/**
 * Wire types shared between the auth-broker server and clients.
 *
 * The broker holds OAuth refresh tokens and exposes a redacted snapshot;
 * clients use `access` tokens directly and call back to the broker when a
 * credential expires or a 401 surfaces on a supposedly-fresh credential.
 */

import type { AuthCredential, AuthCredentialSnapshot, AuthCredentialSnapshotEntry } from "../auth-storage";
import type { UsageReport } from "../usage";

/** GET /v1/healthz response body. */
export interface HealthzResponse {
	ok: boolean;
	version?: string;
}

export interface RefresherSchedule {
	enabled: boolean;
	intervalMs: number;
	skewMs: number;
	nextSweepInMs: number;
}

export type SnapshotEntry = AuthCredentialSnapshotEntry & {
	rotatesInMs: number | null;
};

/** GET /v1/snapshot response body. */
export interface SnapshotResponse extends Omit<AuthCredentialSnapshot, "credentials"> {
	serverNowMs: number;
	refresher: RefresherSchedule;
	credentials: SnapshotEntry[];
}

/** GET /v1/usage response body — matches the local `AuthStorage.fetchUsageReports` shape. */
export interface UsageResponse {
	generatedAt: number;
	reports: UsageReport[];
}

/** POST /v1/credential/:id/refresh response body. */
export interface CredentialRefreshResponse {
	entry: AuthCredentialSnapshotEntry;
}

/** POST /v1/credential/:id/disable request body. */
export interface CredentialDisableRequest {
	cause: string;
}

/** POST /v1/credential/:id/disable response body. */
export interface CredentialDisableResponse {
	ok: boolean;
}

/**
 * POST /v1/credential request body. The OAuth `refresh` must be the *real*
 * refresh token (not the sentinel) — the broker is the canonical writer.
 */
export interface CredentialUploadRequest {
	provider: string;
	credential: AuthCredential;
}

/** POST /v1/credential response body — redacted snapshot of the provider's rows after upsert. */
export interface CredentialUploadResponse {
	entries: AuthCredentialSnapshotEntry[];
}

/**
 * SSE event kinds emitted on `GET /v1/snapshot/stream`. The same value is set
 * as the SSE `event:` name (load-bearing for clients) **and** embedded as a
 * `kind` field inside the JSON body so a Zod discriminated union can validate
 * the payload without consulting the line metadata.
 */
export type SnapshotStreamEventKind = "snapshot" | "entry" | "removed";

/** Initial frame emitted on connect — the full {@link SnapshotResponse}. */
export interface SnapshotStreamSnapshotEvent extends SnapshotResponse {
	kind: "snapshot";
}

/** Single credential added/changed (upsert or refresh). */
export interface SnapshotStreamEntryEvent {
	kind: "entry";
	generation: number;
	serverNowMs: number;
	refresher: RefresherSchedule;
	entry: SnapshotEntry;
}

/** Single credential disabled/deleted. */
export interface SnapshotStreamRemovedEvent {
	kind: "removed";
	generation: number;
	serverNowMs: number;
	refresher: RefresherSchedule;
	id: number;
}

/** Discriminated union of every event the snapshot stream emits. */
export type SnapshotStreamEvent = SnapshotStreamSnapshotEvent | SnapshotStreamEntryEvent | SnapshotStreamRemovedEvent;

/**
 * Default bearer-protected route prefix. The broker exposes `/v1/healthz`
 * unauthenticated for liveness probes; everything else requires a bearer.
 */
export const AUTH_BROKER_API_PREFIX = "/v1";

/** Default port when none is configured. Loopback-only, no external exposure. */
export const DEFAULT_AUTH_BROKER_BIND = "127.0.0.1:8765";

/** Default broker→provider refresh skew. Refresh credentials this close to expiry. */
export const DEFAULT_REFRESH_SKEW_MS = 5 * 60_000;

/** Default broker refresh-loop cadence. */
export const DEFAULT_REFRESH_INTERVAL_MS = 60_000;

/** Default freshness window for the encrypted local broker snapshot cache. */
export const DEFAULT_SNAPSHOT_CACHE_TTL_MS = 60 * 60_000;

/** Keepalive cadence for `GET /v1/snapshot/stream` SSE comments. */
export const DEFAULT_STREAM_KEEPALIVE_MS = 20_000;

/**
 * Bun.serve `idleTimeout` (seconds) used by the broker. Default Bun idle
 * timeout (10s) would close long-lived SSE connections between keepalives.
 */
export const DEFAULT_SERVER_IDLE_TIMEOUT_S = 255;