Resume interrupted editor co-op runs

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

server/src/netplay.rs

@@ -9,6 +9,8 @@
 //   {"t":"create","sides":[0,2,3,4]?,"map_w":96?,"map_h":128?,"difficulty":1?,"mission":12?,"doc":{..}?}
 //                                                  -> "doc": an editor campaign (CampaignDoc JSON) for a co-op
 //                                                     match of its mission "mission"; it goes along with "start"
+//                                                     "seed":77?,"carry":[..]? with a doc: an interrupted run goes
+//                                                     on - "start" then has this seed, the carry and "resume":true
 //   {"t":"join","code":"ABC123"}
 //   {"t":"take_side","side":2}
 //   {"t":"ready","ready":true}
@@ -85,6 +87,7 @@ struct Room {
     difficulty: u8,
     mission: Option<usize>,
     doc: Option<Value>, // editor campaign of a co-op match (sent to every client at the start)
+    resume: Option<(u32, Value)>, // a resumed editor campaign run: its seed and what the masters carry
 }
 
 #[derive(Debug)]
@@ -358,6 +361,10 @@ impl Netplay {
         let difficulty = msg.get("difficulty").and_then(|v| v.as_u64()).unwrap_or(1).clamp(0, 2) as u8;
         let mission = mission_of(msg.get("mission"));
         let doc = msg.get("doc").filter(|d| !d.is_null()).cloned();
+        let resume = match (&doc, msg.get("seed").and_then(|v| v.as_u64())) {
+            (Some(_), Some(seed)) => Some((seed as u32, msg.get("carry").filter(|c| c.is_array()).cloned().unwrap_or_else(|| json!([])))),
+            _ => None,
+        };
         match &doc {
             Some(d) => {
                 let count = d.get("missions").and_then(|m| m.as_array()).map_or(0, |m| m.len());
@@ -375,7 +382,7 @@ impl Netplay {
         }
         let name = self.clients.get(&conn).map(|c| c.name.clone()).unwrap_or_else(|| "Guest".into());
         let seats = sides.iter().map(|s| (*s, new_seat(*s, false))).collect::<HashMap<_, _>>();
-        let room = Room { code: code.clone(), sides, seats, pending: HashMap::new(), turn: 0, started: false, paused: false, missing: false, seed: None, map_w, map_h, difficulty, mission, doc };
+        let room = Room { code: code.clone(), sides, seats, pending: HashMap::new(), turn: 0, started: false, paused: false, missing: false, seed: None, map_w, map_h, difficulty, mission, doc, resume };
         self.rooms.insert(code.clone(), room);
         if let Some(c) = self.clients.get_mut(&conn) {
             c.room = Some(code.clone());
@@ -630,7 +637,7 @@ impl Netplay {
             r.started = true;
             r.paused = false;
             r.missing = false;
-            r.seed = Some(random_seed());
+            r.seed = Some(r.resume.as_ref().map_or_else(random_seed, |x| x.0));
             r.turn = 0;
             r.sides = active;
         }
@@ -640,6 +647,10 @@ impl Netplay {
                 if let Some(doc) = &r.doc {
                     m["doc"] = doc.clone();
                 }
+                if let Some((_, carry)) = &r.resume {
+                    m["carry"] = carry.clone();
+                    m["resume"] = json!(true);
+                }
                 m
             }
             None => return,
@@ -971,6 +982,22 @@ mod tests {
         assert_eq!(start_red["mission"].as_u64(), Some(2));
     }
 
+    #[test]
+    fn a_resumed_run_starts_with_its_seed_and_carry() {
+        let mut net = Netplay::new();
+        let (tx, mut rx) = mpsc::unbounded_channel();
+        let red = net.connect(tx, Some("red".into()), None);
+        let doc = json!({"format":"dungeoncraft-campaign","name":"Mine","missions":[{"key":"a","title":"First"},{"key":"b","title":"Second","size":[96,96]}]});
+        let carry = json!([[0, {"gold": 100.0, "creatures": []}]]);
+        net.handle(red, json!({"t":"create","sides":[0,2],"mission":1,"doc":doc,"seed":4242,"carry":carry}));
+        net.handle(red, json!({"t":"ready"}));
+        net.handle(red, json!({"t":"start"}));
+        let start = until(&mut rx, "start");
+        assert_eq!(start["seed"].as_u64(), Some(4242));
+        assert_eq!(start["carry"], carry);
+        assert_eq!(start["resume"].as_bool(), Some(true));
+    }
+
     #[test]
     fn an_editor_campaign_goes_from_the_create_to_every_start() {
         let mut net = Netplay::new();