Products: chat command filter, request signing, saved state

Co-Authored-By: Claude Opus 5.5 <[email protected]>

internal/products/chat.go

@@ -0,0 +1,80 @@
+package products
+
+import (
+	"encoding/json"
+	"strconv"
+	"strings"
+)
+
+// outfitCommands are the chat commands whose arguments are product IDs: putting products on and taking them off.
+var outfitCommands = map[string]bool{
+	"*use": true, "*putOn": true, "*putOnOutfit": true, "*remove": true, "*takeOff": true,
+}
+
+// bodyProduct is the avatar body every full outfit starts from; a *use list with it is a whole outfit (the client
+// re-sends its outfit that way every 30 s or so).
+const bodyProduct = 80
+
+// strippedCommand is a chat line with community products taken out of its outfit command.
+type strippedCommand struct {
+	text     string  // the line to send instead
+	changed  bool    // products were taken out
+	empty    bool    // nothing is left to send
+	outfit   bool    // the line was a whole outfit (*use with the body)
+	products []int64 // the community products it named
+}
+
+// stripCommand takes products for which isCommunity is true out of an outfit command's arguments.
+func stripCommand(text string, isCommunity func(int64) bool) strippedCommand {
+	fields := strings.Fields(text)
+	if len(fields) == 0 || !outfitCommands[fields[0]] {
+		return strippedCommand{text: text}
+	}
+	r := strippedCommand{text: text}
+	kept := []string{fields[0]}
+	for _, f := range fields[1:] {
+		id, err := strconv.ParseInt(f, 10, 64)
+		if err == nil && id == bodyProduct && fields[0] == "*use" {
+			r.outfit = true
+		}
+		if err == nil && isCommunity(id) {
+			r.products = append(r.products, id)
+			continue
+		}
+		kept = append(kept, f)
+	}
+	if len(r.products) == 0 {
+		return r
+	}
+	r.changed = true
+	r.empty = len(kept) == 1
+	r.text = strings.Join(kept, " ")
+	return r
+}
+
+// chatMessage is the JSON the client sends on a chat queue's "messages" mount.
+type chatMessage struct {
+	fields map[string]json.RawMessage
+	text   string
+	userID int64
+}
+
+func parseChatMessage(b []byte) (*chatMessage, bool) {
+	var fields map[string]json.RawMessage
+	if json.Unmarshal(b, &fields) != nil {
+		return nil, false
+	}
+	m := &chatMessage{fields: fields}
+	if json.Unmarshal(fields["message"], &m.text) != nil {
+		return nil, false
+	}
+	json.Unmarshal(fields["userId"], &m.userID)
+	return m, true
+}
+
+func (m *chatMessage) withText(text string) []byte {
+	b, _ := json.Marshal(text)
+	m.fields["message"] = b
+	out, _ := json.Marshal(m.fields)
+	return out
+}