1 files changed, 150 insertions, 0 deletions
diff --git a/internal/game/exit_migrate.go b/internal/game/exit_migrate.go
new file mode 100644
index 0000000..845a6b2
--- /dev/null
+++ b/internal/game/exit_migrate.go
@@ -0,0 +1,150 @@
+package game
+
+import (
+	"strconv"
+	"strings"
+
+	"thehouseoficarus/internal/player"
+)
+
+// rewritePlayerRoomIDs remaps room-ID-embedded state in a single player per
+// idMap (oldID -> newID): discovered-exit player flag keys
+// (hidden_exit_<id>_<dir>), current RoomID, EnterSeqRoom, MapSymbols keys, and
+// Stats.RoomsVisited keys. Returns whether any field was changed.
+//
+// idMap is assumed to be a bijection (see Room.RewriteRoomIDs); the flag-key
+// and int-map rekeys use delete-all-then-set-all so a swap (A<->B) cannot
+// clobber an entry mid-rewrite.
+func rewritePlayerRoomIDs(p *player.Player, idMap map[int]int) bool {
+	if p == nil || len(idMap) == 0 {
+		return false
+	}
+	changed := false
+	if remapScalar(idMap, &p.RoomID) {
+		changed = true
+	}
+	if p.EnterSeqRoom != 0 && remapScalar(idMap, &p.EnterSeqRoom) {
+		changed = true
+	}
+	if len(p.Flags) > 0 && rewriteDiscoveredExitFlags(p.Flags, idMap) {
+		changed = true
+	}
+	if len(p.MapSymbols) > 0 && rekeyIntMap(p.MapSymbols, idMap) {
+		changed = true
+	}
+	if len(p.Stats.RoomsVisited) > 0 && rekeyIntMap(p.Stats.RoomsVisited, idMap) {
+		changed = true
+	}
+	return changed
+}
+
+func remapScalar(idMap map[int]int, n *int) bool {
+	if newID, ok := idMap[*n]; ok && newID != *n {
+		*n = newID
+		return true
+	}
+	return false
+}
+
+// rewriteDiscoveredExitFlags rewrites hidden_exit_<roomID>_<dir> flag keys,
+// remapping the embedded roomID per idMap. Flag values are preserved.
+func rewriteDiscoveredExitFlags(flags map[string]any, idMap map[int]int) bool {
+	type move struct {
+		oldKey, newKey string
+		val            any
+	}
+	var moves []move
+	for k, v := range flags {
+		if !strings.HasPrefix(k, hiddenExitFlagPrefix) {
+			continue
+		}
+		rest := k[len(hiddenExitFlagPrefix):] // "<roomID>_<dir>"
+		idx := strings.IndexByte(rest, '_')
+		if idx <= 0 {
+			continue
+		}
+		n, err := strconv.Atoi(rest[:idx])
+		if err != nil {
+			continue
+		}
+		newID, ok := idMap[n]
+		if !ok || newID == n {
+			continue
+		}
+		moves = append(moves, move{k, hiddenExitFlagPrefix + strconv.Itoa(newID) + "_" + rest[idx+1:], v})
+	}
+	if len(moves) == 0 {
+		return false
+	}
+	for _, m := range moves {
+		delete(flags, m.oldKey)
+	}
+	for _, m := range moves {
+		flags[m.newKey] = m.val
+	}
+	return true
+}
+
+// rekeyIntMap rekeys a map[int]V per idMap (oldID -> newID), preserving values.
+// Uses delete-all-then-set-all so a swap cannot clobber an entry.
+func rekeyIntMap[V any](m map[int]V, idMap map[int]int) bool {
+	type entry struct {
+		key int
+		val V
+	}
+	var saved []entry
+	for k, v := range m {
+		if newID, ok := idMap[k]; ok && newID != k {
+			saved = append(saved, entry{k, v})
+		}
+	}
+	if len(saved) == 0 {
+		return false
+	}
+	for _, e := range saved {
+		delete(m, e.key)
+	}
+	for _, e := range saved {
+		m[idMap[e.key]] = e.val
+	}
+	return true
+}
+
+// RewriteRoomIDs is the shared entry point called by every room-ID change path
+// (the swapid command and the admin web GUI rename) to migrate room-ID-embedded
+// state across all characters. Online players are updated in memory (and
+// re-saved); offline characters are loaded, rewritten, and saved. It follows
+// the same cross-goroutine mutation precedent as cmd_undig/cmd_summon.
+func (g *Game) RewriteRoomIDs(idMap map[int]int) {
+	if len(idMap) == 0 {
+		return
+	}
+	online := make(map[string]bool)
+	if g.Hub != nil {
+		for _, sess := range g.Hub.AllSessions() {
+			if sess.Player == nil {
+				continue
+			}
+			if rewritePlayerRoomIDs(sess.Player, idMap) {
+				g.AccountStore.SaveCharacter(sess.Player)
+			}
+			online[sess.Player.Name] = true
+		}
+	}
+	names, err := g.AccountStore.ListCharacterNames()
+	if err != nil {
+		return
+	}
+	for _, name := range names {
+		if online[name] {
+			continue
+		}
+		p, err := g.AccountStore.LoadCharacter(name)
+		if err != nil {
+			continue
+		}
+		if rewritePlayerRoomIDs(p, idMap) {
+			g.AccountStore.SaveCharacter(p)
+		}
+	}
+}