#!/usr/bin/env bash

# Copyright (C) 2011-2012 Nicolás Reynolds <fauno@parabola.nu>
# Copyright (C) 2012 Michał Masłowski <mtjm@mtjm.eu>
# Copyright (C) 2012 Joshua Ismael Haase Hernández (xihh) <hahj87@gmail.com>
# Copyright (C) 2014-2015, 2017 Luke Shumaker <lukeshu@parabola.nu>
#
# License: GNU GPLv3+
#
# 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 of the License, 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 Affero 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/>.

. "$(librelib messages)"
. "$(librelib conf)"

usage() {
	print 'Usage: [T=$TORUPATH] [V=true] [F=true] %q [-h]' "${0##*/}"
	print 'Create/update the `$TORUPATH/paths.tch` database.'
	echo
	prose 'The file `%s` is a Tokyo Cabinet database a mapping between paths
	       to PKGBUILD files and `pkgname`s and `pkgbase`s.  PKGBUILD files
	       are scanned for in `$ABSROOT` in each of `$REPOS`.' \
		       '$TORUPATH/paths.tch'
	echo
	prose 'Additionally, it creates a timestamp file at `%s`, so that skip
	       PKGBUILD files that have not changed since the previous
	       invocation.' \
		       '$TORUPATH/lastsync.paths'
	echo
	print 'Configuration:'
	flag \
		'libretools.conf : TORUPATH' 'Where to store `paths.tch`' \
		'libretools.conf : REPOS'    'Which repositories to consider from `$ABSROOT`' \
		'abs.conf : ABSROOT'         'Where to find PKGBUILD files'
	echo
	print 'Options:'
	flag \
		'T=$TORUPATH' 'Override libretools.conf:TORUPATH' \
		'V=true'      'Be verbose' \
		'F=true'      'Ignore timestamps; force re-scan all PKGBUILDs' \
		'-h'          'Show this message'
}

main() {
	setup_traps

	# TODO: better option parsing
	VERBOSE=${V:-false}
	FORCE=${F:-false}
	# TODO: add an option to override/augment libretools.conf:REPOS
	if [[ $# != 0 ]]; then
		if [[ $# == 1 && "$1" == '-h' ]]; then
			usage
			return $EXIT_SUCCESS
		fi
		usage >&2
		return $EXIT_INVALIDARGUMENT
	fi

	declare -i ret=0
	if [[ -n "${T:-}" ]]; then
		load_conf libretools.conf REPOS || ret=$?
		TORUPATH=$T
	else
		load_conf libretools.conf TORUPATH REPOS || ret=$?
	fi
	load_conf abs.conf ABSROOT || ret=$?
	[[ $ret = 0 ]] || exit $ret

	if [ ! -w "$TORUPATH" ]; then
		error "Toru's path isn't writable.  Please check your TORUPATH: %q" "$TORUPATH"
		exit $EXIT_NOPERMISSION
	fi

	local lastsyncfile=${TORUPATH}/lastsync.paths
	local pathfile=${TORUPATH}/paths.tch

	if [ ! -e "${pathfile}" ]; then
		tcamgr create "${pathfile}"
	fi

	local fullrepos=()
	# This loops over ${REPOS[@]} backward.  This is because early entries
	# in REPOS have higher precidence, but the way this is implemented,
	# the later entries have precedence, so we need to flip the order.
	for (( i = ${#REPOS[@]}-1 ; i >= 0 ; i-- )); do
		$VERBOSE && msg "Processing [%s]" "${REPOS[$i]}"

		if [ -d "${ABSROOT}/${REPOS[$i]}" ]; then
			fullrepos+=("${ABSROOT}/${REPOS[$i]}")
		fi
	done

	# Find PKGBUILDs in ${fullrepos[@]}
	find_args=("${fullrepos[@]}" -mindepth 2 -maxdepth 3 -type f -name PKGBUILD)
	if [[ -e $lastsyncfile ]] && ! $FORCE; then
		# if lastfilesync exists, only look at things that have
		# changed since then (unless $FORCE is on)
		find_args+=(-newer "${lastsyncfile}")
	fi
	IFS=$'\n'
	pkgbuilds=($(find "${find_args[@]}"))

	# Add information from each of the PKGBUILDs to the toru cache.
	msg "Updating path cache"
	msg2 "%d PKGBUILDs to update" ${#pkgbuilds[@]}
	local _pkgbuild fullpath
	for _pkgbuild in "${pkgbuilds[@]}"; do
		# plain "$_pkgbuild"
		if ! load_PKGBUILD "${_pkgbuild}" &>/dev/null; then
			error "%q contains errors, skipping" "${_pkgbuild}"
			continue
		fi

		fullpath="$(dirname -- "${_pkgbuild}")"

		for _pkg in "${pkgbase}" "${pkgname[@]}" "${provides[@]}"; do
			$VERBOSE && msg2 '%s -> %s' "${_pkg}" "${fullpath}"
			tcamgr put "${pathfile}" "${_pkg%%[<>=]*}" "${fullpath}"
		done
	done

	date +%s > "${lastsyncfile}"
}

main "$@"