#!/bin/sh
# Copyright 2020-2022  Jonas Smedegaard <dr@jones.dk>
# Copyright 2020-2021  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/>.

# Depends:
#  licensecheck,
#  libimage-exiftool-perl,
#  libipc-system-simple-perl,
#  perl,

set -eu

SKIPFILES='meta'

# cleanup stray hint files from a previous run
find -type f -regextype posix-egrep -regex "^.*:($SKIPFILES)$" -delete

1>&2 echo 'extract metadata from binary files ...'
EXT_meta='otf ttf png'
RE_meta=$(perl -E '$"="|";say ".*\\.(@ARGV)"' $EXT_meta) #"
exiftool '-textOut!' %d%f.%e:meta -short -short -recurse -extractEmbedded $(perl -E 'say map {" -ext $_"} @ARGV' $EXT_meta) .

RE_SKIP="$RE_meta"

# 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() {
	SKIPFILES=$SKIPFILES perl -MGetopt::Long=:config,gnu_getopt -MIPC::System::Simple=capture -MList::Util=uniq \
		-e 'GetOptions ( \%opt, "check=s", "ignore=s", "shortname=s", "subset=s", "merge-licenses" );'\
		-e '@subset = split( " ", $opt{subset} );' \
		-e '$subset_globs = join "\n ", @subset;' \
		-E 'if ( $subset_globs =~ /^[*]$/ ) { say STDERR "check default section(s) ..." }' \
		-E 'elsif ( @subset and $opt{shortname} ) { say STDERR "check $opt{shortname} section(s) @subset ..." }' \
		-E 'elsif (@subset) { say STDERR "check section(s) @subset ..." }' \
		-E 'elsif ($opt{shortname} ) { say STDERR "check $opt{shortname} section(s) @subset ..." }' \
		-E 'else { say STDERR "check remaining upstream section(s) ..." };' \
		-e '@cmd = ( qw(licensecheck --copyright --deb-machine --recursive --lines 0), "--check", $opt{check}, "--ignore", $opt{ignore}, $opt{"merge-licenses"} ? "--merge-licenses" : (), "--" );'\
		-E 'say STDERR "@cmd *" if $ENV{DEBUG};'\
		-e '$_ = $dump = capture( @cmd, glob "*" );'\
		-e 'if ( !$ENV{NOGLOBMERGE} and grep /[*]/, @subset ) { s/^.*?\n\nFiles: \K.*?(?=\n\w)/$subset_globs/s }' \
		-e 'elsif (@subset) { s/^.*?\n\nFiles: \K/$subset_globs\n /s };' \
		-e 'if ( $subset[0] ne "*" ) { s/^.*?\n\n//s };' \
		-e 's/^Files:\K /\n /mg;' \
		-e 's/^Copyright:\K /\n  /mg;' \
		-e 's/(?:(?<=^  )|(?<=\d{4})),\K (?=\d{4})//mg;' \
		-e 's/:(?:$ENV{SKIPFILES})$//mg;' \
		-e 'if ($opt{shortname}) { s/^License: \K(.*)/ join " and\/or ", uniq sort grep( !m{\AUNKNOWN\Z}, split(" and\/or ",$1), $opt{shortname} ) /mge };' \
		-e 'print $_;'\
		-- "$@" \
		>> debian/copyright_hints
}

rm -f debian/copyright_hints

# initially, check all to know roughly what to group and in which order
#rm -f debian/copyright_hints
#_licensecheck --check '.*' --ignore "^($RE_SKIP|debian/.*)$"
#exit 0

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

# cleanup hint files
find -type f -regextype posix-egrep -regex "^.*:($SKIPFILES)$" -delete
