# Functions for parsing changelogs
#
# Copyright (C) 2012, 2018 Patrick McDermott
#
# This file is part of opkbuild.
#
# opkbuild 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.
#
# opkbuild 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 opkbuild.  If not, see <http://www.gnu.org/licenses/>.

OB_CHANGELOG_SOURCE=
OB_CHANGELOG_VERSION=
OB_CHANGELOG_DISTRIBUTION=
OB_CHANGELOG_CHANGES=
OB_CHANGELOG_MAINTAINER=
OB_CHANGELOG_DATE=

_ob_parse_changelog_error()
{
	local file=
	local line_nr=
	local msg_id=
	local file_info=
	local orig_text_domain=

	file="${1}"
	line_nr="${2}"
	msg_id="${3}"
	shift 3

	file_info="$(printf '%20s(l%d):' "${file}" "${line_nr}")"

	orig_text_domain="$(ob_get_text_domain)"
	ob_set_text_domain "${_OB_INTERNAL_TEXT_DOMAIN}"

	ob_warn "${file_info} $(ob_get_msg "${msg_id}")" "${@}"

	ob_set_text_domain "${orig_text_domain}"

	return 0
}

_ob_get_changelog_expect_str()
{
	local orig_text_domain=

	orig_text_domain="$(ob_get_text_domain)"
	ob_set_text_domain "${_OB_INTERNAL_TEXT_DOMAIN}"

	echo "$(ob_get_msg "changelog_expect_${1}")"

	ob_set_text_domain "${orig_text_domain}"

	return 0
}

## @brief Parse a changelog file
## @details \fBob_parse_changelog\fP parses a \fIchangelog\fP file, formatted as
##          specified at
##          <http://specs.proteanos.com/spf-2.0/metadata.html#changelog>.  For
##          each version entry, \fBob_parse_changelog\fP calls \fIentry_cb\fP
##          after setting \fIOB_CHANGELOG_SOURCE\fP to the source package name,
##          \fIOB_CHANGELOG_VERSION\fP to the source package version,
##          \fIOB_CHANGELOG_DISTRIBUTION\fP to the list of distributions into
##          which the package should be installed, \fIOB_CHANGELOG_CHANGES\fP to
##          the formatted heading (source package name, source package version,
##          and distributions list) and change details,
##          \fIOB_CHANGELOG_MAINTAINER\fP to the name and e-mail address of the
##          package maintainer, and \fPOB_CHANGELOG_DATE\fP to the date of
##          packaging.  \fBob_parse_changelog\fP stops parsing either at the end
##          of the \fIchangelog\fP file or when \fIentry_cb\fP returns non-zero.
## @operand file     req The file to parse, or "-" for standard input.
## @operand entry_cb req Callback to run for each entry.
## @return Returns 0 after parsing, or 125 on missing arguments.
## @stderr Prints error messages on parse errors.
## @pure maybe This function sets global variables, but they're only intended
##             for use by \fIentry_cb\fP, which is called during the lifetime of
##             this function.  Whether this function is subshell-safe in
##             practice depends on whether \fIentry_cb\fP is subshell-safe.
ob_parse_changelog()
{
	local file=
	local entry_cb=
	local line_nr=
	local line=
	local line_=
	local expect=
	local blank_lines=
	local source=
	local distribution=
	local version=
	local maintainer=
	local date=

	if [ ${#} -eq 2 ]; then
		file="${1}"
		entry_cb="${2}"
	else
		return 125
	fi

	# Parsing logic based on that of dpkg.

	line_nr=0
	expect='first_heading'

	while IFS= read line; do
		line_nr=$(($line_nr + 1))
		if [ -z "${line}" ]; then
			if [ "${expect}" = 'start_changes' ]; then
				OB_CHANGELOG_CHANGES="${OB_CHANGELOG_CHANGES}
${line}"
			elif [ "${expect}" = 'next_or_eof' ]; then
				:
			elif [ "${expect}" != 'changes_or_trailer' ]; then
				_ob_parse_changelog_error "${file}" "${line_nr}" \
					'changelog_found_blank_line' \
					"$(_ob_get_changelog_expect_str "${expect}")"
			else
				blank_lines="${blank_lines}
${line}"
			fi
		elif [ "${line# }" = "${line}" ]; then
			if [ "${expect}" != 'first_heading' -a \
					"${expect}" != 'next_or_eof' ]; then
				_ob_parse_changelog_error "${file}" "${line_nr}" \
					'changelog_found_heading' \
					"$(_ob_get_changelog_expect_str "${expect}")"
			fi
			source="${line%% (*}"
			line_="${line#* (}"
			distribution="${line_##*) }"
			line_="${line_%) *}"
			version="${line_}"
			if [ -z "${source}" -o -z "${distribution}" -o \
					-z "${version}" -o \
					"${version% *}" != "${version}" ]; then
				_ob_parse_changelog_error "${file}" "${line_nr}" \
					'changelog_bad_heading'
				OB_CHANGELOG_SOURCE=
				OB_CHANGELOG_VERSION=
				OB_CHANGELOG_DISTRIBUTION=
				OB_CHANGELOG_CHANGES=
			else
				if ! ob_validate_source_name "${source}"; then
					_ob_parse_changelog_error \
						"${file}" "${line_nr}" \
						'changelog_bad_source' "${source}"
				fi
				if ! ob_parse_version "${version}"; then
					_ob_parse_changelog_error \
						"${file}" "${line_nr}" \
						'changelog_bad_source_version' "${version}"
				fi
				OB_CHANGELOG_SOURCE="${source}"
				OB_CHANGELOG_VERSION="${version}"
				OB_CHANGELOG_DISTRIBUTION="${distribution}"
				OB_CHANGELOG_CHANGES="${line}"
			fi
			expect='start_changes'
			blank_lines=
		elif [ "${line# -- }" != "${line}" ]; then
			if [ "${expect}" != 'changes_or_trailer' ]; then
				_ob_parse_changelog_error "${file}" "${line_nr}" \
					'changelog_found_trailer' \
					"$(_ob_get_changelog_expect_str "${expect}")"
			fi
			line="${line# -- }"
			maintainer="${line%%  *}"
			date="${line#*  }"
			if [ -z "${maintainer}" -o -z "${date}" -o \
					"${maintainer}" = "${date}" ]; then
				_ob_parse_changelog_error "${file}" "${line_nr}" \
					'changelog_bad_trailer'
				OB_CHANGELOG_MAINTAINER=
				OB_CHANGELOG_DATE=
			elif [ -n "${OB_CHANGELOG_SOURCE}" ]; then
				OB_CHANGELOG_MAINTAINER="${maintainer}"
				OB_CHANGELOG_DATE="${date}"
				"${entry_cb}"
				if [ ${?} -ne 0 ]; then
					return 0
				fi
			fi
			expect='next_or_eof'
			blank_lines=
		elif [ "${line# --}" != "${line}" ]; then
			_ob_parse_changelog_error "${file}" "${line_nr}" \
				'changelog_bad_trailer'
		elif [ "${line##  }" != "${line}" ]; then
			if [ "${expect}" != 'start_changes' -a \
					"${expect}" != 'changes_or_trailer' ]; then
				_ob_parse_changelog_error "${file}" "${line_nr}" \
					'changelog_found_change' \
					"$(_ob_get_changelog_expect_str "${expect}")"
			fi
			OB_CHANGELOG_CHANGES="${OB_CHANGELOG_CHANGES}
${blank_lines}${line}"
			expect='changes_or_trailer'
			blank_lines=
		else
			_ob_parse_changelog_error "${file}" "${line_nr}" \
				'changelog_bad_line'
			blank_lines=
		fi
	done <<-EOF
		$(cat "${file}")
		EOF

	if [ "${expect}" != 'next_or_eof' ]; then
		_ob_parse_changelog_error "${file}" "${line_nr}" \
			'changelog_found_eof' \
			"$(_ob_get_changelog_expect_str "${expect}")"
	fi

	return 0
}