# -*-eselect-*-  vim: ft=eselect
# Copyright 1999-2010 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id$
# Author:  Martin Schlemmer <azarah@gentoo.org>
# Further modifications by Michał Górny <mgorny@gentoo.org>
# Further modifications by Tomáš Chvátal <scarabeus@gentoo.org>
# Further modifications by Donnie Berkholz <dberkholz@gentoo.org>
# Further modifications based off submissions to bug #54984 <cyfred@gentoo.org>
# Further modifications by Jeremy Huddleston <eradicator@gentoo.org>
# Made into eselect module by Jeremy Huddleston <eradicator@gentoo.org>

inherit multilib package-manager config

# Eselect data
DESCRIPTION="Manage the OpenCL implementation used by your system"
MAINTAINER="xarthisius@gentoo.org"
SVN_DATE='$Date$'
VERSION=$(svn_date_to_version "${SVN_DATE}" )
EBUILD_VERSION="1.1.0"

# Our data
ENV_FILE="${EROOT}/etc/env.d/03opencl"
PREFIX="${EROOT}/usr"
DST_PREFIX="${EROOT}/usr"
unset IGNORE_MISSING

get_current_implementation() {
	local ret
	local ldpath=$(load_config "${ENV_FILE}" LDPATH)
	local opencl_profile=$(load_config "${ENV_FILE}" OPENCL_PROFILE)

	if [[ -n ${opencl_profile} ]] ; then
		ret="${opencl_profile}"
	elif [[ -n ${ldpath} ]] ; then
		ret="${ldpath%%:*}"
		ret="${ret##*OpenCL/vendors/}"
		ret="${ret%/lib*}"
	fi

	echo ${ret}
}

get_implementations() {
	local ret
	local libdir
	local dir
	local dir_name

	for libdir in $(list_libdirs) ; do
		[[ ${ROOT} != / ]] && libdir=${libdir#${EROOT}}
		for dir in "${PREFIX}/${libdir}"/OpenCL/vendors/* ; do
			dir_name=$(basename "${dir}")
			[[ -d ${dir} && ${dir_name} != "global" ]] || continue
			has ${dir_name} ${ret} && continue
			ret=${ret:+${ret} }${dir_name}
		done
	done

	echo ${ret}
}

# 1: file
# 2: workdir
upgrade_file() {
	local file=$1
	local filename
	local workdir=$2
	local linkfile=$(relative_name ${file} "${workdir}")

	[[ -f ${file} ]] || return
	filename=$(basename "${file}")

	if [[ -f ${filename} || ( -L ${filename} && ! -e ${filename} ) ]] ; then
		rm -f "${filename}"* || die -q "Failed to delete ${workdir}/${filename}"
	fi

	#echo "DEBUG: ln -s \"${linkfile}\" \"${filename}\""
	if [[ "x${REMOVE_ONLY}" == "xfalse" ]]; then
		ln -s "${linkfile}" "${filename}" || die -q "Failed to create symlink ${workdir}/${filename}"
	fi
}

setup_soname_symlinks() {
	local file=$1
	local target=$2
	local soname
	local scanner

	# if we have .so or dylib we need to make its soname symlinked
	# in order to be easy to find and faster to grab
	if [[ ${file} == *.so || ${file} == *.dylib ]] ; then
		[[ ${file} == *.so ]] && scanner=scanelf || scanner="scanmacho"
		soname=$(${scanner} -qBF '%S|%p' "${file}" | head -n1)
		soname=${soname%|*}  # stupid scanelf must print filename
		[[ ${file} == *.so ]] && soname="${file%/*}"/${soname}
		upgrade_file "${soname}" "${target}"
	fi
}

setup_lib_symlinks() {
	local profile_libdir=$1
	local target=$2
	local file

	mkdir -p "${target}" || die "Failed to create ${target}"

	pushd "${target}" &> /dev/null
		for file in "${profile_libdir}"/lib*.so; do
			upgrade_file "${file}" "${target}"
			setup_soname_symlinks "${file}" "${target}"
		done
	popd &> /dev/null
}

setup_includes_symlinks() {
	local target=$1
	local file
	local sdir

	shift

	mkdir -p "${target}" || die "Failed to create ${target}"
	pushd "${target}" &> /dev/null
#		for file in cl_ext.h cl_gl_ext.h cl_gl.h cl.h cl_platform.h opencl.h cl.hpp; do
			for sdir in "$@"; do
				for file in ${sdir} ; do
					if [[ -f ${sdir}/${file} ]]; then
						upgrade_file "${sdir}/${file}" "${target}"
						break
					fi
				done
			done
#		done
	popd &> /dev/null
}

set_new_implementation() {
	local cl_implem=$1
	local avail_implems=$(get_implementations)
	local libdir
	local moduledir
	local gl_dir
	local cl_local

	# Set a sane umask... bug #83115
	umask 022

	if ! has ${cl_implem} ${avail_implems}; then
		die -q "Invalid opencl implementation selected."
	fi

	if [[ -z ${IGNORE_MISSING+1} ]]; then
		local found_opencl
		for libdir in $(list_libdirs); do
			[[ ${ROOT} != / ]] && libdir=${libdir#${EROOT}}
			[[ -d ${PREFIX}/${libdir}/OpenCL && ! -h ${PREFIX}/${libdir} ]] || continue
			[[ -f "${PREFIX}/${libdir}/OpenCL/vendors/${cl_implem}/libOpenCL.so" ]] && found_opencl=yes
			#echo "DEBUG: ${PREFIX}/${libdir}/OpenCL/vendors/${cl_implem}/libOpenCL.so"
		done

		if [[ -z ${found_opencl} ]]; then
			write_error_msg "The ${cl_implem} OpenCL implementation doesn't seem to provide"
			write_error_msg "libOpenCL.so file. This might be an effect of breakage introduced"
			write_error_msg "by a prioprietary driver installer. Please re-merge the package"
			write_error_msg "providing your OpenCL implementation."
			die -q "Selected OpenCL implementation incomplete."
		fi
	fi

	echo -n "Switching to ${cl_implem} OpenCL interface..."
	if [[ -f ${ENV_FILE} ]] ; then
		rm -f "${ENV_FILE}" || die -q "Failed to remove ${ENV_FILE}"
	fi

	for libdir in $(list_libdirs); do
		# Set libdir correctly to EROOT
		[[ ${ROOT} != / ]] && libdir=${libdir#${EROOT}}

		# First make sure we have an opencl directory and this
		# is a real lib dir, not a symlink
		[[ -d ${PREFIX}/${libdir}/OpenCL && ! -h ${PREFIX}/${libdir} ]] || continue

		# Check if opencl implementation directory exists
		# and use xorg-x11 as fallback (mesa)
		# If even mesa is not around then simply die
		if [[ -d "${PREFIX}/${libdir}/OpenCL/vendors/${cl_implem}" ]] ; then
			cl_local="${cl_implem}"
			REMOVE_ONLY="false" # global variable
		else
			# we are moving to implementation that does not have any support
			# for specified libdir (ie 32bit libs for mesa) so we should
			# remove the current symlinks and continue like nothing happened.
			REMOVE_ONLY="true" # global variable
			cl_local=$(get_current_implementation)
			if ! has ${cl_local} ${avail_implems}; then
				# skipping the libdir cause there was no profile actually
				# selected before
				continue 2
			fi
		fi

		setup_lib_symlinks \
			"${PREFIX}/${libdir}/OpenCL/vendors/${cl_local}/" \
			"${DST_PREFIX}/${libdir}"

		setup_includes_symlinks \
			"${DST_PREFIX}/include/CL" \
			"${PREFIX}/${libdir}/OpenCL/vendors/${cl_implem}/include/CL/" \
			"${PREFIX}/${libdir}/OpenCL/global/include/CL/"

		# Setup the $LDPATH
		if [[ "x${REMOVE_ONLY}" == "xfalse" ]]; then
			# we need this relative to ROOT
			ldpath="${ldpath:+${ldpath}:}${PREFIX#${ROOT}}/${libdir}/OpenCL/vendors/${cl_local}"
		fi
	done

	store_config ${ENV_FILE} LDPATH "${ldpath}"
	store_config ${ENV_FILE} OPENCL_PROFILE "${cl_implem}"

	do_action env update &> /dev/null

	echo " done"
}

### show action ###
describe_show() {
	echo "Print the current OpenCL implementation."
}

do_show() {
	local current=$(get_current_implementation)

	if [[ -n ${current} ]] ; then
		echo ${current}
		return 0
	else
		echo "(none)"
		return 2
	fi
}

### list action ###
describe_list() {
	echo "List the available OpenCL implementations."
}

do_list() {
	local targets=( $(get_implementations) )
	local i

	write_list_start "Available OpenCL implementations:"
	for (( i = 0; i < ${#targets[@]}; i++ )); do
		[[ ${targets[i]} = $(get_current_implementation) ]] \
			&& targets[i]=$(highlight_marker "${targets[i]}")
	done
	write_numbered_list -m "(none found)" "${targets[@]}"
}

### set action ###
describe_set() {
	echo "Select the OpenCL implementation."
}

describe_set_parameters() {
	echo "<target>"
}

describe_set_options() {
	echo "<target> : The profile to activate"
	echo "--use-old : If an implementation is already set, use that one instead"
	echo "--prefix=<val> : Set the source prefix (default: /usr)"
	echo "--dst-prefix=<val> : Set the destination prefix (default: /usr)"
	echo "--ignore-missing : Ignore missing files when setting a new implementation"
}

do_set() {
	local action="error"
	local current=$(get_current_implementation)
	local available=$(get_implementations)
	local new
	local opt

	while [[ ${#@} -gt 0 ]] ; do
		opt=$1
		shift
		case ${opt} in
			--use-old)
				if [[ -n ${current} ]] && has ${current} ${available}; then
					action="old-implementation"
				fi
			;;
			--prefix=*)
				PREFIX=${ROOT}${opt#*=}
				available=$(get_implementations)
			;;
			--dst-prefix=*)
				DST_PREFIX=${ROOT}${opt#*=}
			;;
			--ignore-missing)
				IGNORE_MISSING=1
			;;
			*)
				if [[ ${action} != "old-implementation" ]] ; then
					action="set-implementation"
				fi

				if is_number ${opt} ; then
					targets=( $(get_implementations) )
					new=${targets[$(( ${opt} - 1 ))]}
					if [[ -z ${new} ]] ; then
						die -q "Unrecognized option: ${opt}"
					fi
				elif has ${opt} ${available}; then
					new="${opt}"
				else
					die -q "Unrecognized option: ${opt}"
				fi
			;;
		esac
	done

	case ${action} in
		old-implementation)
			set_new_implementation ${current}
			return $?
		;;
		set-implementation)
			if [[ -n ${new} ]] ; then
				set_new_implementation ${new}
				return $?
			else
				die -q "Please specify an implementation to set"
			fi
		;;
		*)
			die -q "Invalid usage of set action."
		;;
	esac
}