1 files changed, 82 insertions, 0 deletions
diff --git a/src/systems/exchange.rs b/src/systems/exchange.rs
new file mode 100644
index 0000000..9931bdd
--- /dev/null
+++ b/src/systems/exchange.rs
@@ -0,0 +1,82 @@
+
+use specs::{
+	Entities,
+	ReadStorage,
+	WriteStorage,
+	System,
+	Join,
+	Read,
+	Write
+};
+
+use crate::{
+	components::{
+		Controller,
+		Position,
+		Exchanger,
+		Notification,
+		Ear,
+		Inventory,
+		Visible
+	},
+	controls::{Control},
+	resources::{Ground, NewEntities},
+	util::strip_prefix
+};
+
+pub struct Exchange;
+impl <'a> System<'a> for Exchange {
+	type SystemData = (
+		Entities<'a>,
+		ReadStorage<'a, Controller>,
+		ReadStorage<'a, Position>,
+		Read<'a, Ground>,
+		ReadStorage<'a, Exchanger>,
+		Write<'a, NewEntities>,
+		WriteStorage<'a, Ear>,
+		WriteStorage<'a, Inventory>,
+		ReadStorage<'a, Visible>
+	);
+	
+	fn run(&mut self, (entities, controllers, positions, ground, exchangers, new, mut ears, mut inventories, visibles): Self::SystemData) {
+		for (actor, controller, position) in (&entities, &controllers, &positions).join(){
+			let ear = ears.get_mut(actor);
+			match &controller.control {
+				Control::Interact(directions, arg) => {
+					for (ent, exchanger) in ground.components_near(position.pos, directions, &exchangers) {
+						let prefix = exchanger.prefix.as_str();
+						let name = visibles.get(ent).map(|v| v.name.as_str());
+						if let Some(txt) = arg {
+							if let (Some(inventory), Some(action)) = (inventories.get_mut(actor), strip_prefix(&txt, prefix)) {
+								if let Some(exchange) = exchanger.exchanges.get(action) {
+									if exchange.can_trade(inventory){
+										exchange.trade(inventory, &new.encyclopedia);
+										say(ear, format!("Success! '{}' ({})", txt, exchange.show()), name);
+									} else {
+										say(ear, format!("You do not have the required items or inventory space for '{}' ({})", txt, exchange.show()), name);
+									}
+								} else {
+									say(ear, format!("Invalid option: {}", action), name);
+								}
+							break;
+							}
+						} else if let Some(ear) = ear {
+							ear.sounds.push(Notification::Options{
+								description: "".to_string(),
+								options: exchanger.exchanges.iter().map(|(id, exchange)| (format!("{}{}", prefix, id), exchange.show())).collect()
+							});
+							break;
+						}
+					}
+				}
+				_ => {}
+			}
+		}
+	}
+}
+
+fn say(maybe_ear: Option<&mut Ear>, text: String, source: Option<&str>){
+	if let Some(ear) = maybe_ear {
+		ear.sounds.push(Notification::Sound{text, source: source.map(|s| s.to_string())});
+	}
+}