import { defineAsyncComponent, h, type Component } from 'vue'
import {
  PAGE_LOADING_DELAY,
  PAGE_LOADING_TEXT,
  PAGE_LOADING_TIMEOUT,
  PAGE_LOAD_ERROR_TEXT,
} from './lazy-config'

type PageLoader = () => Promise<{ default: unknown }>

/**
 * 页面级异步加载边界（任务 10）：按路由分包页面，加载中/失败都有明确反馈，
 * 不把 chunk 加载错误静默吞掉。
 */
export function defineLazyPage(loader: PageLoader): Component {
  return defineAsyncComponent({
    loader: () => loader().then((mod) => mod.default as Component),
    delay: PAGE_LOADING_DELAY,
    timeout: PAGE_LOADING_TIMEOUT,
    loadingComponent: () => h('div', { class: 'page-loading' }, PAGE_LOADING_TEXT),
    errorComponent: () => h('div', { class: 'page-error' }, PAGE_LOAD_ERROR_TEXT),
  })
}