import { NextResponse } from 'next/server';

import { publicBaseUrl } from '@/lib/config';
import { clientIp, deviceHeader, deviceNumber } from '@/lib/device/headers';
import { computeRefreshRate } from '@/lib/device/refresh';
import { authenticateDevice } from '@/lib/device/session';
import { prisma } from '@/lib/db';
import { rateLimit } from '@/lib/ratelimit';
import { buildCurrentScreen, renderAndStore } from '@/lib/screen/service';

export const dynamic = 'force-dynamic';

/**
 * The only call that matters. The panel wakes, asks what to show, and goes
 * back to sleep for `refresh_rate` seconds.
 *
 * `filename` is the hash of the image bytes: when it matches what the firmware
 * already has, it skips the redraw. That is where the battery life comes from,
 * so the renderer must stay byte-stable for unchanged content.
 */
export async function GET(request: Request) {
  const limit = rateLimit(`display:${clientIp(request)}`, 60, 60_000);
  if (!limit.allowed) {
    return NextResponse.json(
      { error: 'Trop de requêtes' },
      { status: 429, headers: { 'Retry-After': String(limit.retryAfter) } },
    );
  }

  const device = await authenticateDevice(request);
  if (!device) {
    return NextResponse.json({ error: 'Jeton invalide' }, { status: 401 });
  }

  const now = new Date();
  const baseUrl = publicBaseUrl(request);
  const { payload, settings, status } = await buildCurrentScreen(now, baseUrl);
  const image = await renderAndStore(payload, settings.imageFormat);

  const refreshRate = computeRefreshRate({
    now,
    status,
    timezone: settings.timezone,
    openSec: settings.refreshRateOpenSec,
    closedSec: settings.refreshRateClosedSec,
  });

  await prisma.device.update({
    where: { id: device.id },
    data: {
      lastSeenAt: now,
      fwVersion: deviceHeader(request, 'fw-version'),
      batteryVoltage: deviceNumber(request, 'battery-voltage'),
      percentCharged: roundOrNull(deviceNumber(request, 'percent-charged')),
      rssi: roundOrNull(deviceNumber(request, 'rssi')),
      lastFilename: image.filename,
      lastRefreshRate: refreshRate,
    },
  });

  return NextResponse.json(
    {
      image_url: `${baseUrl}/api/device/image/${image.filename}`,
      filename: image.filename,
      refresh_rate: refreshRate,
      // Firmware updates are not this application's business: it drives a
      // display, it does not manage the fleet.
      update_firmware: false,
      reset_firmware: false,
      firmware_url: null,
      firmware_version: null,
      special_function: 'none',
      image_url_timeout: 0,
    },
    { headers: { 'Cache-Control': 'no-store' } },
  );
}

function roundOrNull(value: number | null): number | null {
  return value === null ? null : Math.round(value);
}