feat: add user submission functionality

src/common/modules/redis/providers/redis.service.ts

@@ -1,4 +1,3 @@
-/* eslint-disable @typescript-eslint/no-unsafe-call */
 import { Inject, Injectable } from '@nestjs/common';
 import { REDIS } from '../constants/redis.constants';
 import Redis from 'ioredis';
@@ -17,16 +16,22 @@ export class RedisService {
     return this.redis;
   }
 
-  async set(key: string, val: string, ttl?: number) {
+  async set<T>(key: string, val: T, ttl?: number) {
+    const payload = JSON.stringify(val);
+
     if (ttl) {
-      await this.redis.set(key, val, 'EX', ttl);
+      await this.redis.set(key, payload, 'EX', ttl);
     } else {
-      await this.redis.set(key, val);
+      await this.redis.set(key, payload);
     }
   }
 
-  async get(key: string) {
+  async get<T>(key: string): Promise<T | null> {
-    return await this.redis.get(key);
+    const value = await this.redis.get(key);
+
+    if (!value) return null;
+
+    return JSON.parse(value) as T;
   }
 
   async del(key: string) {

src/i18n/en/scoring.json

@@ -0,0 +1,9 @@
+{
+  "fields": {
+    "resultRange": "Result Range"
+  },
+  "errors": {
+    "resultRangeOverlappingConstraint": "The specified score range has some overlaps with other records.",
+    "resultRangeMinMaxConstraint": "minScore value should be less than maxScore."
+  }
+}

src/i18n/en/submissions.json

@@ -0,0 +1,16 @@
+{
+  "fields": {
+    "testId": "Test's Id",
+    "questionId": "Question's Id",
+    "submission": "Submission",
+    "submissionId": "Submission's Id",
+    "choiceId": "Choice's Id"
+  },
+  "errors": {
+    "alreadyTookTest": "You already took this test.",
+    "choiceNumericConstraint": "You must send either choiceId or numericValue.",
+    "emptyNumericValue": "A numeric value should be provided as answer.",
+    "numericValueRange": "Numeric value is out of specified range.",
+    "emptyChoiceId": "Choice Id should be provided as answer."
+  }
+}

src/i18n/fa/scoring.json

@@ -0,0 +1,9 @@
+{
+  "fields": {
+    "resultRange": "بازه نتیجه"
+  },
+  "errors": {
+    "resultRangeOverlappingConstraint": "بازه امتیاز مشخص شده با بازه های دیگر تداخل دارد.",
+    "resultRangeMinMaxConstraint": "minScore باید کمتر از maxScore باشد."
+  }
+}

src/i18n/fa/submissions.json

@@ -0,0 +1,16 @@
+{
+  "fields": {
+    "testId": "شناسه آزمون",
+    "questionId": "شناسه سوال",
+    "submission": "Submission",
+    "submissionId": "شناسه Submission",
+    "choiceId": "شناسه گزینه"
+  },
+  "errors": {
+    "alreadyTookTest": "قبلا این آزمون را انجام داده اید.",
+    "choiceNumericConstraint": "حتما باید یکی از فیلد های شناسه انتخاب و یا مقدار عددی فرستاده شود.",
+    "emptyNumericValue": "یک مقدار عددی باید به عنوان پاسخ سوال مشخص شود.",
+    "numericValueRange": "مقدار عددی خارج از بازه مشخص شده است.",
+    "emptyChoiceId": "شناسه گزینه باید به عنوان پاسخ مشخص شود."
+  }
+}

src/modules/admin/admin.module.ts

@@ -9,6 +9,8 @@ import { AdminAuthService } from './auth/providers/admin-auth.service';
 import { QuestionsModule } from '../questions/questions.module';
 import { AdminQuestionsController } from './questions/admin-questions.controller';
 import { AdminChoicesController } from './choices/admin-choices.controller';
+import { ScoringModule } from '../scoring/scoring.module';
+import { AdminScoringController } from './scoring/admin-scoring.controller';
 
 @Module({
   imports: [
@@ -17,12 +19,14 @@ import { AdminChoicesController } from './choices/admin-choices.controller';
     AuthModule,
     HashingModule,
     UsersModule,
+    ScoringModule,
   ],
   controllers: [
     AdminTestsController,
     AdminAuthController,
     AdminQuestionsController,
     AdminChoicesController,
+    AdminScoringController,
   ],
   providers: [AdminAuthService],
 })

src/modules/admin/choices/http/admin-choices-get-endpoints.http

@@ -1,5 +1,5 @@
 GET {{baseUrl}}/admin/choices/
 Authorization: Bearer {{$global.accessToken}}
 
-GET {{baseUrl}}/admin/choices/1
+GET {{baseUrl}}/admin/choices/3
 Authorization: Bearer {{$global.accessToken}}

src/modules/admin/choices/http/admin-choices.patch.endpoints.http

@@ -1,7 +1,8 @@
-PATCH {{baseUrl}}/admin/choices/1
+PATCH {{baseUrl}}/admin/choices/3
 Authorization: Bearer {{$global.accessToken}}
 Content-Type: application/json
 
 {
-    "question": 4
+    "text": "Option 1",
+    "order": 1
 }

src/modules/admin/choices/http/admin-choices.post.endpoints.http

@@ -5,6 +5,7 @@ Content-Type: application/json
 {
     "question": 4,
     "text": "Option 2",
-    "value": 2,
+    "value": 1,
-    "order": 2
+    "order": 2,
+    "score": 2
 }

src/modules/admin/questions/http/admin-questions.get.endpoints.http

@@ -1,7 +1,7 @@
 GET {{baseUrl}}/admin/questions
 Authorization: Bearer {{$global.accessToken}}
 
-GET {{baseUrl}}/admin/questions/1
+GET {{baseUrl}}/admin/questions/4
 Authorization: Bearer {{$global.accessToken}}
 
 GET {{baseUrl}}/admin/questions/range-rules?limit=1&page=2&sortBy=id&order=ASC

src/modules/admin/questions/http/admin-questions.patch.endpoints.http

@@ -1,9 +1,9 @@
-PATCH {{baseUrl}}/admin/questions/4
+PATCH {{baseUrl}}/admin/questions/1
 Authorization: Bearer {{$global.accessToken}}
 Content-Type: application/json
 
 {
-    "test": 4
+    "type": "multi-choice"
 }
 
 PATCH {{baseUrl}}/admin/questions/range-rules/1

src/modules/admin/scoring/admin-scoring.controller.ts

@@ -0,0 +1,58 @@
+import { Role } from '@/common/enums/roles.enum';
+import { Roles } from '@/modules/auth/decorators/roles.decorator';
+import { CreateResultRangeDTO } from '@/modules/scoring/dtos/create-result-range.dto';
+import { FindResultRangeDTO } from '@/modules/scoring/dtos/find-result-range.dto';
+import { UpdateResultRangeDTO } from '@/modules/scoring/dtos/update-result-range.dto';
+import { ResultRangeService } from '@/modules/scoring/providers/result-range.service';
+import {
+  Body,
+  Controller,
+  Delete,
+  Get,
+  Param,
+  ParseIntPipe,
+  Patch,
+  Post,
+  Query,
+} from '@nestjs/common';
+
+@Controller('admin/scoring')
+@Roles(Role.SUPERUSER, Role.ADMIN)
+export class AdminScoringController {
+  constructor(
+    /**
+     * Inject ResultRange Service
+     */
+    private readonly resultRangeService: ResultRangeService,
+  ) {}
+
+  @Post('result-ranges')
+  public async createResultRanges(
+    @Body() createResultRangeDto: CreateResultRangeDTO,
+  ) {
+    return await this.resultRangeService.createOne(createResultRangeDto);
+  }
+
+  @Get('result-ranges')
+  public async getAllResultRanges(@Query() query: FindResultRangeDTO) {
+    return await this.resultRangeService.findAllForAdmin(query);
+  }
+
+  @Get('result-ranges/:id')
+  public async getResultRangeById(@Param('id', ParseIntPipe) id: number) {
+    return await this.resultRangeService.findOneForAdmin(id);
+  }
+
+  @Patch('result-ranges/:id')
+  public async updateResultRange(
+    @Param('id', ParseIntPipe) id: number,
+    @Body() updateResultRangeDto: UpdateResultRangeDTO,
+  ) {
+    return await this.resultRangeService.updateOne(id, updateResultRangeDto);
+  }
+
+  @Delete('result-ranges/:id')
+  public async deleteResultRange(@Param('id', ParseIntPipe) id: number) {
+    return await this.resultRangeService.deleteOne(id);
+  }
+}

src/modules/admin/scoring/http/admin-scoring.get.endpoints.http

@@ -0,0 +1,2 @@
+GET {{baseUrl}}/admin/scoring/result-ranges/
+Authorization: Bearer {{$global.accessToken}}

src/modules/admin/scoring/http/admin-scoring.post.endpoints.http

@@ -0,0 +1,11 @@
+POST {{baseUrl}}/admin/scoring/result-ranges/
+Authorization: Bearer {{$global.accessToken}}
+Content-Type: application/json
+
+{
+    "test": 4,
+    "title": "احتمال خیلی بالا",
+    "description": "احتمال ابتلا خیلی بالا است.",
+    "minScore": 21,
+    "maxScore": 40
+}

src/modules/auth/guards/optional-jwt.guard.ts

@@ -0,0 +1,10 @@
+import { User } from '@/modules/users/entities/user.entity';
+import { Injectable } from '@nestjs/common';
+import { AuthGuard } from '@nestjs/passport';
+
+@Injectable()
+export class OptionalJwtGuard extends AuthGuard('jwt') {
+  handleRequest<TUser = User>(err: any, user: TUser): TUser | null {
+    return user ?? null;
+  }
+}

src/modules/auth/http/login.post.endpoints.http

@@ -3,7 +3,7 @@ Content-Type: application/json
 lang: fa
 
 {
-    "phone": "09121111111",
+    "phone": "09333026363",
     "password": "Password1@"
 }
 

src/modules/otp/providers/otp.service.ts

@@ -2,7 +2,7 @@ import { HttpStatus, Injectable, UnauthorizedException } from '@nestjs/common';
 import { LessThan, MoreThanOrEqual, Repository } from 'typeorm';
 import { OTP } from '../entities/otp.entity';
 import { InjectRepository } from '@nestjs/typeorm';
-import { Cron } from '@nestjs/schedule';
+import { Cron, CronExpression } from '@nestjs/schedule';
 import { HashingProvider } from '@/common/modules/hashing/providers/hashing.provider';
 import { AppException } from '@/common/exceptions/app.exception';
 import { AppTimeoutException } from '@/common/exceptions/app-timeout.exception';
@@ -86,7 +86,7 @@ export class OtpService {
     return otp;
   }
 
-  @Cron('0 */10 * * * *')
+  @Cron(CronExpression.EVERY_10_MINUTES)
   public async cleanupExpired(): Promise<void> {
     await this.otpRepository.delete({
       expiresAt: LessThan(new Date()),

src/modules/questions/entities/question.entity.ts

@@ -36,6 +36,7 @@ export class Question {
   content!: string;
 
   @Column({ type: 'int', nullable: false })
+  @Index()
   order!: number;
 
   @Column({ type: 'int', default: 1 })
@@ -51,7 +52,7 @@ export class Question {
   metadata!: QuestionMetadata;
 
   @OneToMany(() => Choice, (choice) => choice.question)
-  choices?: Array<Choice>;
+  choices!: Array<Choice>;
 
   @CreateDateColumn()
   createdAt!: Date;

src/modules/questions/providers/questions-command.provider.ts

@@ -35,14 +35,6 @@ export class QuestionsCommandProvider {
   public async createOne(createQuestionDto: CreateQuestionDTO) {
     const test = await this.testsService.adminGetOne(createQuestionDto.test);
 
-    if (!test) {
-      throw new AppException(
-        'common.errors.entityNotFound',
-        HttpStatus.NOT_FOUND,
-        { entity: '$t(tests.fields.test)' },
-      );
-    }
-
     const newQuestion = this.questionsRepository.create({
       ...createQuestionDto,
       test,
@@ -81,15 +73,7 @@ export class QuestionsCommandProvider {
     }
 
     if (updateQuestionDto.test) {
-      const test = await this.testsService.adminGetOne(updateQuestionDto.test);
+      await this.testsService.adminGetOne(updateQuestionDto.test);
-
-      if (!test) {
-        throw new AppException(
-          'common.errors.entityNotFound',
-          HttpStatus.NOT_FOUND,
-          { entity: '$t(tests.fields.test)' },
-        );
-      }
     }
 
     const type =

src/modules/questions/providers/questions-query.provider.ts

@@ -1,4 +1,4 @@
-import { Injectable } from '@nestjs/common';
+import { HttpStatus, Injectable } from '@nestjs/common';
 import { filterQuestions } from '../helpers/filter-questions.helper';
 import Utils from '@/common/utils';
 import { FindQuestionsDTO } from '../dtos/find-questions.dto';
@@ -9,6 +9,7 @@ import { InjectRepository } from '@nestjs/typeorm';
 import { Question } from '../entities/question.entity';
 import { Repository } from 'typeorm';
 import { TestsService } from '@/modules/tests/providers/tests.service';
+import { AppException } from '@/common/exceptions/app.exception';
 
 @Injectable()
 export class QuestionsQueryProvider {
@@ -33,13 +34,13 @@ export class QuestionsQueryProvider {
     let selectedTest: Test | null = null;
 
     if (query.test) {
-      try {
+      selectedTest = await this.testsService.adminGetOne(query.test, {
-        selectedTest = await this.testsService.adminGetOne(query.test);
+        relations: { questions: true },
-      } catch (err) {
+      });
-        throw new AppTimeoutException(err);
-      }
     }
 
+    console.log(selectedTest);
+
     try {
       const [questions, total] = await this.questionsRepository.findAndCount({
         where: {
@@ -69,13 +70,25 @@ export class QuestionsQueryProvider {
   }
 
   public async findOneForAdmin(id: number) {
+    let question: Question | null = null;
+
     try {
-      return await this.questionsRepository.findOne({
+      question = await this.questionsRepository.findOne({
         where: { id },
-        relations: { test: true },
+        relations: { test: true, rangeRules: true, choices: true },
       });
     } catch (err) {
       throw new AppTimeoutException(err);
     }
+
+    if (!question) {
+      throw new AppException(
+        'common.errors.entityNotFound',
+        HttpStatus.NOT_FOUND,
+        { entity: '$t(questions.fields.question)' },
+      );
+    }
+
+    return question;
   }
 }

src/modules/scoring/decorators/is-valid-range.decorator.ts

@@ -0,0 +1,6 @@
+import { Validate } from 'class-validator';
+import { ResultRangeValidator } from '../validators/result-range.validator';
+
+export const IsValidRange = () => {
+  return Validate(ResultRangeValidator);
+};

src/modules/scoring/dtos/create-result-range.dto.ts

@@ -0,0 +1,27 @@
+import { IsNotEmpty, IsNumber, IsString } from 'class-validator';
+import { IsValidRange } from '../decorators/is-valid-range.decorator';
+
+export class CreateResultRangeDTO {
+  @IsNumber()
+  @IsNotEmpty()
+  test!: number;
+
+  @IsNumber()
+  @IsNotEmpty()
+  minScore!: number;
+
+  @IsNumber()
+  @IsNotEmpty()
+  maxScore!: number;
+
+  @IsString()
+  @IsNotEmpty()
+  title!: string;
+
+  @IsString()
+  @IsNotEmpty()
+  description!: string;
+
+  @IsValidRange()
+  private readonly _resultRangeValidation!: never;
+}

src/modules/scoring/dtos/find-result-range.dto.ts

@@ -0,0 +1,34 @@
+import { PaginationQueryDTO } from '@/common/dtos/pagination-query.dto';
+import { PartialType } from '@nestjs/swagger';
+import { IsEnum, IsNumber, IsOptional, IsString } from 'class-validator';
+import { ResultRangeSortField } from '../enums/result-range-sort-field.enum';
+
+export class FindResultRangeDTO extends PartialType(PaginationQueryDTO) {
+  @IsNumber()
+  @IsOptional()
+  id?: number;
+
+  @IsNumber()
+  @IsOptional()
+  test?: number;
+
+  @IsNumber()
+  @IsOptional()
+  minScore?: number;
+
+  @IsNumber()
+  @IsOptional()
+  maxScore?: number;
+
+  @IsString()
+  @IsOptional()
+  title?: string;
+
+  @IsString()
+  @IsOptional()
+  description?: string;
+
+  @IsEnum(ResultRangeSortField)
+  @IsOptional()
+  sortBy?: ResultRangeSortField;
+}

src/modules/scoring/dtos/update-result-range.dto.ts

@@ -0,0 +1,4 @@
+import { PartialType } from '@nestjs/swagger';
+import { CreateResultRangeDTO } from './create-result-range.dto';
+
+export class UpdateResultRangeDTO extends PartialType(CreateResultRangeDTO) {}

src/modules/scoring/enums/result-range-sort-field.enum.ts

@@ -0,0 +1,8 @@
+export enum ResultRangeSortField {
+  ID = 'id',
+  TEST = 'test',
+  MIN_SCORE = 'minScore',
+  MAX_SCORE = 'maxScore',
+  TITLE = 'title',
+  DESCRIPTION = 'description',
+}

src/modules/scoring/helpers/filter-result-ranges.helper.ts

@@ -0,0 +1,29 @@
+import { FindOptionsWhere, ILike } from 'typeorm';
+import { FindResultRangeDTO } from '../dtos/find-result-range.dto';
+import { ResultRange } from '../entities/result-range.entity';
+
+export const filterResultRanges = (query: FindResultRangeDTO) => {
+  const where: FindOptionsWhere<ResultRange> = {};
+
+  if (query.id) {
+    where.id = query.id;
+  }
+
+  if (query.description) {
+    where.description = ILike(`%${query.description}%`);
+  }
+
+  if (query.title) {
+    where.title = ILike(`%${query.title}%`);
+  }
+
+  if (query.maxScore !== undefined) {
+    where.maxScore = query.maxScore;
+  }
+
+  if (query.minScore !== undefined) {
+    where.minScore = query.minScore;
+  }
+
+  return where;
+};

src/modules/scoring/providers/result-range-command.provider.ts

@@ -0,0 +1,168 @@
+import { BadRequestException, HttpStatus, Injectable } from '@nestjs/common';
+import { Repository } from 'typeorm';
+import { ResultRange } from '../entities/result-range.entity';
+import { InjectRepository } from '@nestjs/typeorm';
+import { CreateResultRangeDTO } from '../dtos/create-result-range.dto';
+import { AppTimeoutException } from '@/common/exceptions/app-timeout.exception';
+import { AppException } from '@/common/exceptions/app.exception';
+import { TestsService } from '@/modules/tests/providers/tests.service';
+import { AppResponse } from '@/common/responses';
+import { I18nService } from 'nestjs-i18n';
+import { UpdateResultRangeDTO } from '../dtos/update-result-range.dto';
+
+@Injectable()
+export class ResultRangeCommandProvider {
+  constructor(
+    /**
+     * Inject ResultRange Repository
+     */
+    @InjectRepository(ResultRange)
+    private readonly resultRangeRepository: Repository<ResultRange>,
+
+    /**
+     * Inject Tests Service
+     */
+    private readonly testsService: TestsService,
+
+    /**
+     * Inject I18n Service
+     */
+    private readonly i18nService: I18nService,
+  ) {}
+
+  private async checkRangeOverlap(
+    test: number,
+    minScore: number,
+    maxScore: number,
+    excludeSelf: boolean = false,
+  ): Promise<void> {
+    const queryBuilder = this.resultRangeRepository
+      .createQueryBuilder('resultRange')
+      .where('resultRange.testId = :test', { test })
+      .andWhere(
+        '(resultRange.minScore BETWEEN :minScore AND :maxScore) OR (resultRange.maxScore BETWEEN :minScore AND :maxScore) OR (:minScore BETWEEN resultRange.minScore AND resultRange.maxScore) OR (:maxScore BETWEEN resultRange.minScore AND resultRange.maxScore)',
+        { minScore, maxScore },
+      );
+
+    let overlappingRanges: Array<ResultRange>;
+
+    try {
+      overlappingRanges = await queryBuilder.getMany();
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+
+    if (overlappingRanges.length > (excludeSelf ? 1 : 0)) {
+      throw new AppException(
+        'scoring.errors.resultRangeOverlappingConstraint',
+        HttpStatus.CONFLICT,
+      );
+    }
+  }
+
+  private async checkResultRangeExistance(resultRangeId: number) {
+    let resultRange: ResultRange | null = null;
+
+    try {
+      resultRange = await this.resultRangeRepository.findOne({
+        where: {
+          id: resultRangeId,
+        },
+        relations: {
+          test: true,
+        },
+      });
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+
+    if (!resultRange) {
+      throw new AppException(
+        'common.errors.entityNotFound',
+        HttpStatus.NOT_FOUND,
+        { entity: '$t(scoring.fields.resultRange)' },
+      );
+    }
+
+    return resultRange;
+  }
+
+  public async createOne(createResultRangeDto: CreateResultRangeDTO) {
+    const test = await this.testsService.adminGetOne(createResultRangeDto.test);
+
+    await this.checkRangeOverlap(
+      test.id,
+      createResultRangeDto.minScore,
+      createResultRangeDto.maxScore,
+    );
+
+    const newResultRange = this.resultRangeRepository.create({
+      ...createResultRangeDto,
+      test,
+    });
+
+    try {
+      await this.resultRangeRepository.save(newResultRange);
+      return new AppResponse(
+        newResultRange,
+        this.i18nService.translate('common.messages.createSuccess', {
+          args: { entity: '$t(scoring.fields.resultRange)' },
+        }),
+      );
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+  }
+
+  public async updateOne(
+    id: number,
+    updateResultRangeDto: UpdateResultRangeDTO,
+  ) {
+    const resultRange = await this.checkResultRangeExistance(id);
+
+    if (updateResultRangeDto.test) {
+      await this.testsService.adminGetOne(updateResultRangeDto.test);
+    }
+
+    const testId =
+      updateResultRangeDto.test !== undefined
+        ? updateResultRangeDto.test
+        : resultRange.test.id;
+
+    const minScore =
+      updateResultRangeDto.minScore !== undefined
+        ? updateResultRangeDto.minScore
+        : resultRange.minScore;
+
+    const maxScore =
+      updateResultRangeDto.maxScore !== undefined
+        ? updateResultRangeDto.maxScore
+        : resultRange.maxScore;
+
+    if (minScore >= maxScore) {
+      throw new BadRequestException(
+        'scoring.errors.resultRangeMinMaxConstraint',
+      );
+    }
+
+    await this.checkRangeOverlap(testId, minScore, maxScore, true);
+
+    Object.assign(resultRange, updateResultRangeDto);
+
+    try {
+      return await this.resultRangeRepository.save(resultRange);
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+  }
+
+  public async deleteOne(id: number) {
+    const resultRange = await this.checkResultRangeExistance(id);
+
+    try {
+      await this.resultRangeRepository.delete(resultRange.id);
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+  }
+}

src/modules/scoring/providers/result-range-query.provider.ts

@@ -0,0 +1,86 @@
+import { Injectable } from '@nestjs/common';
+import { FindManyOptions, Repository } from 'typeorm';
+import { ResultRange } from '../entities/result-range.entity';
+import { InjectRepository } from '@nestjs/typeorm';
+import { TestsService } from '@/modules/tests/providers/tests.service';
+import { AppTimeoutException } from '@/common/exceptions/app-timeout.exception';
+import { FindResultRangeDTO } from '../dtos/find-result-range.dto';
+import { filterResultRanges } from '../helpers/filter-result-ranges.helper';
+import Utils from '@/common/utils';
+import { Test } from '@/modules/tests/entities/test.entity';
+import { PaginatedResponse } from '@/common/responses';
+
+@Injectable()
+export class ResultRangeQueryProvider {
+  constructor(
+    /**
+     * Inject ResultRange Repository
+     */
+    @InjectRepository(ResultRange)
+    private readonly resultRangeRepository: Repository<ResultRange>,
+
+    /**
+     * Inject Tests Service
+     */
+    private readonly testsService: TestsService,
+  ) {}
+
+  public async findAllForAdmin(query: FindResultRangeDTO) {
+    const filters = filterResultRanges(query);
+    const { limit, page, skip, take } =
+      Utils.PaginationUtils.getPaginationOptions(query);
+
+    let selectedTest: Test | null = null;
+
+    if (query.test) {
+      selectedTest = await this.testsService.adminGetOne(query.test);
+    }
+
+    try {
+      const [resultRanges, total] =
+        await this.resultRangeRepository.findAndCount({
+          where: {
+            ...filters,
+            ...(selectedTest && {
+              test: selectedTest,
+            }),
+          },
+          loadRelationIds: true,
+          skip,
+          take,
+          order: query.sortBy
+            ? {
+                [query.sortBy]: query.order ?? 'ASC',
+              }
+            : { id: 'DESC' },
+        });
+
+      return new PaginatedResponse(resultRanges, {
+        page,
+        limit,
+        total,
+      });
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+  }
+
+  public async findOneForAdmin(id: number) {
+    try {
+      return await this.resultRangeRepository.findOne({
+        where: { id },
+        relations: { test: true },
+      });
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+  }
+
+  public async findByOptions(options?: FindManyOptions<ResultRange>) {
+    try {
+      return await this.resultRangeRepository.find(options);
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+  }
+}

src/modules/scoring/providers/result-range.service.ts

@@ -0,0 +1,55 @@
+import { Injectable } from '@nestjs/common';
+import { ResultRangeCommandProvider } from './result-range-command.provider';
+import { CreateResultRangeDTO } from '../dtos/create-result-range.dto';
+import { UpdateResultRangeDTO } from '../dtos/update-result-range.dto';
+import { FindResultRangeDTO } from '../dtos/find-result-range.dto';
+import { ResultRangeQueryProvider } from './result-range-query.provider';
+import { FindManyOptions } from 'typeorm';
+import { ResultRange } from '../entities/result-range.entity';
+
+@Injectable()
+export class ResultRangeService {
+  constructor(
+    /**
+     * Inject ResultRangeCommand Provider
+     */
+    private readonly resultRangeCommandProvider: ResultRangeCommandProvider,
+
+    /**
+     * Inject ResultRangeQuery Provider
+     */
+    private readonly resultRangeQueryProvider: ResultRangeQueryProvider,
+  ) {}
+
+  public async createOne(createResultRangeDto: CreateResultRangeDTO) {
+    return await this.resultRangeCommandProvider.createOne(
+      createResultRangeDto,
+    );
+  }
+
+  public async updateOne(
+    id: number,
+    updateResultRangeDto: UpdateResultRangeDTO,
+  ) {
+    return await this.resultRangeCommandProvider.updateOne(
+      id,
+      updateResultRangeDto,
+    );
+  }
+
+  public async deleteOne(id: number) {
+    return await this.resultRangeCommandProvider.deleteOne(id);
+  }
+
+  public async findAllForAdmin(query: FindResultRangeDTO) {
+    return await this.resultRangeQueryProvider.findAllForAdmin(query);
+  }
+
+  public async findOneForAdmin(id: number) {
+    return await this.resultRangeQueryProvider.findOneForAdmin(id);
+  }
+
+  public async findByOptions(options: FindManyOptions<ResultRange>) {
+    return await this.resultRangeQueryProvider.findByOptions(options);
+  }
+}

src/modules/scoring/scoring.module.ts

@@ -1,8 +1,18 @@
 import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 import { ResultRange } from './entities/result-range.entity';
+import { TestsModule } from '../tests/tests.module';
+import { ResultRangeCommandProvider } from './providers/result-range-command.provider';
+import { ResultRangeService } from './providers/result-range.service';
+import { ResultRangeQueryProvider } from './providers/result-range-query.provider';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([ResultRange])],
+  imports: [TypeOrmModule.forFeature([ResultRange]), TestsModule],
+  providers: [
+    ResultRangeCommandProvider,
+    ResultRangeQueryProvider,
+    ResultRangeService,
+  ],
+  exports: [ResultRangeService],
 })
 export class ScoringModule {}

src/modules/scoring/validators/result-range.validator.ts

@@ -0,0 +1,28 @@
+import {
+  ValidationArguments,
+  ValidatorConstraint,
+  ValidatorConstraintInterface,
+} from 'class-validator';
+import { I18nContext } from 'nestjs-i18n';
+
+@ValidatorConstraint({ name: 'QuestionRange', async: false })
+export class ResultRangeValidator implements ValidatorConstraintInterface {
+  validate(
+    value: any,
+    validationArguments?: ValidationArguments,
+  ): Promise<boolean> | boolean {
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+    const obj = validationArguments?.object as any;
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+    const { minScore, maxScore } = obj;
+    return minScore < maxScore;
+  }
+  defaultMessage?(): string {
+    const i18n = I18nContext.current();
+
+    return (
+      i18n?.t('scoring.errors.resultRangeMinMaxConstraint') ||
+      'minScore value should be less than maxScore.'
+    );
+  }
+}

src/modules/submissions/decorators/submission-answer.decorator.ts

@@ -0,0 +1,6 @@
+import { Validate } from 'class-validator';
+import { SubmissionAnswerValidator } from '../validators/submission-answer.validator';
+
+export const SubmissionAnswer = () => {
+  return Validate(SubmissionAnswerValidator);
+};

src/modules/submissions/dtos/answer-submission.dto.ts

@@ -0,0 +1,15 @@
+import { IsNumber, IsOptional } from 'class-validator';
+import { SubmissionAnswer } from '../decorators/submission-answer.decorator';
+
+export class AnswerSubmissionDTO {
+  @IsNumber()
+  @IsOptional()
+  choiceId?: number;
+
+  @IsNumber()
+  @IsOptional()
+  numericValue?: number;
+
+  @SubmissionAnswer()
+  private readonly _submissionAnswerValidation!: never;
+}

src/modules/submissions/dtos/start-submission.dto.ts

@@ -0,0 +1,12 @@
+import { IsNotEmpty, IsNumber } from 'class-validator';
+import { i18nValidationMessage as t } from 'nestjs-i18n';
+
+export class StartSubmissionDTO {
+  @IsNumber()
+  @IsNotEmpty({
+    message: t('validation.requiredField', {
+      field: '$t(submissions.fields.testId)',
+    }),
+  })
+  testId!: number;
+}

src/modules/submissions/entities/submission-answer.entity.ts

@@ -1,9 +1,16 @@
-import { Column, Entity, ManyToOne, PrimaryGeneratedColumn } from 'typeorm';
+import {
+  Column,
+  Entity,
+  Index,
+  ManyToOne,
+  PrimaryGeneratedColumn,
+} from 'typeorm';
 import { Submission } from './submission.entity';
 import { Question } from '@/modules/questions/entities/question.entity';
 import { Choice } from '@/modules/questions/entities/choice.entity';
 
 @Entity()
+@Index(['submission', 'question'], { unique: true })
 export class SubmissionAnswer {
   @PrimaryGeneratedColumn()
   id!: number;

src/modules/submissions/entities/submission-result.entity.ts

@@ -3,7 +3,9 @@ import {
   Column,
   CreateDateColumn,
   Entity,
+  JoinColumn,
   ManyToOne,
+  OneToOne,
   PrimaryGeneratedColumn,
 } from 'typeorm';
 import { Submission } from './submission.entity';
@@ -15,7 +17,8 @@ export class SubmissionResult {
   @PrimaryGeneratedColumn()
   id!: number;
 
-  @ManyToOne(() => Submission, { onDelete: 'CASCADE' })
+  @OneToOne(() => Submission, { onDelete: 'CASCADE' })
+  @JoinColumn()
   submission!: Submission;
 
   @Column({ type: 'int', nullable: false })
@@ -24,8 +27,8 @@ export class SubmissionResult {
   @Column({ type: 'int', nullable: false })
   probability!: number;
 
-  @ManyToOne(() => ResultRange, { onDelete: 'CASCADE' })
+  @ManyToOne(() => ResultRange, { nullable: true, onDelete: 'CASCADE' })
-  resultRange!: ResultRange;
+  resultRange?: ResultRange;
 
   @CreateDateColumn()
   createdAt!: Date;

src/modules/submissions/entities/submission.entity.ts

@@ -6,18 +6,20 @@ import {
   Entity,
   ManyToOne,
   OneToMany,
+  OneToOne,
   PrimaryGeneratedColumn,
 } from 'typeorm';
 import { SubmissionStatus } from '../enums/submission-status.enum';
 import { SubmissionAnswer } from './submission-answer.entity';
+import { SubmissionResult } from './submission-result.entity';
 
 @Entity()
 export class Submission {
   @PrimaryGeneratedColumn()
   id!: number;
 
-  @ManyToOne(() => User, { nullable: true, onDelete: 'SET NULL' })
+  @ManyToOne(() => User, { onDelete: 'CASCADE' })
-  user?: User;
+  user!: User;
 
   @ManyToOne(() => Test, { onDelete: 'CASCADE' })
   test!: Test;
@@ -32,6 +34,9 @@ export class Submission {
   @OneToMany(() => SubmissionAnswer, (answer) => answer.submission)
   answers!: Array<SubmissionAnswer>;
 
+  @OneToOne(() => SubmissionResult, (result) => result.submission)
+  result?: SubmissionResult;
+
   @CreateDateColumn()
   createdAt!: Date;
 }

src/modules/submissions/http/submissions.post.endpoints.http

@@ -0,0 +1,16 @@
+POST {{baseUrl}}/submissions/start
+Authorization: Bearer {{$global.accessToken}}
+Content-Type: application/json
+
+{
+    "testId": 4
+}
+
+POST {{baseUrl}}/submissions/10/answer
+Authorization: Bearer {{$global.accessToken}}
+Content-Type: application/json
+
+{
+    // "choiceId": 1
+    "numericValue": 60
+}

src/modules/submissions/interfaces/guest-submission-session.interfaces.ts

@@ -0,0 +1,9 @@
+export interface GuestSubmissionSession {
+  testId: number;
+  currentQuestion: number;
+  answers: Array<{
+    questionId: number;
+    choiceId: number;
+    numericValue: number;
+  }>;
+}

src/modules/submissions/providers/answer-submission.provider.ts

@@ -0,0 +1,321 @@
+import {
+  BadRequestException,
+  ForbiddenException,
+  HttpStatus,
+  Injectable,
+} from '@nestjs/common';
+import { Repository } from 'typeorm';
+import { Submission } from '../entities/submission.entity';
+import { InjectRepository } from '@nestjs/typeorm';
+import { AnswerSubmissionDTO } from '../dtos/answer-submission.dto';
+import { AppTimeoutException } from '@/common/exceptions/app-timeout.exception';
+import { User } from '@/modules/users/entities/user.entity';
+import { AppException } from '@/common/exceptions/app.exception';
+import { RedisService } from '@/common/modules/redis/providers/redis.service';
+import { isUUID } from 'class-validator';
+import { GuestSubmissionSession } from '../interfaces/guest-submission-session.interfaces';
+import { Question } from '@/modules/questions/entities/question.entity';
+import { AppResponse } from '@/common/responses';
+import { QuestionType } from '@/modules/questions/enums/question-type.enum';
+import { NumericMetadata } from '@/modules/questions/interfaces/numeric-metadata.interface';
+import { SubmissionAnswer } from '../entities/submission-answer.entity';
+import { ChoicesService } from '@/modules/questions/providers/choices.service';
+import { CalculateResultProvider } from './calculate-result.provider';
+
+@Injectable()
+export class AnswerSubmissionProvider {
+  constructor(
+    /**
+     * Inject Submission Repository
+     */
+    @InjectRepository(Submission)
+    private readonly submissionRepository: Repository<Submission>,
+
+    /**
+     * Inject Redis Service
+     */
+    private readonly redisService: RedisService,
+
+    /**
+     * Inject SubmisionAnswer Repository
+     */
+    @InjectRepository(SubmissionAnswer)
+    private readonly submissionAnswerRepository: Repository<SubmissionAnswer>,
+
+    /**
+     * Inject Choices Service
+     */
+    private readonly choicesService: ChoicesService,
+
+    /**
+     * Inject CalculateResult Provider
+     */
+    private readonly calculateResultProvider: CalculateResultProvider,
+  ) {}
+
+  public async answer(
+    id: string,
+    answerSubmissionDto: AnswerSubmissionDTO,
+    user?: User,
+  ) {
+    if (user) {
+      return await this.answerAuthenticated(id, answerSubmissionDto, user);
+    } else {
+      return await this.answerGuest(id, answerSubmissionDto);
+    }
+  }
+
+  private async answerAuthenticated(
+    id: string,
+    answerSubmissionDto: AnswerSubmissionDTO,
+    user: User,
+  ) {
+    let submission: Submission | null = null;
+
+    const submissionId = Number(id);
+
+    if (Number.isNaN(submissionId)) {
+      throw new AppException(
+        'validation.wrongFieldFormat',
+        HttpStatus.BAD_REQUEST,
+        { field: '$t(submissions.fields.submissionId)' },
+      );
+    }
+
+    try {
+      submission = await this.submissionRepository.findOne({
+        where: { id: submissionId },
+        relations: {
+          user: true,
+          test: {
+            questions: {
+              choices: true,
+              rangeRules: true,
+            },
+          },
+          answers: {
+            question: true,
+          },
+          result: {
+            resultRange: true,
+          },
+        },
+        order: {
+          answers: {
+            question: {
+              order: 'ASC',
+            },
+          },
+          test: {
+            questions: {
+              choices: {
+                order: 'ASC',
+              },
+            },
+          },
+        },
+      });
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+
+    if (!submission) {
+      throw new AppException(
+        'common.errors.entityNotFound',
+        HttpStatus.NOT_FOUND,
+        { entity: '$t(submissions.fields.submission)' },
+      );
+    }
+
+    if (submission.user.id !== user.id) {
+      throw new ForbiddenException('auth.errors.accessDenied');
+    }
+
+    const allQuestions = [...submission.test.questions].sort(
+      (a, b) => a.order - b.order,
+    );
+    const answeredQuestions = submission.answers.map((el) => el.question);
+
+    const questionStats = this.getQuestionStats(
+      allQuestions,
+      answeredQuestions,
+    );
+
+    if (!questionStats.current) {
+      return new AppResponse({
+        isCompleted: true,
+        currentQuestion: null,
+        result: submission.result
+          ? {
+              score: submission.result.score,
+              probability: submission.result.probability,
+              title: submission.result.resultRange?.title,
+              description: submission.result.resultRange?.description,
+            }
+          : null,
+      });
+    }
+
+    this.checkAnswerCorrectness(questionStats.current, answerSubmissionDto);
+
+    const submissionAnswer = this.submissionAnswerRepository.create({
+      submission,
+      question: questionStats.current,
+    });
+
+    if (
+      questionStats.current.type === QuestionType.MULTI_CHOICE &&
+      answerSubmissionDto.choiceId
+    ) {
+      const choice = await this.choicesService.findOneForAdmin(
+        answerSubmissionDto.choiceId,
+      );
+
+      if (!choice) {
+        throw new AppException(
+          'validation.wrongField',
+          HttpStatus.BAD_REQUEST,
+          { field: '$t(submissions.fields.choiceId)' },
+        );
+      }
+
+      submissionAnswer.choice = choice;
+    } else if (
+      questionStats.current.type === QuestionType.NUMERIC &&
+      answerSubmissionDto.numericValue
+    ) {
+      submissionAnswer.numericValue = answerSubmissionDto.numericValue;
+    }
+
+    try {
+      await this.submissionAnswerRepository.save(submissionAnswer);
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+
+    if (!questionStats.next) {
+      const result = await this.calculateResultProvider.calculate(submission);
+      return new AppResponse({
+        isCompleted: true,
+        currentQuestion: null,
+        result,
+      });
+    }
+
+    const nextQuestion = questionStats.next;
+
+    return new AppResponse({
+      isCompleted: false,
+      isFinal:
+        nextQuestion.id === allQuestions[allQuestions.length - 1].id
+          ? true
+          : undefined,
+      currentQuestion: {
+        type: nextQuestion.type,
+        content: nextQuestion.content,
+        required: nextQuestion.required,
+        metadata: nextQuestion.metadata,
+        choices: nextQuestion.choices,
+      },
+    });
+  }
+
+  private async answerGuest(
+    id: string,
+    answerSubmissionDto: AnswerSubmissionDTO,
+  ) {
+    console.log(id, answerSubmissionDto);
+
+    if (!isUUID(id)) {
+      throw new AppException(
+        'validation.wrongFieldFormat',
+        HttpStatus.BAD_REQUEST,
+        { field: '$t(submissions.fields.submissionId)' },
+      );
+    }
+
+    const submission = await this.redisService.get<GuestSubmissionSession>(
+      `guest_submission:${id}`,
+    );
+
+    return submission;
+  }
+
+  private getQuestionStats(
+    allQuestions: Array<Question>,
+    answeredQuestions: Array<Question>,
+  ) {
+    const questionStats: Record<'prev' | 'current' | 'next', Question | null> =
+      {
+        prev: null,
+        current: null,
+        next: null,
+      };
+
+    if (allQuestions.length === 0) {
+      return questionStats;
+    }
+
+    if (answeredQuestions.length > 0) {
+      questionStats.prev = answeredQuestions[answeredQuestions.length - 1];
+    }
+
+    if (!questionStats.prev) {
+      questionStats.current = allQuestions[0];
+    } else {
+      const prevQuestionIdx = allQuestions.findIndex(
+        (val) => val.id === questionStats.prev?.id,
+      );
+
+      questionStats.current = allQuestions[prevQuestionIdx + 1];
+    }
+
+    if (questionStats.current) {
+      const currentQuestionIdx = allQuestions.findIndex(
+        (val) => val.id === questionStats.current?.id,
+      );
+
+      questionStats.next = allQuestions[currentQuestionIdx + 1];
+    }
+
+    return questionStats;
+  }
+
+  private checkAnswerCorrectness(
+    question: Question,
+    answerSubmissionDto: AnswerSubmissionDTO,
+  ) {
+    if (!answerSubmissionDto) throw new BadRequestException();
+
+    const { choiceId, numericValue } = answerSubmissionDto;
+
+    if (question.type === QuestionType.NUMERIC) {
+      if (numericValue === undefined) {
+        throw new BadRequestException('submissions.errors.emptyNumericValue');
+      }
+
+      const metadata = question.metadata as NumericMetadata;
+
+      if (
+        metadata &&
+        (numericValue < metadata.min || numericValue > metadata.max)
+      ) {
+        throw new BadRequestException('submissions.errors.numericValueRange');
+      }
+    }
+
+    if (question.type === QuestionType.MULTI_CHOICE) {
+      if (!choiceId) {
+        throw new BadRequestException('submissions.errors.emptyChoiceId');
+      }
+
+      if (!question.choices.some((c) => c.id === choiceId)) {
+        throw new AppException(
+          'validation.wrongField',
+          HttpStatus.BAD_REQUEST,
+          { field: '$t(submissions.fields.choiceId)' },
+        );
+      }
+    }
+  }
+}

src/modules/submissions/providers/calculate-result.provider.ts

@@ -0,0 +1,114 @@
+import { Injectable } from '@nestjs/common';
+import { LessThanOrEqual, MoreThanOrEqual, Repository } from 'typeorm';
+import { SubmissionResult } from '../entities/submission-result.entity';
+import { InjectRepository } from '@nestjs/typeorm';
+import { Submission } from '../entities/submission.entity';
+import { QuestionType } from '@/modules/questions/enums/question-type.enum';
+import { QuestionsService } from '@/modules/questions/providers/questions.service';
+import { AppTimeoutException } from '@/common/exceptions/app-timeout.exception';
+import { ResultRangeService } from '@/modules/scoring/providers/result-range.service';
+
+@Injectable()
+export class CalculateResultProvider {
+  constructor(
+    /**
+     * Inject SubmissionResult Repository
+     */
+    @InjectRepository(SubmissionResult)
+    private readonly submissionResultRepository: Repository<SubmissionResult>,
+
+    /**
+     * Inject Questions Service
+     */
+    private readonly questionsService: QuestionsService,
+
+    /**
+     * Inject ResultRange Service
+     */
+    private readonly resultRangeService: ResultRangeService,
+  ) {}
+
+  public async calculate(submission: Submission) {
+    let score = 0;
+
+    await Promise.all(
+      submission.answers.map(async (answer) => {
+        if (
+          answer.question.type === QuestionType.MULTI_CHOICE &&
+          answer.choice
+        ) {
+          score += answer.question.weight * answer.choice.score;
+        } else if (
+          answer.question.type === QuestionType.NUMERIC &&
+          answer.numericValue !== undefined
+        ) {
+          const question = await this.questionsService.findOneForAdmin(
+            answer.question.id,
+          );
+
+          if (question.rangeRules && question.rangeRules.length > 0) {
+            question.rangeRules.forEach((rule) => {
+              if (
+                answer.numericValue &&
+                answer.numericValue >= rule.min &&
+                answer.numericValue <= rule.max
+              ) {
+                score += answer.question.weight * rule.score;
+              }
+            });
+          }
+        }
+      }),
+    );
+
+    let totalScores = 0;
+
+    submission.test.questions.forEach((question) => {
+      const answerScores: Array<number> = [];
+      if (question.type === QuestionType.MULTI_CHOICE) {
+        question.choices.forEach((choice) => {
+          answerScores.push(choice.score);
+        });
+      } else if (
+        question.type === QuestionType.NUMERIC &&
+        question.rangeRules &&
+        question.rangeRules.length > 0
+      ) {
+        question.rangeRules.forEach((rule) => {
+          answerScores.push(rule.score);
+        });
+      }
+
+      const maxScore = answerScores.length > 0 ? Math.max(...answerScores) : 0;
+
+      totalScores += question.weight * maxScore;
+    });
+
+    const resultRanges = await this.resultRangeService.findByOptions({
+      where: {
+        minScore: LessThanOrEqual(score),
+        maxScore: MoreThanOrEqual(score),
+      },
+    });
+
+    const submissionResult = this.submissionResultRepository.create({
+      submission,
+      score,
+      probability: Math.ceil((score / totalScores) * 100),
+      resultRange: resultRanges.length > 0 ? resultRanges[0] : undefined,
+    });
+
+    try {
+      await this.submissionResultRepository.save(submissionResult);
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+
+    return {
+      score,
+      probability: submissionResult.probability,
+      title: submissionResult.resultRange?.title,
+      description: submissionResult.resultRange?.description,
+    };
+  }
+}

src/modules/submissions/providers/start-submission.provider.ts

@@ -0,0 +1,142 @@
+import { AccessType } from '@/modules/tests/enums/access-types.enum';
+import { TestsService } from '@/modules/tests/providers/tests.service';
+import { User } from '@/modules/users/entities/user.entity';
+import {
+  BadRequestException,
+  ForbiddenException,
+  Injectable,
+} from '@nestjs/common';
+import { Repository } from 'typeorm';
+import { Submission } from '../entities/submission.entity';
+import { InjectRepository } from '@nestjs/typeorm';
+import { AppTimeoutException } from '@/common/exceptions/app-timeout.exception';
+import { AppResponse } from '@/common/responses';
+import { SubmissionStatus } from '../enums/submission-status.enum';
+import { Test } from '@/modules/tests/entities/test.entity';
+import { randomUUID } from 'crypto';
+import { RedisService } from '@/common/modules/redis/providers/redis.service';
+import { GuestSubmissionSession } from '../interfaces/guest-submission-session.interfaces';
+
+@Injectable()
+export class StartSubmissionProvider {
+  constructor(
+    /**
+     * Inject Tests Service
+     */
+    private readonly testsService: TestsService,
+
+    /**
+     * Inject Submissions Repository
+     */
+    @InjectRepository(Submission)
+    private readonly submissionsRepository: Repository<Submission>,
+
+    /**
+     * Inject Redis Service
+     */
+    private readonly redisService: RedisService,
+  ) {}
+
+  public async start(testId: number, user?: User) {
+    const test = await this.testsService.adminGetOne(testId, {
+      relations: {
+        questions: {
+          choices: true,
+        },
+      },
+      order: {
+        questions: {
+          order: 'ASC',
+          choices: {
+            order: 'ASC',
+          },
+        },
+      },
+      select: {
+        questions: {
+          id: true,
+          order: true,
+          type: true,
+          content: true,
+          required: true,
+          metadata: true,
+          choices: {
+            id: true,
+            order: true,
+            text: true,
+          },
+        },
+      },
+    });
+
+    if (test.accessType !== AccessType.FREE && !user) {
+      throw new ForbiddenException('auth.errors.accessDenied');
+    }
+
+    if (user) {
+      return await this.startAuthenticated(test, user);
+    }
+
+    return await this.startGuest(test);
+  }
+
+  private async startAuthenticated(test: Test, user: User) {
+    let submission: Submission | null = null;
+
+    try {
+      submission = await this.submissionsRepository.findOne({
+        where: {
+          test: {
+            id: test.id,
+          },
+          user: {
+            id: user.id,
+          },
+        },
+      });
+    } catch (err) {
+      throw new AppTimeoutException(err);
+    }
+
+    if (submission && submission.status === SubmissionStatus.COMPLETED) {
+      throw new BadRequestException('submissions.errors.alreadyTookTest');
+    }
+
+    if (!submission) {
+      submission = this.submissionsRepository.create({
+        test,
+        user: user || undefined,
+      });
+
+      try {
+        await this.submissionsRepository.save(submission);
+      } catch (err) {
+        throw new AppTimeoutException(err);
+      }
+    }
+
+    return new AppResponse({
+      submissionId: submission.id,
+      question: test.questions.length > 0 ? test.questions[0] : null,
+    });
+  }
+
+  private async startGuest(test: Test) {
+    const guestSubmissionId = randomUUID();
+
+    await this.redisService.set<GuestSubmissionSession>(
+      `guest_submission:${guestSubmissionId}`,
+      {
+        testId: test.id,
+        currentQuestion: 0,
+        answers: [],
+      },
+      3600,
+    );
+
+    return new AppResponse({
+      guestSubmissionId,
+      question: test.questions[0],
+    });
+  }
+}

src/modules/submissions/providers/submissions.service.ts

@@ -0,0 +1,36 @@
+import { Injectable } from '@nestjs/common';
+import { StartSubmissionProvider } from './start-submission.provider';
+import { User } from '@/modules/users/entities/user.entity';
+import { AnswerSubmissionProvider } from './answer-submission.provider';
+import { AnswerSubmissionDTO } from '../dtos/answer-submission.dto';
+
+@Injectable()
+export class SubmissionsService {
+  constructor(
+    /**
+     * Inject Start Submission Provider
+     */
+    private readonly startSubmissionProvider: StartSubmissionProvider,
+
+    /**
+     * Inject Answer Submission Provider
+     */
+    private readonly answerSubmissionProvider: AnswerSubmissionProvider,
+  ) {}
+
+  public async startSubmission(testId: number, user?: User) {
+    return await this.startSubmissionProvider.start(testId, user);
+  }
+
+  public async answerSubmission(
+    id: string,
+    answerSubmissionDto: AnswerSubmissionDTO,
+    user?: User,
+  ) {
+    return await this.answerSubmissionProvider.answer(
+      id,
+      answerSubmissionDto,
+      user,
+    );
+  }
+}

src/modules/submissions/submissions.controller.ts

@@ -0,0 +1,56 @@
+import {
+  Body,
+  Controller,
+  HttpCode,
+  HttpStatus,
+  Param,
+  Post,
+  UseGuards,
+} from '@nestjs/common';
+import { Public } from '../auth/decorators/public.decorator';
+import { OptionalJwtGuard } from '../auth/guards/optional-jwt.guard';
+import { User } from '../users/entities/user.entity';
+import { ActiveUser } from '@/common/decorators/active-user.decorator';
+import { SubmissionsService } from './providers/submissions.service';
+import { StartSubmissionDTO } from './dtos/start-submission.dto';
+import { AnswerSubmissionDTO } from './dtos/answer-submission.dto';
+
+@Controller('submissions')
+export class SubmissionsController {
+  constructor(
+    /**
+     * Inject Submissions Service
+     */
+    private readonly submissionsService: SubmissionsService,
+  ) {}
+
+  @Public()
+  @Post('start')
+  @HttpCode(HttpStatus.OK)
+  @UseGuards(OptionalJwtGuard)
+  public async startTest(
+    @Body() startSubmissionDto: StartSubmissionDTO,
+    @ActiveUser() user?: User,
+  ) {
+    return await this.submissionsService.startSubmission(
+      startSubmissionDto.testId,
+      user,
+    );
+  }
+
+  @Public()
+  @Post(':id/answer')
+  @HttpCode(HttpStatus.OK)
+  @UseGuards(OptionalJwtGuard)
+  public async answerSubmission(
+    @Param('id') id: string,
+    @Body() answerSubmissionDto: AnswerSubmissionDTO,
+    @ActiveUser() user?: User,
+  ) {
+    return await this.submissionsService.answerSubmission(
+      id,
+      answerSubmissionDto,
+      user,
+    );
+  }
+}

src/modules/submissions/submissions.module.ts

@@ -3,10 +3,30 @@ import { TypeOrmModule } from '@nestjs/typeorm';
 import { Submission } from './entities/submission.entity';
 import { SubmissionAnswer } from './entities/submission-answer.entity';
 import { SubmissionResult } from './entities/submission-result.entity';
+import { SubmissionsController } from './submissions.controller';
+import { StartSubmissionProvider } from './providers/start-submission.provider';
+import { SubmissionsService } from './providers/submissions.service';
+import { TestsModule } from '../tests/tests.module';
+import { AnswerSubmissionProvider } from './providers/answer-submission.provider';
+import { RedisModule } from '@/common/modules/redis/redis.module';
+import { QuestionsModule } from '../questions/questions.module';
+import { CalculateResultProvider } from './providers/calculate-result.provider';
+import { ScoringModule } from '../scoring/scoring.module';
 
 @Module({
   imports: [
     TypeOrmModule.forFeature([Submission, SubmissionAnswer, SubmissionResult]),
+    TestsModule,
+    QuestionsModule,
+    RedisModule,
+    ScoringModule,
+  ],
+  controllers: [SubmissionsController],
+  providers: [
+    StartSubmissionProvider,
+    AnswerSubmissionProvider,
+    CalculateResultProvider,
+    SubmissionsService,
   ],
 })
 export class SubmissionsModule {}

src/modules/submissions/validators/submission-answer.validator.ts

@@ -0,0 +1,30 @@
+import {
+  ValidationArguments,
+  ValidatorConstraint,
+  ValidatorConstraintInterface,
+} from 'class-validator';
+import { I18nContext } from 'nestjs-i18n';
+
+@ValidatorConstraint({ name: 'SubmissionAnswer', async: false })
+export class SubmissionAnswerValidator implements ValidatorConstraintInterface {
+  validate(
+    value: any,
+    validationArguments?: ValidationArguments,
+  ): Promise<boolean> | boolean {
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+    const obj = validationArguments?.object as any;
+    // eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
+    const { choiceId, numericValue } = obj;
+
+    return choiceId !== undefined || numericValue !== undefined;
+  }
+
+  defaultMessage?(): string {
+    const i18n = I18nContext.current();
+
+    return (
+      i18n?.t('submissions.errors.choiceNumericConstraint') ??
+      'You must send either choiceId or numericValue.'
+    );
+  }
+}

src/modules/tests/providers/tests-query.provider.ts

@@ -1,6 +1,6 @@
 import { HttpStatus, Injectable } from '@nestjs/common';
 import { InjectRepository } from '@nestjs/typeorm';
-import { Repository } from 'typeorm';
+import { FindOneOptions, Repository } from 'typeorm';
 import { PaginatedResponse } from '@/common/responses';
 import { AppTimeoutException } from '@/common/exceptions/app-timeout.exception';
 import { FindTestsDTO } from '../dtos/find-tests.dto';
@@ -64,12 +64,27 @@ export class TestsQueryProvider {
     }
   }
 
-  public async findOneForAdmin(id: number) {
+  public async findOneForAdmin(id: number, options?: FindOneOptions<Test>) {
+    let test: Test | null = null;
+
     try {
-      return await this.testRepository.findOneBy({ id });
+      test = await this.testRepository.findOne({
+        where: { id },
+        ...options,
+      });
     } catch (err) {
       throw new AppTimeoutException(err);
     }
+
+    if (!test) {
+      throw new AppException(
+        'common.errors.entityNotFound',
+        HttpStatus.NOT_FOUND,
+        { entity: '$t(tests.fields.test)' },
+      );
+    }
+
+    return test;
   }
 
   public async findOneForUser(id: number) {

src/modules/tests/providers/tests.service.ts

@@ -4,6 +4,8 @@ import { UpdateTestDTO } from '../dtos/update-test.dto';
 import { FindTestsDTO } from '../dtos/find-tests.dto';
 import { TestsQueryProvider } from './tests-query.provider';
 import { TestsCommandProvider } from './tests-command.provider';
+import { FindOneOptions } from 'typeorm';
+import { Test } from '../entities/test.entity';
 
 @Injectable()
 export class TestsService {
@@ -31,8 +33,8 @@ export class TestsService {
     return await this.testsQueryProvider.findAllForUser();
   }
 
-  public async adminGetOne(id: number) {
+  public async adminGetOne(id: number, options?: FindOneOptions<Test>) {
-    return await this.testsQueryProvider.findOneForAdmin(id);
+    return await this.testsQueryProvider.findOneForAdmin(id, options);
   }
 
   public async userGetOne(id: number) {