1 files changed, 45 insertions, 12 deletions
diff --git a/internal/game/action.go b/internal/game/action.go
index 9a07419..8d50eea 100644
--- a/internal/game/action.go
+++ b/internal/game/action.go
@@ -284,22 +284,17 @@ func (g *Game) checkCondition(sess *net.Session, c *action.Condition) bool {
 	}
 
 	if c.PlayerFlag != "" {
-		if p == nil || p.Flags == nil {
-			return c.Not
+		var val any
+		present := false
+		if p != nil && p.Flags != nil {
+			val, present = p.Flags[c.PlayerFlag]
 		}
-		val, ok := p.Flags[c.PlayerFlag]
-		if c.Not {
-			return !ok || val != c.Value
-		}
-		return ok && val == c.Value
+		return flagMatches(present, val, c.Value, c.Not)
 	}
 
 	if c.Flag != "" {
-		val, ok := g.WorldFlags[c.Flag]
-		if c.Not {
-			return !ok || val != c.Value
-		}
-		return ok && val == c.Value
+		val, present := g.WorldFlags[c.Flag]
+		return flagMatches(present, val, c.Value, c.Not)
 	}
 	if c.HasItem != "" {
 		has := p != nil && p.HasItem(c.HasItem)
@@ -317,3 +312,41 @@ func (g *Game) checkCondition(sess *net.Session, c *action.Condition) bool {
 	}
 	return true
 }
+
+// flagMatches evaluates a flag/player_flag condition.
+//
+// If the condition specifies no `value`, the flag matches when it is present
+// and truthy (so `{player_flag: x}` means "x is set" and
+// `{player_flag: x, not: true}` means "x is not set"). If a `value` is given,
+// the flag must be present and equal to it. `not` inverts the result.
+func flagMatches(present bool, val, want any, not bool) bool {
+	var match bool
+	if want == nil {
+		match = present && isTruthy(val)
+	} else {
+		match = present && val == want
+	}
+	if not {
+		return !match
+	}
+	return match
+}
+
+func isTruthy(v any) bool {
+	switch x := v.(type) {
+	case nil:
+		return false
+	case bool:
+		return x
+	case int:
+		return x != 0
+	case int64:
+		return x != 0
+	case float64:
+		return x != 0
+	case string:
+		return x != ""
+	default:
+		return true
+	}
+}