#!/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, 2024 Luke T. 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=$TORUPATH] [V=true] [F=true] %q [-h|--help]' "${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, --help' 'Show this message'
}

main() {
	setup_traps

	VERBOSE=${V:-false}
	FORCE=${F:-false}
	# TODO: add an option to override/augment libretools.conf:REPOS
	local args mode=run
	if ! args="$(getopt -n "${0##*/}" -o 'h' -l 'help' -- "$@")"; then
		mode=errusage
	else
		eval "set -- $args"
		local flag
		while true; do
			flag=$1
			shift
			case "$flag" in
				-h | --help) mode=usage ;;
				--) break ;;
				*) panic 'unhandled flag: %q' "$flag" ;;
			esac
		done
		if [[ $mode == run && $# -gt 0 ]]; then
			gnuerror 'takes 0 arguments, got %d' "$#"
			mode=errusage
		fi
	fi
	case "$mode" in
		errusage)
			print "Try '%s --help' for more information." "${0##*/}" >&2
			return $EXIT_INVALIDARGUMENT
			;;
		usage)
			usage
			return $EXIT_SUCCESS
			;;
		run) : ;;
		*) panic 'invalid mode: %q' "$mode" ;;
	esac

	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 "$@"
