Refactor code structure for improved readability and maintainability; optimize performance across multiple modules.

backend/services/settingsService.js

@@ -173,6 +173,130 @@ class SettingsService extends BaseService{
         return [];
     } 
 
+    async getUserAgeAndLanguage(hashedUserId) {
+        const user = await this.getUserByHashedId(hashedUserId);
+        const userParams = await this.getUserParams(user.id, ['birthdate', 'language']);
+
+        let birthdate = null;
+        let language = 'en';
+
+        for (const param of userParams) {
+            if (param.paramType.description === 'birthdate') {
+                birthdate = param.value;
+            }
+            if (param.paramType.description === 'language') {
+                const languageValue = await UserParamValue.findOne({
+                    where: { id: param.value }
+                });
+                language = languageValue ? languageValue.value : 'en';
+            }
+        }
+
+        return {
+            user,
+            age: birthdate ? this.calculateAge(birthdate) : null,
+            language,
+        };
+    }
+
+    async buildInterestPayload(interest, languageIdByCode) {
+        const translations = await InterestTranslation.findAll({
+            where: { interestsId: interest.id },
+            order: [[ 'id', 'asc' ]]
+        });
+
+        return {
+            id: interest.id,
+            name: interest.name,
+            allowed: interest.allowed,
+            adultOnly: interest.adultOnly,
+            interest_translations: translations.map((translation) => ({
+                id: translation.id,
+                translation: translation.translation,
+                language: translation.language,
+                user_param_value: {
+                    value: languageIdByCode.get(Number(translation.language)) || 'en',
+                },
+            })),
+        };
+    }
+
+    async getPossibleInterests(hashedUserId) {
+        const { user, age, language } = await this.getUserAgeAndLanguage(hashedUserId);
+        const languageType = await UserParamType.findOne({ where: { description: 'language' } });
+        const languageValues = languageType
+            ? await UserParamValue.findAll({ where: { userParamTypeId: languageType.id } })
+            : [];
+        const languageIdByCode = new Map(languageValues.map((entry) => [Number(entry.id), entry.value]));
+
+        const where = { allowed: true };
+        if (age !== null && age < 18) {
+            where[Op.or] = [
+                { adultOnly: false },
+                { adultOnly: { [Op.eq]: null } }
+            ];
+        }
+
+        const interests = await InterestType.findAll({
+            where,
+            order: [[ 'name', 'asc' ]],
+        });
+
+        return Promise.all(interests.map(async (interest) => {
+            const payload = await this.buildInterestPayload(interest, languageIdByCode);
+            if (language && payload.interest_translations.length > 0) {
+                payload.interest_translations.sort((a, b) => {
+                    const aPreferred = a.user_param_value?.value === language ? 0 : 1;
+                    const bPreferred = b.user_param_value?.value === language ? 0 : 1;
+                    return aPreferred - bPreferred;
+                });
+            }
+            return payload;
+        }));
+    }
+
+    async getInterests(hashedUserId) {
+        const { user, language } = await this.getUserAgeAndLanguage(hashedUserId);
+        const languageType = await UserParamType.findOne({ where: { description: 'language' } });
+        const languageValues = languageType
+            ? await UserParamValue.findAll({ where: { userParamTypeId: languageType.id } })
+            : [];
+        const languageIdByCode = new Map(languageValues.map((entry) => [Number(entry.id), entry.value]));
+
+        const selectedInterests = await UserInterest.findAll({
+            where: { userId: user.id },
+            include: [
+                {
+                    model: InterestType,
+                    as: 'interest_type',
+                }
+            ],
+            order: [[ 'id', 'asc' ]],
+        });
+
+        const payloads = [];
+        for (const userInterest of selectedInterests) {
+            const interestType = userInterest.interest_type;
+            if (!interestType) {
+                continue;
+            }
+            const payload = await this.buildInterestPayload(interestType, languageIdByCode);
+            if (language && payload.interest_translations.length > 0) {
+                payload.interest_translations.sort((a, b) => {
+                    const aPreferred = a.user_param_value?.value === language ? 0 : 1;
+                    const bPreferred = b.user_param_value?.value === language ? 0 : 1;
+                    return aPreferred - bPreferred;
+                });
+            }
+            payloads.push({
+                id: interestType.id,
+                user_interest_type: payload,
+            });
+        }
+
+        return payloads;
+    }
+
     async filterSettings(hashedUserId, type) {
         const user = await this.getUserByHashedId(hashedUserId);
         const userParams = await this.getUserParams(user.id, ['birthdate', 'gender']);