dconf

# DConf
#
# Copyright (C) 2021 Rodrigo Silva (MestreLion) <linux@rodrigosilva.com>
# License: GPLv3 or later. See <http://www.gnu.org/licenses/gpl.html>

include gvariant

# Wrapper to dconf, automatically invoking setup_run on write and load,
# and dispatching to extra commands
dconf() {
	cmd=$1
	shift
	case "$cmd" in
	load  ) ;&
	write ) setup_run command dconf "$cmd" "$@";;
	swrite) dconf_write_string "$@";;
	sread ) dconf_read_string  "$@";;
	array ) dconf_array "$@";;
	*     ) command dconf "$cmd" "$@";;
	esac
}

dconf_write_string() {
	local key=$1
	local value=$2
	dconf write "$key" "$(gvariant_quote "$value")"
}

dconf_read_string() {
	local key=$1
	gvariant_unquote "$(dconf read "$key")"
}

dconf_array() {
	local op=$1      # Operation to perform: include, remove, clear/new, set
	local key=$2     # Full path of the DConf key
	local type=$3    # List item type. See gvariant_array()
	shift 3          # Remaining arguments are list items

	# This is a LOT trickier than using gsettings, as dconf:
	# - Does not set exit status on any error, missing keys, etc
	# - Does not return the default value if key is not set, unless -d
	#   (and -d return the default value regardless if a value is set)
	# - And even that default value is useless: the dconf default value is
	#   NOT the same as the gsettings default value from schema, which is the
	#   one that really matters, so dconf default is usually not set either.

	# DConf prints '@as []' on empty lists, and nothing on keys not set
	local list; list=$(dconf read "$key")

	# If not set, try the dconf default value
	if [[ -z "$list" ]]; then list=$(dconf read -d "$key"); fi

	# If default is empty (or unset), try via gsettings
	if [[ -z "$list" ]]; then
		local path=${key%/*}
		local leaf=${key##*/}
		local schema; schema=$(
			gsettings list-schemas --print-paths |
			grep -iF "$path" | cut -f1 -d' ' || true
		)
		if [[ "$schema" ]]; then
			list=$(gsettings get "$schema" "$leaf")
		fi
	fi

	# If still empty, format it.
	if [[ -z "$list" ]]; then list="@a${type} []"; fi

	list=$(gvariant_array "$op" "$type" "$list" "$@")
	dconf write "$key" "$list"
}