import { A, useLocation, useNavigate, useSearchParams } from '@solidjs/router';
import { For, createEffect, createMemo, createSignal, onCleanup, onMount, type JSX } from 'solid-js';
import AdminSidebar from './AdminSidebar';
import { isExternalIdentity } from '~/lib/admin-auth';
import { clearAdminSession, hasAdminSession, setAdminSession } from '~/lib/admin-session';
import { Bell } from 'lucide-solid';

type Tab = { href: string; label: string; exact?: boolean };

const TAB_SETS: Array<{ prefixes: string[]; tabs: Tab[] }> = [
  {
    prefixes: ['/admin/roles'],
    tabs: [
      { href: '/admin/roles', label: 'Roles', exact: true },
      { href: '/admin/roles/create', label: 'Create Role' },
      { href: '/admin/roles/templates', label: 'View Roles' },
    ],
  },
  {
    prefixes: ['/admin/runtime-roles'],
    tabs: [
      { href: '/admin/runtime-roles', label: 'Roles', exact: true },
      { href: '/admin/runtime-roles/new', label: 'Create Role' },
      { href: '/admin/role-ui-configs', label: 'View Roles' },
    ],
  },
];

export default function AdminShell(props: { children: JSX.Element }) {
  const location = useLocation();
  const navigate = useNavigate();
  const [searchParams] = useSearchParams();
  const [checkedSession, setCheckedSession] = createSignal(false);
  const [adminName, setAdminName] = createSignal('Admin');
  const [sidebarOpen, setSidebarOpen] = createSignal(false);
  const [sidebarCollapsed, setSidebarCollapsed] = createSignal(false);
  const [tabsTrackEl, setTabsTrackEl] = createSignal<HTMLDivElement>();
  const [tabRefs, setTabRefs] = createSignal<Record<string, HTMLAnchorElement>>({});
  const [tabIndicator, setTabIndicator] = createSignal({ left: 0, width: 0, ready: false });

  const tabs = createMemo<Tab[]>(() => {
    const path = location.pathname;
    for (const set of TAB_SETS) {
      if (set.prefixes.some((p) => path === p || path.startsWith(`${p}/`))) return set.tabs;
    }
    return [];
  });

  const isTabActive = (tab: Tab) =>
    tab.exact
      ? location.pathname === tab.href
      : location.pathname === tab.href || location.pathname.startsWith(`${tab.href}/`);

  const refreshTabIndicator = () => {
    const activeTab = tabs().find((tab) => isTabActive(tab));
    const track = tabsTrackEl();
    if (!activeTab || !track) {
      setTabIndicator((prev) => ({ ...prev, ready: false }));
      return;
    }
    const el = tabRefs()[activeTab.href];
    if (!el) return;
    setTabIndicator({ left: el.offsetLeft, width: el.offsetWidth, ready: true });
  };

  createEffect(() => {
    tabs();
    location.pathname;
    requestAnimationFrame(refreshTabIndicator);
  });

  onMount(() => {
    const onResize = () => refreshTabIndicator();
    window.addEventListener('resize', onResize);
    onCleanup(() => window.removeEventListener('resize', onResize));

    const isLocalDev =
      typeof window !== 'undefined' &&
      (window.location.hostname === 'localhost' || window.location.hostname === '127.0.0.1');
    const isPreview =
      searchParams._preview === '1' ||
      (typeof sessionStorage !== 'undefined' &&
        sessionStorage.getItem('nxtgauge_admin_preview') === '1');

    if (isPreview || isLocalDev) {
      if (typeof sessionStorage !== 'undefined')
        sessionStorage.setItem('nxtgauge_admin_preview', '1');
      setAdminSession();
      setCheckedSession(true);
      return;
    }

    const verify = async () => {
      if (!hasAdminSession()) {
        const from = encodeURIComponent(location.pathname + location.search);
        navigate(`/login?from=${from}`, { replace: true });
        return;
      }
      try {
        const accessToken =
          typeof sessionStorage !== 'undefined'
            ? sessionStorage.getItem('nxtgauge_admin_access_token') || ''
            : '';
        const response = await fetch('/api/gateway/users/auth/me', {
          method: 'GET',
          headers: {
            Accept: 'application/json',
            'x-portal-target': 'admin',
            ...(accessToken ? { Authorization: `Bearer ${accessToken}` } : {}),
          },
          credentials: 'include',
        });
        const payload = await response.json().catch(() => ({}));
        if (!response.ok || isExternalIdentity(payload)) throw new Error('Unauthorized');
        if (payload?.full_name) setAdminName(payload.full_name);
        setCheckedSession(true);
      } catch {
        clearAdminSession();
        const from = encodeURIComponent(location.pathname + location.search);
        navigate(`/login?from=${from}`, { replace: true });
      }
    };

    void verify();
  });

  const onLogout = async () => {
    await fetch('/api/gateway/users/auth/logout', {
      method: 'POST',
      headers: { Accept: 'application/json', 'x-portal-target': 'admin' },
      credentials: 'include',
    }).catch(() => {});
    clearAdminSession();
    if (typeof sessionStorage !== 'undefined') {
      sessionStorage.removeItem('nxtgauge_admin_access_token');
      sessionStorage.removeItem('nxtgauge_admin_preview');
    }
    navigate('/login', { replace: true });
  };

  const adminInitials = createMemo(() => {
    const parts = adminName().split(' ').map((s) => s.trim()).filter(Boolean);
    if (parts.length === 0) return 'U';
    if (parts.length === 1) return parts[0].slice(0, 1).toUpperCase();
    return `${parts[0][0] || ''}`.toUpperCase();
  });

  const sidebarWidth = () => (sidebarCollapsed() ? 'w-20' : 'w-64');

  return (
    <div class="min-h-screen bg-white">
      {/* ── Header ── */}
      <header class="fixed inset-x-0 top-0 z-50 flex h-16 w-full items-center justify-between border-b border-gray-200 bg-white px-6 shadow-sm">
        {/* Left: logo + role title */}
        <div class="flex items-center gap-8">
          <A href="/admin" class="flex h-10 items-center">
            <img src="/nxtgauge-logo.png" alt="NXTGAUGE" class="h-9 w-auto object-contain" />
          </A>
          <h1 class="text-base font-semibold text-gray-800">Super Admin</h1>
        </div>

        {/* Mobile menu button */}
        <button
          type="button"
          class="inline-flex h-9 w-9 items-center justify-center rounded-lg text-slate-600 hover:bg-slate-100 lg:hidden"
          onClick={() => setSidebarOpen((v) => !v)}
          aria-label="Toggle sidebar"
        >
          <svg class="h-4 w-4" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24">
            <path stroke-linecap="round" d="M4 7h16M4 12h16M4 17h16" />
          </svg>
        </button>

        {/* Right: bell + avatar + logout */}
        <div class="hidden items-center gap-6 lg:flex">
          {/* Bell */}
          <div class="relative">
            <button
              type="button"
              aria-label="Notifications"
              class="relative rounded-full p-2 text-gray-500 transition-colors hover:bg-gray-100"
            >
              <Bell size={20} />
            </button>
          </div>

          {/* Avatar + name */}
          <div class="flex items-center gap-2">
            <button class="flex items-center gap-3 rounded-lg p-1 pr-2 transition-colors hover:bg-gray-100">
              <div class="flex h-8 w-8 items-center justify-center overflow-hidden rounded-full border border-orange-200 bg-orange-100 text-sm font-semibold text-orange-700">
                {adminInitials()}
              </div>
              <div class="flex flex-col items-start">
                <span class="mb-0.5 text-xs font-semibold leading-none text-gray-700">{adminName()}</span>
                <span class="text-[10px] leading-none text-gray-500">Super Admin</span>
              </div>
            </button>

            {/* Logout */}
            <button
              type="button"
              onClick={onLogout}
              class="rounded-lg p-1.5 text-gray-500 transition-colors hover:bg-red-50 hover:text-red-600"
              aria-label="Sign out"
            >
              <svg class="h-5 w-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M17 16l4-4m0 0l-4-4m4 4H7m6 4v1a3 3 0 01-3 3H6a3 3 0 01-3-3V7a3 3 0 013-3h4a3 3 0 013 3v1" />
              </svg>
            </button>
          </div>
        </div>
      </header>

      {/* ── Body ── */}
      {checkedSession() ? (
        <div class="fixed inset-0 top-16 flex">
          {/* Mobile overlay */}
          <div
            class={`absolute inset-0 z-20 bg-black/30 transition-opacity lg:hidden ${sidebarOpen() ? 'pointer-events-auto opacity-100' : 'pointer-events-none opacity-0'}`}
            onClick={() => setSidebarOpen(false)}
          />

          {/* Sidebar */}
          <div
            class={`absolute inset-y-0 left-0 z-30 -translate-x-full transition-transform duration-200 lg:static lg:translate-x-0 ${sidebarOpen() ? 'translate-x-0' : ''}`}
          >
            <AdminSidebar
              collapsed={sidebarCollapsed()}
              onToggle={() => setSidebarCollapsed((v) => !v)}
              onNavigate={() => setSidebarOpen(false)}
              onLogout={onLogout}
            />
          </div>

          {/* Main */}
          <main class="scrollbar min-w-0 flex-1 overflow-y-auto bg-gray-50 p-6">
            <ShowTabs
              tabs={tabs()}
              isTabActive={isTabActive}
              setTabsTrackEl={setTabsTrackEl}
              setTabRefs={setTabRefs}
              tabIndicator={tabIndicator}
            />
            {props.children}
          </main>
        </div>
      ) : (
        <div class="fixed inset-0 top-16 flex">
          <div class="hidden w-64 border-r border-slate-200 bg-[#fcfcfd] lg:block" />
          <main class="flex flex-1 items-center justify-center bg-gray-50">
            <p class="text-sm text-gray-400">Checking session…</p>
          </main>
        </div>
      )}
    </div>
  );
}

function ShowTabs(props: {
  tabs: Tab[];
  isTabActive: (tab: Tab) => boolean;
  setTabsTrackEl: (el: HTMLDivElement) => void;
  setTabRefs: (fn: (prev: Record<string, HTMLAnchorElement>) => Record<string, HTMLAnchorElement>) => void;
  tabIndicator: () => { left: number; width: number; ready: boolean };
}) {
  if (props.tabs.length === 0) return null;

  return (
    <div ref={props.setTabsTrackEl} class="relative mb-6 flex items-center gap-1 border-b border-gray-200">
      <For each={props.tabs}>
        {(tab) => (
          <A
            href={tab.href}
            ref={(el) => props.setTabRefs((prev) => ({ ...prev, [tab.href]: el }))}
            aria-current={props.isTabActive(tab) ? 'page' : undefined}
            class={`px-4 pb-3 pt-3 text-[14px] font-semibold transition-colors ${
              props.isTabActive(tab)
                ? 'text-[#fd6216]'
                : 'text-slate-500 hover:text-slate-800'
            }`}
          >
            {tab.label}
          </A>
        )}
      </For>
      <div
        class={`absolute bottom-0 h-[2px] bg-[#fd6216] transition-all duration-300 ease-out ${props.tabIndicator().ready ? 'opacity-100' : 'opacity-0'}`}
        style={{ left: `${props.tabIndicator().left}px`, width: `${props.tabIndicator().width}px` }}
      />
    </div>
  );
}