'use client';

import { useEffect, useState } from 'react';
import { useLocale, useTranslations } from 'next-intl';
import { desktopDownloadUrl, type DesktopFileInfo, type DesktopLatestInfo, formatFileSize, loadDesktopLatest } from '@/lib/desktop';
import { useIsDesktopClient } from '@/lib/desktop-client';

const BUTTON_CLASS =
  'inline-flex items-center gap-2 rounded-md bg-primary px-4 py-2.5 text-sm font-medium text-primary-foreground hover:opacity-90';

function WindowsIcon() {
  return (
    <svg width="16" height="16" viewBox="0 0 16 16" fill="currentColor" aria-hidden="true">
      <rect x="1" y="1" width="6" height="6" rx="1" />
      <rect x="9" y="1" width="6" height="6" rx="1" />
      <rect x="1" y="9" width="6" height="6" rx="1" />
      <rect x="9" y="9" width="6" height="6" rx="1" />
    </svg>
  );
}

function LinuxIcon() {
  return (
    <svg width="16" height="16" viewBox="0 0 16 16" fill="none" stroke="currentColor" strokeWidth="1.5" aria-hidden="true">
      <rect x="1" y="2" width="14" height="12" rx="1.5" />
      <path d="M4 6l2.5 2L4 10" strokeLinecap="round" strokeLinejoin="round" />
      <line x1="8" y1="10" x2="11" y2="10" strokeLinecap="round" />
    </svg>
  );
}

function DownloadButton({
  file,
  label,
  icon,
  testId,
  locale,
  fileInfoText,
}: {
  file: DesktopFileInfo;
  label: string;
  icon: React.ReactNode;
  testId: string;
  locale: string;
  fileInfoText: (values: { name: string; size: string }) => string;
}) {
  return (
    <div>
      <a href={desktopDownloadUrl(file)} download data-testid={testId} className={BUTTON_CLASS}>
        {icon}
        {label}
      </a>
      <p className="mt-1 text-xs text-muted-foreground">
        {fileInfoText({ name: file.name, size: formatFileSize(file.size, locale) })}
      </p>
    </div>
  );
}

/**
 * Inhalt der Einstellungsseite "Desktop-App" (D-12): vier erklaerende
 * Saetze, dann Version/Downloads oder ein Hinweis, wenn der Server keine
 * Pakete traegt (`loadDesktopLatest()` liefert `null`). Im Desktop-Client
 * (260917-jn2) zusaetzlich ein Block "Verbunden mit: {origin}" -- `isDesktop`
 * ist im Server-HTML und im ersten Client-Render false (Hook mit
 * `useEffect`), der Block rendert also erst nach der Hydration, weshalb
 * `window.location.origin` hier direkt gelesen werden darf (kein
 * Hydration-Fehler).
 */
export function DesktopAppSettings() {
  const t = useTranslations('settings');
  const locale = useLocale();
  const isDesktop = useIsDesktopClient();
  const [info, setInfo] = useState<DesktopLatestInfo | null | undefined>(undefined);

  useEffect(() => {
    let active = true;
    loadDesktopLatest().then((data) => {
      if (active) setInfo(data);
    });
    return () => {
      active = false;
    };
  }, []);

  const fileInfoText = (values: { name: string; size: string }) => t('desktop.fileInfo', values);

  return (
    <div>
      <p className="text-sm text-muted-foreground">{t('desktop.intro')}</p>
      <p className="text-sm text-muted-foreground">{t('desktop.firstStart')}</p>
      <p className="text-sm text-muted-foreground">{t('desktop.tray')}</p>
      <p className="text-sm text-muted-foreground">{t('desktop.update')}</p>

      {isDesktop && (
        <div
          data-testid="desktop-connected"
          className="mt-4 space-y-1 rounded border border-border bg-muted/30 p-3 text-sm"
        >
          <p className="text-foreground">{t('desktop.connectedTo', { origin: window.location.origin })}</p>
          <p className="text-muted-foreground">{t('desktop.changeHint')}</p>
        </div>
      )}

      {info === null && <p className="mt-4 text-sm text-muted-foreground">{t('desktop.unavailable')}</p>}

      {info && (
        <>
          <p className="mt-4 text-sm text-foreground">{t('desktop.versionLabel', { version: info.version })}</p>
          {info.channel === 'beta' && (
            <p className="text-sm text-muted-foreground">{t('desktop.channelBeta', { commit: info.commit })}</p>
          )}
          <div className="mt-4 flex flex-wrap gap-4">
            {info.files.windows && (
              <DownloadButton
                file={info.files.windows}
                label={t('desktop.downloadWindows')}
                icon={<WindowsIcon />}
                testId="desktop-download-windows"
                locale={locale}
                fileInfoText={fileInfoText}
              />
            )}
            {info.files.linux && (
              <DownloadButton
                file={info.files.linux}
                label={t('desktop.downloadLinux')}
                icon={<LinuxIcon />}
                testId="desktop-download-linux"
                locale={locale}
                fileInfoText={fileInfoText}
              />
            )}
          </div>
        </>
      )}
    </div>
  );
}