1 files changed, 46 insertions, 0 deletions
diff --git a/src/systems/replace.rs b/src/systems/replace.rs
new file mode 100644
index 0000000..4ed516b
--- /dev/null
+++ b/src/systems/replace.rs
@@ -0,0 +1,46 @@
+
+use specs::{
+	ReadStorage,
+	System,
+	Join,
+	Write,
+	WriteStorage,
+	Entities
+};
+
+use crate::{
+	components::{
+		Position,
+		Substitute,
+		Removed,
+		Serialise
+	},
+	resources::{NewEntities}
+};
+
+
+pub struct Replace;
+impl <'a> System<'a> for Replace {
+	type SystemData = (
+		Entities<'a>,
+		ReadStorage<'a, Position>,
+		Write<'a, NewEntities>,
+		ReadStorage<'a, Substitute>,
+		WriteStorage<'a, Removed>,
+		ReadStorage<'a, Serialise>
+	);
+	
+	fn run(&mut self, (entities, positions, mut new, substitutes, mut removeds, serialisations): Self::SystemData) {
+		for (entity, position, substitute, serialisation) in (&entities, &positions, &substitutes, (&serialisations).maybe()).join(){
+			// todo: better error handling
+			let mut template = substitute.into.clone();
+			if let Some(serialise) = serialisation {
+				// todo: extraction?
+				template = template.merge(serialise.template.clone());
+			}
+			let preent = new.encyclopedia.construct(&template).unwrap();
+			new.to_build.push((position.pos, preent));
+			removeds.insert(entity, Removed).unwrap();
+		}
+	}
+}