adventure: send Pete the fog-of-war zone map beside the room count

internal/plugin/pete_roster.go

@@ -400,6 +400,7 @@ func buildRosterSnapshot(now time.Time, euro *EuroPlugin) (peteclient.RosterSnap
 				if exp.RunID != "" {
 					if run, rerr := getZoneRun(exp.RunID); rerr == nil && run != nil && run.TotalRooms > 0 {
 						e.Detail.Room = fmt.Sprintf("%d / %d", run.CurrentRoom+1, run.TotalRooms)
+						e.Detail.Map = buildRosterMap(run)
 					}
 				}
 			}
@@ -413,6 +414,71 @@ func buildRosterSnapshot(now time.Time, euro *EuroPlugin) (peteclient.RosterSnap
 	return snap, nil
 }
 
+// buildRosterMap computes the fog-of-war cut of a run's zone graph for the
+// public roster. It sends every visited node with its true kind, plus the
+// one-hop frontier — the destinations of edges leading out of visited nodes,
+// with their kind withheld as "unknown". Edges are directed and stored by
+// from-node, so "one hop out of a visited node" is exactly g.Edges[visited].
+// A frontier node's edges are NOT walked, so nothing past the first closed
+// door reaches the wire — "view source to find the boss room" is not fog of
+// war. Node Label/Content never leave the game box.
+//
+// Output order is deterministic (visited-path order, then frontier in
+// discovery order) so an unchanged run produces a byte-identical snapshot and
+// the roster push does not churn.
+func buildRosterMap(run *DungeonRun) *peteclient.RosterMap {
+	g, ok := loadZoneGraph(run.ZoneID)
+	if !ok || len(run.VisitedNodes) == 0 {
+		return nil
+	}
+
+	// Unique visited nodes in path order — VisitedNodes repeats on backtrack.
+	orderedVisited := make([]string, 0, len(run.VisitedNodes))
+	seen := make(map[string]bool, len(run.VisitedNodes))
+	for _, id := range run.VisitedNodes {
+		if !seen[id] {
+			seen[id] = true
+			orderedVisited = append(orderedVisited, id)
+		}
+	}
+
+	m := &peteclient.RosterMap{
+		ZoneID:      string(run.ZoneID),
+		CurrentNode: run.CurrentNode,
+		Visited:     orderedVisited,
+	}
+
+	// Visited nodes first, in path order, with their real kind.
+	emitted := make(map[string]bool, len(orderedVisited))
+	for _, id := range orderedVisited {
+		emitted[id] = true
+		if n, ok := g.Nodes[id]; ok {
+			m.Nodes = append(m.Nodes, peteclient.RosterMapNode{ID: id, Kind: string(n.Kind)})
+		}
+	}
+
+	// Frontier: destinations of edges out of visited nodes, kind withheld.
+	// Walk visited in path order so the frontier order is stable.
+	for _, from := range orderedVisited {
+		for _, edge := range g.Edges[from] {
+			lock := edge.Lock
+			if lock == LockNone {
+				lock = "" // an open door needs no mark; omitempty drops it
+			}
+			m.Edges = append(m.Edges, peteclient.RosterMapEdge{
+				From: edge.From,
+				To:   edge.To,
+				Lock: string(lock),
+			})
+			if !seen[edge.To] && !emitted[edge.To] {
+				emitted[edge.To] = true
+				m.Nodes = append(m.Nodes, peteclient.RosterMapNode{ID: edge.To, Kind: "unknown"})
+			}
+		}
+	}
+	return m
+}
+
 // resolveRosterToken maps a board token back to the adventurer it names. The
 // token is a one-way HMAC (eventToken), so it can't be inverted — instead we
 // recompute every live player's token and match. The salt is DB-persisted, so a

internal/plugin/pete_roster_map_test.go

@@ -0,0 +1,137 @@
+package plugin
+
+import (
+	"testing"
+)
+
+// mapFixtureGraph registers a small branching graph and returns a cleanup.
+//
+//	n1(entry) --none--------> n2(exploration) --key_required--> n4(boss)
+//	   \--perception_check--> n3(trap) ------------------------/
+//
+// n4 is reachable two ways; the validator wants a single entry and a reachable
+// boss, which this satisfies.
+func mapFixtureGraph(t *testing.T) ZoneID {
+	t.Helper()
+	const zid ZoneID = "map_test_zone"
+	g := ZoneGraph{
+		ZoneID: zid,
+		Entry:  "n1",
+		Boss:   "n4",
+		Nodes: map[string]ZoneNode{
+			"n1": {NodeID: "n1", ZoneID: zid, Kind: NodeKindEntry, IsEntry: true, Label: "The Gate"},
+			"n2": {NodeID: "n2", ZoneID: zid, Kind: NodeKindExploration, Label: "Dusty Hall"},
+			"n3": {NodeID: "n3", ZoneID: zid, Kind: NodeKindTrap, Label: "Spiked Pit"},
+			"n4": {NodeID: "n4", ZoneID: zid, Kind: NodeKindBoss, IsBoss: true, Label: "Throne of Bone"},
+		},
+		Edges: map[string][]ZoneEdge{
+			"n1": {
+				{From: "n1", To: "n2", Lock: LockNone, Weight: 1},
+				{From: "n1", To: "n3", Lock: LockPerception, Weight: 1},
+			},
+			"n2": {{From: "n2", To: "n4", Lock: LockKey, Weight: 1}},
+			"n3": {{From: "n3", To: "n4", Lock: LockNone, Weight: 1}},
+		},
+	}
+	registerZoneGraph(g)
+	t.Cleanup(func() { delete(zoneGraphRegistry, zid) })
+	return zid
+}
+
+func TestBuildRosterMap_FogOfWar(t *testing.T) {
+	zid := mapFixtureGraph(t)
+	run := &DungeonRun{
+		ZoneID:       zid,
+		CurrentNode:  "n2",
+		VisitedNodes: []string{"n1", "n2"},
+		TotalRooms:   4,
+	}
+	m := buildRosterMap(run)
+	if m == nil {
+		t.Fatal("buildRosterMap returned nil for a visited run")
+	}
+	if m.ZoneID != string(zid) || m.CurrentNode != "n2" {
+		t.Fatalf("header wrong: %+v", m)
+	}
+
+	kinds := map[string]string{}
+	for _, n := range m.Nodes {
+		if _, dup := kinds[n.ID]; dup {
+			t.Errorf("node %q emitted twice", n.ID)
+		}
+		kinds[n.ID] = n.Kind
+	}
+
+	// Visited nodes carry their true kind.
+	if kinds["n1"] != "entry" || kinds["n2"] != "exploration" {
+		t.Errorf("visited kinds wrong: %v", kinds)
+	}
+	// Frontier nodes are present but their kind is withheld.
+	if kinds["n3"] != "unknown" {
+		t.Errorf("n3 is one hop out of n1 and must be unknown, got %q", kinds["n3"])
+	}
+	if kinds["n4"] != "unknown" {
+		t.Errorf("n4 (the boss) is one hop out of n2 and must be unknown, got %q", kinds["n4"])
+	}
+
+	// The map must never leak a room the player has not reached a door to.
+	// n4 is a real boss node, but reachable only as frontier — its kind stays
+	// hidden. A node past a frontier door (there is none deeper here) must not
+	// appear at all; assert exactly four nodes.
+	if len(m.Nodes) != 4 {
+		t.Fatalf("want 4 nodes (2 visited + 2 frontier), got %d: %+v", len(m.Nodes), m.Nodes)
+	}
+
+	// Edges out of visited nodes only. n3->n4 must NOT appear: n3 is frontier,
+	// not visited, so walking its doors would leak structure past the fog.
+	var edgeKeys []string
+	for _, e := range m.Edges {
+		edgeKeys = append(edgeKeys, e.From+"->"+e.To+":"+e.Lock)
+	}
+	want := map[string]bool{
+		"n1->n2:":                 true, // LockNone dropped to ""
+		"n1->n3:perception_check": true,
+		"n2->n4:key_required":     true,
+	}
+	if len(edgeKeys) != len(want) {
+		t.Fatalf("want %d edges, got %v", len(want), edgeKeys)
+	}
+	for _, k := range edgeKeys {
+		if !want[k] {
+			t.Errorf("unexpected edge %q (n3->n4 would be a fog leak)", k)
+		}
+	}
+}
+
+func TestBuildRosterMap_EmptyRunIsNil(t *testing.T) {
+	zid := mapFixtureGraph(t)
+	// A run that has visited nothing yet has no map to show.
+	if m := buildRosterMap(&DungeonRun{ZoneID: zid}); m != nil {
+		t.Errorf("empty VisitedNodes should yield nil, got %+v", m)
+	}
+	// An unknown zone (no graph, no legacy fallback row) yields nil, not a panic.
+	if m := buildRosterMap(&DungeonRun{ZoneID: "no_such_zone", VisitedNodes: []string{"x"}}); m != nil {
+		t.Errorf("unknown zone should yield nil, got %+v", m)
+	}
+}
+
+func TestBuildRosterMap_BacktrackDedup(t *testing.T) {
+	zid := mapFixtureGraph(t)
+	// VisitedNodes is an ordered set that repeats on backtrack: n1,n2,n1.
+	run := &DungeonRun{
+		ZoneID:       zid,
+		CurrentNode:  "n1",
+		VisitedNodes: []string{"n1", "n2", "n1"},
+	}
+	m := buildRosterMap(run)
+	seen := map[string]int{}
+	for _, n := range m.Nodes {
+		seen[n.ID]++
+	}
+	if seen["n1"] != 1 {
+		t.Errorf("backtracked node n1 emitted %d times, want 1", seen["n1"])
+	}
+	if len(m.Visited) != 2 {
+		t.Errorf("Visited should dedup to [n1 n2], got %v", m.Visited)
+	}
+}