import React, { useEffect, useState } from 'react';
import DesktopUpdateModal from '@frontend/components/DesktopUpdateModal';
import {
  checkForUpdates,
  getAppVersion,
  type DesktopUpdatePhase,
  type DesktopUpdateProgress,
} from './bridge/updater';
import { scheduleMainWindowTitleSync } from './setMainWindowTitle';
import { PlatformBrandIcon, type PlatformBrandIconId } from '@frontend/components/icons/PlatformBrandIcons';
import { isMacDesktop, isWindowsDesktop } from '@frontend/utils/platform';
import '@frontend/App.css';

const PHASE_LABEL: Record<DesktopUpdatePhase, string> = {
  checking: '업데이트 확인 중',
  uptodate: '최신 버전',
  available: '새 버전 발견',
  downloading: '다운로드 중',
  installing: '설치 중',
  relaunching: '재시작 중',
  error: '업데이트 실패',
};

function formatBytes(n?: number): string {
  if (n == null || !Number.isFinite(n) || n <= 0) return '';
  if (n < 1024 * 1024) return `${(n / 1024).toFixed(1)} KB`;
  return `${(n / (1024 * 1024)).toFixed(1)} MB`;
}

function StartupUpdateSplash({ progress }: { progress: DesktopUpdateProgress | null }) {
  const phase = progress?.phase ?? 'checking';
  const isActive = phase === 'checking';
  const showBar = false;

  const panelClass = phase === 'error'
    ? 'desktop-update-progress--failed'
    : isActive
      ? 'desktop-update-progress--active'
      : '';

  const platformBrand: PlatformBrandIconId | null = isMacDesktop()
    ? 'mac'
    : isWindowsDesktop()
      ? 'windows'
      : null;

  return (
    <div className="desktop-startup-update">
      <div className="desktop-startup-update-card">
        {platformBrand && (
          <div className="desktop-update-platform-brand desktop-update-platform-brand--startup">
            <PlatformBrandIcon platform={platformBrand} />
          </div>
        )}
        <h1 className="desktop-startup-update-title">GoldenChart</h1>
        <p className="desktop-startup-update-sub">
          {progress?.currentVersion ? `현재 v${progress.currentVersion}` : '시작 중…'}
        </p>

        <div className={`desktop-update-progress ${panelClass}`.trim()}>
          <div className="desktop-update-progress-head">
            <span className="desktop-update-progress-title">
              {isActive && <span className="desktop-update-spinner" aria-hidden />}
              {PHASE_LABEL[phase]}
            </span>
          </div>

          {showBar && (
            <div className="desktop-update-bar" role="progressbar" aria-valuemin={0} aria-valuemax={100}>
              <div className="desktop-update-bar-fill desktop-update-bar-fill--indeterminate" />
            </div>
          )}

          <ul className="desktop-update-steps">
            <li className={`desktop-update-step${phase === 'checking' ? ' active' : phase !== 'error' ? ' done' : ''}`}>
              <span className="desktop-update-step-dot" aria-hidden />
              서버에서 버전 확인
            </li>
            <li className="desktop-update-step">
              <span className="desktop-update-step-dot" aria-hidden />
              업데이트 다운로드
              {progress?.downloadedBytes && progress.totalBytes ? (
                <span className="desktop-update-bytes">
                  {formatBytes(progress.downloadedBytes)} / {formatBytes(progress.totalBytes)}
                </span>
              ) : null}
            </li>
            <li className="desktop-update-step">
              <span className="desktop-update-step-dot" aria-hidden />
              설치 및 재시작
            </li>
          </ul>

          {progress?.message && (
            <p className={`desktop-update-message${phase === 'error' ? ' desktop-update-message--error' : ''}`}>
              {progress.message}
            </p>
          )}
        </div>
      </div>
    </div>
  );
}

/** 시작 시 버전 확인 후 children(메인 앱) 렌더 — 새 버전 있으면 업데이트 모달 표시 */
export function StartupUpdateGate({ children }: { children: React.ReactNode }) {
  const [ready, setReady] = useState(false);
  const [startupUpdateOpen, setStartupUpdateOpen] = useState(false);
  const [progress, setProgress] = useState<DesktopUpdateProgress | null>({
    phase: 'checking',
    message: '서버에서 새 버전을 확인하는 중…',
  });

  useEffect(() => {
    let cancelled = false;

    void (async () => {
      let currentVersion = '—';
      try {
        currentVersion = await getAppVersion();
      } catch {
        /* ignore */
      }
      if (cancelled) return;

      setProgress({
        phase: 'checking',
        message: '서버에서 새 버전을 확인하는 중…',
        currentVersion,
      });

      const result = await checkForUpdates();
      if (cancelled) return;

      if (result.available) {
        setProgress({
          phase: 'available',
          message: result.message ?? `새 버전 v${result.version}을(를) 사용할 수 있습니다.`,
          currentVersion,
          newVersion: result.version,
        });
      } else if (result.message?.includes('실패') || result.message?.includes('오류')) {
        setProgress({ phase: 'error', message: result.message, currentVersion });
      }

      scheduleMainWindowTitleSync();
      setReady(true);
      if (result.available) {
        setStartupUpdateOpen(true);
      }
    })();

    return () => {
      cancelled = true;
    };
  }, []);

  if (!ready) {
    return <StartupUpdateSplash progress={progress} />;
  }

  return (
    <>
      {children}
      <DesktopUpdateModal
        open={startupUpdateOpen}
        onClose={() => setStartupUpdateOpen(false)}
        autoStart
      />
    </>
  );
}