feat: 更改加载时间

api/cases.ts

@@ -48,6 +48,13 @@ export type CaseListPage = {
 	results: ClinicalCase[]
 }
 
+export type CaseListPrefetch = {
+	source: CaseListSource
+	query: CaseListQuery
+	page: CaseListPage
+	cachedAt: number
+}
+
 type QueryValue = string | number | boolean | null | undefined
 
 type ServerCaseListPage = {
@@ -88,6 +95,8 @@ const CASE_LIST_PATHS: Record<CaseListSource, string> = {
 }
 
 const TONES: CaseTone[] = ['blue', 'teal', 'pink', 'orange', 'purple', 'green']
+const CASE_LIST_PREFETCH_STORAGE_KEY = 'clinical-thinking-prefetched-case-list'
+const CASE_LIST_PREFETCH_MAX_AGE_MS = 60 * 1000
 
 export async function fetchCaseList(source: CaseListSource = 'recommended', query: CaseListQuery = {}): Promise<ClinicalCase[]> {
 	const page = await fetchCaseListPage(source, query)
@@ -102,6 +111,30 @@ export async function fetchCaseListPage(source: CaseListSource = 'recommended',
 	return page
 }
 
+export function savePrefetchedCaseList(payload: CaseListPrefetch) {
+	uni.setStorageSync(CASE_LIST_PREFETCH_STORAGE_KEY, payload)
+}
+
+export function clearPrefetchedCaseList() {
+	uni.removeStorageSync(CASE_LIST_PREFETCH_STORAGE_KEY)
+}
+
+export function takePrefetchedCaseList(source: CaseListSource, query: CaseListQuery): CaseListPage | null {
+	const value = uni.getStorageSync(CASE_LIST_PREFETCH_STORAGE_KEY)
+	if (!isCaseListPrefetch(value)) return null
+
+	const isFresh = Date.now() - value.cachedAt <= CASE_LIST_PREFETCH_MAX_AGE_MS
+	if (!isFresh) {
+		clearPrefetchedCaseList()
+		return null
+	}
+
+	if (value.source !== source || !isSameCaseListQuery(value.query, query)) return null
+
+	clearPrefetchedCaseList()
+	return value.page
+}
+
 export function readStoredClinicalCase() {
 	const value = uni.getStorageSync('clinical-thinking-selected-case')
 	if (value && typeof value === 'object') return value as ClinicalCase
@@ -224,6 +257,35 @@ function withQuery(path: string, query: Record<string, QueryValue>) {
 	return params ? `${path}?${params}` : path
 }
 
+function isCaseListPrefetch(value: unknown): value is CaseListPrefetch {
+	if (!value || typeof value !== 'object') return false
+	const payload = value as Partial<CaseListPrefetch>
+	return isCaseListSource(payload.source) &&
+		typeof payload.query === 'object' &&
+		payload.query !== null &&
+		!!payload.page &&
+		typeof payload.page === 'object' &&
+		Array.isArray(payload.page.results) &&
+		typeof payload.cachedAt === 'number'
+}
+
+function isCaseListSource(value: unknown): value is CaseListSource {
+	return value === 'recommended' ||
+		value === 'specialty' ||
+		value === 'weak' ||
+		value === 'teaching' ||
+		value === 'teacher-task'
+}
+
+function isSameCaseListQuery(left: CaseListQuery, right: CaseListQuery) {
+	const keys: Array<keyof CaseListQuery> = ['search', 'case_type', 'difficulty', 'department', 'page', 'page_size']
+	return keys.every(key => normalizeQueryValue(left[key]) === normalizeQueryValue(right[key]))
+}
+
+function normalizeQueryValue(value: unknown) {
+	return value === undefined || value === null || value === '' ? '' : String(value)
+}
+
 function readErrorMessage(data: unknown, fallback: string) {
 	if (data && typeof data === 'object') {
 		const payload = data as Record<string, unknown>