datasource db {
  provider = "sqlite"
}

generator client {
  provider = "prisma-client"
  output   = "../src/generated/prisma"
}

model Class {
  id        String   @id @default(uuid())
  slug      String   @unique
  name      String
  sortOrder Int      @default(0)
  createdAt DateTime @default(now())

  decks                Deck[]
  quizSets             QuizSet[]
  materialGroups       MaterialGroup[]
  spacedRepetitionSets SpacedRepetitionSet[]
}

model Deck {
  id          String   @id @default(uuid())
  classId     String
  name        String
  description String?
  sortOrder   Int      @default(0)
  createdAt   DateTime @default(now())

  class                       Class                     @relation(fields: [classId], references: [id], onDelete: Cascade)
  groupId                     String?
  group                       MaterialGroup?            @relation(fields: [groupId], references: [id], onDelete: SetNull)
  cards                       Flashcard[]
  shareLink                   ShareLink?
  progress                    StudyProgress[]
  spacedRepetitionMemberships SpacedRepetitionSetDeck[]
}

model Flashcard {
  id        String @id @default(uuid())
  deckId    String
  front     String
  back      String
  sortOrder Int    @default(0)

  deck                   Deck                        @relation(fields: [deckId], references: [id], onDelete: Cascade)
  spacedRepetitionStates SpacedRepetitionCardState[]
}

model QuizSet {
  id          String   @id @default(uuid())
  classId     String
  name        String
  description String?
  sortOrder   Int      @default(0)
  createdAt   DateTime @default(now())

  class     Class           @relation(fields: [classId], references: [id], onDelete: Cascade)
  groupId   String?
  group     MaterialGroup?  @relation(fields: [groupId], references: [id], onDelete: SetNull)
  questions Question[]
  attempts  QuizAttempt[]
  shareLink ShareLink?
  progress  StudyProgress[]
}

model Question {
  id        String @id @default(uuid())
  quizSetId String
  type      String // "MULTIPLE_CHOICE" | "SATA"
  prompt    String
  rationale String
  category  String
  sortOrder Int    @default(0)

  quizSet QuizSet        @relation(fields: [quizSetId], references: [id], onDelete: Cascade)
  options AnswerOption[]
}

model AnswerOption {
  id         String  @id @default(uuid())
  questionId String
  text       String
  isCorrect  Boolean @default(false)
  sortOrder  Int     @default(0)

  question Question @relation(fields: [questionId], references: [id], onDelete: Cascade)
}

model StudyProgress {
  id              String   @id @default(uuid())
  contentType     String // "DECK" | "QUIZ"
  deckId          String?
  quizSetId       String?
  mode            String // "SEQUENTIAL" | "SHUFFLED"
  currentIndex    Int      @default(0)
  orderJson       String // JSON array of card/question ids
  answersJson     String? // in-progress quiz answers
  cardResultsJson String? // per-card grades for decks
  updatedAt       DateTime @updatedAt

  deck    Deck?    @relation(fields: [deckId], references: [id], onDelete: Cascade)
  quizSet QuizSet? @relation(fields: [quizSetId], references: [id], onDelete: Cascade)

  @@unique([deckId, mode])
  @@unique([quizSetId, mode])
}

model QuizAttempt {
  id              String   @id @default(uuid())
  quizSetId       String
  score           Float
  maxScore        Int
  answersJson     String
  isPartialRetake Boolean  @default(false)
  completedAt     DateTime @default(now())

  quizSet QuizSet @relation(fields: [quizSetId], references: [id], onDelete: Cascade)
}

model ShareLink {
  id         String   @id @default(uuid())
  targetType String // "DECK" | "QUIZ" | "GROUP"
  deckId     String?  @unique
  quizSetId  String?  @unique
  groupId    String?  @unique
  createdAt  DateTime @default(now())

  deck    Deck?          @relation(fields: [deckId], references: [id], onDelete: Cascade)
  quizSet QuizSet?       @relation(fields: [quizSetId], references: [id], onDelete: Cascade)
  group   MaterialGroup? @relation(fields: [groupId], references: [id], onDelete: Cascade)
}

model AuthSecurity {
  id             Int       @id @default(1)
  failedAttempts Int       @default(0)
  lockedUntil    DateTime?
  lastAttemptAt  DateTime?
}

model Setting {
  key   String @id
  value String
}

model StudyActivity {
  id         String   @id @default(uuid())
  type       String // "FLASHCARD" | "QUIZ_QUESTION"
  occurredAt DateTime @default(now())

  @@index([occurredAt])
}

model MaterialGroup {
  id        String   @id @default(uuid())
  classId   String
  name      String
  type      String // "DECK" | "QUIZ"
  sortOrder Int      @default(0)
  createdAt DateTime @default(now())

  class     Class      @relation(fields: [classId], references: [id], onDelete: Cascade)
  decks     Deck[]
  quizSets  QuizSet[]
  shareLink ShareLink?
}

model SpacedRepetitionSet {
  id             String   @id @default(uuid())
  classId        String
  name           String
  description    String?
  newCardsPerDay Int      @default(30)
  sortOrder      Int      @default(0)
  createdAt      DateTime @default(now())
  updatedAt      DateTime @updatedAt

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

  @@index([classId, sortOrder])
}

model SpacedRepetitionSetDeck {
  setId     String
  deckId    String
  sortOrder Int      @default(0)
  addedAt   DateTime @default(now())

  set  SpacedRepetitionSet @relation(fields: [setId], references: [id], onDelete: Cascade)
  deck Deck                @relation(fields: [deckId], references: [id], onDelete: Cascade)

  @@id([setId, deckId])
  @@index([deckId])
}

model SpacedRepetitionCardState {
  id              String    @id @default(uuid())
  setId           String
  flashcardId     String
  due             DateTime
  stability       Float
  difficulty      Float
  elapsedDays     Int
  scheduledDays   Int
  learningSteps   Int       @default(0)
  reps            Int
  lapses          Int
  state           Int
  firstReviewedAt DateTime  @default(now())
  lastReview      DateTime?
  createdAt       DateTime  @default(now())
  updatedAt       DateTime  @updatedAt

  set       SpacedRepetitionSet @relation(fields: [setId], references: [id], onDelete: Cascade)
  flashcard Flashcard           @relation(fields: [flashcardId], references: [id], onDelete: Cascade)

  @@unique([setId, flashcardId])
  @@index([setId, due])
  @@index([setId, firstReviewedAt])
  @@index([flashcardId])
}