implement language as state instead of cookie

website/.eslintrc.json

@@ -1,10 +1,6 @@
 {
   "root": true,
-  "extends": [
-    "eslint:recommended",
-    "plugin:@typescript-eslint/recommended",
-    "next/core-web-vitals"
-  ],
+  "extends": ["eslint:recommended", "plugin:@typescript-eslint/recommended", "next/core-web-vitals"],
   "rules": {
     "unused-imports/no-unused-imports": "warn",
     "simple-import-sort/imports": "warn",
@@ -18,7 +14,8 @@
         "varsIgnorePattern": "^_",
         "caughtErrorsIgnorePattern": "^_"
       }
-    ]
+    ],
+    "@typescript-eslint/no-non-null-assertion": 0
   },
   "plugins": ["simple-import-sort", "unused-imports"]
 }

website/cypress/support/commands.ts

@@ -51,7 +51,7 @@ Cypress.Commands.add("signInUsingEmailedLink", (emailAddress) => {
     // we do a GET to this url to force the python backend to add an entry for our user
     // in the database, otherwise the tos acceptance will error with 404 user not found
     // then we accept the tos
-    cy.request("GET", "/api/available_tasks").then(() => cy.request("POST", "/api/tos", {}));
+    cy.request("GET", "/api/available_tasks?lang=en").then(() => cy.request("POST", "/api/tos", {}));
   });
 });
 

website/src/components/Messages/LabelFlagGroup.tsx

@@ -1,6 +1,6 @@
 import { Button, Flex, Tooltip } from "@chakra-ui/react";
 import { useTranslation } from "next-i18next";
-import { useCookies } from "react-cookie";
+import { useCurrentLocale } from "src/hooks/locale/useCurrentLocale";
 import { getTypeSafei18nKey } from "src/lib/i18n";
 import { getLocaleDisplayName } from "src/lib/languages";
 
@@ -20,8 +20,7 @@ export const LabelFlagGroup = ({
   onChange,
 }: LabelFlagGroupProps) => {
   const { t } = useTranslation("labelling");
-  const [cookies] = useCookies(["NEXT_LOCALE"]);
-  const currentLanguage = cookies["NEXT_LOCALE"];
+  const currentLanguage = useCurrentLocale();
   const expectedLanguageName = getLocaleDisplayName(expectedLanguage, currentLanguage);
   return (
     <Flex wrap="wrap" gap="4">

website/src/hooks/locale/useCurrentLocale.ts

@@ -0,0 +1,3 @@
+import { useRouter } from "next/router";
+
+export const useCurrentLocale = () => useRouter().locale || "en";

website/src/hooks/tasks/useGenericTaskAPI.tsx

@@ -1,27 +1,31 @@
 import { useCallback, useState } from "react";
 import { TaskInfos } from "src/components/Tasks/TaskTypes";
 import { get, post } from "src/lib/api";
+import { API_ROUTES } from "src/lib/routes";
 import { TaskApiHook } from "src/types/Hooks";
 import { BaseTask, ServerTaskResponse, TaskResponse, TaskType as TaskTypeEnum } from "src/types/Task";
 import { AllTaskReplies } from "src/types/TaskResponses";
 import useSWRImmutable from "swr/immutable";
 import useSWRMutation from "swr/mutation";
 
+import { useCurrentLocale } from "../locale/useCurrentLocale";
+
 export const useGenericTaskAPI = <TaskType extends BaseTask, ResponseContent = AllTaskReplies>(
   taskType: TaskTypeEnum
 ): TaskApiHook<TaskType, ResponseContent> => {
   const [response, setResponse] = useState<TaskResponse<TaskType>>({ taskAvailability: "AWAITING_INITIAL" });
-
+  const locale = useCurrentLocale();
   // Note: We use isValidating to indicate we are loading because it signals eash load, not just the first one.
   const { isValidating: isLoading, mutate: requestNewTask } = useSWRImmutable<ServerTaskResponse<TaskType>>(
-    "/api/new_task/" + taskType,
+    API_ROUTES.NEW_TASK(taskType, { lang: locale }),
     get,
     {
       onSuccess: (taskResponse) => {
         setResponse({
           ...taskResponse,
           taskAvailability: "AVAILABLE",
-          taskInfo: TaskInfos.find((taskType) => taskType.type === taskResponse.task.type),
+          // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+          taskInfo: TaskInfos.find((taskType) => taskType.type === taskResponse.task.type)!,
         });
       },
       onError: () => {
@@ -33,7 +37,7 @@ export const useGenericTaskAPI = <TaskType extends BaseTask, ResponseContent = A
     }
   );
 
-  const { trigger: sendTaskContent } = useSWRMutation("/api/update_task", post, {
+  const { trigger: sendTaskContent } = useSWRMutation(API_ROUTES.UPDATE_TASK, post, {
     onSuccess: () => {
       requestNewTask();
     },
@@ -63,9 +67,9 @@ export const useGenericTaskAPI = <TaskType extends BaseTask, ResponseContent = A
       if (response.taskAvailability !== "AVAILABLE") {
         throw new Error("Cannot complete task that is not yet ready");
       }
-      await sendTaskContent({ id: response.id, update_type: response.taskInfo.update_type, content });
+      await sendTaskContent({ id: response.id, update_type: response.taskInfo.update_type, content, lang: locale });
     },
-    [response, sendTaskContent]
+    [response, sendTaskContent, locale]
   );
 
   return { response, isLoading, rejectTask, completeTask };

website/src/lib/languages.ts

@@ -1,3 +1,7 @@
+import { NextApiRequest } from "next";
+
+import { OasstError } from "./oasst_api_client";
+
 const missingDisplayNamesForLocales = {
   eu: "Euskara",
   gl: "Galego",
@@ -6,7 +10,7 @@ const missingDisplayNamesForLocales = {
 /**
  * Returns the locale's name.
  */
-export const getLocaleDisplayName = (locale: string, displayLocale = undefined) => {
+export const getLocaleDisplayName = (locale: string, displayLocale?: string) => {
   // Intl defaults to English for locales that are not oficially translated
   if (missingDisplayNamesForLocales[locale]) {
     return missingDisplayNamesForLocales[locale];
@@ -15,3 +19,20 @@ export const getLocaleDisplayName = (locale: string, displayLocale = undefined)
   // Return the Titlecased version of the language name.
   return displayName.charAt(0).toLocaleUpperCase() + displayName.slice(1);
 };
+
+export const getLanguageFromRequest = (req: NextApiRequest) => {
+  const body = req.method === "GET" ? req.query : req.body;
+  const lang = body["lang"];
+
+  if (!lang || typeof lang !== "string") {
+    throw new OasstError({
+      message: "Invalid language",
+      httpStatusCode: -1,
+      errorCode: -1,
+      path: req.url!,
+      method: req.method!,
+    });
+  }
+
+  return lang;
+};

website/src/lib/routes.ts

@@ -1,4 +1,46 @@
+import { TaskType } from "src/types/Task";
+
+export type RouteQuery = Record<string, string | number | boolean | undefined>;
+
+export const stringifyQuery = (query: RouteQuery | undefined) => {
+  if (!query) {
+    return "";
+  }
+
+  const filteredQuery = Object.fromEntries(Object.entries(query).filter(([, value]) => value !== undefined)) as Record<
+    string,
+    string
+  >;
+
+  return new URLSearchParams(filteredQuery).toString();
+};
+
+const createRoute = (path: string, query?: RouteQuery) => {
+  if (!query) {
+    return path;
+  }
+
+  return `${path}?${stringifyQuery(query)}`;
+};
+
 export const ROUTES = {
   ADMIN_MESSAGE_DETAIL: (id: string) => `/admin/messages/${id}`,
   MESSAGE_DETAIL: (id: string) => `/messages/${id}`,
 };
+
+export type QueryWithLang<T extends RouteQuery | undefined = undefined> = T extends undefined
+  ? { lang: string }
+  : T & { lang: string };
+
+const withLang =
+  <T extends RouteQuery | undefined = undefined>(path: string, q?: T) =>
+  (query: QueryWithLang<T>) => {
+    return createRoute(path, { ...q, ...query });
+  };
+
+export const API_ROUTES = {
+  NEW_TASK: (type: TaskType, query: QueryWithLang) => createRoute(`/api/new_task/${type}`, query),
+  UPDATE_TASK: "/api/update_task",
+  AVAILABLE_TASK: withLang("/api/available_tasks"),
+  RECENT_MESSAGES: withLang("/api/messages"),
+};

website/src/lib/users.ts

@@ -1,32 +1,6 @@
-import parser from "accept-language-parser";
-import type { NextApiRequest } from "next";
-import { i18n } from "src/../next-i18next.config";
 import prisma from "src/lib/prismadb";
 import type { BackendUserCore } from "src/types/Users";
 
-const LOCALE_SET = new Set(i18n.locales);
-
-/**
- * Returns the most appropriate user language using the following priority:
- *
- * 1. The `NEXT_LOCALE` cookie which is set by the client side and will be in
- *    the set of supported locales.
- * 2. The `accept-language` header if it contains a supported locale as set by
- *    the i18n module.
- * 3. "en" as a final fallback.
- */
-export const getUserLanguage = (req: NextApiRequest): string => {
-  const cookieLanguage = req.cookies["NEXT_LOCALE"];
-  if (cookieLanguage) {
-    return cookieLanguage;
-  }
-  const headerLanguages = parser.parse(req.headers["accept-language"]);
-  if (headerLanguages.length > 0 && LOCALE_SET.has(headerLanguages[0].code)) {
-    return headerLanguages[0].code;
-  }
-  return "en";
-};
-
 /**
  * Returns a `BackendUserCore` that can be used for interacting with the Backend service.
  *

website/src/pages/api/available_tasks.ts

@@ -1,12 +1,13 @@
 import { withoutRole } from "src/lib/auth";
+import { getLanguageFromRequest } from "src/lib/languages";
 import { createApiClientFromUser } from "src/lib/oasst_client_factory";
-import { getBackendUserCore, getUserLanguage } from "src/lib/users";
+import { getBackendUserCore } from "src/lib/users";
 
 const handler = withoutRole("banned", async (req, res, token) => {
   const user = await getBackendUserCore(token.sub);
-  const oasstApiClient = createApiClientFromUser(user);
-  const userLanguage = getUserLanguage(req);
-  const availableTasks = await oasstApiClient.fetch_available_tasks(user, userLanguage);
+  const oasstApiClient = createApiClientFromUser(user!);
+  const userLanguage = getLanguageFromRequest(req);
+  const availableTasks = await oasstApiClient.fetch_available_tasks(user!, userLanguage);
   res.status(200).json(availableTasks);
 });
 

website/src/pages/api/messages/index.ts

@@ -1,10 +1,10 @@
 import { withoutRole } from "src/lib/auth";
+import { getLanguageFromRequest } from "src/lib/languages";
 import { createApiClient } from "src/lib/oasst_client_factory";
-import { getUserLanguage } from "src/lib/users";
 
 const handler = withoutRole("banned", async (req, res, token) => {
   const client = await createApiClient(token);
-  const userLanguage = getUserLanguage(req);
+  const userLanguage = getLanguageFromRequest(req);
   const messages = await client.fetch_recent_messages(userLanguage);
   res.status(200).json(messages);
 });

website/src/pages/api/new_task/[task_type].ts

@@ -1,9 +1,10 @@
 import { withoutRole } from "src/lib/auth";
 import { ERROR_CODES } from "src/lib/constants";
+import { getLanguageFromRequest } from "src/lib/languages";
 import { OasstError } from "src/lib/oasst_api_client";
 import { createApiClientFromUser } from "src/lib/oasst_client_factory";
 import prisma from "src/lib/prismadb";
-import { getBackendUserCore, getUserLanguage } from "src/lib/users";
+import { getBackendUserCore } from "src/lib/users";
 
 /**
  * Returns a new task created from the Task Backend.  We do a few things here:
@@ -16,16 +17,16 @@ import { getBackendUserCore, getUserLanguage } from "src/lib/users";
 const handler = withoutRole("banned", async (req, res, token) => {
   // Fetch the new task.
   const { task_type } = req.query;
-  const userLanguage = getUserLanguage(req);
+  const lang = getLanguageFromRequest(req);
 
   const user = await getBackendUserCore(token.sub);
-  const oasstApiClient = createApiClientFromUser(user);
+  const oasstApiClient = createApiClientFromUser(user!);
   let task;
   try {
-    task = await oasstApiClient.fetchTask(task_type as string, user, userLanguage);
+    task = await oasstApiClient.fetchTask(task_type as string, user!, lang);
   } catch (err) {
     if (err instanceof OasstError && err.errorCode === ERROR_CODES.TASK_REQUESTED_TYPE_NOT_AVAILABLE) {
-      res.status(503).json({});
+      res.status(503).json(err);
     } else {
       console.error(err);
       res.status(500).json(err);

website/src/pages/api/update_task.ts

@@ -1,8 +1,9 @@
 import { Prisma } from "@prisma/client";
 import { withoutRole } from "src/lib/auth";
+import { getLanguageFromRequest } from "src/lib/languages";
 import { createApiClient } from "src/lib/oasst_client_factory";
 import prisma from "src/lib/prismadb";
-import { getBackendUserCore, getUserLanguage } from "src/lib/users";
+import { getBackendUserCore } from "src/lib/users";
 
 /**
  * Stores the task interaction with the Task Backend and then returns the next task generated.
@@ -18,6 +19,8 @@ const handler = withoutRole("banned", async (req, res, token) => {
   // Parse out the local task ID and the interaction contents.
   const { id: frontendId, content, update_type } = req.body;
 
+  const lang = getLanguageFromRequest(req);
+
   // do in parallel since they are independent
   const [_, registeredTask, oasstApiClient] = await Promise.all([
     // Record that the user has done meaningful work and is no longer new.
@@ -46,18 +49,9 @@ const handler = withoutRole("banned", async (req, res, token) => {
   });
 
   const user = await getBackendUserCore(token.sub);
-  const userLanguage = getUserLanguage(req);
   let newTask;
   try {
-    newTask = await oasstApiClient.interactTask(
-      update_type,
-      taskId,
-      frontendId,
-      interaction.id,
-      content,
-      user,
-      userLanguage
-    );
+    newTask = await oasstApiClient.interactTask(update_type, taskId, frontendId, interaction.id, content, user!, lang);
   } catch (err) {
     console.error(JSON.stringify(err));
     return res.status(500).json(err);

website/src/pages/dashboard.tsx

@@ -1,34 +1,24 @@
 import { Flex } from "@chakra-ui/react";
 import Head from "next/head";
 import { useTranslation } from "next-i18next";
-import { useEffect, useMemo, useState } from "react";
+import { useMemo } from "react";
 import { LeaderboardWidget, TaskOption, WelcomeCard } from "src/components/Dashboard";
 import { getDashboardLayout } from "src/components/Layout";
 import { get } from "src/lib/api";
 import { AvailableTasks, TaskCategory } from "src/types/Task";
 export { getDefaultStaticProps as getStaticProps } from "src/lib/default_static_props";
 import { TaskCategoryItem } from "src/components/Dashboard/TaskOption";
+import { useCurrentLocale } from "src/hooks/locale/useCurrentLocale";
+import { API_ROUTES } from "src/lib/routes";
 import useSWR from "swr";
 
 const Dashboard = () => {
-  const {
-    t,
-    i18n: { language },
-  } = useTranslation(["dashboard", "common", "tasks"]);
-  const [activeLang, setLang] = useState<string>(null);
-  const { data, mutate: fetchTasks } = useSWR<AvailableTasks>("/api/available_tasks", get, {
+  const { t } = useTranslation(["dashboard", "common", "tasks"]);
+  const lang = useCurrentLocale();
+  const { data } = useSWR<AvailableTasks>(API_ROUTES.AVAILABLE_TASK({ lang }), get, {
     refreshInterval: 2 * 60 * 1000, //2 minutes
-    revalidateOnMount: false, // triggered in the hook below
   });
 
-  useEffect(() => {
-    // re-fetch tasks if the language has changed
-    if (activeLang !== language) {
-      setLang(language);
-      fetchTasks();
-    }
-  }, [activeLang, setLang, language, fetchTasks]);
-
   const availableTaskTypes = useMemo(() => {
     const taskTypes = filterAvailableTasks(data ?? {});
     return { [TaskCategory.Random]: taskTypes };