/**
 * Cookie picker route handler — HTTP + Playwright glue
 *
 * Handles all /cookie-picker/* routes. Imports from cookie-import-browser.ts
 * (decryption) and cookie-picker-ui.ts (HTML generation).
 *
 * Auth model (post-CVE fix):
 *   GET  /cookie-picker              → requires one-time code (?code=) or session cookie
 *   GET  /cookie-picker/browsers     → requires Bearer token or session cookie
 *   GET  /cookie-picker/domains      → requires Bearer token or session cookie
 *   POST /cookie-picker/import       → requires Bearer token or session cookie
 *   POST /cookie-picker/remove       → requires Bearer token or session cookie
 *   GET  /cookie-picker/imported     → requires Bearer token or session cookie
 *
 * The session cookie (gstack_picker) is isolated from the scoped token system.
 * It is NOT valid for /command. This prevents session cookie extraction from
 * re-enabling the auth token leak vulnerability.
 */

import * as crypto from 'crypto';
import type { BrowserManager } from './browser-manager';
import { findInstalledBrowsers, listDomains, withCookieReadRetry, CookieImportError } from './cookie-import-browser';
import { getCookiePickerHTML } from './cookie-picker-ui';
import { getCookieProfiles, runCookieImport, type CookieImportTarget } from './cookie-import-operation';
import { validateCookieStorageSupport } from './cookie-auth-verification';

// ─── Auth State ─────────────────────────────────────────────────
// One-time codes for the cookie picker UI (code → expiry timestamp).
// Codes are generated by generatePickerCode() and consumed on first use.
interface PickerContext {
  target?: CookieImportTarget;
  browser?: string;
  profile?: string;
  clearStorage?: boolean;
  verifyAuth?: boolean;
}

const pendingCodes = new Map<string, PickerContext & { expiry: number }>();
const CODE_TTL_MS = 5 * 60_000;

// Session cookies for authenticated picker access (session → expiry timestamp).
// Sessions are created after a valid code exchange and last 1 hour.
const validSessions = new Map<string, PickerContext & { expiry: number; pickerInstance: string }>();
const SESSION_TTL_MS = 3_600_000; // 1 hour

/** Generate a one-time code for opening the cookie picker UI. */
export function generatePickerCode(context: PickerContext = {}): string {
  const code = crypto.randomUUID();
  pendingCodes.set(code, { ...context, expiry: Date.now() + CODE_TTL_MS });
  return code;
}

/** Return true while the picker still has a live code or session. */
export function hasActivePicker(): boolean {
  const now = Date.now();

  for (const [code, context] of pendingCodes) {
    if (context.expiry > now) return true;
    pendingCodes.delete(code);
  }

  for (const [session, context] of validSessions) {
    if (context.expiry > now) return true;
    validSessions.delete(session);
  }

  return false;
}

/** Extract session ID from the gstack_picker cookie. */
function getSessionFromCookie(req: Request): string | null {
  const cookie = req.headers.get('cookie');
  if (!cookie) return null;
  const match = cookie.match(/gstack_picker=([^;]+)/);
  return match ? match[1] : null;
}

/** Check if a session cookie value is valid and not expired. */
function isValidSession(session: string): boolean {
  const context = validSessions.get(session);
  if (!context) return false;
  if (Date.now() >= context.expiry) { validSessions.delete(session); return false; }
  return true;
}

// ─── Domain State ───────────────────────────────────────────────
// Tracks which domains were imported via the picker.
// /imported only returns cookies for domains in this Set.
// /remove clears from this Set.
const importedDomains = new Set<string>();
const importedCounts = new Map<string, number>();

// ─── JSON Helpers ───────────────────────────────────────────────

function corsOrigin(port: number): string {
  return `http://127.0.0.1:${port}`;
}

function jsonResponse(data: any, opts: { port: number; status?: number }): Response {
  return new Response(JSON.stringify(data), {
    status: opts.status ?? 200,
    headers: {
      'Content-Type': 'application/json',
      'Access-Control-Allow-Origin': corsOrigin(opts.port),
    },
  });
}

function errorResponse(message: string, code: string, opts: { port: number; status?: number; action?: string }): Response {
  return jsonResponse(
    { error: message, code, ...(opts.action ? { action: opts.action } : {}) },
    { port: opts.port, status: opts.status ?? 400 },
  );
}

// ─── Route Handler ──────────────────────────────────────────────

export async function handleCookiePickerRoute(
  url: URL,
  req: Request,
  bm: BrowserManager,
  authToken?: string,
): Promise<Response> {
  const pathname = url.pathname;
  const port = parseInt(url.port, 10) || 9400;

  // CORS preflight
  if (req.method === 'OPTIONS') {
    return new Response(null, {
      status: 204,
      headers: {
        'Access-Control-Allow-Origin': corsOrigin(port),
        'Access-Control-Allow-Methods': 'GET, POST, OPTIONS',
        'Access-Control-Allow-Headers': 'Content-Type, Authorization, X-Gstack-Picker-Instance',
      },
    });
  }

  try {
    // GET /cookie-picker — serve the picker UI (requires code or session cookie)
    if (pathname === '/cookie-picker' && req.method === 'GET') {
      const code = url.searchParams.get('code');

      // Code exchange: validate one-time code, set session cookie, redirect
      if (code) {
        const context = pendingCodes.get(code);
        if (!context || Date.now() >= context.expiry) {
          pendingCodes.delete(code);
          return new Response('Invalid or expired code. Re-run cookie-import-browser.', {
            status: 403,
            headers: { 'Content-Type': 'text/plain' },
          });
        }
        pendingCodes.delete(code); // one-time use
        const session = crypto.randomUUID();
        validSessions.set(session, { ...context, expiry: Date.now() + SESSION_TTL_MS, pickerInstance: crypto.randomUUID() });
        return new Response(null, {
          status: 302,
          headers: {
            'Location': '/cookie-picker',
            'Set-Cookie': `gstack_picker=${session}; HttpOnly; SameSite=Strict; Path=/cookie-picker; Max-Age=3600`,
            'Cache-Control': 'no-store',
          },
        });
      }

      // Session cookie: serve HTML (no auth token inlined)
      const session = getSessionFromCookie(req);
      if (session && isValidSession(session)) {
        const context = validSessions.get(session)!;
        let targetOrigin: string | undefined;
        let storageResetAvailable = false;
        try {
          const url = new URL(context.target?.url ?? '');
          if (['http:', 'https:'].includes(url.protocol)) targetOrigin = url.origin;
        } catch {}
        if (context.target) {
          try { validateCookieStorageSupport(context.target.page); storageResetAvailable = true; } catch {}
        }
        const html = getCookiePickerHTML(port, {
          pickerInstance: context.pickerInstance,
          browser: context.browser,
          profile: context.profile,
          clearStorage: context.clearStorage,
          verifyAuth: context.verifyAuth,
          targetOrigin,
          storageResetAvailable,
          verificationAvailable: !!process.env.GSTACK_COOKIE_AUTH_SELECTOR?.trim() && !!process.env.GSTACK_COOKIE_AUTH_EXPECTED_IDENTITY?.trim(),
        });
        return new Response(html, {
          status: 200,
          headers: { 'Content-Type': 'text/html; charset=utf-8' },
        });
      }

      // No code, no session: reject
      return new Response('Access denied. Open the cookie picker from gstack.', {
        status: 403,
        headers: { 'Content-Type': 'text/plain' },
      });
    }

    // ─── Auth gate: all data/action routes below require Bearer token or session cookie ───
    const authHeader = req.headers.get('authorization');
    const sessionId = getSessionFromCookie(req);
    const hasBearer = !!authToken && !!authHeader && authHeader === `Bearer ${authToken}`;
    const hasSession = sessionId !== null && isValidSession(sessionId);
    if (!hasBearer && !hasSession) {
      return new Response(JSON.stringify({ error: 'Unauthorized' }), {
        status: 401,
        headers: { 'Content-Type': 'application/json' },
      });
    }
    if (req.method === 'POST' && !hasBearer && req.headers.get('origin') !== url.origin) {
      return errorResponse('Cookie picker mutations require a same-origin request.', 'invalid_origin', { port, status: 403 });
    }
    const pickerContext = !hasBearer && hasSession ? validSessions.get(sessionId!)! : undefined;
    if (pickerContext && req.headers.get('X-Gstack-Picker-Instance') !== pickerContext.pickerInstance) {
      return errorResponse('This picker no longer matches the active picker session. Reopen the picker from the intended page before continuing.', 'picker_changed', { port, status: 403 });
    }

    // GET /cookie-picker/browsers — list installed browsers
    if (pathname === '/cookie-picker/browsers' && req.method === 'GET') {
      const browsers = findInstalledBrowsers();
      return jsonResponse({
        browsers: browsers.map(b => ({
          name: b.name,
          aliases: b.aliases,
        })),
      }, { port });
    }

    // GET /cookie-picker/profiles?browser=<name> — list profiles for a browser
    if (pathname === '/cookie-picker/profiles' && req.method === 'GET') {
      const browserName = url.searchParams.get('browser');
      if (!browserName) {
        return errorResponse("Missing 'browser' parameter", 'missing_param', { port });
      }
      let hostname: string | undefined;
      try { hostname = new URL(pickerContext?.target?.url ?? '').hostname || undefined; } catch {}
      return jsonResponse(await getCookieProfiles(browserName, [], hostname), { port });
    }

    // GET /cookie-picker/domains?browser=<name>&profile=<profile> — list domains + counts
    if (pathname === '/cookie-picker/domains' && req.method === 'GET') {
      const browserName = url.searchParams.get('browser');
      if (!browserName) {
        return errorResponse("Missing 'browser' parameter", 'missing_param', { port });
      }
      const profile = url.searchParams.get('profile') || 'Default';
      const result = await withCookieReadRetry(() => listDomains(browserName, profile));
      return jsonResponse({
        browser: result.browser,
        domains: result.domains,
      }, { port });
    }

    // POST /cookie-picker/import — decrypt + import to Playwright session
    if (pathname === '/cookie-picker/import' && req.method === 'POST') {
      let body: any;
      try {
        body = await req.json();
      } catch {
        return errorResponse('Invalid JSON body', 'bad_request', { port });
      }

      const { browser, domains, profile, clearStorage, verifyAuth } = body ?? {};
      if (!browser) return errorResponse("Missing 'browser' field", 'missing_param', { port });
      if (!domains || !Array.isArray(domains) || domains.length === 0) {
        return errorResponse("Missing or empty 'domains' array", 'missing_param', { port });
      }

      const page = pickerContext?.target?.page ?? bm.getActiveSession().getPage();
      const target = pickerContext?.target ?? { page, url: page.url() };
      const result = await runCookieImport({
        browser, domains, profile,
        clearStorage: clearStorage ?? pickerContext?.clearStorage ?? false,
        verifyAuth: verifyAuth ?? pickerContext?.verifyAuth ?? false,
      }, target, domains => bm.trackCookieImportDomains(domains), {
        identitySelector: process.env.GSTACK_COOKIE_AUTH_SELECTOR,
        expectedIdentity: process.env.GSTACK_COOKIE_AUTH_EXPECTED_IDENTITY,
      });
      for (const domain of Object.keys(result.domainCounts)) {
        importedDomains.add(domain);
        importedCounts.set(domain, result.domainCounts[domain]);
      }
      return jsonResponse(result, { port });
    }

    // POST /cookie-picker/remove — clear cookies for domains
    if (pathname === '/cookie-picker/remove' && req.method === 'POST') {
      let body: any;
      try {
        body = await req.json();
      } catch {
        return errorResponse('Invalid JSON body', 'bad_request', { port });
      }

      const { domains } = body;
      if (!domains || !Array.isArray(domains) || domains.length === 0) {
        return errorResponse("Missing or empty 'domains' array", 'missing_param', { port });
      }

      const page = bm.getActiveSession().getPage();
      const context = page.context();
      for (const domain of domains) {
        await context.clearCookies({ domain });
        importedDomains.delete(domain);
        importedCounts.delete(domain);
      }

      console.log(`[cookie-picker] Removed cookies for ${domains.length} domains`);

      return jsonResponse({
        removed: domains.length,
        domains,
      }, { port });
    }

    // GET /cookie-picker/imported — currently imported domains + counts
    if (pathname === '/cookie-picker/imported' && req.method === 'GET') {
      const entries: Array<{ domain: string; count: number }> = [];
      for (const domain of importedDomains) {
        entries.push({ domain, count: importedCounts.get(domain) || 0 });
      }
      entries.sort((a, b) => b.count - a.count);

      return jsonResponse({
        domains: entries,
        totalDomains: entries.length,
        totalCookies: entries.reduce((sum, e) => sum + e.count, 0),
      }, { port });
    }

    return new Response('Not found', { status: 404 });
  } catch (err: any) {
    if (err instanceof CookieImportError) {
      return errorResponse(err.message, err.code, { port, status: 400, action: err.action });
    }
    console.error('[cookie-picker] Operation failed');
    return errorResponse('Cookie picker operation failed. Retry or reopen the picker.', 'internal_error', { port, status: 500 });
  }
}