fix: disconnect race, rename ownership, reserved pickup, economy recovery retry/refund semantics

1 files changed, 51 insertions, 8 deletions

diff --git a/internal/world/ground.go b/internal/world/ground.go
index 879cc71..2d5ea7b 100644
--- a/internal/world/ground.go
+++ b/internal/world/ground.go
@@ -87,23 +87,47 @@ func (w *World) AddGroundItem(roomID int, itemID string, qty int) {
 	w.groundItems[roomID] = append(w.groundItems[roomID], e)
 }
 
+// RemoveReservedItem removes up to qty of itemID from the room's ground,
+// refusing entries reserved for another player. It is ALL-OR-NOTHING:
+// when any part of the quantity is unobtainable (a reserved-for-others
+// entry, or too little accessible stock) nothing is taken and (0, false)
+// is returned. Callers must never lose already-removed items to a failed
+// pickup, so the removal is verified before any state is touched.
 func (w *World) RemoveReservedItem(roomID int, itemID string, qty int, owner string) (int, bool) {
 	w.mu.Lock()
 	defer w.mu.Unlock()
-	removed := 0
-	remaining := qty
-	for _, e := range w.groundItems[roomID] {
-		if remaining <= 0 {
+	entries := w.groundItems[roomID]
+
+	// Pass 1: verify the full quantity is takable by this owner without
+	// mutating anything, so a blocked pickup can never leave the ground
+	// half-emptied with nothing delivered.
+	available := 0
+	for _, e := range entries {
+		if available >= qty {
 			break
 		}
-		if !strings.EqualFold(e.itemID, itemID) {
+		if e.quantity <= 0 || !strings.EqualFold(e.itemID, itemID) {
 			continue
 		}
-		if e.quantity <= 0 {
+		if e.reserveTimer > 0 && e.reservedFor != "" && e.reservedFor != owner {
 			continue
 		}
-		if e.reserveTimer > 0 && e.reservedFor != "" && e.reservedFor != owner {
-			return removed, false
+		available += e.quantity
+	}
+	if available < qty {
+		return 0, false
+	}
+
+	// Pass 2: take. Every entry reachable here is takeable, so no
+	// mid-loop abort is possible.
+	removed := 0
+	remaining := qty
+	for _, e := range entries {
+		if remaining <= 0 {
+			break
+		}
+		if e.quantity <= 0 || !strings.EqualFold(e.itemID, itemID) {
+			continue
 		}
 		take := e.quantity
 		if take > remaining {
@@ -119,6 +143,25 @@ func (w *World) RemoveReservedItem(roomID int, itemID string, qty int, owner str
 	return removed, true
 }
 
+// AccessibleGround returns the ground items in roomID this owner may take:
+// entries reserved for another player are excluded. Pickup flows use this
+// to size requests and match names against takeable stock only.
+func (w *World) AccessibleGround(roomID int, owner string) map[string]int {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+	out := make(map[string]int)
+	for _, e := range w.groundItems[roomID] {
+		if e.quantity <= 0 {
+			continue
+		}
+		if e.reserveTimer > 0 && e.reservedFor != "" && e.reservedFor != owner {
+			continue
+		}
+		out[e.itemID] += e.quantity
+	}
+	return out
+}
+
 func (w *World) RemoveGroundItem(roomID int, itemID string, qty int) int {
 	w.mu.Lock()
 	defer w.mu.Unlock()