# Functions for parsing control files.
#
# Copyright (C) 2012, 2013  Patrick "P. J." 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/>.

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

use output
use locale

control_file=
control_line_nr=

parse_control()
{
	local field_cb="${2}"
	local paragraph_cb="${3}"
	local req_fields="${4}"
	local in_paragraph=
	local line=
	local para_req_fields=
	local got_fields=
	local name=
	local value=

	control_file="${1}"
	control_line_nr=0

	in_paragraph='false'

	while IFS='' read -r line; do
		control_line_nr=$(($control_line_nr + 1))
		if [ "x$(echo ${line})" = 'x' ]; then
			# Paragraph end.
			if ${in_paragraph}; then
				# The first line is blank to consolidate
				# initialization code (see heredocument below).
				in_paragraph='false'
				if [ "x${name}" != 'x' ]; then
					if ! "${field_cb}" "${name}" "${value}"
					then
						return 0
					fi
				fi
				if ! "${paragraph_cb}"; then
					return 0
				fi
				if [ "x${para_req_fields}" != 'x' ]; then
					para_req_fields="$(printf "%s$(get_msg \
						'list_item_separator')" \
						${para_req_fields})"
					parse_control_error \
						'control_missing_fields' \
						"${para_req_fields}"
				fi
			fi
			para_req_fields="$(printf '%s\n' ${req_fields})"
			got_fields="${LF}"
			name=''
			value=''
		elif [ "x${line#\#}" != "x${line}" ]; then
			# Comment.
			in_paragraph='true'
		elif [ "x${line# }" = "x${line}" ]; then
			# "Name: Value" line.
			in_paragraph='true'
			if [ "x${name}" != 'x' ]; then
				if ! "${field_cb}" "${name}" "${value}"; then
					return 0
				fi
			fi
			name="${line%%:*}"
			value="${line#*:}"
			value="${value# }"
			if [ "x${name}" = 'x' -o "x${name}" = "x${line}" ]; then
				parse_control_error 'control_bad_nv'
				continue
			fi
			if [ "x${para_req_fields}" != 'x' ]; then
				# Remove field from list of required fields.
				para_req_fields="$(printf '%s' "${para_req_fields}" | \
					grep -Fv "${name}")"
			fi
			if [ "x${got_fields%${LF}${name}${LF}*}" != \
					"x${got_fields}" ]; then
				# Duplicate field.
				parse_control_error 'control_duplicate_field' \
					"${name}"
			else
				got_fields="${got_fields}${name}${LF}"
			fi
		else
			# Continuation line.
			in_paragraph='true'
			if [ "x${name}" = 'x' ]; then
				# Expecting a "Name: Value" line.
				parse_control_error 'control_found_continuation'
				continue
			fi
			value="${value}${LF}${line# }"
		fi
	done <<-EOF

		$(cat "${control_file}")

		EOF
	# The first blank line above triggers the paragraph end code to
	# consolidate initialization code.
	# The second blank line above is needed because the command substitution
	# removes any trailing newlines.

	if [ "x${name}" != 'x' ]; then
		if ! "${field_cb}" "${name}" "${value}"; then
			return 0
		fi
	fi

	return 0
}

parse_control_error()
{
	local msgid="${1}"
	local file_info=
	shift 1

	if [ ${control_line_nr} -eq 0 ]; then
		file_info="$(printf '%20s:' "${control_file}")"
	else
		file_info="$(printf '%20s(l%d):' "${control_file}" \
			"${control_line_nr}")"
	fi

	warn "${file_info} $(get_msg "${msgid}")" "${@}"

	return 0
}