'use client';

import React from 'react';
import Link from 'next/link';
import { usePathname, useRouter } from 'next/navigation';
import { Bell, Bot, ChevronDown, FolderOpen, ListTodo, LogOut, Mail, Menu, MessageSquare, Puzzle, Settings, Store, Wrench, X } from 'lucide-react';
import { logout } from '@/lib/api';
import { LanguageSwitcher } from '@/components/LanguageSwitcher';
import { Avatar, AvatarFallback } from '@/components/ui/avatar';
import { Button } from '@/components/ui/button';
import { Popover, PopoverContent, PopoverTrigger } from '@/components/ui/popover';
import { appConnectionStatusLabel } from '@/lib/i18n/common';
import { pickAppText } from '@/lib/i18n/core';
import { useAppI18n } from '@/lib/i18n/provider';
import { useChatStore } from '@/lib/store';

type NavItem = {
  key: 'chat' | 'tasks' | 'notifications' | 'skills' | 'files' | 'tools' | 'agents' | 'outlook' | 'marketplace' | 'settings';
  href: string;
  icon: React.ComponentType<{ className?: string }>;
  matchPrefixes?: string[];
};

const NAV_ITEMS: NavItem[] = [
  { key: 'chat', href: '/', icon: MessageSquare },
  { key: 'tasks', href: '/tasks', icon: ListTodo, matchPrefixes: ['/tasks', '/cron'] },
  { key: 'notifications', href: '/notifications', icon: Bell, matchPrefixes: ['/notifications'] },
  { key: 'skills', href: '/skills', icon: Puzzle },
  { key: 'files', href: '/files', icon: FolderOpen, matchPrefixes: ['/files'] },
  { key: 'tools', href: '/mcp', icon: Wrench, matchPrefixes: ['/mcp'] },
  { key: 'agents', href: '/agents', icon: Bot, matchPrefixes: ['/agents'] },
  { key: 'outlook', href: '/outlook', icon: Mail, matchPrefixes: ['/outlook'] },
  { key: 'marketplace', href: '/marketplace', icon: Store, matchPrefixes: ['/marketplace'] },
  {
    key: 'settings',
    href: '/settings',
    icon: Settings,
    matchPrefixes: ['/settings', '/status', '/logs'],
  },
];

function ConnectionDot() {
  const { locale } = useAppI18n();
  const wsStatus = useChatStore((s) => s.wsStatus);
  const beaverReady = useChatStore((s) => s.beaverReady);

  const isOnline = wsStatus === 'connected' && beaverReady === true;
  const isChecking = wsStatus === 'connected' && beaverReady === null;
  const isConnecting = wsStatus === 'connecting' || isChecking;
  const isOffline = wsStatus === 'disconnected' || (wsStatus === 'connected' && beaverReady === false);

  const color = isOnline
    ? 'bg-[#869683]'
    : isConnecting
      ? 'bg-[#8B7E77]'
      : 'bg-[#5F5550]';

  const label = appConnectionStatusLabel(wsStatus, beaverReady, locale);

  return (
    <div className="flex items-center gap-1.5 text-xs text-muted-foreground">
      <span className={`w-2 h-2 rounded-full ${color}`} />
      <span>{label}</span>
    </div>
  );
}

const Header = () => {
  const { locale } = useAppI18n();
  const pathname = usePathname();
  const router = useRouter();
  const [mobileMenuOpen, setMobileMenuOpen] = React.useState(false);
  const user = useChatStore((s) => s.user);
  const isAuthLoading = useChatStore((s) => s.isAuthLoading);
  const setUser = useChatStore((s) => s.setUser);

  const navLabel = React.useCallback((key: NavItem['key']) => {
    if (key === 'chat') return pickAppText(locale, '对话', 'Chat');
    if (key === 'tasks') return 'Task';
    if (key === 'notifications') return pickAppText(locale, '通知', 'Notifications');
    if (key === 'skills') return pickAppText(locale, '技能', 'Skills');
    if (key === 'files') return pickAppText(locale, '文件', 'Files');
    if (key === 'tools') return pickAppText(locale, '工具', 'Tools');
    if (key === 'agents') return pickAppText(locale, '智能体', 'Agents');
    if (key === 'outlook') return 'Outlook';
    if (key === 'marketplace') return pickAppText(locale, '市场', 'Marketplace');
    return pickAppText(locale, '配置', 'Settings');
  }, [locale]);

  const handleLogout = async () => {
    await logout();
    setUser(null);
    router.replace('/login');
    router.refresh();
  };

  React.useEffect(() => {
    setMobileMenuOpen(false);
  }, [pathname]);

  React.useEffect(() => {
    if (!mobileMenuOpen) return;

    const previousOverflow = document.body.style.overflow;
    const handleKeyDown = (event: KeyboardEvent) => {
      if (event.key === 'Escape') {
        setMobileMenuOpen(false);
      }
    };

    document.body.style.overflow = 'hidden';
    document.addEventListener('keydown', handleKeyDown);

    return () => {
      document.body.style.overflow = previousOverflow;
      document.removeEventListener('keydown', handleKeyDown);
    };
  }, [mobileMenuOpen]);

  const userInitial = (user?.username || user?.email || '?').trim().charAt(0).toUpperCase();

  const renderNavLinks = (compact = false) =>
    NAV_ITEMS.map((item) => {
      const isActive =
        item.href === '/'
          ? pathname === '/'
          : item.matchPrefixes?.some((prefix) => pathname.startsWith(prefix)) ?? pathname.startsWith(item.href);
      const Icon = item.icon;
      return (
        <Link
          key={item.href}
          href={item.href}
          onClick={compact ? () => setMobileMenuOpen(false) : undefined}
          className={`flex h-11 shrink-0 items-center gap-2 rounded-full text-sm font-medium transition-colors ${
            compact ? 'justify-start rounded-lg border border-transparent bg-background px-4' : 'px-4'
          } ${
            isActive
              ? 'bg-primary text-primary-foreground'
              : compact
                ? 'text-[#4F4642] hover:border-[#E6E1DE] hover:bg-muted hover:text-[#0B0B0B]'
                : 'text-[#4F4642] hover:bg-[#F7F5F4] hover:text-[#0B0B0B]'
          }`}
        >
          <Icon className="h-4 w-4" />
          {navLabel(item.key)}
        </Link>
      );
    });

  return (
    <>
      <header className="fixed left-0 right-0 top-0 z-50 border-b border-[#E6E1DE] bg-[#F7F6F5]/95 backdrop-blur">
        <div className="mx-auto max-w-[1720px] px-4 sm:px-6 lg:px-8">
          <div className="flex h-16 items-center justify-between gap-3">
            <div className="flex min-w-0 items-center gap-2">
              <button
                type="button"
                className="inline-flex h-11 w-11 items-center justify-center rounded-full border border-[#E6E1DE] bg-white text-[#1D1715] transition-colors hover:bg-[#F7F5F4] min-[1800px]:hidden"
                aria-label={mobileMenuOpen ? pickAppText(locale, '关闭导航', 'Close navigation') : pickAppText(locale, '打开导航', 'Open navigation')}
                aria-expanded={mobileMenuOpen}
                aria-controls="app-primary-mobile-nav"
                onClick={() => setMobileMenuOpen((open) => !open)}
              >
                {mobileMenuOpen ? <X className="h-5 w-5" /> : <Menu className="h-5 w-5" />}
              </button>
              <Link href="/" className="hidden h-11 shrink-0 items-center min-[360px]:flex">
                <span className="font-serif text-[26px] font-semibold leading-none text-[#0B0B0B] sm:text-[28px]">
                  Beaver
                </span>
              </Link>
            </div>

            <nav className="hidden items-center gap-1 rounded-full border border-[#E6E1DE] bg-white px-1.5 py-1 shadow-[0_1px_2px_rgba(0,0,0,0.04)] min-[1800px]:flex">
              {renderNavLinks(false)}
            </nav>

            <div className="flex min-w-0 shrink-0 items-center justify-end gap-2 sm:gap-3">
              <div className="hidden shrink-0 xl:block">
                <ConnectionDot />
              </div>
              <div className="flex shrink-0 items-center gap-2">
                <LanguageSwitcher />
                {user ? (
                  <Popover>
                    <PopoverTrigger asChild>
                      <button
                        type="button"
                        className="flex h-11 w-11 min-w-0 items-center justify-center gap-2 rounded-full border border-[#E6E1DE] bg-white px-1.5 text-sm font-medium text-[#1D1715] transition-colors hover:bg-[#F7F5F4] sm:w-auto sm:max-w-[11rem] sm:justify-start sm:px-2"
                        aria-label={pickAppText(locale, '打开账号菜单', 'Open account menu')}
                      >
                        <Avatar className="h-8 w-8 border border-[#E6E1DE]">
                          <AvatarFallback className="bg-primary text-xs font-semibold text-primary-foreground">
                            {userInitial}
                          </AvatarFallback>
                        </Avatar>
                        <span className="hidden min-w-0 max-w-24 truncate sm:block">{user.username}</span>
                        <ChevronDown className="hidden h-4 w-4 text-muted-foreground sm:block" />
                      </button>
                    </PopoverTrigger>
                    <PopoverContent align="end" className="w-80 rounded-3xl border-border/70 p-0 shadow-2xl">
                      <div className="overflow-hidden rounded-3xl bg-[linear-gradient(180deg,#F7F5F4,#FFFFFF)]">
                        <div className="border-b border-border/60 px-6 py-5">
                          <p className="truncate text-center text-sm font-medium text-muted-foreground">
                            {user.email}
                          </p>
                        </div>

                        <div className="flex flex-col items-center gap-4 px-6 py-6 text-center">
                          <Avatar className="h-24 w-24 border-4 border-white shadow-sm">
                            <AvatarFallback className="bg-primary text-4xl font-semibold text-primary-foreground">
                              {userInitial}
                            </AvatarFallback>
                          </Avatar>
                          <div className="space-y-1">
                            <p className="text-2xl font-semibold tracking-tight text-foreground">
                              {pickAppText(locale, `${user.username}，你好！`, `Hi, ${user.username}`)}
                            </p>
                            <p className="text-sm text-muted-foreground">
                              {pickAppText(locale, '当前已登录到你的工作区实例。', 'You are currently signed in to your workspace instance.')}
                            </p>
                          </div>
                        </div>

                        <div className="border-t border-border/60 bg-white/90 px-4 py-4">
                          <Button
                            type="button"
                            variant="outline"
                            onClick={handleLogout}
                            className="h-12 w-full justify-center rounded-2xl text-sm font-semibold"
                          >
                            <LogOut className="mr-2 h-4 w-4" />
                            {pickAppText(locale, '退出登录', 'Sign Out')}
                          </Button>
                        </div>
                      </div>
                    </PopoverContent>
                  </Popover>
                ) : !isAuthLoading ? null : null}
              </div>
            </div>
          </div>
        </div>
      </header>
      {mobileMenuOpen && (
        <>
          <button
            type="button"
            className="fixed inset-x-0 bottom-0 top-16 z-40 bg-black/40 min-[1800px]:hidden"
            aria-label={pickAppText(locale, '关闭导航', 'Close navigation')}
            onClick={() => setMobileMenuOpen(false)}
          />
          <nav
            id="app-primary-mobile-nav"
            aria-label={pickAppText(locale, '主导航', 'Primary navigation')}
            className="fixed bottom-0 left-0 top-16 z-[45] isolate w-[min(86vw,320px)] overflow-y-auto border-r border-[#E6E1DE] bg-background text-foreground shadow-[12px_0_32px_rgba(29,23,21,0.24)] animate-in slide-in-from-left-full duration-200 min-[1800px]:hidden"
          >
            <div className="min-h-full bg-background px-4 py-5">
              <div className="grid gap-2 bg-background">
              {renderNavLinks(true)}
              </div>
            </div>
          </nav>
        </>
      )}
    </>
  );
};

export default Header;
