// Bridge to the Tauri desktop core. On the web build there is no Tauri runtime, so
// isDesktop() is false and none of these calls run. Uses the global injected by
// `withGlobalTauri` (tauri.conf.json), so the shared frontend needs no
// @tauri-apps/api dependency and the web bundle is unaffected.

interface TauriGlobal {
  core: { invoke: <T>(cmd: string, args?: Record<string, unknown>) => Promise<T> };
}

declare global {
  interface Window {
    __TAURI__?: TauriGlobal;
  }
}

export interface IntegrationStatus {
  is_appimage: boolean;
  is_integrated: boolean;
  appimage_path: string | null;
}

/** True when running inside the Tauri desktop shell (vs. the web build). */
export function isDesktop(): boolean {
  return typeof window !== "undefined" && !!window.__TAURI__;
}

export function invoke<T>(cmd: string, args?: Record<string, unknown>): Promise<T> {
  const tauri = window.__TAURI__;
  if (!tauri) return Promise.reject(new Error("Not running in the desktop app."));
  return tauri.core.invoke<T>(cmd, args).catch((err: unknown) => {
    // Every failed command names itself in the log — so a broken "basic function"
    // in some environment is diagnosable. Skip log_event to avoid recursion.
    if (cmd !== "log_event") logEvent("error", `invoke '${cmd}' failed: ${String(err)}`);
    throw err;
  });
}

/** Route a frontend message into the desktop log (stdout + file). No-op on web. */
export function logEvent(level: "info" | "warn" | "error" | "debug", message: string): void {
  if (!isDesktop()) return;
  void invoke("log_event", { level, message }).catch(() => {});
}

// Desktop (Linux AppImage) self-integration: add/remove an applications-menu entry.
export const desktop = {
  integrationStatus: () => invoke<IntegrationStatus>("integration_status"),
  integrate: () => invoke<IntegrationStatus>("integrate_desktop"),
  unintegrate: () => invoke<IntegrationStatus>("unintegrate_desktop"),
};

// --- opt-in server sync (M10.7) ----------------------------------------------
// The desktop app is local-first: none of this runs unless the user links a server,
// and the app is fully usable having never done so.

/** Never carries the device token — that stays on the Rust side, out of the webview. */
export interface SyncStatus {
  linked: boolean;
  server_url: string | null;
  last_cursor: number;
  last_sync_at: string | null;
}

export interface ServerInfo {
  site_name: string | null;
  version: string | null;
  sync_protocol_version: number | null;
  min_client_protocol_version: number | null;
  sync_features: string[];
}

/**
 * The M10.6 handshake verdict. `incompatible` carries `client_must_update` so the
 * message can name which side has to change rather than just saying "incompatible".
 */
export type Compatibility =
  | { status: "ok" }
  | { status: "degraded"; unavailable: string[] }
  | { status: "incompatible"; reason: string; client_must_update: boolean };

export interface ProbeResult {
  base_url: string;
  server: ServerInfo;
  compatibility: Compatibility;
}

export interface Identity {
  id: string;
  email: string;
  display_name: string;
}

export interface LinkResult {
  status: SyncStatus;
  identity: Identity;
  compatibility: Compatibility;
}

export interface PushSummary {
  batches: number;
  sent: number;
  created: number;
  applied: number;
  kept: number;
  noop: number;
  rejected: number;
  errors: string[];
}

export interface PullSummary {
  pages: number;
  notes_applied: number;
  notes_deleted: number;
  labels_applied: number;
  labels_deleted: number;
  cursor: number;
  clobbered_dirty: number;
  blobs_downloaded: number;
  /** Attachments whose bytes didn't arrive. Retried next sync, never fatal. */
  blobs_failed: number;
}

export interface SyncOutcome {
  push: PushSummary;
  pull: PullSummary;
  status: SyncStatus;
}

/**
 * What happened to this device's token on the SERVER when unlinking. Unlinking
 * always succeeds locally, so this is the only part that can disappoint — and the
 * user who unlinked to retire a machine is exactly who needs to be told.
 */
export type RevokeOutcome =
  | { status: "revoked" }
  | { status: "unsupported" }
  | { status: "failed"; reason: string }
  | { status: "skipped" };

export interface UnlinkResult {
  status: SyncStatus;
  revoked: RevokeOutcome;
}

/** Either a password login or a token pasted from the web app's Linked devices. */
export interface LinkInput {
  url: string;
  email?: string;
  password?: string;
  token?: string;
  name?: string;
}

export const sync = {
  /** Ask who's at an address without committing to anything. */
  probe: (url: string) => invoke<ProbeResult>("sync_probe", { url }),
  link: (input: LinkInput) => invoke<LinkResult>("sync_link", { input }),
  /** Stops syncing AND revokes this device's token server-side; see UnlinkResult. */
  unlink: () => invoke<UnlinkResult>("sync_unlink"),
  status: () => invoke<SyncStatus>("sync_status"),
  /**
   * One full cycle: push, then pull. There is deliberately no bare "pull" — pulling
   * without pushing first overwrites unsent local edits.
   */
  now: () => invoke<SyncOutcome>("sync_now"),
  hasPending: () => invoke<boolean>("sync_has_pending"),
};

// --- In-app updates (M10.9) --------------------------------------------------

/** `stable` follows tagged releases; `dev` follows every green build. */
export type UpdateChannel = "stable" | "dev";

export interface UpdateStatus {
  channel: UpdateChannel;
  current_version: string;
  /** The newer version on offer, or null when already up to date. */
  available: string | null;
  notes: string | null;
  /** False when this install can't replace itself — see `blocked_reason`. */
  can_install: boolean;
  blocked_reason: string | null;
}

export const updates = {
  channel: () => invoke<UpdateChannel>("update_channel_get"),
  setChannel: (channel: UpdateChannel) => invoke<UpdateChannel>("update_channel_set", { channel }),
  /** Ask the feed what's out there. Never installs anything. */
  check: () => invoke<UpdateStatus>("update_check"),
  /**
   * Download, verify, apply, relaunch. Resolves only on failure — a success
   * restarts the app out from under the caller.
   */
  install: () => invoke<void>("update_install"),
};