#!/bin/sh -e

CONF_PATH=/etc/dma  # set in Makefile

# Determine mailname
if test -f "${__object}/parameter/mailname"
then
	mailname=$(cat "${__object}/parameter/mailname")
else
	case $(cat "${__global}/explorer/os")
	in
		(debian|devuan|ubuntu)
			# On Debian-like systems use /etc/mailname unless --mailname is used
			mailname='/etc/mailname'
			;;
		(*)
			mailname=$__target_fqdn
			;;
	esac
fi


# Generate config
conf_should=$(
	if test -s "${__object}/parameter/smart-host"
	then
		printf 'SMARTHOST %s\n' "$(cat "${__object}/parameter/smart-host")"
	fi

	printf 'MAILNAME %s\n' "${mailname}"

	if test -s "${__object}/explorer/auth_conf"
	then
		printf "AUTHPATH %s\n" "$(cat "${__object}/explorer/auth_conf")"
	fi

	case $(cat "${__object}/parameter/security")
	in
		(ssl|tls)
			default_smtp_port=465
			echo 'SECURETRANSFER'
			;;
		(starttls)
			default_smtp_port=587
			echo 'SECURETRANSFER'
			echo 'STARTTLS'
			;;
		(opportunistic)
			default_smtp_port=25  # XXX: correct?
			echo 'SECURETRANSFER'
			echo 'STARTTLS'
			echo 'OPPORTUNISTIC_TLS'
			;;
		(insecure)
			default_smtp_port=25
			echo 'INSECURE'
			;;
	esac

	if test -s "${__object}/parameter/port"
	then
		printf 'PORT %u\n' "$(cat "${__object}/parameter/port")"
	elif test "${default_smtp_port}" -ne 25
	then
		printf 'PORT %u\n' "${default_smtp_port}"
	fi

	if test -f "${__object}/parameter/masquerade"
	then
		while read -r line
		do
			printf 'MASQUERADE %s\n' "${line}"
		done <"${__object}/parameter/masquerade"
	fi

	if test -f "${__object}/parameter/defer"
	then
		echo 'DEFER'
	fi

	if test -f "${__object}/parameter/full-bounce"
	then
		echo 'FULLBOUNCE'
	fi

	if test -f "${__object}/parameter/null-client"
	then
		test -s "${__object}/parameter/smart-host" || {
			echo '--null-client requires a --smart-host to be defined' >&2
			exit 1
		}

		echo 'NULLCLIENT'
	fi
)
conf_should=$(echo "$conf_should" | sort -s -k 1,1)

config_updated=false
if ! echo "$conf_should" | cmp -s "${__object}/explorer/conf" -
then
	# config needs to be updated
	echo "dma_conf='${CONF_PATH:?}/dma.conf'"
	cat <<'EOF'
awk -F '\n' '
function comment_line(line) { return match(line, /^[ \t]*#+[ \t]*/) }
function empty_line(line) { return match(line, /^[ \t]*$/) }
function is_word(s) { return s ~ /^[A-Z_]+$/ }

function first(line, sep) {
	if (!sep) sep = SUBSEP
	return index(line, sep) ? substr(line, 1, index(line, sep) - 1) : line
}

function rest(line, sep) {
	if (!sep) sep = SUBSEP
	if (index(line, sep))
		return substr(line, index(line, sep) + 1)
}

function conf_pop(word, value) {
	if (!(word in conf)) return 0
	if (!value) {
		if (index(conf[word], SUBSEP))  # more than one element?
			value = substr(conf[word], 1, index(conf[word], SUBSEP) - 1)
		else
			value = conf[word]
	}

	if (index(conf[word], SUBSEP)) {
		if (index(conf[word], value SUBSEP) != 1) return 0
		conf[word] = substr(conf[word], length(value) + 2)
	} else {
		if (conf[word] != value) return 0
		delete conf[word]
	}
	return value
}

function print_conf(word, value) {
	printf "%s", word
	if (value) printf " %s", value
	printf "\n"
}

function print_confs(word,    value) {
	if (!(word in conf)) return
	if (conf[word]) {
		while (value = conf_pop(word))
			print_conf(word, value)
	} else {
		print_conf(word)
		delete conf[word]
	}
}

BEGIN {
	while (getline < "/dev/stdin") {
		word = first($0, " ")
		if ((word in conf))
			conf[word] = conf[word] SUBSEP rest($0, " ")
		else
			conf[word] = rest($0, " ")
	}
}

# first pass, gather information
NR == FNR {
	if (comment_line($0)) {
		# comment line
		word = first(substr($0, RLENGTH + 1), " ")
		if (is_word(word)) last_occ["#" word] = FNR
	} else {
		word = first($0, " ")
		if (is_word(word)) last_occ[word] = FNR
	}
}

NR > FNR && FNR == 1 {
	# before second pass prepare hashes

	for (k in last_occ)
		if (k ~ /^\#/ && (substr(k, 2) in last_occ))
			delete last_occ[k]

	for (k in last_occ) {
		line_map[last_occ[k]] = k
	}
}

# second pass, output new config
NR > FNR {
	if (comment_line($0) || empty_line($0)) {
		# comment or empty line
		print

		if ((FNR in line_map)) {
			if (line_map[FNR] ~ /^\#/) {
				# the "matching" comment line is here
				k = substr(line_map[FNR], 2)
				if ((k in conf)) print_confs(k)
			}

			if (("INSECURE" in conf) && line_map[FNR] ~ /^\#?SECURE$/) {
				# INSECURE goes where SECURE comment is
				print_confs("INSECURE")
			}
		}
	} else {
		sub(/[ \t]*\#.*$/, "", $0)  # ignore comments
		word = first($0, " ")

		if ((word in conf) && rest($0, " ") == first(conf[word])) {
			# keep config options we want
			conf_pop(word)
			print
		}

		if ((FNR in line_map) && line_map[FNR] == word) {
			# rest of config options should be here
			print_confs(word)
		}
	}
}

END {
	# print rest of config options
	for (word in conf) print_confs(word)
}
' "${dma_conf}" "${dma_conf}" <<'EOF' >"${dma_conf}.tmp" \
 && mv "${dma_conf}.tmp" "${dma_conf}"
EOF
	echo "${conf_should}"
	echo 'EOF'

	config_updated=true
	echo 'config updated' >>"${__messages_out}"
fi


if test -f "${__object}/parameter/send-test-email"
then
	modified=false

	if grep -q '^__mail_alias/root:' "${__messages_in}"
	then
		modified=true
	elif grep -q '^__dma_auth/' "${__messages_in}"
	then
		modified=true
	elif $config_updated
	then
		modified=true
	fi

	if $modified
	then
		cat <<-EOF
		sendmail root <<EOM
		Subject: [cdist] Test mail from '${__target_fqdn}'

		Hi,

		you can ignore this message.
		Its sole purpose is to notify you that root mail on ${__target_fqdn}
		will be redirected to you.

		Enjoy!
		EOM
		EOF
	fi
fi