// This is your Prisma schema file,
// learn more about it in the docs: https://pris.ly/d/prisma-schema

generator client {
  provider = "prisma-client-js"
  previewFeatures = ["fullTextIndex"]
}

datasource db {
  provider = "mysql"
  url      = env("DATABASE_URL")
}

// =============================================
// 基础审计字段模型
// =============================================

model ApplicationUser {
  id               String   @id @default(uuid()) @db.VarChar(36)
  realName         String   @map("real_name") @db.VarChar(50)
  studentId        String?  @map("student_id") @db.VarChar(20)
  avatarUrl        String?  @map("avatar_url") @db.VarChar(500)
  gender           Gender   @default(Male)
  currentSchoolId  String?  @map("current_school_id") @db.VarChar(36)
  accountStatus    AccountStatus @map("account_status") @default(Active)
  email            String?  @db.VarChar(100)
  phone            String?  @db.VarChar(20)
  bio              String?  @db.Text
  passwordHash     String   @map("password_hash") @db.VarChar(255)
  
  createdAt        DateTime @default(now()) @map("created_at")
  createdBy        String   @map("created_by") @db.VarChar(36)
  updatedAt        DateTime @updatedAt @map("updated_at")
  updatedBy        String   @map("updated_by") @db.VarChar(36)
  isDeleted        Boolean  @default(false) @map("is_deleted")
  
  // Relations
  classMemberships ClassMember[]
  createdQuestions Question[] @relation("CreatedQuestions")
  createdExams     Exam[] @relation("CreatedExams")
  submissions      StudentSubmission[]
  messages         Message[]
  
  @@index([studentId])
  @@index([email])
  @@index([phone])
  @@index([currentSchoolId])
  @@map("application_users")
}

enum Gender {
  Male
  Female
}

enum AccountStatus {
  Active
  Suspended
  Graduated
}

// =============================================
// 组织架构模块
// =============================================

model School {
  id         String   @id @default(uuid()) @db.VarChar(36)
  name       String   @db.VarChar(100)
  regionCode String   @map("region_code") @db.VarChar(20)
  address    String?  @db.VarChar(200)
  
  createdAt  DateTime @default(now()) @map("created_at")
  createdBy  String   @map("created_by") @db.VarChar(36)
  updatedAt  DateTime @updatedAt @map("updated_at")
  updatedBy  String   @map("updated_by") @db.VarChar(36)
  isDeleted  Boolean  @default(false) @map("is_deleted")
  
  grades     Grade[]
  
  @@index([regionCode])
  @@map("schools")
}

model Grade {
  id             String   @id @default(uuid()) @db.VarChar(36)
  schoolId       String   @map("school_id") @db.VarChar(36)
  name           String   @db.VarChar(50)
  sortOrder      Int      @map("sort_order")
  enrollmentYear Int      @map("enrollment_year")
  
  createdAt      DateTime @default(now()) @map("created_at")
  createdBy      String   @map("created_by") @db.VarChar(36)
  updatedAt      DateTime @updatedAt @map("updated_at")
  updatedBy      String   @map("updated_by") @db.VarChar(36)
  isDeleted      Boolean  @default(false) @map("is_deleted")
  
  school         School   @relation(fields: [schoolId], references: [id])
  classes        Class[]
  
  @@index([schoolId])
  @@index([enrollmentYear])
  @@map("grades")
}

model Class {
  id            String   @id @default(uuid()) @db.VarChar(36)
  gradeId       String   @map("grade_id") @db.VarChar(36)
  name          String   @db.VarChar(50)
  inviteCode    String   @unique @map("invite_code") @db.VarChar(10)
  headTeacherId String?  @map("head_teacher_id") @db.VarChar(36)
  
  createdAt     DateTime @default(now()) @map("created_at")
  createdBy     String   @map("created_by") @db.VarChar(36)
  updatedAt     DateTime @updatedAt @map("updated_at")
  updatedBy     String   @map("updated_by") @db.VarChar(36)
  isDeleted     Boolean  @default(false) @map("is_deleted")
  
  grade         Grade         @relation(fields: [gradeId], references: [id])
  members       ClassMember[]
  assignments   Assignment[]
  schedules     Schedule[]
  
  @@index([gradeId])
  @@map("classes")
}

model ClassMember {
  id          String     @id @default(uuid()) @db.VarChar(36)
  classId     String     @map("class_id") @db.VarChar(36)
  userId      String     @map("user_id") @db.VarChar(36)
  roleInClass ClassRole  @map("role_in_class") @default(Student)
  
  createdAt   DateTime   @default(now()) @map("created_at")
  createdBy   String     @map("created_by") @db.VarChar(36)
  updatedAt   DateTime   @updatedAt @map("updated_at")
  updatedBy   String     @map("updated_by") @db.VarChar(36)
  isDeleted   Boolean    @default(false) @map("is_deleted")
  
  class       Class      @relation(fields: [classId], references: [id], onDelete: Cascade)
  user        ApplicationUser @relation(fields: [userId], references: [id], onDelete: Cascade)
  
  @@unique([classId, userId])
  @@index([userId])
  @@map("class_members")
}

enum ClassRole {
  Student
  Monitor
  Committee
  Teacher
}

// =============================================
// 教材与知识图谱模块
// =============================================

model Subject {
  id        String     @id @default(uuid()) @db.VarChar(36)
  name      String     @db.VarChar(50)
  code      String     @unique @db.VarChar(20)
  icon      String?    @db.VarChar(50)
  
  createdAt DateTime   @default(now()) @map("created_at")
  createdBy String     @map("created_by") @db.VarChar(36)
  updatedAt DateTime   @updatedAt @map("updated_at")
  updatedBy String     @map("updated_by") @db.VarChar(36)
  isDeleted Boolean    @default(false) @map("is_deleted")
  
  textbooks Textbook[]
  questions Question[]
  exams     Exam[]
  
  @@map("subjects")
}

model Textbook {
  id          String         @id @default(uuid()) @db.VarChar(36)
  subjectId   String         @map("subject_id") @db.VarChar(36)
  name        String         @db.VarChar(100)
  publisher   String         @db.VarChar(100)
  versionYear String         @map("version_year") @db.VarChar(20)
  coverUrl    String?        @map("cover_url") @db.VarChar(500)
  
  createdAt   DateTime       @default(now()) @map("created_at")
  createdBy   String         @map("created_by") @db.VarChar(36)
  updatedAt   DateTime       @updatedAt @map("updated_at")
  updatedBy   String         @map("updated_by") @db.VarChar(36)
  isDeleted   Boolean        @default(false) @map("is_deleted")
  
  subject     Subject        @relation(fields: [subjectId], references: [id])
  units       TextbookUnit[]
  
  @@index([subjectId])
  @@map("textbooks")
}

model TextbookUnit {
  id         String           @id @default(uuid()) @db.VarChar(36)
  textbookId String           @map("textbook_id") @db.VarChar(36)
  name       String           @db.VarChar(100)
  sortOrder  Int              @map("sort_order")
  
  createdAt  DateTime         @default(now()) @map("created_at")
  createdBy  String           @map("created_by") @db.VarChar(36)
  updatedAt  DateTime         @updatedAt @map("updated_at")
  updatedBy  String           @map("updated_by") @db.VarChar(36)
  isDeleted  Boolean          @default(false) @map("is_deleted")
  
  textbook   Textbook         @relation(fields: [textbookId], references: [id], onDelete: Cascade)
  lessons    TextbookLesson[]
  
  @@index([textbookId])
  @@index([sortOrder])
  @@map("textbook_units")
}

model TextbookLesson {
  id        String           @id @default(uuid()) @db.VarChar(36)
  unitId    String           @map("unit_id") @db.VarChar(36)
  name      String           @db.VarChar(100)
  sortOrder Int              @map("sort_order")
  
  createdAt DateTime         @default(now()) @map("created_at")
  createdBy String           @map("created_by") @db.VarChar(36)
  updatedAt DateTime         @updatedAt @map("updated_at")
  updatedBy String           @map("updated_by") @db.VarChar(36)
  isDeleted Boolean          @default(false) @map("is_deleted")
  
  unit            TextbookUnit     @relation(fields: [unitId], references: [id], onDelete: Cascade)
  knowledgePoints KnowledgePoint[]
  
  @@index([unitId])
  @@index([sortOrder])
  @@map("textbook_lessons")
}

model KnowledgePoint {
  id                      String             @id @default(uuid()) @db.VarChar(36)
  lessonId                String             @map("lesson_id") @db.VarChar(36)
  parentKnowledgePointId  String?            @map("parent_knowledge_point_id") @db.VarChar(36)
  name                    String             @db.VarChar(200)
  difficulty              Int
  description             String?            @db.Text
  
  createdAt               DateTime           @default(now()) @map("created_at")
  createdBy               String             @map("created_by") @db.VarChar(36)
  updatedAt               DateTime           @updatedAt @map("updated_at")
  updatedBy               String             @map("updated_by") @db.VarChar(36)
  isDeleted               Boolean            @default(false) @map("is_deleted")
  
  lesson                  TextbookLesson     @relation(fields: [lessonId], references: [id], onDelete: Cascade)
  parentKnowledgePoint    KnowledgePoint?    @relation("KnowledgePointHierarchy", fields: [parentKnowledgePointId], references: [id], onDelete: Cascade)
  childKnowledgePoints    KnowledgePoint[]   @relation("KnowledgePointHierarchy")
  questionAssociations    QuestionKnowledge[]
  
  @@index([lessonId])
  @@index([parentKnowledgePointId])
  @@index([difficulty])
  @@map("knowledge_points")
}

// =============================================
// 题库资源模块
// =============================================

model Question {
  id             String             @id @default(uuid()) @db.VarChar(36)
  subjectId      String             @map("subject_id") @db.VarChar(36)
  content        String             @db.Text
  optionsConfig  Json?              @map("options_config")
  questionType   QuestionType       @map("question_type")
  answer         String             @db.Text
  explanation    String?            @db.Text
  difficulty     Int                @default(3)
  
  createdAt      DateTime           @default(now()) @map("created_at")
  createdBy      String             @map("created_by") @db.VarChar(36)
  updatedAt      DateTime           @updatedAt @map("updated_at")
  updatedBy      String             @map("updated_by") @db.VarChar(36)
  isDeleted      Boolean            @default(false) @map("is_deleted")
  
  subject        Subject            @relation(fields: [subjectId], references: [id])
  creator        ApplicationUser    @relation("CreatedQuestions", fields: [createdBy], references: [id])
  knowledgePoints QuestionKnowledge[]
  examNodes      ExamNode[]
  
  @@index([subjectId])
  @@index([questionType])
  @@index([difficulty])
  @@fulltext([content])
  @@map("questions")
}

model QuestionKnowledge {
  id                String          @id @default(uuid()) @db.VarChar(36)
  questionId        String          @map("question_id") @db.VarChar(36)
  knowledgePointId  String          @map("knowledge_point_id") @db.VarChar(36)
  weight            Int             @default(100)
  
  createdAt         DateTime        @default(now()) @map("created_at")
  createdBy         String          @map("created_by") @db.VarChar(36)
  updatedAt         DateTime        @updatedAt @map("updated_at")
  updatedBy         String          @map("updated_by") @db.VarChar(36)
  isDeleted         Boolean         @default(false) @map("is_deleted")
  
  question          Question        @relation(fields: [questionId], references: [id], onDelete: Cascade)
  knowledgePoint    KnowledgePoint  @relation(fields: [knowledgePointId], references: [id], onDelete: Cascade)
  
  @@unique([questionId, knowledgePointId])
  @@index([knowledgePointId])
  @@map("question_knowledge")
}

enum QuestionType {
  SingleChoice
  MultipleChoice
  TrueFalse
  FillBlank
  Subjective
}

// =============================================
// 试卷工程模块
// =============================================

model Exam {
  id                String     @id @default(uuid()) @db.VarChar(36)
  subjectId         String     @map("subject_id") @db.VarChar(36)
  title             String     @db.VarChar(200)
  examType          String     @default("Uncategorized") @map("exam_type") @db.VarChar(50) // e.g. Midterm, Final, Unit, Weekly
  totalScore        Decimal    @map("total_score") @default(0) @db.Decimal(5, 1)
  suggestedDuration Int        @map("suggested_duration")
  status            ExamStatus @default(Draft)
  description       String?    @db.Text
  
  createdAt         DateTime   @default(now()) @map("created_at")
  createdBy         String     @map("created_by") @db.VarChar(36)
  updatedAt         DateTime   @updatedAt @map("updated_at")
  updatedBy         String     @map("updated_by") @db.VarChar(36)
  isDeleted         Boolean    @default(false) @map("is_deleted")
  
  subject           Subject        @relation(fields: [subjectId], references: [id])
  creator           ApplicationUser @relation("CreatedExams", fields: [createdBy], references: [id])
  nodes             ExamNode[]
  assignments       Assignment[]
  
  @@index([subjectId])
  @@index([status])
  @@index([createdBy])
  @@map("exams")
}

model ExamNode {
  id           String     @id @default(uuid()) @db.VarChar(36)
  examId       String     @map("exam_id") @db.VarChar(36)
  parentNodeId String?    @map("parent_node_id") @db.VarChar(36)
  nodeType     NodeType   @map("node_type")
  questionId   String?    @map("question_id") @db.VarChar(36)
  title        String?    @db.VarChar(200)
  description  String?    @db.Text
  score        Decimal    @db.Decimal(5, 1)
  sortOrder    Int        @map("sort_order")
  
  createdAt    DateTime   @default(now()) @map("created_at")
  createdBy    String     @map("created_by") @db.VarChar(36)
  updatedAt    DateTime   @updatedAt @map("updated_at")
  updatedBy    String     @map("updated_by") @db.VarChar(36)
  isDeleted    Boolean    @default(false) @map("is_deleted")
  
  exam         Exam       @relation(fields: [examId], references: [id], onDelete: Cascade)
  parentNode   ExamNode?  @relation("ExamNodeHierarchy", fields: [parentNodeId], references: [id], onDelete: Cascade)
  childNodes   ExamNode[] @relation("ExamNodeHierarchy")
  question     Question?  @relation(fields: [questionId], references: [id])
  submissionDetails SubmissionDetail[]
  
  @@index([examId])
  @@index([parentNodeId])
  @@index([sortOrder])
  @@index([questionId])
  @@map("exam_nodes")
}

enum ExamStatus {
  Draft
  Published
}

enum NodeType {
  Group
  Question
}

// =============================================
// 教学执行模块
// =============================================

model Assignment {
  id                  String              @id @default(uuid()) @db.VarChar(36)
  examId              String              @map("exam_id") @db.VarChar(36)
  classId             String              @map("class_id") @db.VarChar(36)
  title               String              @db.VarChar(200)
  startTime           DateTime            @map("start_time")
  endTime             DateTime            @map("end_time")
  allowLateSubmission Boolean             @map("allow_late_submission") @default(false)
  autoScoreEnabled    Boolean             @map("auto_score_enabled") @default(true)
  status              AssignmentStatus    @default(Active)

  createdAt           DateTime            @default(now()) @map("created_at")
  createdBy           String              @map("created_by") @db.VarChar(36)
  updatedAt           DateTime            @updatedAt @map("updated_at")
  updatedBy           String              @map("updated_by") @db.VarChar(36)
  isDeleted           Boolean             @default(false) @map("is_deleted")
  
  exam                Exam                @relation(fields: [examId], references: [id])
  class               Class               @relation(fields: [classId], references: [id])
  submissions         StudentSubmission[]
  
  @@index([examId])
  @@index([classId])
  @@index([startTime])
  @@index([endTime])
  @@map("assignments")
}

model StudentSubmission {
  id               String             @id @default(uuid()) @db.VarChar(36)
  assignmentId     String             @map("assignment_id") @db.VarChar(36)
  studentId        String             @map("student_id") @db.VarChar(36)
  submissionStatus SubmissionStatus   @map("submission_status") @default(Pending)
  startedAt        DateTime?          @map("started_at")
  submitTime       DateTime?          @map("submit_time")
  timeSpentSeconds Int?               @map("time_spent_seconds")
  totalScore       Decimal?           @map("total_score") @db.Decimal(5, 1)
  
  createdAt        DateTime           @default(now()) @map("created_at")
  createdBy        String             @map("created_by") @db.VarChar(36)
  updatedAt        DateTime           @updatedAt @map("updated_at")
  updatedBy        String             @map("updated_by") @db.VarChar(36)
  isDeleted        Boolean            @default(false) @map("is_deleted")
  
  assignment       Assignment         @relation(fields: [assignmentId], references: [id], onDelete: Cascade)
  student          ApplicationUser    @relation(fields: [studentId], references: [id], onDelete: Cascade)
  details          SubmissionDetail[]
  
  @@unique([assignmentId, studentId])
  @@index([studentId])
  @@index([submitTime])
  @@index([submissionStatus])
  @@map("student_submissions")
}

model SubmissionDetail {
  id             String          @id @default(uuid()) @db.VarChar(36)
  submissionId   String          @map("submission_id") @db.VarChar(36)
  examNodeId     String          @map("exam_node_id") @db.VarChar(36)
  studentAnswer  String?         @map("student_answer") @db.Text
  gradingData    Json?           @map("grading_data")
  score          Decimal?        @db.Decimal(5, 1)
  judgement      JudgementResult?
  teacherComment String?         @map("teacher_comment") @db.Text
  
  createdAt      DateTime        @default(now()) @map("created_at")
  createdBy      String          @map("created_by") @db.VarChar(36)
  updatedAt      DateTime        @updatedAt @map("updated_at")
  updatedBy      String          @map("updated_by") @db.VarChar(36)
  isDeleted      Boolean         @default(false) @map("is_deleted")
  
  submission     StudentSubmission @relation(fields: [submissionId], references: [id], onDelete: Cascade)
  examNode       ExamNode        @relation(fields: [examNodeId], references: [id])
  
  @@unique([submissionId, examNodeId])
  @@index([examNodeId])
  @@index([judgement])
  @@map("submission_details")
}

enum SubmissionStatus {
  Pending
  Submitted
  Grading
  Graded
}

enum AssignmentStatus {
  Active
  Archived
}

enum JudgementResult {
  Correct
  Incorrect
  Partial
}

// =============================================
// 辅助功能模块
// =============================================

model Message {
  id        String   @id @default(uuid()) @db.VarChar(36)
  userId    String   @map("user_id") @db.VarChar(36)
  title     String   @db.VarChar(200)
  content   String   @db.Text
  type      String   @db.VarChar(20) // Announcement, Notification, Alert
  senderName String  @map("sender_name") @db.VarChar(50)
  isRead    Boolean  @default(false) @map("is_read")
  
  createdAt DateTime @default(now()) @map("created_at")
  updatedAt DateTime @updatedAt @map("updated_at")
  
  user      ApplicationUser @relation(fields: [userId], references: [id], onDelete: Cascade)

  @@index([userId])
  @@map("messages")
}

model Schedule {
  id        String   @id @default(uuid()) @db.VarChar(36)
  classId   String   @map("class_id") @db.VarChar(36)
  subject   String   @db.VarChar(50)
  room      String?  @db.VarChar(50)
  dayOfWeek Int      @map("day_of_week") // 1-7
  period    Int      // 1-8
  startTime String   @map("start_time") @db.VarChar(10) // HH:mm
  endTime   String   @map("end_time") @db.VarChar(10) // HH:mm
  
  createdAt DateTime @default(now()) @map("created_at")
  updatedAt DateTime @updatedAt @map("updated_at")

  class     Class    @relation(fields: [classId], references: [id], onDelete: Cascade)

  @@index([classId])
  @@map("schedules")
}