#!/bin/bash

# Copyright (C) 2017 by Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
#
# This is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the
# Free Software Foundation, Inc.,
# 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.

d=. ; while [ ! -d "$d/nx-X11/extras" ] && [ "$(readlink -e "$d")" != "/" ]; do d="$d/.."; done

# only continue, if in nx-libs tree
if [ -d "$d/nx-X11/extras" ]; then

	if which quilt 1>/dev/null; then

		echo "$(basename $0): quilt utility found, so we use it..."
		echo

		export QUILT_PATCHES="../Mesa.patches"
		export QUILT_PATCH_OPTS="--reject-format=unified"
		export QUILT_DIFF_ARGS="-p ab --no-timestamps --no-index --color=auto"
		export QUILT_REFRESH_ARGS="-p ab --no-timestamps --no-index"
		export QUILT_COLORS="diff_hdr=1;32:diff_add=1;34:diff_rem=1;31:diff_hunk=1;33:diff_ctx=35:diff_cctx=33"
		mkdir -p "$d/nx-X11/extras/Mesa.patches"

		cd "$d/nx-X11/extras/Mesa/"

		# "--quiltrc -" disables reading global or user-local configuration files.
		# These can override the environment settings if the quiltrc is not
		# carefully crafted.
		# For instance, it should set variables only if they aren't already
		# provided through the environment, but since the quiltrc file is
		# actually sourced as a shell script, there's no way to assume that
		# a user's quiltrc is "sane".
		quilt --quiltrc - "$@"

		cd - 1> /dev/null


	else

		echo "$(basename $0): no quilt utility found, falling back to stupidly (un)applying our patches..."
		echo

		CMDLINE_ARGS="$@"

		# we are really stupid here, we only understand 'push -a' and 'pop -a'
		# this should be sufficient for the build process...

		cd "$d/nx-X11/extras/Mesa/"

		# make sure all need dirs and files exist
		mkdir -p ./Mesa.patches/
		touch "../Mesa.patches/series"

		# this file will be needed temporarily
		touch "../Mesa.patches/.applied-patches"

		if [ "$CMDLINE_ARGS" = "push -a" ]; then

			grep -E -v "^#.*" < "../Mesa.patches/series" | while read patchfile; do
				if [ -n "$patchfile" ] && [ -r "../Mesa.patches/$patchfile" ] && ! grep -q "$patchfile" < "../Mesa.patches/.applied-patches"; then
					echo "Applying patch ../Mesa.patches/$patchfile"
					patch -p1 < "../Mesa.patches/$patchfile"
					echo "$patchfile" >> "../Mesa.patches/.applied-patches"
					echo
				fi
			done

		elif [ "$CMDLINE_ARGS" = "pop -a" ]; then

			tac "../Mesa.patches/.applied-patches" | while read patchfile; do
				if [ -n "$patchfile" ] && [ -r "../Mesa.patches/$patchfile" ]; then
					echo "Removing patch ../Mesa.patches/$patchfile"
					patch -R -p1 < "../Mesa.patches/$patchfile"
					sed -e "/$patchfile/d" "../Mesa.patches/.applied-patches" > "../Mesa.patches/.applied-patches.tmp"
					mv "../Mesa.patches/.applied-patches.tmp" "../Mesa.patches/.applied-patches"
					echo
				fi
			done

		else

			echo "$(basename $0): Doing nothing! Cmdline options not understood: $CMDLINE_ARGS"

		fi

		# remove the .applied-patches file, if empty again
		if [ ! -s "../Mesa.patches/.applied-patches" ]; then
			rm -f "../Mesa.patches/.applied-patches"
		fi

		cd - 1> /dev/null

	fi

fi