Updated users to get exams related to their level

src/interfaces/exam.ts

@@ -3,6 +3,7 @@ import {Module} from ".";
 export type Exam = ReadingExam | ListeningExam | WritingExam | SpeakingExam | LevelExam;
 export type Variant = "full" | "partial";
 export type InstructorGender = "male" | "female" | "varied";
+export type Difficulty = "easy" | "medium" | "hard";
 
 export interface ReadingExam {
 	parts: ReadingPart[];
@@ -12,6 +13,7 @@ export interface ReadingExam {
 	type: "academic" | "general";
 	isDiagnostic: boolean;
 	variant?: Variant;
+	difficulty?: Difficulty;
 }
 
 export interface ReadingPart {
@@ -29,6 +31,7 @@ export interface LevelExam {
 	minTimer: number;
 	isDiagnostic: boolean;
 	variant?: Variant;
+	difficulty?: Difficulty;
 }
 
 export interface ListeningExam {
@@ -38,6 +41,7 @@ export interface ListeningExam {
 	minTimer: number;
 	isDiagnostic: boolean;
 	variant?: Variant;
+	difficulty?: Difficulty;
 }
 
 export interface ListeningPart {
@@ -69,6 +73,7 @@ export interface WritingExam {
 	minTimer: number;
 	isDiagnostic: boolean;
 	variant?: Variant;
+	difficulty?: Difficulty;
 }
 
 interface WordCounter {
@@ -84,6 +89,7 @@ export interface SpeakingExam {
 	isDiagnostic: boolean;
 	variant?: Variant;
 	instructorGender: InstructorGender;
+	difficulty?: Difficulty;
 }
 
 export type Exercise =

src/pages/api/exam/[module]/index.ts

@@ -6,6 +6,7 @@ import {withIronSessionApiRoute} from "iron-session/next";
 import {sessionOptions} from "@/lib/session";
 import {Exam, InstructorGender, Variant} from "@/interfaces/exam";
 import {getExams} from "@/utils/exams.be";
+import {Module} from "@/interfaces";
 const db = getFirestore(app);
 
 export default withIronSessionApiRoute(handler, sessionOptions);
@@ -24,7 +25,7 @@ async function GET(req: NextApiRequest, res: NextApiResponse) {
 	}
 
 	const {module, avoidRepeated, variant, instructorGender} = req.query as {
-		module: string;
+		module: Module;
 		avoidRepeated: string;
 		variant?: Variant;
 		instructorGender?: InstructorGender;

src/utils/exams.be.ts

@@ -1,11 +1,12 @@
-import {collection, getDocs, query, where, setDoc, doc, Firestore} from "firebase/firestore";
+import {collection, getDocs, query, where, setDoc, doc, Firestore, getDoc} from "firebase/firestore";
 import {shuffle} from "lodash";
-import {Exam, InstructorGender, Variant} from "@/interfaces/exam";
+import {Difficulty, Exam, InstructorGender, Variant} from "@/interfaces/exam";
-import {Stat} from "@/interfaces/user";
+import {Stat, User} from "@/interfaces/user";
+import {Module} from "@/interfaces";
 
 export const getExams = async (
 	db: Firestore,
-	module: string,
+	module: Module,
 	avoidRepeated: string,
 	// added userId as due to assignments being set from the teacher to the student
 	// we need to make sure we are serving exams not executed by the user and not
@@ -29,6 +30,7 @@ export const getExams = async (
 
 	const variantExams: Exam[] = filterByVariant(allExams, variant);
 	const genderedExams: Exam[] = filterByInstructorGender(variantExams, instructorGender);
+	const difficultyExams: Exam[] = await filterByDifficulty(db, genderedExams, module, userId);
 
 	if (avoidRepeated === "true") {
 		const statsQ = query(collection(db, "stats"), where("user", "==", userId));
@@ -38,12 +40,12 @@ export const getExams = async (
 			id: doc.id,
 			...doc.data(),
 		})) as unknown as Stat[];
-		const filteredExams = genderedExams.filter((x) => !stats.map((s) => s.exam).includes(x.id));
+		const filteredExams = difficultyExams.filter((x) => !stats.map((s) => s.exam).includes(x.id));
 
-		return filteredExams.length > 0 ? filteredExams : genderedExams;
+		return filteredExams.length > 0 ? filteredExams : difficultyExams;
 	}
 
-	return genderedExams;
+	return difficultyExams;
 };
 
 const filterByInstructorGender = (exams: Exam[], instructorGender?: InstructorGender) => {
@@ -56,3 +58,15 @@ const filterByVariant = (exams: Exam[], variant?: Variant) => {
 	const filtered = variant && variant === "partial" ? exams.filter((x) => x.variant === "partial") : exams.filter((x) => x.variant !== "partial");
 	return filtered.length > 0 ? filtered : exams;
 };
+
+const filterByDifficulty = async (db: Firestore, exams: Exam[], module: Module, userID?: string) => {
+	if (!userID) return exams;
+	const userRef = await getDoc(doc(db, "users", userID));
+	if (!userRef.exists()) return exams;
+
+	const user = {...userRef.data(), id: userRef.id} as User;
+	const difficulty = user.levels[module] <= 3 ? "easy" : user.levels[module] <= 6 ? "medium" : "hard";
+
+	const filteredExams = exams.filter((exam) => exam.difficulty === difficulty);
+	return filteredExams.length === 0 ? exams : filteredExams;
+};