package gateway

// This file owns the outbound WS frame role gate (design/11 §7.1 「WS 下行帧的
// 角色门」, decided by the owner on 2026-10-03). It is the ONE place that decides
// which connections a downstream frame may reach:
//
//   - a frame whose type is listed in frameReachesAll is a 「状态机信号」: it
//     carries no content, so every authenticated connection receives it;
//   - EVERY other frame type — reply text (message.*), thinking, tool calls and
//     results, persisted/edited/deleted messages, graph updates, sub-agent and
//     task traffic, private persona/device state — goes to owner + admin only.
//
// The classification is fail-closed: a new frame type answers false until someone
// deliberately registers it here AND in design/11 §7.1, so forgetting to classify
// a type can never leak content. No call site decides visibility for itself (a
// per-call-site flag is exactly how one missed spot becomes a leak), which is why
// hub.broadcast looks the class up from the frame it was handed.
//
// This gate decides who is PUSHED to. Data visibility stays with the REST gates:
// a viewer still reads its 12 read-only monitoring endpoints through viewerAuth
// (design/11 §7.1 「语义澄清」).

// frameReachesAll reports whether a downstream frame type may be delivered to
// every authenticated connection. Only the 「状态机信号」 of the design/11 §7.1
// whitelist qualify: session_busy / pending_ack / pending_drain / session_idle /
// session_interrupted / pending_full / session_read. Each one only reports that a
// session changed busy state, so a read-only monitor can follow the conversation's
// activity without receiving the conversation itself.
//
// Widening this list is a contract change: register the reason (「不含内容」) in
// design/11 §7.1 and mirror it in ws_frame_scope_test.go first.
func frameReachesAll(typ string) bool {
	switch typ {
	case EventSessionBusy,
		EventPendingAck,
		EventPendingDrain,
		EventSessionIdle,
		EventSessionInterrupt,
		EventPendingFull,
		wsSessionRead:
		return true
	default:
		return false
	}
}