#!/bin/sh
# Copyright 2020  Jonas Smedegaard <dr@jones.dk>
# Copyright 2020  Purism, SPC
# Description: helper script to update copyright_hints
#
# This program 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, or (at your option)
# any later version.
#
# This program 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, see <http://www.gnu.org/licenses/>.

set -eu

# cleanup stray hint files from a previous run
find -type f -name '*:meta' -delete

# omit files not copyright protected nor stating copyright or licensing
RE_omit='src/_locales/[a-zA-Z_]+/messages\.json'

1>&2 echo 'extract metadata from binary files ...'
RE_meta='.*\.(png|ttf|woff2)'
exiftool '-textOut!' %d%f.%e:meta -short -short -recurse -ext png -ext ttf -ext woff2 .

# TODO: automate more of this manual cleanup:
#  * strip garbage copyright holders
#  * optionally merge equally licensed Files sections
#  * do "sort -k2 -k1,1 -u" on copyright holders
#  * merge copyright years for each copyright holder
# TODO: strip files matching glob in current (only, no later) section
_licensecheck() {
	GLOB=$1
	shift
	case "$GLOB" in
		'*') 1>&2 echo "check default section(s) ...";;
		'') 1>&2 echo "check remaining upstream section(s) ...";;
		*) 1>&2 echo "check section(s) $GLOB ...";;
	esac
	licensecheck --copyright --deb-machine --recursive --lines 0 "$@" -- * \
		| GLOB=$GLOB perl -0777 -p \
		-e 'BEGIN { our $GLOB = join "\n ", split(" ",$ENV{GLOB}) }' \
		-e 's/^.*?\n\nFiles: \K/$GLOB\n /s if $GLOB;' \
		-e 's/^.*?\n\nFiles: \K.*?(?=\n\w)/$GLOB/s if $GLOB and $GLOB =~ /^[*]\//;' \
		-e 's/^.*?\n\n//s unless $GLOB and $GLOB =~ /^[*]$/m;' \
		-e 's/^Files:\K /\n /mg;' \
		-e 's/^Copyright:\K /\n  /mg;' \
		-e 's/(?:(?<=^  )|(?<=\d{4})),\K (?=\d{4})//mg;' \
		-e 's/:(?:meta|skip)$//mg;' \
		>> debian/copyright_hints
}

rm -f debian/copyright_hints

# check generally
#  * omit non-copyright-protected Debian files
_licensecheck '*' --check '.*' --ignore "^($RE_omit|$RE_meta|debian/.*)$"
_licensecheck '*/debian' --check '^debian/' --ignore '^debian/(changelog|copyright(_hints)?|source/lintian-overrides)$'

# cleanup hint files
find -type f -name '*:meta' -delete