import React from 'react';
import { NavLink, useParams, useLocation, Link } from 'react-router-dom';
import { CheckSquare, GalleryHorizontal, Home, Trophy, Camera } from 'lucide-react';
import { useEventData } from '../hooks/useEventData';
import { useTranslation } from '../i18n/useTranslation';
import { useEventBranding } from '../context/EventBrandingContext';
import { isTaskModeEnabled } from '../lib/engagement';

function TabLink({
  to,
  children,
  isActive,
  accentColor,
  radius,
  style,
  compact = false,
}: {
  to: string;
  children: React.ReactNode;
  isActive: boolean;
  accentColor: string;
  radius: number;
  style?: React.CSSProperties;
  compact?: boolean;
}) {
  const activeStyle = isActive
    ? {
        background: `linear-gradient(135deg, ${accentColor}, ${accentColor}cc)`,
        color: '#ffffff',
        boxShadow: `0 12px 30px ${accentColor}33`,
        borderRadius: radius,
        ...style,
      }
    : { borderRadius: radius, ...style };

  return (
    <NavLink
      to={to}
      className={`
        flex ${compact ? 'h-10 text-[10px]' : 'h-14 text-xs'} flex-col items-center justify-center gap-1 rounded-lg border border-transparent p-2 font-medium transition-all duration-200 ease-out
        touch-manipulation backdrop-blur-md
        ${isActive ? 'scale-[1.04]' : 'text-white/70 hover:text-white'}
      `}
      style={activeStyle}
    >
      {children}
    </NavLink>
  );
}

export default function BottomNav() {
  const { token } = useParams();
  const location = useLocation();
  const { event, status } = useEventData();
  const { t } = useTranslation();
  const { branding } = useEventBranding();
  const navRef = React.useRef<HTMLDivElement | null>(null);
  const radius = branding.buttons?.radius ?? 12;
  const buttonStyle = branding.buttons?.style ?? 'filled';
  const linkColor = branding.buttons?.linkColor ?? branding.secondaryColor;
  const surface = branding.palette?.surface ?? branding.backgroundColor;

  const isReady = status === 'ready' && !!event;

  if (!token || !isReady) return null;

  const base = `/e/${encodeURIComponent(token)}`;
  const currentPath = location.pathname;
  const tasksEnabled = isTaskModeEnabled(event);

  const labels = {
    home: t('navigation.home'),
    tasks: t('navigation.tasks'),
    achievements: t('navigation.achievements'),
    gallery: t('navigation.gallery'),
    upload: t('home.actions.items.upload.label'),
  };

  const isHomeActive = currentPath === base || currentPath === `/${token}`;
  const isTasksActive = currentPath.startsWith(`${base}/tasks`);
  const isAchievementsActive = currentPath.startsWith(`${base}/achievements`);
  const isGalleryActive = currentPath.startsWith(`${base}/gallery`) || currentPath.startsWith(`${base}/photos`);
  const isUploadActive = currentPath.startsWith(`${base}/upload`);

  const compact = isUploadActive;
  const navPaddingBottom = `calc(env(safe-area-inset-bottom, 0px) + ${compact ? 12 : 18}px)`;
  const setBottomOffset = React.useCallback(() => {
    if (typeof document === 'undefined' || !navRef.current) {
      return;
    }

    const height = Math.ceil(navRef.current.getBoundingClientRect().height);
    document.documentElement.style.setProperty('--guest-bottom-nav-offset', `${height}px`);
  }, []);

  React.useLayoutEffect(() => {
    if (typeof window === 'undefined') {
      return;
    }

    setBottomOffset();

    const handleResize = () => setBottomOffset();
    if (typeof ResizeObserver !== 'undefined' && navRef.current) {
      const observer = new ResizeObserver(() => setBottomOffset());
      observer.observe(navRef.current);
      window.addEventListener('resize', handleResize);

      return () => {
        observer.disconnect();
        window.removeEventListener('resize', handleResize);
        document.documentElement.style.removeProperty('--guest-bottom-nav-offset');
      };
    }

    window.addEventListener('resize', handleResize);

    return () => {
      window.removeEventListener('resize', handleResize);
      document.documentElement.style.removeProperty('--guest-bottom-nav-offset');
    };
  }, [setBottomOffset, compact]);

  return (
    <div
      ref={navRef}
      className={`guest-bottom-nav fixed inset-x-0 bottom-0 z-30 border-t border-white/15 bg-gradient-to-t from-black/55 via-black/30 to-black/5 px-4 shadow-2xl backdrop-blur-xl transition-all duration-200 dark:border-white/10 dark:from-gray-950/85 dark:via-gray-900/55 dark:to-gray-900/20 ${
        compact ? 'pt-1' : 'pt-2 pb-1'
      }`}
      style={{ paddingBottom: navPaddingBottom }}
    >
      <div className="pointer-events-none absolute -top-7 inset-x-0 h-7 bg-gradient-to-b from-black/0 via-black/30 to-black/60 dark:via-black/40 dark:to-black/70" aria-hidden />
      <div className="mx-auto flex max-w-lg items-center gap-3">
        <div className="flex flex-1 justify-evenly gap-2">
          <TabLink
            to={`${base}`}
            isActive={isHomeActive}
            accentColor={branding.primaryColor}
            radius={radius}
            compact={compact}
            style={buttonStyle === 'outline' ? { background: 'transparent', color: linkColor, border: `1px solid ${linkColor}` } : undefined}
          >
            <div className="flex flex-col items-center gap-1">
              <Home className="h-5 w-5" aria-hidden />
              <span>{labels.home}</span>
            </div>
          </TabLink>
          {tasksEnabled ? (
            <TabLink
              to={`${base}/tasks`}
              isActive={isTasksActive}
              accentColor={branding.primaryColor}
              radius={radius}
              compact={compact}
              style={buttonStyle === 'outline' ? { background: 'transparent', color: linkColor, border: `1px solid ${linkColor}` } : undefined}
            >
              <div className="flex flex-col items-center gap-1">
                <CheckSquare className="h-5 w-5" aria-hidden />
                <span>{labels.tasks}</span>
              </div>
            </TabLink>
          ) : null}
        </div>

        <Link
          to={`${base}/upload`}
          aria-label={labels.upload}
          className={`relative flex ${compact ? 'h-12 w-12' : 'h-16 w-16'} items-center justify-center rounded-full text-white shadow-2xl transition-all duration-300 ${
            isUploadActive
              ? 'translate-y-6 scale-75 opacity-0 pointer-events-none'
              : 'hover:scale-105'
          }`}
          style={{
            background: `radial-gradient(circle at 20% 20%, ${branding.secondaryColor}, ${branding.primaryColor})`,
            boxShadow: `0 20px 35px ${branding.primaryColor}44`,
            borderRadius: radius,
          }}
          tabIndex={isUploadActive ? -1 : 0}
          aria-hidden={isUploadActive}
        >
          <Camera className="h-6 w-6" aria-hidden />
        </Link>

        <div className="flex flex-1 justify-evenly gap-2">
          <TabLink
            to={`${base}/achievements`}
            isActive={isAchievementsActive}
            accentColor={branding.primaryColor}
            radius={radius}
            style={buttonStyle === 'outline' ? { background: 'transparent', color: linkColor, border: `1px solid ${linkColor}` } : undefined}
            compact={compact}
          >
            <div className="flex flex-col items-center gap-1">
              <Trophy className="h-5 w-5" aria-hidden />
              <span>{labels.achievements}</span>
            </div>
          </TabLink>
          <TabLink
            to={`${base}/gallery`}
            isActive={isGalleryActive}
            accentColor={branding.primaryColor}
            radius={radius}
            style={buttonStyle === 'outline' ? { background: 'transparent', color: linkColor, border: `1px solid ${linkColor}` } : undefined}
            compact={compact}
          >
            <div className="flex flex-col items-center gap-1">
              <GalleryHorizontal className="h-5 w-5" aria-hidden />
              <span>{labels.gallery}</span>
            </div>
          </TabLink>
        </div>
      </div>
    </div>
  );
}