optimize init method

lib/theme.js

@@ -1,7 +1,7 @@
 import cookie from 'react-cookies'
 import BLOG from '@/blog.config'
 import { ALL_THEME } from '@/themes'
-import { getQueryVariable } from './utils'
+import { isBrowser, getQueryVariable } from './utils'
 
 /**
  * 初始化主题 , 优先级 query > cookies > systemPrefer
@@ -27,14 +27,14 @@ export const initDarkMode = (isDarkMode, updateDarkMode) => {
  * @param {*} changeTheme
  */
 export const initTheme = (theme, changeTheme) => {
-  const queryTheme = getQueryVariable('theme')
-  if (queryTheme && ALL_THEME.indexOf(queryTheme) > -1) {
-    changeTheme(queryTheme)
-  } else {
-    const userTheme = loadThemeFromCookies()
-    if (userTheme !== theme) {
-      changeTheme(userTheme)
+  if (isBrowser()) {
+    const queryTheme = getQueryVariable('theme') || loadThemeFromCookies() || BLOG.THEME
+    let currentTheme = theme
+    if (queryTheme !== theme && ALL_THEME.indexOf(queryTheme) > -1) {
+      currentTheme = queryTheme
     }
+    changeTheme(currentTheme)
+    saveThemeToCookies(currentTheme)
   }
 }