fix: fix bugs and structure

src/modules/submissions/helpers/get-next-transition.helper.ts

@@ -0,0 +1,63 @@
+import { Question } from '@/modules/questions/entities/question.entity';
+import { AnswerSubmissionDTO } from '../dtos/answer-submission.dto';
+import { QuestionTransitionType } from '@/modules/questions/enums/question-transition-type.enum';
+import { QuestionType } from '@/modules/questions/enums/question-type.enum';
+import { SingleChoiceCondition } from '@/modules/questions/interfaces/single-choice-condition.interface';
+import { NumericCondition } from '@/modules/questions/interfaces/numeric-condition.interface';
+import { AppException } from '@/common/exceptions/app.exception';
+import { HttpStatus } from '@nestjs/common';
+
+export const getNextTransition = (
+  question: Question,
+  answerSubmissionDto: AnswerSubmissionDTO,
+) => {
+  const transitions = question.outgoingTransitions ?? [];
+
+  const endTransition = transitions.find(
+    (t) => t.type === QuestionTransitionType.END,
+  );
+
+  if (
+    question.type === QuestionType.MULTI_CHOICE &&
+    answerSubmissionDto.choiceId !== undefined
+  ) {
+    const transition = transitions.find(
+      (t) =>
+        t.type === QuestionTransitionType.CHOICE &&
+        (t.condition as SingleChoiceCondition).choiceId ===
+          answerSubmissionDto.choiceId,
+    );
+
+    if (transition) return transition;
+  }
+
+  if (
+    question.type === QuestionType.NUMERIC &&
+    answerSubmissionDto.numericValue !== undefined
+  ) {
+    const value = answerSubmissionDto.numericValue;
+
+    const transition = transitions.find((t) => {
+      if (t.type !== QuestionTransitionType.NUMBER_RANGE) return false;
+
+      const condition = t.condition as NumericCondition;
+
+      return value >= condition.min && value <= condition.max;
+    });
+
+    if (transition) return transition;
+  }
+
+  const defaultTransition = transitions.find(
+    (t) => t.type === QuestionTransitionType.DEFAULT,
+  );
+
+  if (defaultTransition) return defaultTransition;
+
+  if (endTransition) return endTransition;
+
+  throw new AppException(
+    'submissions.errors.nextQuestionNotFound',
+    HttpStatus.BAD_REQUEST,
+  );
+};