// CompetenceTrack — Full Database Schema
// SQLite via Prisma ORM | UUIDs for portability | UTC timestamps

generator client {
  provider = "prisma-client-js"
}

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

// ─── Core Organizational Entities ───────────────────────────────────

model School {
  id        String   @id @default(cuid())
  name      String
  schoolType String  // ELEMENTARY, MIDDLE, GYMNASIUM, OTHER
  country   String   @default("DE")
  timezone  String   @default("Europe/Berlin")
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  users           User[]
  schoolYears     SchoolYear[]
  classGroups     ClassGroup[]
  students        Student[]
  subjects        Subject[]
  competencyTemplates CompetencyTemplate[]
  gradingSchemes  GradingScheme[]
  auditLogs       AuditLog[]
  dataExportRequests DataExportRequest[]
  behaviorCategories BehaviorCategory[]
  behaviorIncidents  BehaviorIncident[]
  rubrics            Rubric[]
  commentCategories  CommentCategory[]
  commentBankEntries CommentBankEntry[]
  notebooks          Notebook[]
  drawings           Drawing[]
  notifications      Notification[]
  calendarEvents     CalendarEvent[]
  parentStudentLinks ParentStudentLink[]
}

model User {
  id              String   @id @default(cuid())
  schoolId        String?
  email           String   @unique
  passwordHash    String
  firstName       String
  lastName        String
  role            String   @default("TEACHER") // TEACHER, SCHOOL_ADMIN, SUPER_ADMIN, STUDENT, PARENT
  locale          String   @default("de")
  twoFactorSecret String?
  isDemo          Boolean  @default(false)
  createdAt       DateTime @default(now())
  updatedAt       DateTime @updatedAt
  deletedAt       DateTime?

  school           School?           @relation(fields: [schoolId], references: [id])
  classGroupTeachers ClassGroupTeacher[]
  learningProgressEntries LearningProgressEntry[]
  assessments     Assessment[]
  generatedReports Report[]
  auditLogs       AuditLog[]
  dataExportRequests DataExportRequest[]
  teacherNotes    TeacherNote[]
  attendanceSessions AttendanceSession[]
  lessonPlans     LessonPlan[]
  parentMessagesSent ParentMessage[]
  behaviorIncidentsLogged   BehaviorIncident[] @relation("BehaviorLogger")
  behaviorIncidentsResolved BehaviorIncident[] @relation("BehaviorResolver")
  rubrics                   Rubric[]
  commentBankEntries        CommentBankEntry[]
  notebooks                 Notebook[]
  drawings                  Drawing[]
  notifications             Notification[]
  calendarEvents            CalendarEvent[]
  parentLinks               ParentStudentLink[]
}

model SchoolYear {
  id        String   @id @default(cuid())
  schoolId  String
  label     String   // e.g. "2025/2026"
  startDate DateTime
  endDate   DateTime
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  school      School     @relation(fields: [schoolId], references: [id])
  classGroups ClassGroup[]
  enrollments Enrollment[]
  computedGrades ComputedGrade[]
  reports     Report[]
}

model ClassGroup {
  id           String   @id @default(cuid())
  schoolId     String
  schoolYearId String
  name         String   // e.g. "3a"
  gradeLevel   Int
  schoolType   String   @default("ELEMENTARY")
  seatingOrder String?  // JSON array of student IDs
  createdAt    DateTime @default(now())
  updatedAt    DateTime @updatedAt

  school              School              @relation(fields: [schoolId], references: [id])
  schoolYear          SchoolYear          @relation(fields: [schoolYearId], references: [id])
  teachers            ClassGroupTeacher[]
  enrollments         Enrollment[]
  classCompetencyAssignments ClassCompetencyAssignment[]
  assessments         Assessment[]
  learningProgressEntries LearningProgressEntry[]
  gradingSchemes      GradingScheme[]
  computedGrades      ComputedGrade[]
  reports             Report[]
  attendanceSessions  AttendanceSession[]
  lessonPlans         LessonPlan[]
  behaviorIncidents   BehaviorIncident[]
  notebooks           Notebook[]
  drawings            Drawing[]
  calendarEvents      CalendarEvent[]
}

model ClassGroupTeacher {
  id           String @id @default(cuid())
  classGroupId String
  userId       String
  role         String @default("SUBJECT_TEACHER") // HOMEROOM_TEACHER, SUBJECT_TEACHER

  classGroup ClassGroup @relation(fields: [classGroupId], references: [id])
  user       User       @relation(fields: [userId], references: [id])

  @@unique([classGroupId, userId])
}

model Student {
  id          String    @id @default(cuid())
  schoolId    String
  firstName   String
  lastName    String
  dateOfBirth DateTime?
  externalId  String?   // for import matching
  createdAt   DateTime  @default(now())
  updatedAt   DateTime  @updatedAt
  deletedAt   DateTime?

  school                School                @relation(fields: [schoolId], references: [id])
  enrollments           Enrollment[]
  learningProgressEntries LearningProgressEntry[]
  assessmentResults     AssessmentResult[]
  computedGrades        ComputedGrade[]
  reports               Report[]
  teacherNotes          TeacherNote[]
  attendanceRecords     AttendanceRecord[]
  parentContacts        ParentContact[]
  parentMessages        ParentMessage[]
  behaviorIncidents     BehaviorIncident[]
  parentStudentLinks    ParentStudentLink[]
}

model Enrollment {
  id           String    @id @default(cuid())
  studentId    String
  classGroupId String
  schoolYearId String
  startDate    DateTime
  endDate      DateTime? // null = still enrolled

  student     Student     @relation(fields: [studentId], references: [id])
  classGroup  ClassGroup  @relation(fields: [classGroupId], references: [id])
  schoolYear  SchoolYear  @relation(fields: [schoolYearId], references: [id])
}

// ─── Subject & Competency Structure ────────────────────────────────

model Subject {
  id           String @id @default(cuid())
  schoolId     String? // null = global/template
  name         String
  gradeLevelMin Int   @default(1)
  gradeLevelMax Int   @default(13)

  school              School?              @relation(fields: [schoolId], references: [id])
  competencyTemplates CompetencyTemplate[]
  assessments         Assessment[]
  classCompetencyAssignments ClassCompetencyAssignment[]
  gradingSchemes      GradingScheme[]
  computedGrades      ComputedGrade[]
  attendanceSessions  AttendanceSession[]
  lessonPlans         LessonPlan[]
  rubrics             Rubric[]
  commentBankEntries  CommentBankEntry[]
  notebooks           Notebook[]
  drawings            Drawing[]
  calendarEvents      CalendarEvent[]
}

model CompetencyTemplate {
  id               String  @id @default(cuid())
  name             String
  description      String?
  subjectId        String?
  schoolType       String  @default("ELEMENTARY")
  gradeLevelMin    Int     @default(1)
  gradeLevelMax    Int     @default(4)
  isGlobalTemplate Boolean @default(false)
  createdByUserId  String?
  version          Int     @default(1)
  schoolId         String?
  createdAt        DateTime @default(now())
  updatedAt        DateTime @updatedAt

  subject              Subject?              @relation(fields: [subjectId], references: [id])
  school               School?               @relation(fields: [schoolId], references: [id])
  categories           CompetencyCategory[]
  classCompetencyAssignments ClassCompetencyAssignment[]
}

model CompetencyCategory {
  id                  String  @id @default(cuid())
  competencyTemplateId String
  name                String
  order               Int     @default(0)
  color               String? // hex color for chart petals

  competencyTemplate CompetencyTemplate @relation(fields: [competencyTemplateId], references: [id])
  competencies       Competency[]
  reportSections     ReportSection[]
}

model Competency {
  id          String  @id @default(cuid())
  categoryId  String
  code        String  // e.g. "D.3.LES.01"
  title       String
  description String?
  order       Int     @default(0)

  category              CompetencyCategory     @relation(fields: [categoryId], references: [id])
  masteryLevelDefinitions MasteryLevelDefinition[]
  learningProgressEntries LearningProgressEntry[]
  assessmentCompetencyLinks AssessmentCompetencyLink[]
}

model MasteryLevelDefinition {
  id           String  @id @default(cuid())
  competencyId String
  levelValue   Int     // e.g. 1-4
  label        String  // e.g. "noch nicht erreicht", "entwickelt sich", "kompetent", "weit entwickelt"
  description  String?

  competency Competency @relation(fields: [competencyId], references: [id])
}

model ClassCompetencyAssignment {
  id                  String @id @default(cuid())
  classGroupId        String
  subjectId           String
  competencyTemplateId String
  schoolYearId        String
  clonedTemplateId    String? // if customized, points to the school's cloned copy

  classGroup         ClassGroup         @relation(fields: [classGroupId], references: [id])
  subject            Subject            @relation(fields: [subjectId], references: [id])
  competencyTemplate CompetencyTemplate @relation(fields: [competencyTemplateId], references: [id])

  @@unique([classGroupId, subjectId, schoolYearId])
}

// ─── Progress Tracking & Assessment ────────────────────────────────

model LearningProgressEntry {
  id              String   @id @default(cuid())
  studentId       String
  competencyId    String
  teacherId       String
  classGroupId    String
  date            DateTime
  masteryLevelValue Int
  note            String?
  createdAt       DateTime @default(now())
  updatedAt       DateTime @updatedAt

  student     Student     @relation(fields: [studentId], references: [id])
  competency  Competency  @relation(fields: [competencyId], references: [id])
  teacher     User        @relation(fields: [teacherId], references: [id])
  classGroup  ClassGroup  @relation(fields: [classGroupId], references: [id])
}

model Assessment {
  id           String   @id @default(cuid())
  classGroupId String
  subjectId    String
  teacherId    String
  title        String
  date         DateTime
  type         String   @default("TEST") // TEST, ORAL, PROJECT, HOMEWORK, OTHER
  maxScore     Float?
  weight       Float    @default(1.0)
  createdAt    DateTime @default(now())
  updatedAt    DateTime @updatedAt

  classGroup           ClassGroup           @relation(fields: [classGroupId], references: [id])
  subject              Subject              @relation(fields: [subjectId], references: [id])
  teacher              User                 @relation(fields: [teacherId], references: [id])
  assessmentCompetencyLinks AssessmentCompetencyLink[]
  assessmentResults    AssessmentResult[]
}

model AssessmentCompetencyLink {
  id           String @id @default(cuid())
  assessmentId String
  competencyId String
  weight       Float  @default(1.0)

  assessment Assessment @relation(fields: [assessmentId], references: [id])
  competency Competency @relation(fields: [competencyId], references: [id])

  @@unique([assessmentId, competencyId])
}

model AssessmentResult {
  id               String  @id @default(cuid())
  assessmentId     String
  studentId        String
  score            Float?
  masteryLevelValue Int?
  note             String?

  assessment Assessment @relation(fields: [assessmentId], references: [id])
  student    Student    @relation(fields: [studentId], references: [id])

  @@unique([assessmentId, studentId])
}

// ─── Grading ───────────────────────────────────────────────────────

model GradingScheme {
  id              String @id @default(cuid())
  classGroupId    String?
  subjectId       String?
  schoolId        String?
  name            String
  type            String @default("NUMERIC_GRADE") // NUMERIC_GRADE, VERBAL_FEEDBACK, COMBINED
  scaleDefinition String // JSON: e.g. {"min":1,"max":6,"labels":{"1":"sehr gut","6":"ungenügend"}}

  classGroup     ClassGroup?     @relation(fields: [classGroupId], references: [id])
  subject        Subject?        @relation(fields: [subjectId], references: [id])
  school         School?         @relation(fields: [schoolId], references: [id])
  gradingWeightRules GradingWeightRule[]
}

model GradingWeightRule {
  id              String @id @default(cuid())
  gradingSchemeId String
  sourceType      String // LEARNING_PROGRESS, ASSESSMENT
  targetRef       String? // competencyId, assessmentId, or categoryId
  weightPercent   Float  @default(50.0)

  gradingScheme GradingScheme @relation(fields: [gradingSchemeId], references: [id])
}

model ComputedGrade {
  id              String   @id @default(cuid())
  studentId       String
  subjectId       String
  classGroupId    String
  schoolYearId    String
  period          String   @default("Semester 1")
  computedValue   Float
  computedAt      DateTime @default(now())
  isFinalized     Boolean  @default(false)
  overriddenValue Float?
  overrideReason  String?

  student     Student     @relation(fields: [studentId], references: [id])
  subject     Subject     @relation(fields: [subjectId], references: [id])
  classGroup  ClassGroup  @relation(fields: [classGroupId], references: [id])
  schoolYear  SchoolYear  @relation(fields: [schoolYearId], references: [id])
}

// ─── Reporting ─────────────────────────────────────────────────────

model Report {
  id              String   @id @default(cuid())
  studentId       String
  classGroupId    String
  schoolYearId    String
  period          String
  generatedByUserId String
  generatedAt     DateTime @default(now())
  status          String   @default("DRAFT") // DRAFT, FINAL
  pdfFilePath     String?
  includesGrades  Boolean  @default(false)

  student        Student     @relation(fields: [studentId], references: [id])
  classGroup     ClassGroup  @relation(fields: [classGroupId], references: [id])
  schoolYear     SchoolYear  @relation(fields: [schoolYearId], references: [id])
  generatedByUser User       @relation(fields: [generatedByUserId], references: [id])
  sections       ReportSection[]
}

model ReportSection {
  id                  String  @id @default(cuid())
  reportId            String
  competencyCategoryId String?
  generatedText       String
  order               Int     @default(0)

  report            Report             @relation(fields: [reportId], references: [id])
  competencyCategory CompetencyCategory? @relation(fields: [competencyCategoryId], references: [id])
}

// ─── Auditing & Compliance ─────────────────────────────────────────

model AuditLog {
  id         String   @id @default(cuid())
  userId     String?
  schoolId   String?
  action     String
  entityType String
  entityId   String?
  timestamp  DateTime @default(now())
  metadata   String?  // JSON

  user  User?  @relation(fields: [userId], references: [id])
  school School? @relation(fields: [schoolId], references: [id])
}

model DataExportRequest {
  id            String    @id @default(cuid())
  requestedByUserId String
  schoolId      String?
  scope         String    // STUDENT, CLASS, SCHOOL
  scopeId       String?   // studentId, classGroupId, or schoolId
  status        String    @default("PENDING") // PENDING, PROCESSING, COMPLETED, FAILED
  filePath      String?
  requestedAt   DateTime  @default(now())
  completedAt   DateTime?

  requestedByUser User @relation(fields: [requestedByUserId], references: [id])
  school          School? @relation(fields: [schoolId], references: [id])
}

// ─── Attendance Tracking ────────────────────────────────────────────

model AttendanceSession {
  id           String   @id @default(cuid())
  classGroupId String
  teacherId    String
  date         DateTime
  subjectId    String?
  period       String?  // e.g. "1. Stunde", "Morning"
  status       String   @default("OPEN") // OPEN, COMPLETED
  note         String?
  createdAt    DateTime @default(now())
  updatedAt    DateTime @updatedAt

  classGroup   ClassGroup  @relation(fields: [classGroupId], references: [id])
  teacher      User        @relation(fields: [teacherId], references: [id])
  subject      Subject?    @relation(fields: [subjectId], references: [id])
  records      AttendanceRecord[]

  @@index([classGroupId, date])
}

model AttendanceRecord {
  id               String  @id @default(cuid())
  sessionId        String
  studentId        String
  status           String  @default("PRESENT") // PRESENT, ABSENT, EXCUSED, LATE
  arrivalTime      String? // for LATE status, e.g. "08:25"
  comment          String?

  session          AttendanceSession @relation(fields: [sessionId], references: [id])
  student          Student           @relation(fields: [studentId], references: [id])

  @@unique([sessionId, studentId])
  @@index([studentId])
}

// ─── Teacher Notes ─────────────────────────────────────────────────

model TeacherNote {
  id          String   @id @default(cuid())
  studentId   String
  teacherId   String
  category    String   // GENERAL, BEHAVIOR, ACADEMIC, INTERVENTION, PARENT_CONTACT
  content     String
  isPrivate   Boolean  @default(true)
  createdAt   DateTime @default(now())
  updatedAt   DateTime @updatedAt

  student     Student  @relation(fields: [studentId], references: [id])
  teacher     User     @relation(fields: [teacherId], references: [id])

  @@index([studentId])
  @@index([teacherId])
}

// ─── Lesson Planning ────────────────────────────────────────────────

model LessonPlan {
  id            String   @id @default(cuid())
  teacherId     String
  classGroupId  String
  subjectId     String?
  title         String
  description   String?
  date          DateTime
  durationMin   Int      @default(45)
  status        String   @default("draft") // draft|scheduled|completed|cancelled
  objectives    String? // JSON array of strings
  materials     String? // JSON array of strings
  homework      String?
  reflection    String?
  linkedCompetencyIds String? // JSON array of competency IDs
  createdAt     DateTime @default(now())
  updatedAt     DateTime @updatedAt

  teacher       User       @relation(fields: [teacherId], references: [id])
  classGroup    ClassGroup @relation(fields: [classGroupId], references: [id])
  subject       Subject?   @relation(fields: [subjectId], references: [id])

  @@index([teacherId])
  @@index([classGroupId])
  @@index([date])
}

// ─── Parent Communication ──────────────────────────────────────────

model ParentContact {
  id               String   @id @default(cuid())
  studentId        String
  firstName        String
  lastName         String
  email            String?
  phone            String?
  relationship     String   @default("parent") // parent|guardian|emergency
  preferredContact String   @default("email") // email|phone|both
  preferredLanguage String  @default("de")
  notes            String?
  createdAt        DateTime @default(now())
  updatedAt        DateTime @updatedAt

  student     Student        @relation(fields: [studentId], references: [id])
  messages    ParentMessage[]

  @@index([studentId])
  @@unique([studentId, email])
}

model ParentMessage {
  id           String   @id @default(cuid())
  parentId     String
  teacherId    String
  studentId    String
  subject      String
  body         String
  category     String   @default("general") // general|progress|assessment|behavior|attendance|event
  priority     String   @default("normal") // low|normal|high|urgent
  status       String   @default("sent") // draft|sent|delivered|read|replied
  readAt       DateTime?
  reply        String?
  replyAt      DateTime?
  createdAt    DateTime @default(now())
  updatedAt    DateTime @updatedAt

  parent       ParentContact @relation(fields: [parentId], references: [id])
  teacher      User          @relation(fields: [teacherId], references: [id])
  student      Student       @relation(fields: [studentId], references: [id])

  @@index([teacherId])
  @@index([parentId])
  @@index([studentId])
  @@index([createdAt])
}

// ─── Behavior Tracking ─────────────────────────────────────────────

model BehaviorCategory {
  id        String   @id @default(cuid())
  schoolId  String
  school    School   @relation(fields: [schoolId], references: [id])
  name      String
  color     String   // hex color, e.g. "#10b981"
  valence   String   // "positive" | "negative" | "neutral"
  icon      String?  // emoji
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  incidents BehaviorIncident[]

  @@unique([schoolId, name])
  @@index([schoolId])
}

model BehaviorIncident {
  id           String   @id @default(cuid())
  studentId    String
  student      Student  @relation(fields: [studentId], references: [id])
  teacherId    String
  teacher      User     @relation("BehaviorLogger", fields: [teacherId], references: [id])
  classGroupId String?
  classGroup   ClassGroup? @relation(fields: [classGroupId], references: [id])
  schoolId     String
  school       School   @relation(fields: [schoolId], references: [id])
  categoryId   String
  category     BehaviorCategory @relation(fields: [categoryId], references: [id])
  date         DateTime
  severity     String   // "minor" | "moderate" | "major"
  description  String
  location     String?  // e.g., "Klassenzimmer", "Pausenhof", "Flur"
  followUpAction String? // e.g., "Elterngespräch", "Nachsitzen", "Lob im Kreis"
  resolved     Boolean  @default(false)
  resolvedAt   DateTime?
  resolvedById String?
  resolvedBy   User?    @relation("BehaviorResolver", fields: [resolvedById], references: [id])
  createdAt    DateTime @default(now())
  updatedAt    DateTime @updatedAt

  @@index([studentId, date])
  @@index([classGroupId, date])
  @@index([schoolId, date])
  @@index([teacherId])
}

// ─── Rubric Library ────────────────────────────────────────────────

model Rubric {
  id          String   @id @default(cuid())
  schoolId    String
  school      School   @relation(fields: [schoolId], references: [id])
  teacherId   String
  teacher     User     @relation(fields: [teacherId], references: [id])
  subjectId   String?
  subject     Subject? @relation(fields: [subjectId], references: [id])
  title       String
  description String?
  type        String   @default("ANALYTIC") // ANALYTIC | HOLISTIC
  maxPoints   Int      @default(100)
  isPublic    Boolean  @default(false) // shared across school
  version     Int      @default(1)
  createdAt   DateTime @default(now())
  updatedAt   DateTime @updatedAt

  criteria RubricCriterion[]

  @@index([schoolId])
  @@index([teacherId])
  @@index([subjectId])
}

model RubricCriterion {
  id          String   @id @default(cuid())
  rubricId    String
  rubric      Rubric   @relation(fields: [rubricId], references: [id], onDelete: Cascade)
  name        String   // e.g., "Inhalt", "Sprache", "Darstellung"
  description String?
  weight      Float    @default(1.0) // relative weight for this criterion
  maxPoints   Int      // max points for this criterion
  order       Int      @default(0)
  createdAt   DateTime @default(now())
  updatedAt   DateTime @updatedAt

  levels RubricLevel[]

  @@index([rubricId])
}

model RubricLevel {
  id           String   @id @default(cuid())
  criterionId  String
  criterion    RubricCriterion @relation(fields: [criterionId], references: [id], onDelete: Cascade)
  label        String   // e.g., "Sehr gut", "Gut", "Befriedigend", "Ausreichend"
  description  String   // descriptor for this level
  points       Int      // points for this level
  order        Int      @default(0)
  createdAt    DateTime @default(now())
  updatedAt    DateTime @updatedAt

  @@index([criterionId])
}

// ─── Report Card Comments Bank ────────────────────────────────────

model CommentCategory {
  id        String   @id @default(cuid())
  schoolId  String
  school    School   @relation(fields: [schoolId], references: [id])
  name      String
  color     String   // hex color
  icon      String?  // emoji
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  comments CommentBankEntry[]

  @@unique([schoolId, name])
  @@index([schoolId])
}

model CommentBankEntry {
  id          String   @id @default(cuid())
  schoolId    String
  school      School   @relation(fields: [schoolId], references: [id])
  teacherId   String
  teacher     User     @relation(fields: [teacherId], references: [id])
  categoryId  String
  category    CommentCategory @relation(fields: [categoryId], references: [id])
  subjectId   String?
  subject     Subject? @relation(fields: [subjectId], references: [id])
  title       String   // short title
  text        String   // the full comment text
  gradeLevel  String?  // e.g., "3", "3-4", "all" — which grade levels this applies to
  schoolType  String?  // e.g., "ELEMENTARY", "SECONDARY"
  isPublic    Boolean  @default(false) // shared across school
  usageCount  Int      @default(0) // how many times used
  tags        String?  // comma-separated tags for search
  createdAt   DateTime @default(now())
  updatedAt   DateTime @updatedAt

  @@index([schoolId])
  @@index([teacherId])
  @@index([categoryId])
  @@index([subjectId])
}

// ─── Digital Notebooks ─────────────────────────────────────────────

model Notebook {
  id          String   @id @default(cuid())
  schoolId    String
  ownerId     String   // userId of the student or teacher
  ownerType   String   // STUDENT | TEACHER
  subjectId   String?  // null = personal/general notebook
  classGroupId String?
  title       String
  description String?
  notebookType String  @default("lined") // lined | grid | blank | dotted | music | calligraphy
  color       String   @default("#10b981") // cover color
  icon        String?  // lucide icon name
  isArchived  Boolean  @default(false)
  isPublic    Boolean  @default(false) // shared with class
  sortOrder   Int      @default(0)
  isDemo      Boolean  @default(false)
  createdAt   DateTime @default(now())
  updatedAt   DateTime @updatedAt
  deletedAt   DateTime?

  school     School    @relation(fields: [schoolId], references: [id])
  owner      User      @relation(fields: [ownerId], references: [id])
  subject    Subject?  @relation(fields: [subjectId], references: [id])
  classGroup ClassGroup? @relation(fields: [classGroupId], references: [id])
  pages      NotebookPage[]

  @@index([schoolId])
  @@index([ownerId])
  @@index([subjectId])
  @@index([classGroupId])
  @@index([isArchived])
}

model NotebookPage {
  id          String   @id @default(cuid())
  notebookId  String
  pageNumber  Int
  title       String?
  contentType String   @default("text") // text | drawing | mixed
  textContent String?  // markdown/rich text content
  drawingData String?  // JSON with strokes/paths for canvas
  background  String   @default("lined") // lined | grid | blank | dotted | music
  isBookmark  Boolean  @default(false)
  createdAt   DateTime @default(now())
  updatedAt   DateTime @updatedAt

  notebook   Notebook @relation(fields: [notebookId], references: [id], onDelete: Cascade)
  versions   NotebookPageVersion[]

  @@index([notebookId])
  @@index([pageNumber])
}

model NotebookPageVersion {
  id          String   @id @default(cuid())
  pageId      String
  version     Int
  textContent String?
  drawingData String?
  editedBy    String?
  editSummary String?
  createdAt   DateTime @default(now())

  page        NotebookPage @relation(fields: [pageId], references: [id], onDelete: Cascade)

  @@index([pageId, version])
  @@map("notebook_page_versions")
}

// ─── Drawing Canvas ────────────────────────────────────────────────

model Drawing {
  id          String   @id @default(cuid())
  schoolId    String
  ownerId     String
  title       String
  description String?
  drawingData String   // JSON with all strokes, paths, colors
  imageData   String?  // base64 encoded PNG thumbnail
  subjectId   String?
  classGroupId String?
  isPublic    Boolean  @default(false)
  isDemo      Boolean  @default(false)
  createdAt   DateTime @default(now())
  updatedAt   DateTime @updatedAt

  school     School    @relation(fields: [schoolId], references: [id])
  owner      User      @relation(fields: [ownerId], references: [id])
  subject    Subject?  @relation(fields: [subjectId], references: [id])
  classGroup ClassGroup? @relation(fields: [classGroupId], references: [id])

  @@index([schoolId])
  @@index([ownerId])
  @@index([subjectId])
}

model Notification {
  id          String   @id @default(cuid())
  schoolId    String
  userId      String   // recipient
  type        String   // ASSESSMENT_DUE, MISSING_OBSERVATION, NOTEBOOK_SHARED, BEHAVIOR_ALERT, GRADE_COMPUTED, etc.
  title       String
  message     String
  isRead      Boolean  @default(false)
  actionUrl   String?  // optional deep link
  relatedId   String?  // optional related entity ID
  createdAt   DateTime @default(now())
  updatedAt   DateTime @updatedAt
  deletedAt   DateTime?

  school      School   @relation(fields: [schoolId], references: [id])
  user        User     @relation(fields: [userId], references: [id])

  @@index([userId, isRead])
  @@index([schoolId])
  @@map("notifications")
}

// ─── Calendar Events ──────────────────────────────────────────────

model CalendarEvent {
  id                 String    @id @default(cuid())
  schoolId           String
  teacherId          String
  title              String
  date               DateTime
  startTime          String?   // HH:mm format, null = all day
  endTime            String?   // HH:mm format, null = all day
  eventType          String    @default("reminder") // assessment | lesson | reminder
  subjectId          String?
  classGroupId       String?
  notes              String?
  allDay             Boolean   @default(false)
  recurrencePattern  String?   // JSON: { type: "daily|weekly|monthly|yearly", interval: 1, endDate?: string, daysOfWeek?: number[] }
  recurrenceEnd      DateTime? // When recurrence ends
  parentEventId      String?   // For generated instances of a recurring event
  createdAt          DateTime  @default(now())
  updatedAt          DateTime  @updatedAt

  school       School         @relation(fields: [schoolId], references: [id])
  teacher      User           @relation(fields: [teacherId], references: [id])
  subject      Subject?       @relation(fields: [subjectId], references: [id])
  classGroup   ClassGroup?    @relation(fields: [classGroupId], references: [id])
  parentEvent  CalendarEvent? @relation("EventRecurrence", fields: [parentEventId], references: [id])
  childEvents  CalendarEvent[] @relation("EventRecurrence")

  @@index([schoolId])
  @@index([teacherId])
  @@index([date])
  @@index([subjectId])
  @@index([classGroupId])
  @@index([parentEventId])
}

// ─── Parent-Student Link ──────────────────────────────────────────────

model ParentStudentLink {
  id            String   @id @default(cuid())
  parentId      String   // User with PARENT role
  studentId     String   // Student record
  schoolId      String
  relationship  String?  // mother, father, guardian, etc.
  createdAt     DateTime @default(now())
  updatedAt     DateTime @updatedAt

  parent        User     @relation(fields: [parentId], references: [id])
  student       Student  @relation(fields: [studentId], references: [id])
  school        School   @relation(fields: [schoolId], references: [id])

  @@unique([parentId, studentId])
  @@map("parent_student_links")
}