import { useEffect, useMemo, useState } from "react";
import { Blocks, Home, LogOut, MapPin, Package, UserRoundCheck } from "lucide-react";

import { clearToken, getDestinations } from "@/api";
import type { Destination } from "@/api";
import { ToastStack } from "@/components/admin/ToastStack";
import { Button } from "@/components/ui/button";
import { LeadsPage } from "@/pages/leads/LeadsPage";
import { ProductsPage } from "@/pages/products/ProductsPage";
import { StructurePage } from "@/pages/structure/StructurePage";
import type { Tab, Toast } from "@/types/admin";

const sidebarGroups: { id: string; label: string; items: { id: Tab; label: string; icon: typeof Home; description: string }[] }[] = [
  {
    id: "workspace",
    label: "工作台",
    items: [{ id: "structure", label: "维护地图", icon: Blocks, description: "前台结构总览" }],
  },
  {
    id: "frontend",
    label: "前台页面",
    items: [
      { id: "home", label: "小程序首页", icon: Home, description: "轮播、主题、CTA" },
      { id: "destinations", label: "目的地页", icon: MapPin, description: "主视觉、热门、省内" },
      { id: "products", label: "商品维护", icon: Package, description: "列表、卡片、详情" },
    ],
  },
  {
    id: "operations",
    label: "业务处理",
    items: [{ id: "leads", label: "需求线索", icon: UserRoundCheck, description: "表单和跟进" }],
  },
];

const tabs = sidebarGroups.flatMap((group) => group.items);
const hiddenTabs: Partial<Record<Tab, { label: string; description: string }>> = {
  leadList: { label: "线索查询跟进", description: "表单查询和状态流转" },
};

export function AdminShell({ onLogout }: { onLogout: () => void }) {
  const [activeTab, setActiveTab] = useState<Tab>("structure");
  const [destinations, setDestinations] = useState<Destination[]>([]);
  const [hasUnsavedChanges, setHasUnsavedChanges] = useState(false);
  const [toasts, setToasts] = useState<Toast[]>([]);

  useEffect(() => {
    getDestinations()
      .then((result) => setDestinations(result.items))
      .catch(() => setDestinations([]));
  }, [activeTab]);

  useEffect(() => {
    setHasUnsavedChanges(false);
  }, [activeTab]);

  const activeMeta = useMemo(() => tabs.find((tab) => tab.id === activeTab) ?? hiddenTabs[activeTab], [activeTab]);
  const activeLabel = activeMeta?.label ?? "";
  const activeDescription = activeMeta?.description ?? "";

  const notify = (toast: Omit<Toast, "id">) => {
    const id = `toast-${Date.now()}-${Math.random().toString(16).slice(2)}`;
    setToasts((items) => [...items, { ...toast, id }]);
    window.setTimeout(() => {
      setToasts((items) => items.filter((item) => item.id !== id));
    }, 4200);
  };

  const logout = () => {
    clearToken();
    onLogout();
  };

  return (
    <main className="admin-shell">
      <aside className="sidebar">
        <div className="brand-block">
          <b>万趣小程序管理端</b>
          <span>按前台结构管理</span>
        </div>
        <nav>
          {sidebarGroups.map((group) => (
            <section className="sidebar-group" key={group.id} aria-label={group.label}>
              <span>{group.label}</span>
              {group.items.map((tab) => {
                const Icon = tab.icon;
                return (
                  <Button
                    variant="ghost"
                    aria-label={tab.label}
                    className={activeTab === tab.id ? "active" : ""}
                    key={tab.id}
                    onClick={() => setActiveTab(tab.id)}
                    title={tab.label}
                  >
                    <Icon size={18} />
                    <span>
                      <b>{tab.label}</b>
                      <small>{tab.description}</small>
                    </span>
                  </Button>
                );
              })}
            </section>
          ))}
        </nav>
        <Button variant="ghost" aria-label="退出登录" className="logout-button" onClick={logout} title="退出登录">
          <LogOut size={17} />
          退出登录
        </Button>
      </aside>
      <section className="main-panel">
        <header className="topbar">
          <div>
            <span>{activeLabel}</span>
            <small>{activeDescription} · 结构化维护 · 内存开发模式</small>
          </div>
          <div className="topbar-actions">
            <span className={hasUnsavedChanges ? "admin-dirty-chip is-dirty" : "admin-dirty-chip"}>
              {hasUnsavedChanges ? "有未提交修改" : "内容已同步"}
            </span>
          </div>
        </header>
        {activeTab === "structure" ? (
          <StructurePage onJump={setActiveTab} onDirtyChange={setHasUnsavedChanges} notify={notify} />
        ) : activeTab === "home" ? (
          <StructurePage key="home-workbench" fixedPage="home" onJump={setActiveTab} onDirtyChange={setHasUnsavedChanges} notify={notify} />
        ) : activeTab === "destinations" ? (
          <StructurePage key="destination-workbench" fixedPage="destination" onJump={setActiveTab} onDirtyChange={setHasUnsavedChanges} notify={notify} />
        ) : activeTab === "products" ? (
          <ProductsPage destinations={destinations} onDirtyChange={setHasUnsavedChanges} notify={notify} />
        ) : activeTab === "leads" ? (
          <StructurePage key="demand-workbench" fixedPage="demand" onJump={setActiveTab} onDirtyChange={setHasUnsavedChanges} notify={notify} />
        ) : (
          <LeadsPage notify={notify} />
        )}
      </section>
      <ToastStack toasts={toasts} onClose={(id) => setToasts((items) => items.filter((item) => item.id !== id))} />
    </main>
  );
}