import { createRouter, createWebHistory, type RouteRecordRaw } from "vue-router";
import StartTask from "@/components/StartTask.vue";

const routes: RouteRecordRaw[] = [
  {
    path: "/",
    redirect: "/login",
  },
  {
    path: "/login",
    component: () => import("@/components/Login.vue"),
    meta: { requiresAuth: false },
  },
  {
    path: "/welcome",
    component: () => import("@/components/Welcome.vue"),
    meta: { requiresAuth: true },
  },
  {
    path: "/study",
    name: "study",
    component: () => import("@/components/Study.vue"),
    meta: { requiresAuth: true, title: "学习任务" },
  },
  {
    path: "/review",
    component: () => import("@/components/Review.vue"),
    meta: { requiresAuth: true, title: "复习总览" },
  },
  {
    path: "/review/detail/task/:taskNum",
    component: () => import("@/components/ReviewDetail.vue"),
    meta: { requiresAuth: true, title: "复习详情" },
  },
  {
    path: "/review/detail/:type/:id",
    component: () => import("@/components/ReviewDetail.vue"),
    meta: { requiresAuth: true, title: "复习详情" },
  },
  {
    path: "/review/recall/:taskNum",
    component: () => import("@/components/ReviewRecall.vue"),
    meta: { requiresAuth: true, title: "回忆复习", wide: true },
  },
  {
    path: "/start-task/:taskNum",
    name: "start-task",
    component: StartTask,
    meta: { requiresAuth: true, title: "学习会话" },
  },
  {
    path: "/add-task",
    name: "add-task",
    component: () => import("@/components/TaskForm.vue"),
    meta: {
      requiresAuth: true,
      title: "创建学习任务",
      action: "add",
      buttonText: "添加",
    },
  },
  {
    path: "/update-task/:taskId",
    name: "update-task",
    component: () => import("@/components/TaskForm.vue"),
    meta: {
      requiresAuth: true,
      title: "更新学习任务",
      action: "update",
      buttonText: "更新",
    },
  },
];

const router = createRouter({
  history: createWebHistory(),
  routes,
});

router.onError((error, to) => {
  const message = String((error as Error)?.message || "");
  const isChunkLoadError =
    message.includes("Failed to fetch dynamically imported module") ||
    message.includes("Importing a module script failed") ||
    message.includes("Loading chunk");
  if (isChunkLoadError && typeof window !== "undefined") {
    window.location.assign(to.fullPath);
  }
});

router.beforeEach((to) => {
  if (to.meta.requiresAuth === false) return true;
  const isLoggedIn = localStorage.getItem("isLoggedIn") === "true";
  if (!isLoggedIn) {
    return "/login";
  }
  // 如果有活跃会话且未处于 start-task 页面，自动恢复
  if (!to.path.startsWith("/start-task")) {
    const stored = localStorage.getItem("activeSession");
    if (stored) {
      try {
        const { taskNum } = JSON.parse(stored);
        if (taskNum) {
          return `/start-task/${encodeURIComponent(taskNum)}?resume=true`;
        }
      } catch {}
    }
  }
  return true;
});

export default router;