#!/bin/sh

set -eu

. /usr/share/sh/libopkbuild.shso.2

FIELDS="Package Source Version Architecture Platform Maintainer $(: \
	) Essential Depends Recommends Suggests Pre-Depends Conflicts $(: \
	) Provides Replaces Description Homepage"

field_package='proquivs-dummy'
field_source='proquivs-dummy'
field_version='1.0'
field_architecture='all'
field_platform='all'
field_maintainer='"J. Random Hacker" <jrandom@example.com>'
field_essential=''
field_depends=''
field_recommends=''
field_suggests=''
field_pre_depends=''
field_conflicts=''
field_provides=''
field_replaces=''
field_description='Trivial package for testing
This is a trivial package generated by proquivs.  It should not be uploaded to
the ProteanOS package archive.'
field_homepage=''

control()
{
	local ctl="${1}"
	shift 1
	local name=
	local value=

	exec 3>"${ctl}"

	cat 1>&3 <<-EOF
		#######################################################
		# Fields are commented out and set to default values. #
		# Uncomment and edit as needed.                       #
		#######################################################
		EOF

	for name in ${FIELDS}; do
		eval "value=\"\$(printf '%s' \"\${field_$(\
			printf '%s' "${name}" | tr 'A-Z-' 'a-z_')}\" | \
			sed 's/^/ /')\""
		printf '%s:%s\n' "${name}" "${value}" | sed 's/^/# /' 1>&3
	done

	exec 3>&-

	return 0
}

field_cb()
{
	local name="${1}"
	local value="${2}"
	local user_data="${3}"
	shift 3

	case " ${FIELDS} " in
		*" ${name} "*)
			;;
		*)
			return 0
			;;
	esac
	eval "field_$(printf '%s' "${name}" | tr 'A-Z-' 'a-z_')=\"\${value}\""

	return 0
}

build()
{
	local ctl="${1}"
	shift 1
	local name=
	local value=

	ob_parse_control "${ctl}" field_cb '' '' "${FIELDS}"
	if [ -n "${field_source}" ] && \
			! ob_validate_source_name "${field_source}"; then
		printf 'proquivs: Error: Invalid source name "%s"\n' \
			"${field_source}" 1>&2
		return 1
	fi
	if [ -n "${field_package}" ] && \
			! ob_validate_binary_name "${field_package}"; then
		printf 'proquivs: Error: Invalid package name "%s"\n' \
			"${field_package}" 1>&2
		return 1
	fi

	if ! mkdir 'proquivs'; then
		printf 'proquivs: Error: Failed to create package\n' 1>&2
		return 1
	fi
	cd 'proquivs'

	printf '2.0\n' 1>'format'

	exec 3>'control'
	printf 'Maintainer: %s\n' "${field_maintainer}" 1>&3
	if [ -n "${field_homepage}" ]; then
		printf 'Homepage: %s\n' "${field_homepage}" 1>&3
	fi
	exec 3>&-

	cat 1>'changelog' <<-EOF
		${field_source} (${field_version}) UNRELEASED

		  * Initial release.

		 -- ${field_maintainer}  $(LC_ALL='POSIX' \
			 date '+%a, %d %b %Y %H:%M:%S %z')
		EOF

	cat 1>'build' <<-EOF
		#!/usr/bin/make -f

		build install:
			$(printf '\t')@:
		EOF
	chmod 0755 'build'

	mkdir -- "${field_package}.pkg"

	exec 3>"${field_package}.pkg/control"
	printf 'Architecture: %s\n' "${field_architecture}" 1>&3
	printf 'Platform: %s\n' "${field_platform}" 1>&3
	for name in Essential Depends Recommends Suggests Pre-Depends \
			Conflicts Provides Replaces; do
		eval "value=\"\$(printf '%s' \"\${field_$(\
			printf '%s' "${name}" | tr 'A-Z-' 'a-z_')}\" | \
			sed 's/^/ /')\""
		if [ -n "${value}" ]; then
			printf '%s:%s\n' "${name}" "${value}" 1>&3
		fi
	done
	printf 'Description:%s\n' "$(printf '%s' "${field_description}" | \
		sed 's/^/ /')" 1>&3
	exec 3>&-

	1>"${field_package}.pkg/docs"

	if ! opkbuild -b; then
		cd '..'
		rm -Rf 'proquivs'
		printf 'proquivs: Error: Failed to create package\n' 1>&2
		return 1
	fi

	cd '..'
	rm -Rf 'proquivs'
	# Remove .changes file.  This package shouldn't be uploaded to a
	# pro-archman incoming queue.
	rm -f -- "${field_source}_${field_version}$(: \
		)_$(cat /etc/proteanos_arch)_$(cat /etc/proteanos_plat).changes"

	printf '\nproquivs: Package "%s_%s_%s_%s.opk" built\n' \
		"${field_package}" "${field_version}" \
		"${field_architecture}" "${field_platform}"

	return 0
}

usage()
{
	printf 'Usage: %s control|build <control-file>\n' "${0}"
	printf 'The "control" command writes a template to the specified '$(: \
		)'file name.\n'
	printf 'The "build" command creates a package as described in the '$(: \
		)'specified file.\n'
	return 0
}

main()
{
	local cmd=
	local ctl=

	if [ ${#} -ne 2 ]; then
		usage 1>&2
		return 1
	fi
	cmd="${1}"
	ctl="${2}"
	case "${cmd}" in
		'control' | 'build')
			;;
		*)
			return 1
			;;
	esac

	if "${cmd}" "${ctl}"; then
		return 0
	else
		return ${?}
	fi
}

main "${@}"