI=5

# Kids, don't do this at home!
inherit python-utils-r1
PYTHON_COMPAT=( "${_PYTHON_ALL_IMPLS[@]}" )

# Inherited purely to have PYTHON_TARGET flags which will satisfy USE
# dependencies and trigger necessary rebuilds.
inherit python-r1

DESCRIPTION="Python script wrapper"
HOMEPAGE="https://bitbucket.org/mgorny/python-exec/"
SRC_URI="https://www.bitbucket.org/mgorny/${PN}/downloads/${P}.tar.bz2"

LICENSE="BSD-2"
SLOT="2"
KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~m68k ~mips ~ppc ~ppc64 ~s390 ~sh ~sparc ~x86 ~ppc-aix ~amd64-fbsd ~x86-fbsd ~x64-freebsd ~x86-freebsd ~amd64-linux ~arm-linux ~x86-linux ~ppc-macos ~x64-macos ~x86-macos ~m68k-mint ~sparc-solaris ~sparc64-solaris ~x64-solaris ~x86-solaris"
IUSE=""

# eselect-python because of /usr/bin/python* collisions and new config
# python versions because of missing $scriptdir/python* symlinks
RDEPEND="
	!<app-eselect/eselect-python-20160206
	!<dev-lang/python-2.7.10-r4:2.7
	!<dev-lang/python-3.3.5-r4:3.3
	!<dev-lang/python-3.4.3-r4:3.4
	!<dev-lang/python-3.5.0-r3:3.5"

src_configure() {
	local pyimpls=() i EPYTHON
	for i in "${PYTHON_COMPAT[@]}"; do
		python_export "${i}" EPYTHON
		pyimpls+=( "${EPYTHON}" )
	done

	local myconf=(
		--with-python-impls="${pyimpls[*]}"
	)

	econf "${myconf[@]}"
}

src_install() {
	default

	# Prepare and own the template
	sed -n -e '/^#/p' config/python-exec.conf.example \
		> "${T}"/python-exec.conf || die
	insinto /etc/python-exec
	doins "${T}"/python-exec.conf

	local f
	for f in python{,2,3}; do
		# symlink the C wrapper for python to avoid shebang recursion
		# bug #568974
		dosym python-exec2c /usr/bin/"${f}"
	done
	for f in python{,2,3}-config 2to3 idle pydoc pyvenv; do
		# those are python scripts (except for new python-configs)
		# so symlink them via the python wrapper
		dosym ../lib/python-exec/python-exec2 /usr/bin/"${f}"
	done
}

pkg_preinst() {
	if [[ -e ${EROOT}etc/python-exec/python-exec.conf ]]; then
		# preserve current configuration
		cp "${EROOT}"etc/python-exec/python-exec.conf \
			"${ED}"etc/python-exec/python-exec.conf || die
	else
		# preserve previous Python version preference
		local py old_pythons=()
		local config_base=${EROOT}etc/env.d/python

		# start with the 'global' preference (2 vs 3)
		if [[ -f ${config_base}/config ]]; then
			old_pythons+=( "$(<${config_base}/config)" )
		fi

		# then try specific py3 selection
		for py in 3; do
			local target=

			if [[ -f ${config_base}/python${py} ]]; then
				# try the newer config files
				target=$(<${config_base}/python${py})
			elif [[ -L ${EROOT}/usr/bin/python${py} ]]; then
				# check the older symlink format
				target=$(readlink "${EROOT}/usr/bin/python${py}")

				# check if it's actually old eselect symlink
				[[ ${target} == python?.? ]] || target=
			fi

			# add the extra target if found and != global
			if [[ ${target} && ${old_pythons[0]} != ${target} ]]; then
				old_pythons+=( "${target}" )
			fi
		done

		if [[ ${old_pythons[@]} ]]; then
			einfo "Keeping the following Python preference: ${old_pythons[*]}"

			local IFS=$'\n'
			echo "${old_pythons[*]}" \
				>> "${ED}"etc/python-exec/python-exec.conf || die
		fi
	fi
}