/**
 * Lifecycle events — PROTOCOL §9.1.
 *
 * `hello` (first on connect), `sync` (after agent.attach / on reconnect), `status`
 * (agent status changes). All are server→client events and never carry a correlation `id`
 * (§5.1). Reuses AgentStatus, Message, PermissionRequest, UiRequest — no duplication.
 */
import { Type, type Static } from '@sinclair/typebox';
import { AgentStatusSchema } from '@/contracts/agent-info';
import { MessageSchema } from '@/types/message';
import {
  PermissionRequestSchema,
  UiRequestSchema,
} from '@/contracts/event';

/** The protocol version carried by `hello` (single source of truth, §7). */
export const PROTOCOL_VERSION = '0.1.0';

/** `hello` — emitted immediately on connect (§9.1). Client checks the version (§7). */
export const HelloSchema = Type.Object({
  type: Type.Literal('hello'),
  protocol_version: Type.Literal(PROTOCOL_VERSION),
  server_version: Type.String(),
  capabilities: Type.Array(Type.String()),
});

/** `sync` — agent bootstrap state, sent after `agent.attach` or direct `hello` (§9.1, §6.4). */
export const SyncSchema = Type.Object({
  type: Type.Literal('sync'),
  /** Present on daemon connections; direct connections have one implicit agent (§5.2). */
  agent_id: Type.Optional(Type.String()),
  status: AgentStatusSchema,
  /** The agent's authoritative active mode at the time of the snapshot. */
  mode: Type.String(),
  /**
   * The attached runtime's secret-free capabilities (saga vr7kgx.6). Current servers always
   * emit it; optionality lets an older/malformed runtime degrade to no controls rather than
   * forcing the browser to infer support from the protocol version (§7). Projected from the
   * child runtime's `hello.capabilities` by the daemon; on a direct connection it mirrors the
   * child's own hello. The top-level daemon `hello` remains transport-scoped and does NOT
   * advertise per-runtime model support globally.
   */
  capabilities: Type.Optional(Type.Array(Type.String())),
  /**
   * The attached runtime's authoritative generation epoch (saga vr7kgx.6 hardening). The
   * daemon increments it on every same-`agent_id` child-runtime replacement and includes
   * it in every daemon-authored `sync` (attach + post-replacement re-sync). A browser uses
   * it to fence stale catalogs/responses emitted by a superseded generation so an old
   * stream's late events cannot mutate current-generation state. Optional + additive: an
   * older/direct-connection `sync` omits it and a client treats absence as a stable
   * baseline (no fencing needed on a single-generation direct connection).
   */
  runtime_epoch: Type.Optional(Type.Integer({ minimum: 0 })),
  live_window: Type.Object({
    messages: Type.Array(MessageSchema),
    compaction_index: Type.Optional(Type.Integer()),
  }),
  pending_requests: Type.Array(Type.Union([PermissionRequestSchema, UiRequestSchema])),
});

/** `status` — agent status change (§9.1). */
export const StatusEventSchema = Type.Object({
  type: Type.Literal('status'),
  agent_id: Type.Optional(Type.String()),
  status: AgentStatusSchema,
  detail: Type.Optional(Type.String()),
});

export const LifecycleEventSchema = Type.Union([
  HelloSchema,
  SyncSchema,
  StatusEventSchema,
]);

export type Hello = Static<typeof HelloSchema>;
export type Sync = Static<typeof SyncSchema>;
export type StatusEvent = Static<typeof StatusEventSchema>;
export type LifecycleEvent = Static<typeof LifecycleEventSchema>;