import { useUIStore, type ViewMode } from '../stores/uiStore';
import { useMailStore } from '../stores/mailStore';
import { useContactStore } from '../stores/contactStore';
import { useAuthStore } from '../stores/authStore';
import {
  InboxIcon,
  SentIcon,
  ContactsIcon,
  ComposeIcon,
  UsersIcon,
  PersonIcon,
  ShieldIcon,
  CalendarIcon
} from './icons';
import { ConnectionIndicator } from './ConnectionIndicator';
import { countPendingPermissions, splitByPermission } from '../lib/mailGroups';

/**
 * 窄屏底部导航。
 *
 * 移动端把主导航放底部而不是顶部：拇指够得到。
 * 宽屏用的是左侧竖条（Sidebar），两者共用 uiStore 的 viewMode，
 * 所以从窄拖到宽不会丢失当前位置。
 *
 * 这里只放最常用的几项 + 一个「更多」入口（打开抽屉式 Sidebar）——
 * 底部塞满图标会挤成一排看不懂的小方块。
 */
const items: {
  short: string;
  mode: ViewMode;
  Icon: (p: { className?: string }) => JSX.Element;
  adminOnly?: boolean;
}[] = [
  { short: '收件', mode: 'inbox', Icon: InboxIcon },
  { short: '授权', mode: 'permissions', Icon: ShieldIcon },
  { short: '发件', mode: 'sent', Icon: SentIcon },
  { short: '日历', mode: 'calendar', Icon: CalendarIcon },
  { short: '联系人', mode: 'contacts', Icon: ContactsIcon },
  { short: '管理', mode: 'admin', Icon: UsersIcon, adminOnly: true }
];

export default function NarrowNav() {
  const viewMode = useUIStore(s => s.viewMode);
  const setViewMode = useUIStore(s => s.setViewMode);
  const composing = useUIStore(s => s.composing);
  const startCompose = useUIStore(s => s.startCompose);
  const narrowPane = useUIStore(s => s.narrowPane);

  const inbox = useMailStore(s => s.inbox);
  // 与 Sidebar 同一判据：权限请求归「授权」，不算进收件箱未读
  const { normal, permissions } = splitByPermission(inbox);
  const unread = normal.filter(m => m.status === 'unread').length;
  const pendingPerms = countPendingPermissions(permissions);
  const contacts = useContactStore(s => s.contacts);

  const user = useAuthStore(s => s.user);
  const isAdmin = user?.role === 'admin';

  const visible = items.filter(n => !n.adminOnly || isAdmin);

  return (
    <nav
      className="narrow-nav shrink-0 border-t border-chrome-700 bg-chrome-900 flex items-stretch"
      // 底部安全区：iPhone 的手势条会盖住最后一排
      style={{ paddingBottom: 'env(safe-area-inset-bottom)' }}
    >
      {visible.map(({ short, mode, Icon }) => {
        // 详情栏打开时不高亮任何导航项：此刻用户看的是某封邮件，
        // 高亮「收件」会让人以为点它能回到列表（其实是同一项）
        const active = viewMode === mode && !composing && narrowPane === 'list';
        const badge =
          mode === 'inbox'
            ? unread
            : mode === 'permissions'
            ? pendingPerms
            : mode === 'contacts'
            ? contacts.length
            : 0;
        return (
          <button
            key={mode}
            onClick={() => setViewMode(mode)}
            className={`relative flex-1 py-2 flex flex-col items-center justify-center gap-0.5 transition-colors ${
              active ? 'text-white' : 'text-chrome-400 active:bg-chrome-800'
            }`}
          >
            <Icon />
            <span className="text-3xs leading-none">{short}</span>
            {badge > 0 && (
              <span
                className={`absolute top-1 right-[22%] min-w-[15px] h-[15px] px-1 rounded-full text-3xs font-bold flex items-center justify-center ${
                  mode === 'inbox'
                    ? 'bg-red-600 text-white'
                    : mode === 'permissions'
                    ? 'bg-orange-700 text-white'
                    : 'bg-chrome-600 text-chrome-100'
                }`}
              >
                {badge > 99 ? '99+' : badge}
              </span>
            )}
            {active && <span className="absolute top-0 left-1/4 right-1/4 h-0.5 bg-blue-400" />}
          </button>
        );
      })}

      <button
        onClick={() => startCompose()}
        className={`flex-1 py-2 flex flex-col items-center justify-center gap-0.5 ${
          composing ? 'text-blue-300' : 'text-blue-400 active:bg-chrome-800'
        }`}
      >
        <ComposeIcon />
        <span className="text-3xs leading-none">新建</span>
      </button>

      <button
        onClick={() => setViewMode('account')}
        className={`flex-1 py-2 flex flex-col items-center justify-center gap-0.5 ${
          viewMode === 'account' && !composing
            ? 'text-white'
            : 'text-chrome-400 active:bg-chrome-800'
        }`}
      >
        <div className="relative">
          <PersonIcon />
          <span className="absolute -top-0.5 -right-1.5">
            <ConnectionIndicator />
          </span>
        </div>
        <span className="text-3xs leading-none">我的</span>
      </button>
    </nav>
  );
}