/**
 * ╔══════════════════════════════════════════════════════════════════════╗
 * ║              SAMSUNG TV PROXY — Bun + Puppeteer SSR Server          ║
 * ╚══════════════════════════════════════════════════════════════════════╝
 *
 * Renders web pages to SSR HTML (with full CSS/resource inlining) or MJPEG
 * screenshots, served to Samsung TVs (Tizen browser) and other limited
 * clients.  Multi-browser page-pool, render-cache, URL-rotation views,
 * WebSocket debug dashboard, IP ban management, and device tracking.
 *
 * ─────────────────────────────────────────────────────────────────────────
 * QUICK-SEARCH INDEX — jump by section name or semantic topic:
 * ─────────────────────────────────────────────────────────────────────────
 *
 *   SEC | ~LINE | FLAG / TOPIC                      | WHAT IT DOES
 *   ────┼───────┼───────────────────────────────────┼───────────────────────
 *   01  |  35   | CONFIG                            | All tunables (pool, timeouts, intervals)
 *   02  |  57   | TYPES / interfaces                | View, URLItem, CachedRender, DeviceEntry…
 *   03  | 115   | DATABASE / SQLite / schema        | views + banned_ips tables, migrations
 *   04  | 158   | DB HELPERS / dbLoad / dbInsert    | CRUD: dbLoadAll, dbInsert, dbUpdate, dbDelete
 *   05  | 202   | BAN SYSTEM / dbBanIP / dbIsBanned | IP ban persistence layer
 *   06  | 219   | VIEW CACHE / viewCache            | In-memory mirror of DB views table
 *   07  | 230   | DEVICE TRACKING / devices         | Per-IP tracking, ban gate, warmup trigger
 *   08  | 252   | DEBUG DATA / getDebugData         | Aggregates server+views+devices for API/WS
 *   09  | 285   | PAGE POOL / PagePool / acquire    | Multi-browser page lifecycle (acquire/release/reset)
 *   10  | 383   | WS DEBUG / debugClients           | Real-time debug-over-WebSocket push
 *   11  | 393   | RENDER CACHE / renderCache        | URL→HTML cache with TTL, inFlight tracking
 *   12  | 417   | WARMUP / warmupView / warmupCache | Pre-cache active-device views on interval
 *   13  | 461   | CACHE INVALIDATION / invalidate   | Purge all cache entries for a view
 *   14  | 475   | RENDER QUEUE / renderQueue        | FIFO queue with timeout; drains into PagePool
 *   15  | 506   | RENDER ENGINE / renderViewToCache | Core: SSR or MJPEG render → cache write
 *   16  | 549   | GET-OR-RENDER / getOrRender       | Cache-hit → inFlight → queue → render decision tree
 *   17  | 590   | CACHE STATS / cacheStats          | Telemetry: per-cache-entry TTL/URL info
 *   18  | 620   | ROTATION / getCurrentURLIndex     | Time-based URL cycling (+ remainingSec)
 *   19  | 645   | SSR INLINING / injectMetaRefresh  | Meta-refresh injection, script stripping
 *   20  | 663   | CSS IMPORT RESOLVER / @import     | Recursive @import resolver (max 3 levels)
 *   21  | 694   | COMPUTED STYLE BAKING / bake      | Inline computed styles for Tizen compat
 *   22  | 777   | RESOURCE INLINING / inlineAll     | CSS/images/favicons/bg→data: URIs in-page
 *   23  | 887   | SSR RENDER / renderSSR            | Full SSR pipeline: acquire→goto→inline→strip
 *   24  | 932   | SCREENSHOT / renderScreenshotFrame| JPEG screenshot renderer (MJPEG mode)
 *   25  | 961   | SCREENSHOT HTML / screenshotHTML  | Wrap JPEG base64 in refresh-page HTML
 *   26  | 981   | ERROR PAGE / errorPage            | Styled error HTML with auto-retry meta-refresh
 *   27  | 1002  | VIEW SERVING / serveView          | /v/:id → rotation→render→response pipeline
 *   28  | 1032  | API / handleAPI                   | REST: CRUD views, ban/unban, disconnect, refresh
 *   29  | 1181  | STATIC FILES / serveStatic        | Serves ../public (SPA fallback to index.html)
 *   30  | 1198  | HTTP SERVER / Bun.serve           | Main fetch handler: /ws, /v/:id, /api, static
 *   31  | 1293  | INIT+SHUTDOWN / init / shutdown   | Bootstrap + graceful drain + signal handlers
 *
 * ─────────────────────────────────────────────────────────────────────────
 * DATA-FLOW MAP (how a GET /v/:id request travels):
 * ─────────────────────────────────────────────────────────────────────────
 *
 *   Client GET /v/:id
 *     │
 *     ▼
 *   Bun.serve.fetch()                    [ SEC 30 ]
 *     │
 *     ├─ deviceTrack(ip…)                [ SEC 07 ]  ← blocks banned IPs
 *     │
 *     ▼
 *   serveView(view)                      [ SEC 27 ]
 *     │
 *     ├─ getCurrentURLIndex(view)        [ SEC 18 ]  ← time-based rotation
 *     │
 *     ▼
 *   getOrRender(view, idx)               [ SEC 16 ]
 *     │
 *     ├── cache HIT?  ──▶ return cached body
 *     ├── inFlight?   ──▶ await existing promise
 *     ├── pool free?  ──▶ renderViewToCache()  [ SEC 15 ]
 *     │                     │
 *     │                     ├─ renderSSR()          [ SEC 23 ]
 *     │                     │   ├─ pagePool.acquire()   [ SEC 09 ]
 *     │                     │   ├─ page.goto(url)
 *     │                     │   ├─ inlineAllResources() [ SEC 22 ]
 *     │                     │   │   └─ resolveCSSImports() [ SEC 20 ]
 *     │                     │   ├─ [opt] bakeComputedStyles() [ SEC 21 ]
 *     │                     │   ├─ stripScriptTags()
 *     │                     │   └─ pagePool.release()
 *     │                     │
 *     │                     └─ renderScreenshotFrame() [ SEC 24 ]
 *     │                         └─ screenshotHTML()    [ SEC 25 ]
 *     │
 *     └── pool full? ──▶ enqueue → drainRenderQueue() [ SEC 14 ]
 *
 * ─────────────────────────────────────────────────────────────────────────
 * KEY DATA STRUCTURES (grep these to find type definitions & usage):
 * ─────────────────────────────────────────────────────────────────────────
 *
 *   View              — id, name, urls(URLItem[]), method(ssr|mjpeg), cacheTtl, viewport
 *   CachedRender      — body(string), urlIndex, createdAt, expiresAt
 *   ActiveRender      — promise(Promise<string>), urlIndex  (in-flight dedup)
 *   QueuedRender      — resolve/reject callbacks, key, queuedAt  (FIFO overflow)
 *   DeviceEntry       — ip, viewId, userAgent, lastSeen, requestCount
 *   BrowserSlot       — browser, available(Page[]), inUse, max
 *
 * ─────────────────────────────────────────────────────────────────────────
 * HOW TO SEARCH THIS FILE (for humans & AIs):
 * ─────────────────────────────────────────────────────────────────────────
 *
 *   There is no need to read the file line-by-line.  Use grep / text-search
 *   on any of the keywords below to jump directly to what you need:
 *
 *     "CONFIG"                → tunables (port, timeouts, pool sizing)
 *     "interface View"         → View type definition
 *     "CREATE TABLE"           → DB schema
 *     "dbLoadAll|dbInsert"     → DB CRUD operations
 *     "dbBanIP|banned"         → IP banning
 *     "viewCache"              → in-memory view mirror
 *     "deviceTrack"            → device tracking & ban gate
 *     "class PagePool"         → browser/page pool management
 *     "acquire|release"        → page lifecycle
 *     "renderCache|CachedRender" → render cache
 *     "getOrRender"            → cache/inflight/queue decision
 *     "renderQueue|drainRenderQueue" → overflow queue
 *     "renderViewToCache"      → actual render execution
 *     "warmupView|warmupCache" → pre-caching
 *     "cacheInvalidate"        → cache purging
 *     "getCurrentURLIndex"     → URL rotation logic
 *     "renderSSR"              → SSR rendering
 *     "renderScreenshotFrame"  → MJPEG rendering
 *     "inlineAllResources"     → CSS/image inlining
 *     "bakeComputedStyles"     → style baking for Tizen
 *     "resolveCSSImports"      → @import recursion
 *     "serveView"              → /v/:id response builder
 *     "handleAPI"              → REST API handler
 *     "Bun.serve"              → HTTP server entry
 *     "shutdown"               → graceful shutdown
 *     "getDebugData"           → debug telemetry
 *     "WebSocket|ws"           → debug WS
 *     "errorPage"              → error HTML template
 *     "screenshotHTML"         → MJPEG wrapper HTML
 *
 * ─────────────────────────────────────────────────────────────────────────
 * MODIFICATION GUIDE (what to touch when adding/changing features):
 * ─────────────────────────────────────────────────────────────────────────
 *
 *   To add a new View field:
 *     1. Add to `interface View`             [ SEC 02 ]
 *     2. Add column migration                [ SEC 03 ]
 *     3. Update `rowToView()`                [ SEC 03 ]
 *     4. Update `dbInsert()` / `dbUpdate()`  [ SEC 04 ]
 *     5. Update `CreateViewBody`             [ SEC 02 ]
 *     6. Update API handler                  [ SEC 28 ]
 *     7. Update `getDebugData()`             [ SEC 08 ]  (if visible in debug)
 *
 *   To add a new API endpoint:
 *     1. Add route in `handleAPI()`          [ SEC 28 ]
 *     2. If real-time: add to `getDebugData()` [ SEC 08 ]
 *     3. If admin: consider ban/auth gate    [ SEC 07 ]
 *
 *   To change rendering behavior:
 *     - SSR pipeline:    `renderSSR()`        [ SEC 23 ]
 *     - MJPEG pipeline:  `renderScreenshotFrame()` [ SEC 24 ]
 *     - Inlining logic:  `inlineAllResources()`    [ SEC 22 ]
 *     - Style baking:    `bakeComputedStyles()`    [ SEC 21 ]
 *     - Script removal:  `stripScriptTags()`       [ SEC 19 ]
 *
 * ─────────────────────────────────────────────────────────────────────────
 * EXTERNAL DEPENDENCIES:
 * ─────────────────────────────────────────────────────────────────────────
 *
 *   bun:sqlite   — embedded SQLite (views.db, banned_ips.db)
 *   puppeteer    — headless Chromium (launched via /usr/bin/chromium)
 *   Bun          — runtime: Bun.file(), Bun.serve(), WebSocket upgrade
 *   crypto       — randomUUID() for view IDs
 *
 * ═══════════════════════════════════════════════════════════════════════
 */

import { Database } from "bun:sqlite";
import type { Browser, Page } from "puppeteer";
import puppeteer from "puppeteer";

// ═══════════════════════════════════════════════════════════════
// CONFIG
// ═══════════════════════════════════════════════════════════════

const CONFIG = {
  PORT: parseInt(process.env.PORT || "3099"),
  BROWSER_COUNT: 2,
  PAGES_PER_BROWSER: 8,
  PAGE_POOL_WARM: 4,
  PAGE_ACQUIRE_TIMEOUT_MS: 3000,
  RENDER_TIMEOUT_MS: 25000,
  MAX_CONCURRENT_RENDERS: 16,
  QUEUE_TIMEOUT_MS: 30000,
  CACHE_CLEANUP_INTERVAL_MS: 30000,
  WARMUP_INTERVAL_MS: 60000,
} as const;

// ═══════════════════════════════════════════════════════════════
// TYPES
// ═══════════════════════════════════════════════════════════════

interface URLItem {
  url: string;
  durationSec: number;
  waitBeforeCaptureMs?: number;
  forceDarkMode?: boolean;
  bakeStyles?: boolean;
}

interface View {
  id: string;
  name: string;
  urls: URLItem[];
  method: "mjpeg" | "ssr";
  metaRefreshEnabled: boolean;
  cacheTtlSec: number;
  viewportWidth: number;
  viewportHeight: number;
  createdAt: number;
}

interface ViewRow {
  id: string;
  name: string;
  urls: string;
  method: string;
  meta_refresh_enabled: number;
  cache_ttl_sec: number;
  viewport_width: number;
  viewport_height: number;
  created_at: number;
}

interface CreateViewBody {
  name: string;
  urls: URLItem[];
  method: "mjpeg" | "ssr";
  metaRefreshEnabled?: boolean;
  cacheTtlSec?: number;
  viewportWidth?: number;
  viewportHeight?: number;
}
type UpdateViewBody = Partial<CreateViewBody>;

interface CachedRender {
  body: string;
  urlIndex: number;
  createdAt: number;
  expiresAt: number;
}

interface ActiveRender {
  promise: Promise<string>;
  urlIndex: number;
}

interface QueuedRender {
  resolve: (body: string) => void;
  reject: (err: Error) => void;
  key: string;
  viewId: string;
  urlIndex: number;
  queuedAt: number;
}

interface DeviceEntry {
  ip: string;
  viewId: string;
  viewName: string;
  userAgent: string;
  lastSeen: number;
  requestCount: number;
}

// ═══════════════════════════════════════════════════════════════
// DATABASE
// ═══════════════════════════════════════════════════════════════

const db = new Database("/app/data/views.db", { create: true });

db.run(`
  CREATE TABLE IF NOT EXISTS views (
    id                    TEXT PRIMARY KEY,
    name                  TEXT NOT NULL,
    urls                  TEXT NOT NULL DEFAULT '[]',
    method                TEXT NOT NULL DEFAULT 'ssr',
    meta_refresh_enabled  INTEGER NOT NULL DEFAULT 0,
    cache_ttl_sec         INTEGER NOT NULL DEFAULT 60,
    viewport_width        INTEGER NOT NULL DEFAULT 1920,
    viewport_height       INTEGER NOT NULL DEFAULT 1080,
    bake_styles           INTEGER NOT NULL DEFAULT 0,
    created_at            INTEGER NOT NULL DEFAULT (unixepoch())
  )
`);

db.run(`
  CREATE TABLE IF NOT EXISTS banned_ips (
    ip                    TEXT PRIMARY KEY,
    banned_at             INTEGER NOT NULL DEFAULT (unixepoch()),
    reason                TEXT,
    banned_by             TEXT
  )
`);

// Migrations for upgrading from older schema
try {
  db.run("ALTER TABLE views ADD COLUMN cache_ttl_sec INTEGER NOT NULL DEFAULT 60");
} catch {}
try {
  db.run("ALTER TABLE views ADD COLUMN viewport_width INTEGER NOT NULL DEFAULT 1920");
} catch {}
try {
  db.run("ALTER TABLE views ADD COLUMN viewport_height INTEGER NOT NULL DEFAULT 1080");
} catch {}
try {
  db.run("ALTER TABLE views ADD COLUMN bake_styles INTEGER NOT NULL DEFAULT 0");
} catch {}

function rowToView(row: ViewRow): View {
  return {
    id: row.id,
    name: row.name,
    urls: JSON.parse(row.urls),
    method: row.method as View["method"],
    metaRefreshEnabled: row.meta_refresh_enabled === 1,
    cacheTtlSec: row.cache_ttl_sec ?? 60,
    viewportWidth: row.viewport_width ?? 1920,
    viewportHeight: row.viewport_height ?? 1080,
    createdAt: row.created_at,
  };
}

// Seed a default view on first run (only when table is empty)
const viewCount = (db.query("SELECT COUNT(*) as n FROM views").get() as { n: number }).n;
if (viewCount === 0) {
  db.run(
    `INSERT INTO views (id,name,urls,method,meta_refresh_enabled,cache_ttl_sec,viewport_width,viewport_height,created_at)
     VALUES (?,?,?,?,?,?,?,?,?)`,
    [
      crypto.randomUUID(),
      "Demo View",
      JSON.stringify([
        { url: "https://www.google.com", durationSec: 30, waitBeforeCaptureMs: 0, forceDarkMode: false, bakeStyles: false },
        { url: "https://duck.ai", durationSec: 30, waitBeforeCaptureMs: 0, forceDarkMode: false, bakeStyles: false },
        { url: "https://www.msn.com", durationSec: 30, waitBeforeCaptureMs: 0, forceDarkMode: false, bakeStyles: false },
      ]),
      "ssr",
      0,
      60,
      1920,
      1080,
      Math.floor(Date.now() / 1000),
    ],
  );
}

function dbLoadAll(): View[] {
  return (db.query("SELECT * FROM views ORDER BY created_at DESC").all() as ViewRow[]).map(
    rowToView,
  );
}

function dbLoad(id: string): View | null {
  const row = db.query("SELECT * FROM views WHERE id = ?").get(id) as ViewRow | undefined;
  return row ? rowToView(row) : null;
}

function dbInsert(v: View): void {
  db.run(
    `INSERT INTO views (id,name,urls,method,meta_refresh_enabled,cache_ttl_sec,viewport_width,viewport_height,created_at)
     VALUES (?,?,?,?,?,?,?,?,?)`,
    [
      v.id,
      v.name,
      JSON.stringify(v.urls),
      v.method,
      v.metaRefreshEnabled ? 1 : 0,
      v.cacheTtlSec,
      v.viewportWidth,
      v.viewportHeight,
      v.createdAt,
    ],
  );
}

function dbUpdate(v: View): void {
  db.run(
    "UPDATE views SET name=?,urls=?,method=?,meta_refresh_enabled=?,cache_ttl_sec=?,viewport_width=?,viewport_height=? WHERE id=?",
    [
      v.name,
      JSON.stringify(v.urls),
      v.method,
      v.metaRefreshEnabled ? 1 : 0,
      v.cacheTtlSec,
      v.viewportWidth,
      v.viewportHeight,
      v.id,
    ],
  );
}

function dbDelete(id: string): boolean {
  return db.run("DELETE FROM views WHERE id = ?", [id]).changes > 0;
}

function dbBanIP(ip: string, reason?: string): void {
  db.run(
    "INSERT OR REPLACE INTO banned_ips (ip, banned_at, reason, banned_by) VALUES (?, ?, ?, ?)",
    [ip, Math.floor(Date.now() / 1000), reason ?? "Manual ban", "admin"],
  );
}

function dbUnbanIP(ip: string): boolean {
  return db.run("DELETE FROM banned_ips WHERE ip = ?", [ip]).changes > 0;
}

function dbIsBanned(ip: string): boolean {
  return db.query("SELECT ip FROM banned_ips WHERE ip = ?").get(ip) != null;
}

function dbGetBannedIPs(): Array<{
  ip: string;
  banned_at: number;
  reason: string;
  banned_by: string;
}> {
  return db.query("SELECT * FROM banned_ips ORDER BY banned_at DESC").all() as Array<{
    ip: string;
    banned_at: number;
    reason: string;
    banned_by: string;
  }>;
}

// ═══════════════════════════════════════════════════════════════
// IN-MEMORY VIEW CACHE
// ═══════════════════════════════════════════════════════════════

const viewCache = new Map<string, View>();

function viewCacheInit(): void {
  for (const v of dbLoadAll()) viewCache.set(v.id, v);
}

function viewCacheGet(id: string): View | null {
  return viewCache.get(id) ?? null;
}

function viewCacheAll(): View[] {
  return [...viewCache.values()].sort((a, b) => b.createdAt - a.createdAt);
}

// ═══════════════════════════════════════════════════════════════
// DEVICE TRACKING
// ═══════════════════════════════════════════════════════════════

const devices = new Map<string, DeviceEntry>();
const warmedUpViews = new Set<string>();
const DEVICE_TTL_MS = 120_000;

function deviceTrack(ip: string, viewId: string, viewName: string, userAgent: string): boolean {
  // Check if IP is banned
  if (dbIsBanned(ip)) {
    console.warn(`[security] Blocked connection from banned IP: ${ip}`);
    return false;
  }

  const existing = devices.get(ip);
  if (existing) {
    existing.viewId = viewId;
    existing.viewName = viewName;
    existing.userAgent = userAgent;
    existing.lastSeen = Date.now();
    existing.requestCount++;
  } else {
    devices.set(ip, { ip, viewId, viewName, userAgent, lastSeen: Date.now(), requestCount: 1 });

    // First user connecting to this view - trigger warmup
    if (!warmedUpViews.has(viewId)) {
      warmedUpViews.add(viewId);
      warmupView(viewId).catch((err) => {
        console.error(`[warmup] Failed to warm up view ${viewId}:`, err);
      });
    }
  }
  return true;
}

function devicesPrune(): void {
  const cutoff = Date.now() - DEVICE_TTL_MS;
  for (const [ip, d] of devices) {
    if (d.lastSeen < cutoff) devices.delete(ip);
  }
}

function devicesSnapshot(): DeviceEntry[] {
  devicesPrune();
  return [...devices.values()].sort((a, b) => b.lastSeen - a.lastSeen);
}

// ═══════════════════════════════════════════════════════════════
// DEBUG DATA HELPER (used by both REST and WebSocket)
// ═══════════════════════════════════════════════════════════════

function getDebugData() {
  const viewsDebug = viewCacheAll().map((v) => {
    const idx = getCurrentURLIndex(v);
    return {
      id: v.id,
      name: v.name,
      urls: v.urls,
      method: v.method,
      metaRefreshEnabled: v.metaRefreshEnabled,
      cacheTtlSec: v.cacheTtlSec,
      viewportWidth: v.viewportWidth,
      viewportHeight: v.viewportHeight,
      currentUrlIndex: idx,
      currentUrl: v.urls[idx]?.url ?? "",
      remainingSec: getRemainingSec(v),
      totalCycleSec: v.urls.reduce((s, u) => s + u.durationSec, 0),
      cacheEntries: cacheStats().filter((c) => c.viewId === v.id),
    };
  });

  return {
    server: {
      uptime: Math.round(process.uptime()),
      activeRenders: pagePool?.activeRenders ?? 0,
      queueLength: renderQueue.length,
      cacheEntries: renderCache.size,
      browsers: CONFIG.BROWSER_COUNT,
      pagesPerBrowser: CONFIG.PAGES_PER_BROWSER,
      maxConcurrentRenders: CONFIG.MAX_CONCURRENT_RENDERS,
    },
    views: viewsDebug,
    devices: devicesSnapshot(),
  };
}

// ═══════════════════════════════════════════════════════════════
// BROWSER + PAGE POOL
// ═══════════════════════════════════════════════════════════════

interface BrowserSlot {
  browser: Browser;
  available: Page[];
  inUse: number;
  max: number;
}

class PagePool {
  private slots: BrowserSlot[] = [];
  private pageToSlot = new WeakMap<Page, BrowserSlot>();
  private waiters: Array<{
    resolve: (p: Page) => void;
    reject: (e: Error) => void;
    timeout: ReturnType<typeof setTimeout>;
  }> = [];

  async init(): Promise<void> {
    for (let i = 0; i < CONFIG.BROWSER_COUNT; i++) {
      const browser = await puppeteer.launch({
        executablePath: "/usr/bin/chromium",
        headless: true,
        args: [
          "--no-sandbox",
          "--disable-setuid-sandbox",
          "--disable-dev-shm-usage",
          "--disable-gpu",
          "--disable-software-rasterizer",
          "--disable-extensions",
          "--mute-audio",
        ],
      });
      browser.on("disconnected", () => {
        console.error(`[browser-pool] Browser ${i} disconnected`);
      });

      const slot: BrowserSlot = { browser, available: [], inUse: 0, max: CONFIG.PAGES_PER_BROWSER };
      for (let j = 0; j < CONFIG.PAGE_POOL_WARM; j++) {
        const page = await this.createPage(slot);
        slot.available.push(page);
      }
      this.slots.push(slot);
    }
    console.log(
      `[browser-pool] ${CONFIG.BROWSER_COUNT} browsers × ${CONFIG.PAGES_PER_BROWSER} pages ready`,
    );
  }

  private async createPage(slot: BrowserSlot): Promise<Page> {
    const page = await slot.browser.newPage();
    await page.setViewport({ width: 1920, height: 1080 });
    await page.setRequestInterception(true);
    page.on("request", (req) => {
      const t = req.resourceType();
      if (t === "media" || t === "websocket" || t === "manifest" || t === "font") {
        req.abort();
      } else {
        req.continue();
      }
    });
    this.pageToSlot.set(page, slot);
    return page;
  }

  async resetPage(page: Page): Promise<boolean> {
    try {
      await page.goto("about:blank", { waitUntil: "domcontentloaded", timeout: 5000 });
      await page.emulateMediaFeatures([]);

      // Clear storage via CDP — avoids opaque-origin SecurityError
      const client = await page.createCDPSession();
      await client.send("Storage.clearDataForOrigin", {
        origin: "*",
        storageTypes: "all",
      });
      await client.send("Network.clearBrowserCookies");
      await client.detach();
      return true;
    } catch (err) {
      console.warn(`[page-pool] resetPage failed, discarding page: ${err}`);
      try {
        await page.close();
      } catch {}
      return false;
    }
  }

  acquire(): Promise<Page> {
    for (const slot of this.slots) {
      if (slot.available.length > 0) {
        slot.inUse++;
        return Promise.resolve(slot.available.pop()!);
      }
      if (slot.inUse < slot.max) {
        slot.inUse++;
        return this.createPage(slot);
      }
    }
    return new Promise((resolve, reject) => {
      const timeout = setTimeout(() => {
        const idx = this.waiters.findIndex((w) => w.timeout === timeout);
        if (idx >= 0) this.waiters.splice(idx, 1);
        reject(new Error("Page pool exhausted"));
      }, CONFIG.PAGE_ACQUIRE_TIMEOUT_MS);
      this.waiters.push({ resolve, reject, timeout });
    });
  }

  async release(page: Page): Promise<void> {
    const slot = this.pageToSlot.get(page);
    if (!slot) {
      await page.close().catch(() => {});
      return;
    }
    slot.inUse--;

    const ok = await this.resetPage(page);
    if (!ok) {
      // Page was closed during reset — don't recycle it
      this.pageToSlot.delete(page);
      return;
    }

    if (this.waiters.length > 0) {
      const w = this.waiters.shift()!;
      clearTimeout(w.timeout);
      slot.inUse++;
      w.resolve(page);
      return;
    }
    if (slot.available.length + slot.inUse < slot.max) {
      slot.available.push(page);
    } else {
      await page.close().catch(() => {});
      this.pageToSlot.delete(page);
    }
  }

  get activeRenders(): number {
    return this.slots.reduce((s, slot) => s + slot.inUse, 0);
  }

  async shutdown(): Promise<void> {
    for (const slot of this.slots) {
      for (const p of slot.available) await p.close().catch(() => {});
      await slot.browser.close().catch(() => {});
    }
    this.slots = [];
  }
}

let pagePool: PagePool;

// ═══════════════════════════════════════════════════════════════
// WEBSOCKET DEBUG CLIENTS
// ═══════════════════════════════════════════════════════════════

const debugClients = new Map<any, { interval: number; timer: ReturnType<typeof setInterval> }>();
const DEBUG_DEFAULT_INTERVAL_MS = 1000;
const DEBUG_MIN_INTERVAL_MS = 100;

// ═══════════════════════════════════════════════════════════════
// RENDER CACHE + QUEUE
// ═══════════════════════════════════════════════════════════════

const renderCache = new Map<string, CachedRender>();
const inFlightRenders = new Map<string, ActiveRender>();
const renderQueue: QueuedRender[] = [];

function renderCacheKey(viewId: string, urlIndex: number): string {
  return `${viewId}:${urlIndex}`;
}

function cachePurgeExpired(): void {
  const now = Date.now();
  for (const [key, entry] of renderCache) {
    if (now >= entry.expiresAt) renderCache.delete(key);
  }
}

setInterval(cachePurgeExpired, CONFIG.CACHE_CLEANUP_INTERVAL_MS);

async function warmupView(viewId: string): Promise<void> {
  const view = viewCacheGet(viewId);
  if (!view) {
    console.warn(`[warmup] View ${viewId} not found`);
    return;
  }

  console.log(`[warmup] Starting precache for view "${view.name}" (${view.urls.length} URLs)`);

  for (let i = 0; i < view.urls.length; i++) {
    const key = renderCacheKey(view.id, i);
    const cached = renderCache.get(key);
    const now = Date.now();

    if (!cached || now >= cached.expiresAt) {
      try {
        await getOrRender(view, i);
        console.log(`[warmup] Precached ${view.name} URL ${i}: ${view.urls[i].url}`);
      } catch (err: any) {
        console.error(`[warmup] Failed to precache ${view.name} URL ${i}: ${err.message}`);
      }
    }
  }

  console.log(`[warmup] Precache complete for view "${view.name}"`);
}

async function warmupCache(): Promise<void> {
  const activeDevices = devicesSnapshot();
  if (activeDevices.length === 0) {
    return;
  }

  console.log(`[warmup] Starting periodic precache for ${activeDevices.length} active device(s)`);

  const views = viewCacheAll();
  for (const view of views) {
    for (let i = 0; i < view.urls.length; i++) {
      const key = renderCacheKey(view.id, i);
      const cached = renderCache.get(key);
      const now = Date.now();

      if (!cached || now >= cached.expiresAt) {
        try {
          await getOrRender(view, i);
          console.log(`[warmup] Precached ${view.name} URL ${i}: ${view.urls[i].url}`);
        } catch (err: any) {
          console.error(`[warmup] Failed to precache ${view.name} URL ${i}: ${err.message}`);
        }
      }
    }
  }

  console.log(`[warmup] Periodic precache complete`);
}

setInterval(warmupCache, CONFIG.WARMUP_INTERVAL_MS);

function cacheInvalidate(viewId: string): void {
  const prefix = `${viewId}:`;
  for (const key of renderCache.keys()) {
    if (key.startsWith(prefix)) renderCache.delete(key);
  }
  for (let i = renderQueue.length - 1; i >= 0; i--) {
    if (renderQueue[i].viewId === viewId) {
      renderQueue[i].reject(new Error("View deleted"));
      renderQueue.splice(i, 1);
    }
  }
  // Allow re-warming if view is recreated
  warmedUpViews.delete(viewId);
}

function drainRenderQueue(): void {
  const now = Date.now();

  for (let i = renderQueue.length - 1; i >= 0; i--) {
    if (now - renderQueue[i].queuedAt > CONFIG.QUEUE_TIMEOUT_MS) {
      const q = renderQueue[i];
      q.reject(new Error("Render queue timeout"));
      console.log(
        `[queue] Dropped waiter for ${q.key} (timeout ${Math.round((now - q.queuedAt) / 1000)}s)`,
      );
      renderQueue.splice(i, 1);
    }
  }

  while (renderQueue.length > 0 && pagePool.activeRenders < CONFIG.MAX_CONCURRENT_RENDERS) {
    const next = renderQueue.shift()!;
    const view = viewCacheGet(next.viewId);
    if (!view) {
      next.reject(new Error("View deleted while queued"));
      continue;
    }

    const cached = renderCache.get(next.key);
    if (cached && Date.now() < cached.expiresAt) {
      next.resolve(cached.body);
      continue;
    }

    console.log(
      `[queue] Dequeued ${next.key} (waited ${Math.round((now - next.queuedAt) / 1000)}s)`,
    );
    const renderPromise = renderViewToCache(view, next.urlIndex, next.key);
    inFlightRenders.set(next.key, { promise: renderPromise, urlIndex: next.urlIndex });
    renderPromise.then(
      (body) => {
        inFlightRenders.delete(next.key);
        next.resolve(body);
      },
      (err) => {
        inFlightRenders.delete(next.key);
        next.reject(err);
      },
    );
  }
}

async function renderViewToCache(view: View, urlIndex: number, key: string): Promise<string> {
  const urlItem = view.urls[urlIndex];
  const forceDarkMode = urlItem.forceDarkMode ?? false;
  const bakeStyles = urlItem.bakeStyles ?? false;
  const waitBeforeCaptureMs = urlItem.waitBeforeCaptureMs ?? 0;

  let body: string;
  if (view.method === "mjpeg") {
    const jpeg = await renderScreenshotFrame(
      urlItem.url,
      view.viewportWidth,
      view.viewportHeight,
      forceDarkMode,
      waitBeforeCaptureMs,
    );
    body = jpeg.toString("base64");
  } else {
    body = await renderSSR(
      urlItem.url,
      view.viewportWidth,
      view.viewportHeight,
      forceDarkMode,
      bakeStyles,
      waitBeforeCaptureMs,
    );
  }

  const now = Date.now();
  const entry: CachedRender = {
    body,
    urlIndex,
    createdAt: now,
    expiresAt: now + view.cacheTtlSec * 1000,
  };
  renderCache.set(key, entry);

  drainRenderQueue();

  return body;
}

async function getOrRender(view: View, urlIndex: number): Promise<string> {
  const key = renderCacheKey(view.id, urlIndex);
  const now = Date.now();

  const cached = renderCache.get(key);
  if (cached && now < cached.expiresAt) {
    return cached.body;
  }

  const inFlight = inFlightRenders.get(key);
  if (inFlight) {
    return inFlight.promise;
  }

  if (pagePool.activeRenders < CONFIG.MAX_CONCURRENT_RENDERS) {
    const promise = renderViewToCache(view, urlIndex, key);
    inFlightRenders.set(key, { promise, urlIndex });
    try {
      return await promise;
    } finally {
      inFlightRenders.delete(key);
    }
  }

  console.log(`[queue] Enqueuing ${key} (position=${renderQueue.length})`);
  return new Promise((resolve, reject) => {
    renderQueue.push({
      resolve,
      reject,
      key,
      viewId: view.id,
      urlIndex,
      queuedAt: Date.now(),
    });
  });
}

function cacheStats(): Array<{
  key: string;
  viewId: string;
  urlIndex: number;
  url: string;
  createdAt: number;
  expiresAt: number;
  ttlRemainingSec: number;
}> {
  const now = Date.now();
  const result: Array<{
    key: string;
    viewId: string;
    urlIndex: number;
    url: string;
    createdAt: number;
    expiresAt: number;
    ttlRemainingSec: number;
  }> = [];

  for (const [key, entry] of renderCache) {
    const [viewId] = key.split(":");
    const view = viewCacheGet(viewId);
    result.push({
      key,
      viewId,
      urlIndex: entry.urlIndex,
      url: view?.urls[entry.urlIndex]?.url ?? "?",
      createdAt: entry.createdAt,
      expiresAt: entry.expiresAt,
      ttlRemainingSec: Math.max(0, Math.round((entry.expiresAt - now) / 1000)),
    });
  }

  return result.sort((a, b) => a.ttlRemainingSec - b.ttlRemainingSec);
}

// ═══════════════════════════════════════════════════════════════
// ROTATION LOGIC
// ═══════════════════════════════════════════════════════════════

function getCurrentURLIndex(view: View): number {
  if (view.urls.length <= 1) return 0;
  const totalCycle = view.urls.reduce((s, u) => s + u.durationSec, 0);
  if (totalCycle <= 0) return 0;
  const elapsed = Math.floor(Date.now() / 1000) % totalCycle;
  let acc = 0;
  for (let i = 0; i < view.urls.length; i++) {
    acc += view.urls[i].durationSec;
    if (elapsed < acc) return i;
  }
  return view.urls.length - 1;
}

function getRemainingSec(view: View): number {
  if (view.urls.length <= 1) {
    return view.urls[0]?.durationSec || 30;
  }
  const totalCycle = view.urls.reduce((s, u) => s + u.durationSec, 0);
  if (totalCycle <= 0) return 30;
  const elapsed = Math.floor(Date.now() / 1000) % totalCycle;
  let acc = 0;
  for (let i = 0; i < view.urls.length; i++) {
    acc += view.urls[i].durationSec;
    if (elapsed < acc) return acc - elapsed;
  }
  return view.urls[0].durationSec;
}

// ═══════════════════════════════════════════════════════════════
// SINGLE-PASS INLINING (SSR mode)
// ═══════════════════════════════════════════════════════════════

function injectMetaRefresh(html: string, intervalSec: number): string {
  const sec = Math.max(1, Math.ceil(intervalSec));
  const tag = `<meta http-equiv="refresh" content="${sec}">`;
  if (html.includes("</head>")) {
    return html.replace("</head>", `  ${tag}\n</head>`);
  }
  if (/<html[^>]*>/i.test(html)) {
    return html.replace(/(<html[^>]*>)/i, `$1\n<head>${tag}</head>`);
  }
  return `<html><head>${tag}</head><body>${html}</body></html>`;
}

function stripScriptTags(html: string): string {
  return html
    .replace(/<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi, "")
    .replace(/\s+on\w+\s*=\s*"[^"]*"/gi, "")
    .replace(/\s+on\w+\s*=\s*'[^']*'/gi, "");
}

// ── Recursive @import resolver (max 3 levels deep) ──
async function resolveCSSImports(cssText: string, baseUrl: string, depth = 0): Promise<string> {
  if (depth > 3) return cssText;
  const importRe =
    /@import\s+(?:url\s*\(\s*["']?([^)"']+)["']?\s*\)|["']([^"']+)["'])\s*([^;]*);/gi;
  const replacements: Array<{ match: string; resolved: string }> = [];

  let m: RegExpExecArray | null;
  while ((m = importRe.exec(cssText)) !== null) {
    const importUrl = new URL(m[1] || m[2], baseUrl).href;
    // Skip font services — font files are blocked by request interception
    if (/fonts\.googleapis\.com|fonts\.gstatic\.com/.test(importUrl)) {
      replacements.push({ match: m[0], resolved: "/* removed font import: " + importUrl + " */" });
      continue;
    }
    try {
      const res = await fetch(importUrl);
      if (!res.ok) throw new Error("failed");
      let imported = await res.text();
      imported = await resolveCSSImports(imported, importUrl, depth + 1);
      replacements.push({
        match: m[0],
        resolved: "/* begin " + importUrl + " */\n" + imported + "\n/* end " + importUrl + " */",
      });
    } catch {
      replacements.push({ match: m[0], resolved: "/* unresolved import: " + importUrl + " */" });
    }
  }

  for (const r of replacements) {
    cssText = cssText.replace(r.match, r.resolved);
  }
  return cssText;
}

// ═══════════════════════════════════════════════════════════════
// CSS COLLECTION (simplified — all CSS into single style tag)
// ═══════════════════════════════════════════════════════════════

/**
 * Collect all CSS from loaded stylesheets and inject into a single <style> tag in head.
 * Simplified alternative to per-element computed style baking.
 * Toggle via URLItem.bakeStyles.
 */
async function bakeComputedStyles(page: Page): Promise<void> {
  await page.evaluate((): void => {
    const cssTexts: string[] = [];

    // Collect from all stylesheets (external and inline)
    for (const sheet of document.styleSheets) {
      try {
        const rules = sheet.cssRules || sheet.rules;
        if (!rules) continue;
        let cssText = "";
        for (const rule of rules) {
          cssText += rule.cssText + "\n";
        }
        if (cssText.trim()) {
          cssTexts.push(`/* ${sheet.href || "inline"} */\n${cssText}`);
        }
      } catch {
        // Cross-origin stylesheets — skip (already inlined by inlineAllResources)
      }
    }

    // Also grab any inline <style> tags content directly
    const styleTags = document.querySelectorAll("style");
    for (const tag of styleTags) {
      const content = tag.textContent?.trim();
      if (content) {
        cssTexts.push(`/* inline style tag */\n${content}`);
      }
    }

    // Create single consolidated style tag in head
    if (cssTexts.length > 0) {
      const consolidated = document.createElement("style");
      consolidated.textContent = cssTexts.join("\n\n");

      // Insert as first element in head so it can be overridden
      const head = document.head;
      if (head.firstChild) {
        head.insertBefore(consolidated, head.firstChild);
      } else {
        head.appendChild(consolidated);
      }
    }
  });
}

async function inlineAllResources(page: Page, html: string): Promise<string> {
  interface InlinePayload {
    css: Array<{ url: string; text: string }>;
    images: Array<{ src: string; dataUri: string }>;
    favicons: Array<{ href: string; dataUri: string }>;
    bgImages: Array<{ url: string; dataUri: string }>;
  }

  let payload: InlinePayload;

  try {
    payload = await page.evaluate((): Promise<InlinePayload> => {
      function blobToDataUri(blob: Blob): Promise<string> {
        return new Promise((resolve) => {
          const reader = new FileReader();
          reader.onloadend = () => resolve(reader.result as string);
          reader.readAsDataURL(blob);
        });
      }
      async function collect(): Promise<InlinePayload> {
        const result: InlinePayload = { css: [], images: [], favicons: [], bgImages: [] };
        // CSS
        const cssLinks = [...document.querySelectorAll<HTMLLinkElement>('link[rel="stylesheet"]')];
        const cssResults = await Promise.allSettled(
          cssLinks.map(async (link) => {
            const res = await fetch(link.href);
            if (!res.ok) throw new Error("fetch failed");
            return { url: link.href, text: await res.text() };
          }),
        );
        result.css = cssResults
          .filter(
            (r): r is PromiseFulfilledResult<{ url: string; text: string }> =>
              r.status === "fulfilled",
          )
          .map((r) => r.value);
        // Images
        const imgs = [
          ...document.querySelectorAll<HTMLImageElement>('img[src]:not([src^="data:"])'),
        ];
        const imgResults = await Promise.allSettled(
          imgs.map(async (img) => {
            const res = await fetch(img.src);
            if (!res.ok) throw new Error("fetch failed");
            return { src: img.src, dataUri: await blobToDataUri(await res.blob()) };
          }),
        );
        result.images = imgResults
          .filter(
            (r): r is PromiseFulfilledResult<{ src: string; dataUri: string }> =>
              r.status === "fulfilled",
          )
          .map((r) => r.value);
        // Background images
        const styleText = [...document.querySelectorAll<HTMLStyleElement>("style")]
          .map((s) => s.textContent ?? "")
          .join("\n");
        const elemStyle = [...document.querySelectorAll<HTMLElement>("[style]")]
          .map((e) => e.getAttribute("style") ?? "")
          .join("\n");
        const allStyle = styleText + "\n" + elemStyle;
        const urlRegex = /url\s*\(\s*["']?([^)"'\s]+)["']?\s*\)/gi;
        const bgUrls = new Set<string>();
        let m: RegExpExecArray | null;
        while ((m = urlRegex.exec(allStyle)) !== null) {
          if (!m[1].startsWith("data:") && !m[1].startsWith("#")) bgUrls.add(m[1]);
        }
        const bgResults = await Promise.allSettled(
          [...bgUrls].map(async (url) => {
            if (!/\.(png|jpe?g|gif|svg|webp|ico)/i.test(url)) throw new Error("not image");
            const res = await fetch(url);
            if (!res.ok) throw new Error("fetch failed");
            return { url, dataUri: await blobToDataUri(await res.blob()) };
          }),
        );
        result.bgImages = bgResults
          .filter(
            (r): r is PromiseFulfilledResult<{ url: string; dataUri: string }> =>
              r.status === "fulfilled",
          )
          .map((r) => r.value);
        // Favicons
        const icons = [...document.querySelectorAll<HTMLLinkElement>('link[rel*="icon"]')];
        const iconResults = await Promise.allSettled(
          icons.map(async (link) => {
            if (link.href.startsWith("data:")) throw new Error("skip");
            const res = await fetch(link.href);
            if (!res.ok) throw new Error("fetch failed");
            return { href: link.href, dataUri: await blobToDataUri(await res.blob()) };
          }),
        );
        result.favicons = iconResults
          .filter(
            (r): r is PromiseFulfilledResult<{ href: string; dataUri: string }> =>
              r.status === "fulfilled",
          )
          .map((r) => r.value);
        return result;
      }
      return collect();
    });
  } catch {
    return html;
  }

  for (const css of payload.css) {
    const escaped = css.url.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");

    // Match both double and single-quoted href
    const linkRegex = new RegExp(`<link\\b[^>]*\\bhref\\s*=\\s*["']${escaped}["'][^>]*>`, "gi");
    const linkMatch = html.match(linkRegex);

    // Preserve media attribute if present
    let mediaAttr = "";
    if (linkMatch) {
      const m2 = linkMatch[0].match(/\bmedia\s*=\s*["']([^"']*)["']/i);
      if (m2 && m2[1]) mediaAttr = ` media="${m2[1]}"`;
    }

    // Resolve @import rules recursively
    const resolvedCSS = await resolveCSSImports(css.text, css.url);

    html = html.replace(
      linkRegex,
      `<style${mediaAttr}>/* inlined: ${css.url} */\n${resolvedCSS}\n</style>`,
    );
  }
  for (const img of payload.images) {
    const escaped = img.src.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
    html = html.replace(
      new RegExp(`(<img\\b[^>]*\\bsrc\\s*=\\s*)"${escaped}"`, "gi"),
      `$1"${img.dataUri}"`,
    );
  }
  for (const bg of payload.bgImages) {
    const escaped = bg.url.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
    html = html.replace(
      new RegExp(`url\\s*\\(\\s*["']?${escaped}["']?\\s*\\)`, "gi"),
      `url(${bg.dataUri})`,
    );
  }
  for (const fav of payload.favicons) {
    const escaped = fav.href.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
    html = html.replace(
      new RegExp(`(<link\\b[^>]*\\bhref\\s*=\\s*)"${escaped}"`, "gi"),
      `$1"${fav.dataUri}"`,
    );
  }
  html = html.replace(
    /<link\b[^>]*\brel\s*=\s*"(?:preload|prefetch|preconnect|dns-prefetch|modulepreload)"[^>]*>/gi,
    "",
  );
  html = html.replace(/\s+crossorigin\s*=\s*"[^"]*"/gi, "");
  html = html.replace(/\s+integrity\s*=\s*"[^"]*"/gi, "");
  return html;
}

async function renderSSR(
  url: string,
  viewportWidth = 1920,
  viewportHeight = 1080,
  forceDarkMode = false,
  bakeStyles = false,
  waitBeforeCaptureMs = 0,
): Promise<string> {
  const page = await pagePool.acquire();
  try {
    await page.setViewport({ width: viewportWidth, height: viewportHeight });
    if (forceDarkMode) {
      await page.emulateMediaFeatures([{ name: "prefers-color-scheme", value: "dark" }]);
    }

    // Try networkidle0 first; fall back to whatever we have on timeout
    try {
      await page.goto(url, { waitUntil: "networkidle0", timeout: CONFIG.RENDER_TIMEOUT_MS });
    } catch (err: any) {
      if (err.message?.includes("timeout")) {
        console.warn(`[renderSSR] networkidle0 timeout for ${url}, using current content`);
      } else {
        throw err;
      }
    }

    // Wait before capture (for animations, dynamic content, etc.)
    if (waitBeforeCaptureMs > 0) {
      await new Promise((r) => setTimeout(r, waitBeforeCaptureMs));
    }

    let html = await page.content();
    html = await inlineAllResources(page, html);

    // Set inlined HTML back to page so bake can collect all CSS
    await page.setContent(html, { waitUntil: "domcontentloaded" });

    // Bake: collect all CSS into single style tag
    if (bakeStyles) {
      await bakeComputedStyles(page);
      html = await page.content();
    }

    html = stripScriptTags(html);
    return html;
  } finally {
    await pagePool.release(page);
  }
}

// ═══════════════════════════════════════════════════════════════
// SCREENSHOT RENDERING
// ═══════════════════════════════════════════════════════════════

async function renderScreenshotFrame(
  url: string,
  viewportWidth = 1920,
  viewportHeight = 1080,
  forceDarkMode = false,
  waitBeforeCaptureMs = 0,
): Promise<Buffer> {
  const page = await pagePool.acquire();
  try {
    await page.setViewport({ width: viewportWidth, height: viewportHeight });
    if (forceDarkMode) {
      await page.emulateMediaFeatures([{ name: "prefers-color-scheme", value: "dark" }]);
    }

    try {
      await page.goto(url, { waitUntil: "networkidle0", timeout: CONFIG.RENDER_TIMEOUT_MS });
    } catch (err: any) {
      if (err.message?.includes("timeout")) {
        console.warn(`[renderScreenshot] networkidle0 timeout for ${url}, using current content`);
      } else {
        throw err;
      }
    }

    // Wait before capture (for animations, dynamic content, etc.)
    if (waitBeforeCaptureMs > 0) {
      await new Promise((r) => setTimeout(r, waitBeforeCaptureMs));
    }

    return Buffer.from(await page.screenshot({ type: "jpeg", quality: 75, fullPage: false }));
  } finally {
    await pagePool.release(page);
  }
}

function screenshotHTML(jpegBase64: string, refreshSec: number): string {
  const sec = Math.max(2, Math.ceil(refreshSec));
  return `<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="refresh" content="${sec}">
<style>
  *{margin:0;padding:0;box-sizing:border-box;}
  html,body{width:100%;height:100%;background:#000;}
  img{display:block;width:100%;height:100%;object-fit:contain;}
</style>
</head>
<body>
<img src="data:image/jpeg;base64,${jpegBase64}" alt="">
</body>
</html>`;
}

// ═══════════════════════════════════════════════════════════════
// ERROR PAGE
// ═══════════════════════════════════════════════════════════════

function errorPage(message: string, retrySec = 10): string {
  return `<!DOCTYPE html>
<html>
<head><meta charset="utf-8"><title>Error</title>
<meta http-equiv="refresh" content="${retrySec}">
<style>
  *{margin:0;padding:0;box-sizing:border-box;}
  body{background:#1a1a2e;color:#e94560;display:flex;align-items:center;justify-content:center;height:100vh;font-family:sans-serif;font-size:clamp(14px,3vw,24px);}
  .box{text-align:center;padding:40px;}
  .icon{font-size:clamp(32px,8vw,64px);margin:0;}
  .tag{font-size:clamp(10px,2vw,14px);color:#888;}
</style>
</head>
<body>
<div class="box">
  <p class="icon">⚠</p>
  <p>${message}</p>
  <p class="tag">Samsung TV Proxy — retrying in ${retrySec}s</p>
</div>
</body>
</html>`;
}

// ═══════════════════════════════════════════════════════════════
// VIEW SERVING — /v/:id
// ═══════════════════════════════════════════════════════════════

async function serveView(view: View): Promise<Response> {
  const idx = getCurrentURLIndex(view);
  let body: string;

  try {
    body = await getOrRender(view, idx);
  } catch (err: any) {
    console.error(`[serve:${view.id}] Render failed: ${err.message}`);
    return new Response(errorPage(`Failed: ${view.urls[idx]?.url}`), {
      status: 502,
      headers: { "Content-Type": "text/html; charset=utf-8" },
    });
  }

  let html: string;
  if (view.method === "mjpeg") {
    html = screenshotHTML(body, getRemainingSec(view));
  } else {
    html = view.metaRefreshEnabled ? injectMetaRefresh(body, getRemainingSec(view)) : body;
  }

  return new Response(html, {
    headers: {
      "Content-Type": "text/html; charset=utf-8",
      "Cache-Control": "no-cache, no-store, must-revalidate",
    },
  });
}

// ═══════════════════════════════════════════════════════════════
// HTTP HELPERS
// ═══════════════════════════════════════════════════════════════

function json(data: unknown, status = 200): Response {
  return new Response(JSON.stringify(data), {
    status,
    headers: { "Content-Type": "application/json" },
  });
}

// ═══════════════════════════════════════════════════════════════
// API
// ═══════════════════════════════════════════════════════════════

async function handleAPI(req: Request, path: string): Promise<Response> {
  const method = req.method;
  const url = new URL(req.url);

  // GET /api/views
  if (path === "/api/views" && method === "GET") {
    return json(viewCacheAll());
  }

  // GET /api/debug
  if (path === "/api/debug" && method === "GET") {
    return json(getDebugData());
  }

  // GET /api/banned
  if (path === "/api/banned" && method === "GET") {
    return json(dbGetBannedIPs());
  }

  // POST /api/views
  if (path === "/api/views" && method === "POST") {
    try {
      const body: CreateViewBody = JSON.parse(await req.text());
      if (!body.name?.trim()) return json({ error: "Name is required" }, 400);
      if (!body.urls?.length) return json({ error: "At least one URL is required" }, 400);
      for (const u of body.urls) {
        if (!u.url?.trim()) return json({ error: "Each URL must have a url" }, 400);
        if (typeof u.durationSec !== "number" || u.durationSec <= 0)
          return json({ error: "Each URL must have positive durationSec" }, 400);
      }
      if (!["mjpeg", "ssr"].includes(body.method))
        return json({ error: 'method must be "mjpeg" or "ssr"' }, 400);

      const view: View = {
        id: crypto.randomUUID(),
        name: body.name.trim(),
        urls: body.urls.map((u) => ({
          url: u.url.trim(),
          durationSec: Math.max(1, Math.round(u.durationSec)),
          waitBeforeCaptureMs: Math.max(0, u.waitBeforeCaptureMs ?? 0),
          forceDarkMode: u.forceDarkMode ?? false,
          bakeStyles: u.bakeStyles ?? false,
        })),
        method: body.method,
        metaRefreshEnabled: body.metaRefreshEnabled ?? false,
        cacheTtlSec: Math.max(0, body.cacheTtlSec ?? 60),
        viewportWidth: Math.max(320, Math.min(7680, body.viewportWidth ?? 1920)),
        viewportHeight: Math.max(240, Math.min(4320, body.viewportHeight ?? 1080)),
        createdAt: Math.floor(Date.now() / 1000),
      };

      dbInsert(view);
      viewCache.set(view.id, view);
      console.log(`[api] Created "${view.name}" (${view.id}) method=${view.method}`);
      return json(view, 201);
    } catch {
      return json({ error: "Invalid JSON body" }, 400);
    }
  }

  // /api/views/:id
  const viewMatch = path.match(/^\/api\/views\/([a-f0-9-]+)$/);
  if (viewMatch) {
    const viewId = viewMatch[1];

    if (method === "GET") {
      const view = viewCacheGet(viewId);
      if (!view) return json({ error: "View not found" }, 404);
      return json(view);
    }

    if (method === "PUT") {
      const view = viewCacheGet(viewId);
      if (!view) return json({ error: "View not found" }, 404);

      try {
        const body: UpdateViewBody = JSON.parse(await req.text());
        if (body.name !== undefined) view.name = body.name.trim();
        if (body.urls !== undefined) {
          if (body.urls.length === 0) return json({ error: "At least one URL is required" }, 400);
          view.urls = body.urls.map((u) => ({
            url: u.url.trim(),
            durationSec: Math.max(1, Math.round(u.durationSec)),
            waitBeforeCaptureMs: Math.max(0, u.waitBeforeCaptureMs ?? 0),
            forceDarkMode: u.forceDarkMode ?? false,
            bakeStyles: u.bakeStyles ?? false,
          }));
        }
        if (body.method !== undefined) {
          if (!["mjpeg", "ssr"].includes(body.method))
            return json({ error: 'method must be "mjpeg" or "ssr"' }, 400);
          view.method = body.method;
        }
        if (body.metaRefreshEnabled !== undefined)
          view.metaRefreshEnabled = body.metaRefreshEnabled;
        if (body.cacheTtlSec !== undefined) view.cacheTtlSec = Math.max(0, body.cacheTtlSec);
        if (body.viewportWidth !== undefined)
          view.viewportWidth = Math.max(320, Math.min(7680, body.viewportWidth));
        if (body.viewportHeight !== undefined)
          view.viewportHeight = Math.max(240, Math.min(4320, body.viewportHeight));

        dbUpdate(view);
        cacheInvalidate(viewId);
        viewCache.set(view.id, view);
        console.log(`[api] Updated "${view.name}" (${view.id})`);
        return json(view);
      } catch {
        return json({ error: "Invalid JSON body" }, 400);
      }
    }

    if (method === "DELETE") {
      if (!dbDelete(viewId)) return json({ error: "View not found" }, 404);
      cacheInvalidate(viewId);
      viewCache.delete(viewId);
      console.log(`[api] Deleted ${viewId}`);
      return json({ ok: true });
    }

    // GET /api/views/:id/export - Export single view as JSON
    if (method === "GET" && url.searchParams.get("export") === "true") {
      const view = viewCacheGet(viewId);
      if (!view) return json({ error: "View not found" }, 404);

      const exportData = {
        name: view.name,
        urls: view.urls,
        method: view.method,
        metaRefreshEnabled: view.metaRefreshEnabled,
        cacheTtlSec: view.cacheTtlSec,
        viewportWidth: view.viewportWidth,
        viewportHeight: view.viewportHeight,
      };

      return new Response(JSON.stringify(exportData, null, 2), {
        headers: {
          "Content-Type": "application/json",
          "Content-Disposition": `attachment; filename="view-${viewId}.json"`,
        },
      });
    }
  }

  // POST /api/views/import - Import a view from JSON
  if (path === "/api/views/import" && method === "POST") {
    try {
      const importData = JSON.parse(await req.text());

      if (!importData.name?.trim()) return json({ error: "Name is required" }, 400);
      if (!importData.urls?.length) return json({ error: "At least one URL is required" }, 400);
      for (const u of importData.urls) {
        if (!u.url?.trim()) return json({ error: "Each URL must have a url" }, 400);
        if (typeof u.durationSec !== "number" || u.durationSec <= 0)
          return json({ error: "Each URL must have positive durationSec" }, 400);
      }
      const method = importData.method ?? "ssr";
      if (!["mjpeg", "ssr"].includes(method))
        return json({ error: 'method must be "mjpeg" or "ssr"' }, 400);

      const view: View = {
        id: crypto.randomUUID(),
        name: importData.name.trim(),
        urls: importData.urls.map((u: URLItem) => ({
          url: u.url.trim(),
          durationSec: Math.max(1, Math.round(u.durationSec)),
          waitBeforeCaptureMs: Math.max(0, u.waitBeforeCaptureMs ?? 0),
          forceDarkMode: u.forceDarkMode ?? false,
          bakeStyles: u.bakeStyles ?? false,
        })),
        method: method,
        metaRefreshEnabled: importData.metaRefreshEnabled ?? false,
        cacheTtlSec: Math.max(0, importData.cacheTtlSec ?? 60),
        viewportWidth: Math.max(320, Math.min(7680, importData.viewportWidth ?? 1920)),
        viewportHeight: Math.max(240, Math.min(4320, importData.viewportHeight ?? 1080)),
        createdAt: Math.floor(Date.now() / 1000),
      };

      dbInsert(view);
      viewCache.set(view.id, view);
      console.log(`[api] Imported "${view.name}" (${view.id}) method=${view.method}`);
      return json(view, 201);
    } catch {
      return json({ error: "Invalid JSON body" }, 400);
    }
  }

  // POST /api/admin/disconnect/:ip
  const disconnectMatch = path.match(/^\/api\/admin\/disconnect\/(.+)$/);
  if (disconnectMatch && method === "POST") {
    const ip = decodeURIComponent(disconnectMatch[1]);
    devices.delete(ip);
    console.log(`[admin] Disconnected device: ${ip}`);
    return json({ ok: true, message: `Device ${ip} disconnected` });
  }

  // POST /api/admin/ban/:ip
  const banMatch = path.match(/^\/api\/admin\/ban\/(.+)$/);
  if (banMatch && method === "POST") {
    const ip = decodeURIComponent(banMatch[1]);
    try {
      const body = JSON.parse(await req.text());
      const reason = body.reason || "Banned by administrator";
      const bannedDevice = devices.get(ip);
      dbBanIP(ip, reason);
      devices.delete(ip);
      if (bannedDevice) cacheInvalidate(bannedDevice.viewId);
      console.log(`[admin] Banned IP: ${ip}, reason: ${reason}`);
      return json({ ok: true, message: `IP ${ip} banned` });
    } catch {
      return json({ error: "Invalid JSON body" }, 400);
    }
  }

  // POST /api/admin/unban/:ip
  const unbanMatch = path.match(/^\/api\/admin\/unban\/(.+)$/);
  if (unbanMatch && method === "POST") {
    const ip = decodeURIComponent(unbanMatch[1]);
    const success = dbUnbanIP(ip);
    if (success) {
      console.log(`[admin] Unbanned IP: ${ip}`);
      return json({ ok: true, message: `IP ${ip} unbanned` });
    } else {
      return json({ error: "IP not found in ban list" }, 404);
    }
  }

  // POST /api/admin/refresh/:ip
  const refreshMatch = path.match(/^\/api\/admin\/refresh\/(.+)$/);
  if (refreshMatch && method === "POST") {
    const ip = decodeURIComponent(refreshMatch[1]);
    const device = devices.get(ip);
    if (device) {
      cacheInvalidate(device.viewId);
      console.log(`[admin] Forced cache refresh for view: ${device.viewId}`);
      return json({ ok: true, message: `Cache refreshed for view ${device.viewId}` });
    } else {
      return json({ error: "Device not found" }, 404);
    }
  }

  return json({ error: "Not found" }, 404);
}

// ═══════════════════════════════════════════════════════════════
// STATIC
// ═══════════════════════════════════════════════════════════════

const STATIC_DIR = new URL("../public", import.meta.url).pathname;

async function serveStatic(path: string): Promise<Response | null> {
  const filePath = path === "/" ? "/index.html" : path;
  if (!filePath.startsWith("/") || filePath.includes("..")) return null;
  try {
    const file = Bun.file(STATIC_DIR + filePath);
    await file.slice(0, 0).text();
    return new Response(file);
  } catch {
    try {
      return new Response(Bun.file(STATIC_DIR + "/index.html"));
    } catch {
      return null;
    }
  }
}

// ═══════════════════════════════════════════════════════════════
// SERVER
// ═══════════════════════════════════════════════════════════════

const server = Bun.serve<{ interval: number }>({
  port: CONFIG.PORT,
  idleTimeout: (CONFIG.QUEUE_TIMEOUT_MS + 10_000) / 1000, // 40s — enough for worst-case queue wait
  websocket: {
    open(ws) {
      const interval = ws.data?.interval ?? DEBUG_DEFAULT_INTERVAL_MS;
      const timer = setInterval(() => {
        try {
          ws.send(JSON.stringify(getDebugData()));
        } catch {
          clearInterval(timer);
          debugClients.delete(ws);
        }
      }, interval);
      debugClients.set(ws, { interval, timer });
      // Send initial payload immediately
      try {
        ws.send(JSON.stringify(getDebugData()));
      } catch {}
    },
    message(ws, msg) {
      try {
        const data = JSON.parse(msg as string);
        if (data.type === "debug-interval" && typeof data.interval === "number") {
          const client = debugClients.get(ws);
          if (!client) return;
          const interval = Math.max(DEBUG_MIN_INTERVAL_MS, data.interval);
          clearInterval(client.timer);
          client.interval = interval;
          client.timer = setInterval(() => {
            try {
              ws.send(JSON.stringify(getDebugData()));
            } catch {
              clearInterval(client.timer);
              debugClients.delete(ws);
            }
          }, interval);
          // Push immediately after rate change
          try {
            ws.send(JSON.stringify(getDebugData()));
          } catch {}
        }
      } catch {
        /* ignore malformed messages */
      }
    },
    close(ws) {
      const client = debugClients.get(ws);
      if (client) {
        clearInterval(client.timer);
        debugClients.delete(ws);
      }
    },
  },

  async fetch(req) {
    const url = new URL(req.url);
    const path = url.pathname;

    // ── WebSocket upgrade for debug panel ──
    if (path === "/ws") {
      const qInterval = parseInt(url.searchParams.get("interval") ?? "");
      const wsInterval = Math.max(
        DEBUG_MIN_INTERVAL_MS,
        Number.isFinite(qInterval) ? qInterval : DEBUG_DEFAULT_INTERVAL_MS,
      );
      if (server.upgrade(req, { data: { interval: wsInterval } })) {
        return; // upgraded — Bun will call websocket.open
      }
      return new Response("WebSocket upgrade failed", { status: 500 });
    }

    // View serving — /v/:id
    const viewMatch = path.match(/^\/v\/([a-f0-9-]+)$/);
    if (viewMatch) {
      const view = viewCacheGet(viewMatch[1]);
      const ip = server.requestIP(req)?.address ?? "unknown";
      if (!view) {
        return new Response(errorPage("View not found"), {
          status: 404,
          headers: { "Content-Type": "text/html; charset=utf-8" },
        });
      }
      if (view.urls.length === 0) {
        return new Response(errorPage("No URLs configured"), {
          status: 500,
          headers: { "Content-Type": "text/html; charset=utf-8" },
        });
      }

      const tracked = deviceTrack(
        ip,
        view.id,
        view.name,
        req.headers.get("User-Agent") ?? "unknown",
      );
      if (!tracked) {
        return new Response(errorPage("Access denied"), {
          status: 403,
          headers: { "Content-Type": "text/html; charset=utf-8" },
        });
      }
      return serveView(view);
    }

    // API
    if (path.startsWith("/api/")) {
      return handleAPI(req, path);
    }

    // Health
    if (path === "/health") {
      return json({
        status: "ok",
        uptime: process.uptime(),
        views: viewCacheAll().length,
        cacheEntries: renderCache.size,
        activeRenders: pagePool?.activeRenders ?? 0,
        queueLength: renderQueue.length,
      });
    }

    // Static
    const staticResponse = await serveStatic(path);
    if (staticResponse) return staticResponse;

    return new Response("Not found", { status: 404 });
  },

  error(err) {
    console.error("[server]", err);
    return new Response("Internal Server Error", { status: 500 });
  },
});

// ═══════════════════════════════════════════════════════════════
// INIT & SHUTDOWN
// ═══════════════════════════════════════════════════════════════

async function init() {
  viewCacheInit();
  pagePool = new PagePool();
  await pagePool.init();

  console.log(`\n🚀 Samsung TV Proxy Server`);
  console.log(`   http://localhost:${CONFIG.PORT}`);
  console.log(`   Views:  http://localhost:${CONFIG.PORT}/v/<view-id>`);
  console.log(`   Health: http://localhost:${CONFIG.PORT}/health`);
  console.log(`   Debug:  http://localhost:${CONFIG.PORT}/api/debug`);
  console.log(`   Browsers: ${CONFIG.BROWSER_COUNT} × ${CONFIG.PAGES_PER_BROWSER} pages`);
  console.log(`   Cache TTL cleanup: ${CONFIG.CACHE_CLEANUP_INTERVAL_MS / 1000}s intervals\n`);
}

async function shutdown() {
  console.log("\n[shutdown] Closing…");

  if (inFlightRenders.size > 0) {
    console.log(`[shutdown] Waiting for ${inFlightRenders.size} in-flight render(s)…`);
    await Promise.allSettled([...inFlightRenders.values()].map((r) => r.promise));
  }

  await pagePool.shutdown();
  server.stop();
  process.exit(0);
}

process.on("SIGINT", shutdown);
process.on("SIGTERM", shutdown);

init();