# Functions for handling feed index files
#
# Copyright (C) 2013, 2014  Patrick McDermott
#
# This file is part of the ProteanOS Development Kit.
#
# The ProteanOS Development Kit 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.
#
# The ProteanOS Development Kit 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 the ProteanOS Development Kit.  If not, see
# <http://www.gnu.org/licenses/>.

_feed_dep_fields=
_feed_pkg_cb=
_feed_deps_cb=
_feed_fname_cb=
_feed_md5sum_cb=
_feed_sha256sum_cb=
_feed_pkgs=
_feed_pkg_include=
_feed_pkg=
_feed_deps=

feed_download()
{
	local base_url="${1}"
	local list_file="${2}"
	local use_gzip="${3}"
	local root="${4}"
	shift 4
	local url=
	local gunzip=

	if ${use_gzip}; then
		url="${base_url}/Packages.gz"
		case "${list_file}" in
			*.gz) gunzip='cat';;
			*)    gunzip="${GUNZIP}";;
		esac
	else
		url="${base_url}/Packages"
	fi

	if ! ${WGET} -q -O "${list_file}.tmp" -- "${url}"; then
		return 1
	fi
	if ! ${gunzip} <"${list_file}.tmp" >"${list_file}"; then
		rm -f -- "${list_file}.tmp"
		return 1
	fi
	rm -f -- "${list_file}.tmp"

	return 0
}

feed_download_cert()
{
	local base_url="${1}"
	local list_file="${2}"
	local use_gzip="${3}"
	local root="${4}"
	shift 4
	local url=
	local usign=
	local opkg_cert=

	if ${use_gzip}; then
		url="${base_url}/Packages.gz"
		# Don't bother with gunzip, because only opkg-lede after storing
		# compressed package lists (commit cd113c7) supports signature
		# checking with usign (commit 71f02a3).
	else
		url="${base_url}/Packages"
	fi

	if ! ${WGET} -q -O "${list_file}.tmp" -- "${url}"; then
		return 1
	fi
	if ! ${WGET} -q -O "${list_file}.sig" -- "${base_url}/Packages.sig"
	then
		rm -f -- "${list_file}.tmp"
		return 1
	fi

	if ${in_place} && ${USIGN_EMBEDDED}; then
		usign="${builddir}/3rdparty/usign/usign"
	else
		usign="${USIGN}"
	fi
	if ${in_place}; then
		opkg_cert="${builddir}/opkg-cert"
	else
		opkg_cert="${OPKG_CERT}"
	fi

	if ! ROOT="${root}" TMPDIR="${root}" USIGN="${usign}" \
			WGET="${WGET}" GUNZIP="${GUNZIP}" "${opkg_cert}" \
			verify "${list_file}.sig" "${list_file}.tmp"; then
		rm -f -- "${list_file}.tmp" "${list_file}.sig"
		return 1
	fi
	mv -- "${list_file}.tmp" "${list_file}"

	return 0
}

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

	name="$(printf '%s\n' "${name}" | tr 'A-Z' 'a-z')"

	if [ "x${name}" = 'xpackage' ]; then
		_feed_pkg="${value}"
	elif [ "x${name}" = 'xfilename' ]; then
		${_feed_fname_cb} "${_feed_pkg}" "${value}"
	elif [ "x${name}" = 'xmd5sum' ]; then
		${_feed_md5sum_cb} "${_feed_pkg}" "${value}"
	elif [ "x${name}" = 'xsha256sum' ]; then
		${_feed_sha256sum_cb} "${_feed_pkg}" "${value}"
	elif [ "x${_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="${dep%%|*}"
		# Trim whitespace.
		dep="$(printf '%s\n' "${dep}" | sed 's/^ *//; s/ *$//')"
		# In practice, this would suffice for control files generated by
		# opkbuild:
		#     dep="${dep#[ ${HT}${LF}]}"
		#     dep="${dep%[ ${HT}${LF}]}"
		new_deps="${new_deps} ${dep}"
	done
	unset IFS

	${_feed_deps_cb} "${_feed_pkg}" "${new_deps# }"

	_feed_pkg_include='false'
	_feed_pkg=''
	_feed_deps=''

	return 0
}

feed_find_pkgs()
{
	local feed_idx="${1}"
	local dep_fields="${2}"
	local pkg_cb="${3}"
	local deps_cb="${4}"
	local fname_cb="${5}"
	local md5sum_cb="${6}"
	local sha256sum_cb="${7}"
	shift 7

	_feed_dep_fields=" $(printf '%s ' ${dep_fields} | tr 'A-Z' 'a-z')"
	_feed_pkg_cb="${pkg_cb}"
	_feed_deps_cb="${deps_cb}"
	_feed_fname_cb="${fname_cb}"
	_feed_md5sum_cb="${md5sum_cb}"
	_feed_sha256sum_cb="${sha256sum_cb}"

	_feed_pkgs=''
	_feed_pkg_include='false'
	_feed_pkg=''
	_feed_deps=''

	parse_control '-' _feed_field_cb _feed_para_cb 'Package' <<-EOF
		$({ ${GUNZIP} -c -- "${feed_idx}" || cat "${feed_idx}"; } \
			2>/dev/null)
		EOF

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

	return 0
}