QuestionService: Add fetch random question endpoint

question-service/app/crud/questions.py

@@ -1,6 +1,7 @@
 from bson import ObjectId
 from bson.errors import InvalidId
 from dotenv import load_dotenv
+from random import randint
 import motor.motor_asyncio
 import os
 from typing import List
@@ -10,6 +11,7 @@
     QuestionNotFoundError,
     BatchUploadFailedError,
     InvalidQuestionIdError,
+    RandomQuestionNotFoundError
 )
 from models.questions import (
     CategoryEnum,
@@ -100,6 +102,24 @@ async def batch_create_questions(
         "message": f"{len(result.inserted_ids)} questions added successfully."
     })
 
+async def fetch_random_question(
+    category: CategoryEnum | None,
+    complexity: ComplexityEnum | None,
+) -> QuestionModel:
+    query = {}
+    if category:
+        query["categories"] = category
+    if complexity:
+        query["complexity"] = complexity
+
+    count = await question_collection.count_documents(query)
+    if count == 0:
+        raise RandomQuestionNotFoundError(category, complexity)
+
+    random_index = randint(0, count - 1)
+    random_question = await question_collection.find(query).skip(random_index).limit(1).to_list(1)
+    return QuestionModel.parse_obj(random_question[0])
+
 def get_question_categories() -> List[CategoryEnum]:
     return [category for category in CategoryEnum]
 

question-service/app/exceptions/questions_exceptions.py

@@ -15,6 +15,13 @@ class QuestionNotFoundError(Exception):
     def __init__(self, question_id):
         self.question_id = question_id
         super().__init__(f"Question with ID '{question_id}' not found.")
+
+class RandomQuestionNotFoundError(Exception):
+    """Raised when a question with the given ID is not found."""
+    def __init__(self, category, complexity):
+        self.category = category
+        self.complexity = complexity
+        super().__init__(f"Question with category '{category}' and complexity '{complexity}' not found.")
 
 class BatchUploadFailedError(Exception):
     """Raised when batch upload fails to upload any questions successfully"""

question-service/app/routers/questions.py

@@ -9,12 +9,14 @@
     get_question_categories,
     get_question_complexities,
     update_question_by_id,
+    fetch_random_question,
 )
 from exceptions.questions_exceptions import (
     DuplicateQuestionError,
     QuestionNotFoundError,
     BatchUploadFailedError,
     InvalidQuestionIdError,
+    RandomQuestionNotFoundError,
 )
 from fastapi import APIRouter, HTTPException, Query
 from models.questions import (
@@ -29,6 +31,20 @@
 
 router = APIRouter()
 
+@router.get("/random",
+            response_description="Get a random question based on category and complexity",
+            response_model=QuestionModel
+            )
+async def get_random_question(
+    category: CategoryEnum | None = None,
+    complexity: ComplexityEnum | None = None,
+):
+    try:
+        question = await fetch_random_question(category, complexity)
+        return question
+    except RandomQuestionNotFoundError as e:
+        raise HTTPException(status_code=404, detail=str(e))
+
 @router.post("/",
             response_description="Create new question",
             response_model=QuestionModel,