import { type NextRequest } from 'next/server';
import { randomBytes } from 'node:crypto';
import { getSupabaseAdmin } from '@/lib/supabase/admin';
import { jsonNoStore } from '@/lib/admin/response';
import { validateSubdomain } from '@/lib/validation';
import { setTunnelActive } from '@/lib/redis';
import { hashToken, FRP_SERVER_ADDR, FRP_SERVER_PORT } from '@/lib/device';

export const runtime = 'nodejs';
export const dynamic = 'force-dynamic';

type DeviceTokenRow = { id: number; user_id: string };

/**
 * Authenticate a request by its `Authorization: Bearer <device-token>` header.
 * Returns the matching, non-revoked device_tokens row (and bumps last_used_at),
 * or null when the token is missing/invalid/revoked.
 */
async function authDevice(req: NextRequest): Promise<DeviceTokenRow | null> {
  const auth = req.headers.get('authorization') ?? '';
  const m = /^Bearer\s+(.+)$/i.exec(auth.trim());
  if (!m) return null;

  const admin = getSupabaseAdmin();
  const { data, error } = await admin
    .from('device_tokens')
    .select('id, user_id')
    .eq('token_hash', hashToken(m[1]))
    .is('revoked_at', null)
    .maybeSingle<DeviceTokenRow>();
  if (error || !data) return null;

  await admin
    .from('device_tokens')
    .update({ last_used_at: new Date().toISOString() })
    .eq('id', data.id);

  return data;
}

type Tunnel = { subdomain: string; token: string };

/** GET — return the device's current tunnel config. */
export async function GET(req: NextRequest) {
  const device = await authDevice(req);
  if (!device) return jsonNoStore({ error: 'unauthorized' }, { status: 401 });

  const admin = getSupabaseAdmin();
  const { data: tunnel, error } = await admin
    .from('tunnels')
    .select('subdomain, token')
    .eq('user_id', device.user_id)
    .maybeSingle<Tunnel>();
  if (error) return jsonNoStore({ error: 'failed' }, { status: 500 });
  if (!tunnel) return jsonNoStore({ error: 'no_tunnel' }, { status: 404 });

  return jsonNoStore({
    subdomain: tunnel.subdomain,
    token: tunnel.token,
    server_addr: FRP_SERVER_ADDR,
    server_port: FRP_SERVER_PORT,
  });
}

type PostBody = { subdomain?: unknown };

/** POST — claim/change the subdomain (rotates the frp token). */
export async function POST(req: NextRequest) {
  const device = await authDevice(req);
  if (!device) return jsonNoStore({ error: 'unauthorized' }, { status: 401 });

  let body: PostBody;
  try {
    body = (await req.json()) as PostBody;
  } catch {
    return jsonNoStore({ error: 'invalid json' }, { status: 400 });
  }

  const v = validateSubdomain(body.subdomain);
  if (!v.ok) {
    return jsonNoStore({ error: v.error }, { status: 400 });
  }
  const subdomain = v.value;

  const admin = getSupabaseAdmin();

  const { data: existing, error: existingErr } = await admin
    .from('tunnels')
    .select('user_id')
    .eq('subdomain', subdomain)
    .maybeSingle<{ user_id: string }>();
  if (existingErr) {
    return jsonNoStore({ error: 'failed' }, { status: 500 });
  }
  if (existing && existing.user_id !== device.user_id) {
    return jsonNoStore({ error: 'subdomain taken' }, { status: 409 });
  }

  const token = randomBytes(32).toString('hex');
  const { data, error } = await admin
    .from('tunnels')
    .upsert(
      { user_id: device.user_id, subdomain, token, is_active: true },
      { onConflict: 'user_id' },
    )
    .select('subdomain, token')
    .single<Tunnel>();
  if (error) {
    if ((error as { code?: string }).code === '23505') {
      return jsonNoStore({ error: 'subdomain taken' }, { status: 409 });
    }
    return jsonNoStore({ error: 'failed' }, { status: 500 });
  }

  await setTunnelActive(subdomain, true);

  return jsonNoStore({
    subdomain: data.subdomain,
    token: data.token,
    server_addr: FRP_SERVER_ADDR,
    server_port: FRP_SERVER_PORT,
  });
}

/** DELETE — unpair this device by revoking its token (tunnel is kept). */
export async function DELETE(req: NextRequest) {
  const device = await authDevice(req);
  if (!device) return jsonNoStore({ error: 'unauthorized' }, { status: 401 });

  const admin = getSupabaseAdmin();
  const { error } = await admin
    .from('device_tokens')
    .update({ revoked_at: new Date().toISOString() })
    .eq('id', device.id);
  if (error) return jsonNoStore({ error: 'failed' }, { status: 500 });

  return jsonNoStore({ ok: true });
}