// Launch Punktfunk as Steam games so gamescope focuses + fullscreens them.
//
// THE LAUNCH MECHANISM (verified against MoonDeck): gamescope only gives focus/fullscreen to
// the window tree Steam launched via `reaper` (it detects the "current app" by AppID — see
// gamescope#484). So we cannot launch the flatpak from the plugin backend; we register non-Steam
// shortcuts whose exe is `/bin/sh` running our wrapper script (bin/punktfunkrun.sh), and start
// them with RunGame. The wrapper then execs the flatpak client as a reaper descendant.
//
// TWO shortcuts, both named "Punktfunk" (so they share ONE Steam Input controller-config key —
// see applyControllerConfig):
//   • STREAM  — hidden, stateful: the per-session launcher. Its launch options carry the host
//     reference and the card's profile (PF_REF/PF_PROFILE/PF_REQUEST_ACCESS), rewritten per
//     launch, so one shortcut serves every host. Hidden — an implementation detail.
//   • GAMEPAD UI — visible, stateless: fixed launch options = bare `--browse` (PF_BROWSE, no
//     host) → the client's console home (host picker + pairing + settings, gamepad-navigable).
//     This is the library-visible "Punktfunk" app the user opens directly.
//
// Both get the shipped artwork and the native-touch controller config.

import { applyControllerConfig, runnerInfo, shortcutArt } from "./backend";

// SteamClient is a Steam-internal global injected into the CEF context; it is not fully typed
// by @decky/ui, so declare the surface we use. Signatures verified against MoonDeck + the
// decky-frontend-lib SteamClient.Apps typings.
declare const SteamClient: {
  Apps: {
    AddShortcut(
      name: string,
      exePath: string,
      startDir: string,
      launchOptions: string,
    ): Promise<number>;
    SetShortcutName(appId: number, name: string): void;
    SetShortcutExe(appId: number, exe: string): void;
    SetShortcutStartDir(appId: number, dir: string): void;
    SetShortcutIcon(appId: number, iconPath: string): void;
    SetAppLaunchOptions(appId: number, options: string): void;
    // assetType: 0 = grid (portrait capsule), 1 = hero, 2 = logo, 3 = wide grid.
    SetCustomArtworkForApp(
      appId: number,
      base64Image: string,
      imageType: string,
      assetType: number,
    ): Promise<unknown>;
    RunGame(gameId: string, _unused: string, _i: number, _j: number): void;
    TerminateApp(gameId: string, _b: boolean): void;
  };
};

// Steam removed `SteamClient.Apps.SetAppHidden`; visibility goes through
// `collectionStore.SetAppsAsHidden` — but that looks the app up in appStore, which only
// registers a freshly-created shortcut a moment later (calling it immediately throws on a
// null overview). So visibility changes are BEST-EFFORT + DEFERRED, never launch-blocking.
declare const collectionStore:
  | { SetAppsAsHidden?: (appIds: number[], hidden: boolean) => void }
  | undefined;

// SteamUI's appStore indexes every registered app/shortcut by appId; a remembered appId whose
// overview is gone was deleted out from under us (the user removed the library entry). We must
// verify this because the remembered appId lives in Steam's CEF localStorage — which survives a
// plugin UNINSTALL/REINSTALL — so a manually-deleted shortcut otherwise leaves a dangling appId
// that the reuse path below silently repoints (SetShortcut* on a dead id is a no-op), and the
// entry never comes back.
declare const appStore:
  | { GetAppOverviewByAppID?: (appId: number) => unknown | null }
  | undefined;

/** True if a remembered appId still maps to a live Steam shortcut. When appStore is unavailable
 *  we can't tell, so assume it exists — better to keep reusing than risk a duplicate library
 *  entry from a false "missing". A confident null means the shortcut was deleted → recreate. */
function shortcutStillExists(appId: number): boolean {
  try {
    // Call it as a METHOD on appStore — NEVER as an extracted function. Its implementation
    // reads the store's own state (`this.m_mapApps`), so `const get = appStore.GetAppOverview…;
    // get(id)` throws on the lost `this`, and the catch below turns that into a permanent
    // "true". That is not a stale-data bug but a total one: the guard then answers "still
    // exists" for EVERY appId, so a dangling id is never dropped, the reuse path repoints a
    // dead shortcut (silent no-ops), and "recreate" reports success having done nothing.
    // `typeof` first: `appStore` is a Steam-injected global, and a bare reference to a missing
    // one is a ReferenceError that optional chaining does NOT prevent.
    if (typeof appStore === "undefined" || !appStore?.GetAppOverviewByAppID) {
      return true; // no way to verify — preserve the reuse path
    }
    return appStore.GetAppOverviewByAppID(appId) != null;
  } catch {
    return true;
  }
}

/** Set a shortcut's library visibility (best-effort, deferred — the overview registers a moment
 *  after AddShortcut). Hides the stateful stream shortcut; keeps the gamepad-UI one visible. */
function setShortcutHidden(appId: number, hidden: boolean): void {
  const attempt = () => {
    try {
      collectionStore?.SetAppsAsHidden?.([appId], hidden);
    } catch {
      /* overview not registered yet, or the API changed — cosmetic, ignore */
    }
  };
  attempt(); // succeeds immediately for an already-registered (reused) shortcut
  setTimeout(attempt, 2500); // fresh shortcut: retry once its app overview lands
};

// Bump when the shipped artwork changes so existing shortcuts re-apply it once (per appId).
// v3: CI zips through 0.17.1 shipped no assets/ at all, yet v2 was still recorded as applied
// on those installs — the bump makes them re-apply once on the first build that has the files.
const ART_VERSION = 3;
function artKey(appId: number): string {
  return `punktfunk:shortcutArt:${appId}`;
}

/**
 * Apply the plugin's grid/hero/logo/icon to a shortcut (idempotent, once per ART_VERSION per
 * appId). Cosmetic and fully best-effort: any failure is swallowed and retried on the next call.
 */
async function applyArtwork(appId: number, isRetry = false): Promise<void> {
  try {
    if (localStorage.getItem(artKey(appId)) === `${ART_VERSION}`) {
      return;
    }
    const art = await shortcutArt();
    const assets: [string | undefined, number][] = [
      [art.grid, 0],
      [art.hero, 1],
      [art.logo, 2],
      [art.gridwide, 3],
    ];
    let applied = false;
    for (const [data, assetType] of assets) {
      if (data) {
        await SteamClient.Apps.SetCustomArtworkForApp(appId, data, "png", assetType);
        applied = true;
      }
    }
    if (art.icon_path) {
      SteamClient.Apps.SetShortcutIcon(appId, art.icon_path);
      applied = true;
    }
    // Only record "done" when something actually landed — a plugin build whose assets/ is
    // missing/empty must keep retrying on later mounts instead of poisoning the marker.
    if (applied) {
      localStorage.setItem(artKey(appId), `${ART_VERSION}`);
    }
  } catch (e) {
    // A shortcut fresh out of AddShortcut may not be registered yet (the same race
    // setShortcutHidden defers around) — one deferred second attempt, then leave it to
    // the next mount.
    if (!isRetry) {
      setTimeout(() => void applyArtwork(appId, true), 2500);
    }
    console.warn("punktfunk: shortcut artwork not applied", e);
  }
}

// The shortcut name is user-visible (Steam overlay + library) — brand-case it. BOTH shortcuts
// share it so Steam keys them to the SAME controller config (configset key = lowercase name).
const SHORTCUT_NAME = "Punktfunk";

// The shortcut's exe is /bin/sh, NOT the script itself: Decky extracts plugin zips without
// preserving the exec bit, and ~/homebrew/plugins is root-owned so the unprivileged plugin
// backend can't chmod it back on. Passing the script as an argument to the always-executable
// shell removes the +x dependency entirely. SteamOS /bin/sh is bash; the wrapper is plain
// POSIX sh regardless.
const SHELL = "/bin/sh";

// The 64-bit "gameid" RunGame wants, derived from a 32-bit non-Steam shortcut appId: the
// standard non-Steam-game encoding (appid << 32 | 0x02000000). MoonDeck/decky tools use this.
function gameIdFromAppId(appId: number): string {
  return ((BigInt(appId) << 32n) | 0x02000000n).toString();
}

// Persist each shortcut's appId across reloads so we reuse ONE per role instead of churning the
// library (an appId is stable for the life of the shortcut). The STREAM key is the historical
// one, so existing single-shortcut installs migrate into the (now hidden) stream role, and the
// visible gamepad-UI shortcut is created alongside.
const STORAGE_KEY_STREAM = "punktfunk:shortcutAppId";
const STORAGE_KEY_UI = "punktfunk:uiAppId";

function remember(key: string, appId: number) {
  try {
    localStorage.setItem(key, String(appId));
  } catch {
    /* ignore */
  }
}
function recall(key: string): number | null {
  try {
    const v = localStorage.getItem(key);
    return v ? Number(v) : null;
  } catch {
    return null;
  }
}

// Install the native-touch controller config once per plugin session (idempotent file writes in
// the root backend). Keyed by the shared shortcut NAME, so this single call covers both
// shortcuts. Gated in localStorage so we don't rewrite Steam's config dir on every launch; bump
// CONFIG_VERSION to force a reinstall after the shipped .vdf changes.
const CONFIG_KEY = "punktfunk:controllerConfig";
const CONFIG_VERSION = 1;
async function ensureControllerConfig(): Promise<void> {
  try {
    if (localStorage.getItem(CONFIG_KEY) === `${CONFIG_VERSION}`) {
      return;
    }
    const r = await applyControllerConfig(SHORTCUT_NAME);
    // `ok` alone isn't done: with zero account configset dirs (fresh Steam) the backend
    // succeeds without pointing any account at the template — keep retrying until one lands.
    if (r?.ok && (r.applied ?? []).some((a) => a.startsWith("configset:"))) {
      localStorage.setItem(CONFIG_KEY, `${CONFIG_VERSION}`);
    } else {
      console.warn("punktfunk: controller config not fully applied", r);
    }
  } catch (e) {
    console.warn("punktfunk: controller config not applied", e);
  }
}

/**
 * Ensure the STREAM shortcut (hidden, stateful) — the per-session launcher whose launch options
 * are rewritten per stream. Branded, artworked, native-touch config applied, and HIDDEN (it is
 * an implementation detail; the visible entry is the gamepad-UI shortcut). Returns its appId +
 * the current runner path. Reuses/repoints the remembered shortcut (the plugin dir can change
 * across reinstalls, and pre-two-shortcut installs had this one visible).
 */
async function ensureStreamShortcut(): Promise<{ appId: number; runner: string; clientBin: string }> {
  const info = await runnerInfo();
  if (!info.exists) {
    throw new Error(`launch wrapper missing at ${info.runner}`);
  }
  const startDir = info.runner.replace(/\/[^/]*$/, ""); // the plugin's bin/ dir
  void ensureControllerConfig(); // fire-and-forget — never blocks the launch

  // Reuse the remembered shortcut only if it still exists — a stale appId (shortcut deleted, key
  // outlived it across a reinstall) must fall through to AddShortcut, not be silently repointed.
  const remembered = recall(STORAGE_KEY_STREAM);
  if (remembered != null && shortcutStillExists(remembered)) {
    SteamClient.Apps.SetShortcutExe(remembered, SHELL);
    SteamClient.Apps.SetShortcutStartDir(remembered, startDir);
    SteamClient.Apps.SetShortcutName(remembered, SHORTCUT_NAME);
    setShortcutHidden(remembered, true); // migrate pre-two-shortcut installs (were visible)
    void applyArtwork(remembered);
    return { appId: remembered, runner: info.runner, clientBin: info.client_bin ?? "" };
  }

  const appId = await SteamClient.Apps.AddShortcut(SHORTCUT_NAME, SHELL, startDir, "");
  SteamClient.Apps.SetShortcutName(appId, SHORTCUT_NAME);
  setShortcutHidden(appId, true);
  void applyArtwork(appId);
  remember(STORAGE_KEY_STREAM, appId);
  return { appId, runner: info.runner, clientBin: info.client_bin ?? "" };
}

/**
 * Ensure the GAMEPAD-UI shortcut (visible, stateless) — the library-facing "Punktfunk" entry
 * that opens the client's console home (bare `--browse`: host picker + pairing + settings).
 * Fixed launch options (no per-session state), branded, artworked, native-touch config applied,
 * kept VISIBLE. Idempotent — call on plugin mount so the library entry always exists and stays
 * repointed to the current plugin dir. Best-effort: returns null on any failure.
 */
export async function ensureGamepadUiShortcut(): Promise<number | null> {
  try {
    const info = await runnerInfo();
    if (!info.exists) {
      return null;
    }
    const startDir = info.runner.replace(/\/[^/]*$/, "");
    void ensureControllerConfig();
    // PF_BROWSE → the wrapper runs the SESSION's `--browse --fullscreen` (console home), which is
    // the one branch this rework deliberately left alone. %command% expands to the shortcut exe
    // (/bin/sh); the wrapper rides behind as an arg. PF_CLIENT_BIN only when the backend resolved
    // a NATIVE client — else the wrapper's flatpak default stands and this shortcut is exactly
    // what it always was.
    const clientBin = safeClientBin(info.client_bin) ? `PF_CLIENT_BIN=${info.client_bin} ` : "";
    const launchOpts = `${clientBin}PF_BROWSE=1 %command% "${info.runner}"`;

    // Reuse the remembered entry only if it still exists; a stale appId (deleted shortcut whose
    // localStorage key survived a plugin reinstall) falls through to AddShortcut so the visible
    // library entry actually comes back instead of repointing a dead id.
    let appId = recall(STORAGE_KEY_UI);
    if (appId != null && shortcutStillExists(appId)) {
      SteamClient.Apps.SetShortcutExe(appId, SHELL);
      SteamClient.Apps.SetShortcutStartDir(appId, startDir);
      SteamClient.Apps.SetShortcutName(appId, SHORTCUT_NAME);
    } else {
      appId = await SteamClient.Apps.AddShortcut(SHORTCUT_NAME, SHELL, startDir, "");
      SteamClient.Apps.SetShortcutName(appId, SHORTCUT_NAME);
      remember(STORAGE_KEY_UI, appId);
    }
    SteamClient.Apps.SetAppLaunchOptions(appId, launchOpts);
    setShortcutHidden(appId, false); // the visible library entry
    void applyArtwork(appId);
    return appId;
  } catch (e) {
    console.warn("punktfunk: gamepad-UI shortcut not ensured", e);
    return null;
  }
}

/**
 * Force the visible "Punktfunk" library entry back into existence — the recovery button for
 * "my shortcut disappeared". Drops any remembered appId that no longer maps to a live shortcut
 * (so it can't shadow a fresh AddShortcut), then re-ensures. Safe to press anytime: a shortcut
 * that still exists is left in place (no duplicate); a missing one is recreated. Covers the case
 * self-heal-on-mount can't — deleting the shortcut WITHOUT reinstalling (no mount → no ensure).
 * Returns the (new or existing) visible appId, or null on failure.
 */
export async function recreateShortcuts(): Promise<number | null> {
  for (const key of [STORAGE_KEY_STREAM, STORAGE_KEY_UI]) {
    const id = recall(key);
    if (id != null && !shortcutStillExists(id)) {
      try {
        localStorage.removeItem(artKey(id)); // stale art marker for the dead appId
        localStorage.removeItem(key);
      } catch {
        /* ignore */
      }
    }
  }
  // Recreate the visible entry now; the hidden stream shortcut re-registers lazily on next launch.
  return ensureGamepadUiShortcut();
}

/** Launch the stateless gamepad-UI shortcut (console home) from the plugin, e.g. a QAM button. */
export async function launchGamepadUi(): Promise<void> {
  const appId = await ensureGamepadUiShortcut();
  if (appId != null) {
    SteamClient.Apps.RunGame(gameIdFromAppId(appId), "", -1, 100);
  }
}

/** Per-launch extras beyond the host reference (all optional — {} is the plain stream). */
export interface LaunchOpts {
  /** A pinned card: stream with this settings profile, one-off (PF_PROFILE → `--profile`). */
  profileId?: string;
  /**
   * Ask the host's operator to admit this Deck rather than typing a PIN (PF_REQUEST_ACCESS).
   * The connect PARKS until somebody approves it, and the launch runs SUPERVISED — see the
   * wrapper for why `--exec` is dropped on this path alone.
   */
  requestAccess?: boolean;
}

// Host refs and profile ids ride Steam launch options as env-prefix tokens (`PF_REF=<ref>`),
// so they must be space/quote-free — Steam's tokenizer and the wrapper's env both break
// otherwise. Real values are UUIDs or `addr:port`, so this rejects nothing in practice; it is
// VALIDATION, never encoding (the client must receive the opaque token verbatim).
const UNSAFE_TOKEN = /["'\\$`\s]/;
export function isSafeLaunchId(id: string): boolean {
  return (
    id.length > 0 &&
    id.length <= 128 &&
    UNSAFE_TOKEN.exec(id) === null &&
    /^[\x21-\x7e]+$/.test(id)
  );
}

/**
 * Is a resolved native-client path safe to put in Steam's launch options? Same rule, separate
 * name because the failure is different: an unsafe id is a bug in our own data, an unsafe path
 * is just where the user installed the client — so the browse shortcut degrades to its flatpak
 * default rather than refusing to exist.
 */
function safeClientBin(bin: string | undefined): bin is string {
  return !!bin && isSafeLaunchId(bin);
}

/**
 * Stream `ref` fullscreen in Gaming Mode, optionally with a pinned card's profile. Encodes the
 * target into the STREAM shortcut's launch options — one hidden shortcut serves every host —
 * then RunGame.
 *
 * No Wake-on-LAN here any more. The plugin used to fire a magic packet itself and then stretch
 * the connect budget to 75 s to cover the host's resume, which was a workaround for the era
 * before the CLI existed. `punktfunk launch` now runs the real wake-and-wait loop (packet at
 * t=0, re-sent every 6 s, presence polled every second) and only dials once the host answers —
 * strictly better, and it deletes a backend method, a frontend call and a shell branch.
 */
export async function launchStream(ref: string, opts: LaunchOpts = {}): Promise<void> {
  if (!isSafeLaunchId(ref)) {
    throw new Error(`unsupported host reference: ${ref}`);
  }
  if (opts.profileId && !isSafeLaunchId(opts.profileId)) {
    throw new Error(`unsupported profile id: ${opts.profileId}`);
  }
  const { appId, runner, clientBin } = await ensureStreamShortcut();
  const env = [`PF_REF=${ref}`];
  // Set only for a NATIVE client install; absent, the wrapper takes its flatpak default, so every
  // existing Deck install produces byte-identical launch options to before.
  if (clientBin) {
    // The one launch-option value that comes from the backend rather than a store id, and so
    // the one that could carry a space: a path like `/home/deck/my apps/punktfunk-client` would
    // split Steam's tokenizer and land its tail in front of %command% as a bogus env token.
    if (!isSafeLaunchId(clientBin)) {
      throw new Error(`client path can't ride Steam's launch options: ${clientBin}`);
    }
    env.push(`PF_CLIENT_BIN=${clientBin}`);
  }
  if (opts.profileId) {
    env.push(`PF_PROFILE=${opts.profileId}`);
  }
  if (opts.requestAccess) {
    env.push("PF_REQUEST_ACCESS=1");
  }
  // KEY=value ... %command% args — %command% expands to the shortcut exe (/bin/sh); the wrapper
  // script rides behind it as an argument and reads PF_* from the environment.
  SteamClient.Apps.SetAppLaunchOptions(appId, `${env.join(" ")} %command% "${runner}"`);
  SteamClient.Apps.RunGame(gameIdFromAppId(appId), "", -1, 100);
}

/** Stop the running stream shortcut (best-effort; the in-stream chord/back also works). */
export function stopStream(): void {
  const appId = recall(STORAGE_KEY_STREAM);
  if (appId != null) {
    SteamClient.Apps.TerminateApp(gameIdFromAppId(appId), false);
  }
}