[type/__uci_section] Only generate UCI commands if state differs

cdist/conf/type/__uci_section/explorer/options

@@ -25,4 +25,24 @@ section=$("${__type_explorer:?}/match")
 test -n "${section}" || exit 0
 
 uci -s -N -d "${RS}" show "${section}" 2>/dev/null \
-| grep -v -e "^${section}=" || true
+| awk -v VSEP="${RS}" '
+  {
+	  # Strip off the config and section parts
+	  is_opt = sub(/^([^.]*\.){2}/, "")
+
+	  if (!is_opt) {
+		  # this line represents the section -> skip
+		  next
+	  }
+
+	  if (index($0, VSEP)) {
+		  # Put values each on a line, like --option and --list parameters
+		  opt = substr($0, 1, index($0, "=") - 1)
+		  split(substr($0, length(opt) + 2), values, VSEP)
+		  for (i in values) {
+			  printf "%s=%s\n", opt, values[i]
+		  }
+	  } else {
+		  print
+	  }
+  }'

cdist/conf/type/__uci_section/files/functions.sh

@@ -6,14 +6,6 @@ grep_line() {
 	{ shift; printf '%s\n' "$@"; } | grep -qxF "$1"
 }
 
-prefix_lines() {
-	while test $# -gt 0
-	do
-		echo "$2" | awk -v prefix="$1" '$0 { printf "%s %s\n", prefix, $0 }'
-		shift; shift
-	done
-}
-
 print_errors() {
 	awk -v prefix="${1:-Found errors:}" -v suffix="${2-}" '
 		BEGIN {

cdist/conf/type/__uci_section/files/option_state.awk

@@ -0,0 +1,91 @@
+# -*- mode: awk; indent-tabs-mode:t -*-
+# Usage: awk -f option_state.awk option_type option_name
+# e.g. awk -f option_state.awk option title
+#      awk -f option_state.awk list entry
+
+function unquote(s) {
+	# simplified dequoting of single quoted strings
+	if (s ~ /^'.*'$/) {
+		s = substr(s, 2, length(s) - 2)
+		sub(/'\\''/, "'", s)
+	}
+	return s
+}
+
+function valueof(line) {
+	if (line !~ /^[[:alpha:]_]+=/) return 0
+	return unquote(substr(line, index(line, "=") + 1))
+}
+
+BEGIN {
+	__object = ENVIRON["__object"]
+	if (!__object) exit 1
+
+	opttype = ARGV[1]
+	optname = ARGV[2]
+
+	if (opttype !~ /^(option|list)/ || !optname) {
+		print "invalid"
+		exit (e=1)
+	}
+
+	ARGV[1] = __object "/parameter/" opttype
+	ARGV[2] = __object "/explorer/options"
+
+	state = "present"
+}
+
+NR == FNR {
+	# memoize "should" state
+	if (index($0, optname "=") == 1) {
+		should[++should_count] = valueof($0)
+	}
+
+	# go to next line (important!)
+	next
+}
+
+{
+	# compare "is" state
+	if (index($0, optname "=") != 1)
+		next
+	++is_count
+
+	v = valueof($0)
+
+	if (v == should[is_count]) {
+		# looks good, but can't say definitely just from this line
+	} else if (is_count > should_count) {
+		# there are more "is" records than "should" -> definitely different
+		state = "different"
+		exit
+	} else {
+		# see if we can find the "is" value somewhere in "should"
+		for (i in should) {
+			if (v == should[i]) {
+				# value found -> could be rearranged
+				# FIXME: Duplicate values are not properly handled here. Do they matter?
+				state = "rearranged"
+				next
+			}
+		}
+
+		# "is" value could not be found in "should" -> definitely different
+		state = "different"
+		exit
+	}
+}
+
+END {
+	if (e) exit
+
+	if (!is_count) {
+		# no "is" values -> absent
+		state = "absent"
+	} else if (is_count < should_count) {
+		# "is" was shorter than "should" -> different
+		state = "different"
+	}
+
+	print state
+}

cdist/conf/type/__uci_section/gencode-remote

@@ -70,7 +70,8 @@ in
 		fi
 
 		# Make sure the section itself is present
-		if test "${state_is}" = absent
+		if test "${state_is}" = absent \
+			|| test "${type_is}" != "${type_should#*.}"
 		then
 			printf 'set %s\n' "${section}" >>"${__messages_out:?}"
 			# shellcheck disable=SC2140
@@ -78,7 +79,7 @@ in
 		fi
 
 		# Delete options/lists not in "should"
-		sed -e 's/=.*$//;s/^.*\.//' "${__object:?}/explorer/options" \
+		sed -e 's/=.*$//' "${__object:?}/explorer/options" \
 		| while read -r _optname
 		  do
 			  grep_line "${_optname}" "${listnames_should}" "${optnames_should}" || {
@@ -87,18 +88,55 @@ in
 			  } </dev/null
 		  done
 
-		# Set "should" options
-		prefix_lines option "${optnames_should}" list "${listnames_should}" \
-		| while read -r _type _optname
-		  do
-			  test -n "${_type}${_optname}" || continue  # ignore empty lines
+		opt_proc_error() {
+			printf 'An error occurred during processing of option %s\n' "${1:?}" >&2
+			exit 1
+		}
 
-			  case $_type
+		# Set "should" options
+		echo "${optnames_should}" \
+		| grep -e . \
+		| while read -r _optname
+		  do
+			  _opt_state=$(awk -f "${__type:?}/files/option_state.awk" option "${_optname}") \
+				  || opt_proc_error "${_optname}"
+			  case ${_opt_state}
 			  in
-				  (list)
+				  (invalid)
+					  opt_proc_error "${_optname}"
+					  ;;
+				  (present)
+					  ;;
+				  (*)
+					  printf 'set %s\n' "${section}.${_optname}" >>"${__messages_out:?}"
+
+					  # shellcheck disable=SC2140
+					  uci_cmd set "${section}.${_optname}"="$(
+						  grep -e "^${_optname}=" "${__object:?}/parameter/option" \
+						  | sed -e 's/^.*=//' \
+						  | unquote_lines \
+						  | head -n 1)"
+					  ;;
+			  esac
+		  done
+
+		echo "${listnames_should}" \
+		| grep -e . \
+		| while read -r _optname
+		  do
+			  _list_state=$(awk -f "${__type:?}/files/option_state.awk" list "${_optname}") \
+				  || opt_proc_error "${_optname}"
+			  case ${_list_state}
+			  in
+				  (invalid)
+					  opt_proc_error "${_optname}"
+					  ;;
+				  (present)
+					  ;;
+				  (*)
 					  printf 'set_list %s\n' "${section}.${_optname}" >>"${__messages_out:?}"
 
-					  if grep -q -e "^${_optname}=" "${__object:?}/explorer/options"
+					  if test "${_list_state}" != absent
 					  then
 						  uci_cmd delete "${section}.${_optname}"
 					  fi
@@ -112,16 +150,6 @@ in
 						    uci_cmd add_list "${section}.${_optname}"="${_value}"
 					    done
 					  ;;
-				  (option)
-					  printf 'set %s\n' "${section}.${_optname}" >>"${__messages_out:?}"
-
-					  # shellcheck disable=SC2140
-					  uci_cmd set "${section}.${_optname}"="$(
-						  grep "^${_optname}=" "${__object:?}/parameter/option" \
-						  | sed -e 's/^.*=//' \
-						  | unquote_lines \
-						  | head -n 1)"
-					  ;;
 			  esac
 		  done
 		;;