index_state_to_string
state = index_state_to_string(zones, zones->index_state);
target = (zones->changing ? index_state_to_string(zones, zones->index_target) : NULL);
old_state = index_state_to_string(zones, zones->index_target);
new_state = index_state_to_string(zones, zones->index_target);
state = index_state_to_string(zones, zones->index_state);