feat: Automatically detect and warn to correct the language of post

locales/en-US.yml

@@ -2227,3 +2227,5 @@ moreUrlsDescription: "Enter the pages you want to pin to the help menu in the lo
   left corner using this notation:\n\"Display name\": https://example.com/"
 messagingUnencryptedInfo: "Chats on Firefish are not end-to-end encrypted. Don't share
   any sensitive infomation over Firefish."
+autocorrectNoteLanguage: Automatically detect and warn to correct the language of your post.
+incorrectLanguageWarning: "It looks like your post is in {detected}, but the language you selected is {current}.\nWould you like to post in {detected} instead?"

locales/zh-CN.yml

@@ -2056,3 +2056,5 @@ searchRangeDescription: "如果您要过滤时间段，请按以下格式输入
 messagingUnencryptedInfo: "Firefish 上的聊天没有经过端到端加密，请不要在聊天中分享您的敏感信息。"
 noAltTextWarning: 有些附件没有描述。您是否忘记写描述了？
 showNoAltTextWarning: 当您尝试发布没有描述的帖子附件时显示警告
+autocorrectNoteLanguage: 自动检测和弹窗纠正您所使用的帖子语言
+incorrectLanguageWarning: "看上去您帖子使用的语言是{detected}，但您选择的语言是{current}。\n要改为以{detected}发帖吗？"

packages/client/src/components/MkPostForm.vue

@@ -1020,6 +1020,37 @@ function deleteDraft() {
 }
 
 async function post() {
+	// For text that is too short, the false positive rate may be too high, so we don't show alarm.
+	if (defaultStore.state.autocorrectNoteLanguage && text.value.length > 10) {
+		const detectedLanguage: string = detectLanguage(text.value) ?? "";
+
+		const currentLanguageName : string | undefined | false = 
+			language.value &&
+			langmap[language.value]?.nativeName
+		const detectedLanguageName : string | undefined | false = 
+			detectedLanguage !== "" && 
+			detectedLanguage !== language.value &&
+			langmap[detectedLanguage]?.nativeName;
+
+		if (currentLanguageName && detectedLanguageName) {
+			// "canceled" means "post with detected language".
+			const { canceled } = await os.confirm({
+				type: "warning",
+				text: i18n.t("incorrectLanguageWarning", {
+								detected: `${detectedLanguageName}`,
+								current: `${currentLanguageName}`,
+							}),
+				okText: i18n.ts.no,
+				cancelText: i18n.ts.yes,
+				isPlaintext: true,
+			});
+	
+			if (canceled) {
+				language.value = detectedLanguage;
+			}
+		}
+	}
+
 	if (
 		defaultStore.state.showNoAltTextWarning &&
 		files.value.some((f) => f.comment == null || f.comment.length === 0)

packages/client/src/i18n.ts

@@ -22,7 +22,7 @@ class I18n<T extends Record<string, any>> {
 
 			if (args) {
 				for (const [k, v] of Object.entries(args)) {
-					str = str.replace(`{${k}}`, v.toString());
+					str = str.replaceAll(`{${k}}`, v.toString());
 				}
 			}
 			return str;

packages/client/src/pages/settings/general.vue

@@ -124,6 +124,9 @@
 			<FormSwitch v-model="showNoAltTextWarning" class="_formBlock">{{
 				i18n.ts.showNoAltTextWarning
 			}}</FormSwitch>
+			<FormSwitch v-model="autocorrectNoteLanguage" class="_formBlock">{{
+				i18n.ts.autocorrectNoteLanguage
+			}}</FormSwitch>
 
 			<FormSelect v-model="serverDisconnectedBehavior" class="_formBlock">
 				<template #label>{{ i18n.ts.whenServerDisconnected }}</template>
@@ -530,6 +533,9 @@ const pullToRefreshThreshold = computed(
 const showNoAltTextWarning = computed(
 	defaultStore.makeGetterSetter("showNoAltTextWarning"),
 );
+const autocorrectNoteLanguage = computed(
+	defaultStore.makeGetterSetter("autocorrectNoteLanguage"),
+);
 
 // This feature (along with injectPromo) is currently disabled
 // function onChangeInjectFeaturedNote(v) {

packages/client/src/pages/settings/preferences-backups.vue

@@ -125,6 +125,7 @@ const defaultStoreSaveKeys: (keyof (typeof defaultStore)["state"])[] = [
 	"enablePullToRefresh",
 	"pullToRefreshThreshold",
 	"showNoAltTextWarning",
+	"autocorrectNoteLanguage",
 ];
 const coldDeviceStorageSaveKeys: (keyof typeof ColdDeviceStorage.default)[] = [
 	"lightTheme",

packages/client/src/store.ts

@@ -432,6 +432,10 @@ export const defaultStore = markRaw(
 			where: "account",
 			default: true,
 		},
+		autocorrectNoteLanguage: {
+			where: "account",
+			default: true,
+		}
 	}),
 );