♻️ Extract crud (#2653)

Author: KATO-Hiro

src/lib/services/answers.ts

@@ -20,6 +20,29 @@ export async function getAnswers(user_id: string) {
   return answersMap;
 }
 
+/**
+ * Fetches task answers for a specific user and a list of selected task IDs.
+ *
+ * @param selectedTaskIds - An array of task IDs to filter the answers.
+ * @param userId - The ID of the user whose answers are to be fetched.
+ *
+ * @returns A promise that resolves to an array of TaskAnswer objects.
+ * @note conditions: task_id IN (...) AND user_id = userId
+ */
+export async function getAnswersWithSelectedTaskIds(selectedTaskIds: string[], userId: string) {
+  return await prisma.taskAnswer.findMany({
+    where: {
+      task_id: { in: selectedTaskIds },
+      user_id: userId,
+    },
+    select: {
+      task_id: true,
+      user_id: true,
+      status_id: true,
+    },
+  });
+}
+
 export async function getAnswersOrderedByUpdatedDesc(user_id: string): Promise<TaskAnswer[]> {
   const answers_from_db = await prisma.taskAnswer.findMany({
     where: {

src/lib/services/task_results.ts

@@ -5,7 +5,7 @@ import {
   getSubmissionStatusMapWithId,
   getSubmissionStatusMapWithName,
 } from '$lib/services/submission_status';
-import { getTasks, getTask } from '$lib/services/tasks';
+import { getTasks, getTasksWithSelectedTaskIds, getTask } from '$lib/services/tasks';
 import { getUser } from '$lib/services/users';
 import * as answer_crud from '$lib/services/answers';
 
@@ -199,36 +199,9 @@ export async function getTaskResultsByTaskId(
     return new Map();
   }
 
-  // Step 2: Bulk fetch all tasks (1 query)
-  // Using Prisma's `where: { task_id: { in: taskIds } }` for efficient filtering
-  const tasks = await db.task.findMany({
-    where: {
-      task_id: { in: taskIds }, // SQL: WHERE task_id IN ('id1', 'id2', ...)
-    },
-    select: {
-      contest_id: true,
-      task_table_index: true,
-      task_id: true,
-      title: true,
-      grade: true,
-    },
-  });
-
-  // Step 3: Bulk fetch all answers (1 query)
-  // Using compound conditions: task_id IN (...) AND user_id = userId
-  const answers = userId
-    ? await db.taskAnswer.findMany({
-        where: {
-          task_id: { in: taskIds }, // SQL: WHERE task_id IN (...)
-          user_id: userId, // SQL: AND user_id = 'userId'
-        },
-        select: {
-          task_id: true,
-          user_id: true,
-          status_id: true,
-        },
-      })
-    : [];
+  // Step 2 & 3: Bulk fetch all tasks and answers (2 query)
+  const tasks = await getTasksWithSelectedTaskIds(taskIds);
+  const answers = userId ? await answer_crud.getAnswersWithSelectedTaskIds(taskIds, userId) : [];
 
   // Step 4: Create Maps for O(1) lookup
   const tasksMap = new Map(tasks.map((task: Task) => [task.task_id, task]));

src/lib/services/tasks.ts

@@ -1,7 +1,7 @@
 import { default as db } from '$lib/server/database';
 import { classifyContest } from '$lib/utils/contest';
 import type { TaskGrade } from '$lib/types/task';
-import type { Task } from '$lib/types/task';
+import type { Task, Tasks } from '$lib/types/task';
 
 // See:
 // https://www.prisma.io/docs/concepts/components/prisma-client/filtering-and-sorting
@@ -11,6 +11,28 @@ export async function getTasks(): Promise<Task[]> {
   return tasks;
 }
 
+/**
+ * Fetches tasks with the specified task IDs.
+ * @param taskIds - An array of task IDs to filter the tasks.
+ *
+ * @returns A promise that resolves to an array of Task objects.
+ * @note conditions: { task_id: { in: taskIds } }` for efficient filtering
+ */
+export async function getTasksWithSelectedTaskIds(selectedTaskIds: string[]): Promise<Tasks> {
+  return await db.task.findMany({
+    where: {
+      task_id: { in: selectedTaskIds }, // SQL: WHERE task_id IN ('id1', 'id2', ...)
+    },
+    select: {
+      contest_id: true,
+      task_table_index: true,
+      task_id: true,
+      title: true,
+      grade: true,
+    },
+  });
+}
+
 export async function getTasksByTaskId(): Promise<Map<string, Task>> {
   const tasks = await db.task.findMany();
   const tasksMap = new Map();