/**
 * Next.js Instrumentation 钩子
 *
 * 在应用启动时执行一次性初始化操作。
 * 文档：https://nextjs.org/docs/app/building-your-application/optimizing/instrumentation
 *
 * V3-3: 注册 ExamHomeworkServicePort 实现
 * 将 modules 层的 data-access 函数注入到 shared 层的 ServicePort，
 * 使 app 层可以通过 EXAM_HOMEWORK_SERVICE_PROVIDER.get() 调用，
 * 而不直接依赖 modules 内部实现。
 */

import { registerExamHomeworkService } from "@/shared/services/exam-homework-port"
import { getExamById, getExams, getExamCreatorId, getExamTitleById } from "@/modules/exams/data-access"
import {
  getHomeworkAssignmentById,
  getHomeworkAssignments,
  getAssignmentMaxScoreById,
} from "@/modules/homework/data-access"
import { getExamWithQuestionsForHomework } from "@/modules/exams/data-access"
import type { DataScope } from "@/shared/types/permissions"
import type { Exam } from "@/modules/exams/types"
import type { HomeworkAssignmentListItem } from "@/modules/homework/types"

/**
 * 适配器：将 getExamById 的返回值补全为 Exam 类型
 * data-access 返回的对象包含 questions 数组但缺少 questionCount 字段
 */
const adaptExam = (raw: Awaited<ReturnType<typeof getExamById>>): Exam | null => {
  if (!raw) return null
  return {
    ...raw,
    questionCount: raw.questions?.length ?? 0,
  }
}

/**
 * 适配器：将 getHomeworkAssignmentById 的返回值补全为 HomeworkAssignmentListItem 类型
 * data-access 返回的对象缺少 averageScore 和 overdueCount 字段
 */
const adaptAssignment = (raw: Awaited<ReturnType<typeof getHomeworkAssignmentById>>): HomeworkAssignmentListItem | null => {
  if (!raw) return null
  return {
    id: raw.id,
    sourceExamId: raw.sourceExamId,
    sourceExamTitle: raw.sourceExamTitle,
    title: raw.title,
    status: raw.status,
    availableAt: raw.availableAt,
    dueAt: raw.dueAt,
    allowLate: raw.allowLate,
    lateDueAt: raw.lateDueAt,
    maxAttempts: raw.maxAttempts,
    createdAt: raw.createdAt,
    updatedAt: raw.updatedAt,
    targetCount: raw.targetCount,
    submittedCount: raw.submittedCount,
    gradedCount: raw.gradedCount,
    averageScore: null,
    overdueCount: 0,
  }
}

export async function register(): Promise<void> {
  registerExamHomeworkService({
    // 考试
    getExamById: async (id: string, scope?: DataScope) => adaptExam(await getExamById(id, scope)),
    getExams,
    getExamCreatorId,
    getExamTitleById,

    // 作业
    getHomeworkAssignmentById: async (id: string, scope?: DataScope) => adaptAssignment(await getHomeworkAssignmentById(id, scope)),
    getHomeworkAssignments,
    getAssignmentMaxScoreByIds: getAssignmentMaxScoreById,

    // 跨模块
    getExamWithQuestionsForHomework,
  })
}