# ProteanOS Development Kit
# lib/feed.sh
# Functions for handling feed index files
#
# Copyright (C) 2013  Patrick "P. J." McDermott
#
# 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 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/>.

[ "x${_FEED_SM+set}" = 'xset' ] && return 0
_FEED_SM=1

use fd
use control

feed_pkg_cb=
feed_dep_fields=
feed_pkgs=
feed_deps_fd=
feed_fnames_fd=
feed_pkg_include=
feed_pkg=
feed_deps=

feed_download()
{
	local feed_index="${1}"

	wget -O - "${feed_index}"

	return 0
}

# TODO: Write to a filenames file.
feed_find_pkgs()
{
	local pkg_cb="${1}"
	local dep_fields="${2}"
	local deps_file="${3}"
	local fnames_file="${4}"

	feed_pkg_cb="${pkg_cb}"
	feed_dep_fields=" $(printf '%s ' ${dep_fields})"
	feed_pkgs=''

	fopen "${deps_file}" 'a'
	feed_deps_fd=${FD}
	fopen "${fnames_file}" 'a'
	feed_fnames_fd=${FD}

	feed_pkg_include='false'
	feed_pkg=''
	feed_deps=''

	parse_control '-' feed_field_cb feed_para_cb 'Package'

	fclose ${feed_deps_fd}

	printf '%s\n' "${feed_pkgs# }"

	return 0
}

feed_field_cb()
{
	local name="${1}"
	local value="${2}"

	if [ "x${name}" = 'xPackage' ]; then
		feed_pkg="${value}"
	elif [ "x${name}" = 'xFilename' ]; then
		printf '%s %s\n' "${feed_pkg}" "${value}" >&${feed_fnames_fd}
	elif [ "x${feed_dep_fields#* ${name} }" != "x${feed_dep_fields}" ]; then
		feed_deps="${feed_deps}${value}, "
	fi

	if ${feed_pkg_cb} ${name} ${value}; then
		feed_pkg_include='true'
	fi

	return 0
}

feed_para_cb()
{
	local new_deps=
	local dep=

	if ${feed_pkg_include}; then
		feed_pkgs="${feed_pkgs} ${feed_pkg}"
	fi

	new_deps=''
	IFS=','
	for dep in ${feed_deps%, }; do
		unset IFS
		# Trim off versions and disjunctions.
		dep="${dep%%(*}"
		dep="${dep%%|*}"
		# Trim whitespace.
		dep="${dep##[ ${HT}${LF}]}"
		dep="${dep%%[ ${HT}${LF}]}"
		new_deps="${new_deps} ${dep}"
	done
	unset IFS

	printf '%s%s\n' "${feed_pkg}" "${new_deps}" >&${feed_deps_fd}

	feed_pkg_include='false'
	feed_pkg=''
	feed_deps=''

	return 0
}