// ReLoop v2 schema — persona forgetting curve model
// Generated fresh; old FSRS fields dropped. DB reset via `prisma migrate reset`.
//
// NOTE: After editing tag-relation onDelete rules, run:
//   prisma migrate dev --name relax_tag_cascade
// on the Dev VM before deploying. This migrates SkillSnapshot.tagId to nullable
// and sets both SkillSnapshot and StudyLog tag FKs to ON DELETE SET NULL.

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

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

// ─── Enums ────────────────────────────────────────────────────────

enum Persona {
  senior
  mid
  junior
  crammer
}

enum ReviewIntensity {
  strict
  moderate
  relaxed
}

enum StudyResult {
  correct
  incorrect
  partial
}

enum ReviewStatus {
  pending
  done
  skipped
  expired
}

enum SubscriptionTier {
  free
  pro
  school
}

// ─── Models ───────────────────────────────────────────────────────

model User {
  id                Int              @id @default(autoincrement())
  email             String           @unique
  password          String
  nickname          String
  persona           Persona          @default(mid)
  currentGrade      Int?
  targetGrade       Int?
  reviewIntensity   ReviewIntensity  @default(moderate)
  onboardedAt       DateTime?
  subscriptionTier  SubscriptionTier @default(free)
  subscriptionUntil DateTime?
  createdAt         DateTime         @default(now())
  updatedAt         DateTime         @updatedAt

  subjects        Subject[]
  studyLogs       StudyLog[]
  reviewSchedules ReviewSchedule[]
  skillSnapshots  SkillSnapshot[]

  @@map("users")
}

model Subject {
  id        Int      @id @default(autoincrement())
  name      String
  color     String   @default("#6366f1")
  userId    Int
  user      User     @relation(fields: [userId], references: [id], onDelete: Cascade)
  createdAt DateTime @default(now())

  tags      Tag[]
  studyLogs StudyLog[]

  @@unique([userId, name])
  @@index([userId])
  @@map("subjects")
}

model Tag {
  id        Int      @id @default(autoincrement())
  name      String
  subjectId Int
  subject   Subject  @relation(fields: [subjectId], references: [id], onDelete: Cascade)
  createdAt DateTime @default(now())

  studyLogs      StudyLog[]
  skillSnapshots SkillSnapshot[]

  @@unique([subjectId, name])
  @@index([subjectId])
  @@map("tags")
}

model StudyLog {
  id              Int         @id @default(autoincrement())
  userId          Int
  user            User        @relation(fields: [userId], references: [id], onDelete: Cascade)
  subjectId       Int
  subject         Subject     @relation(fields: [subjectId], references: [id])
  tagId           Int?
  tag             Tag?        @relation(fields: [tagId], references: [id], onDelete: SetNull)
  problemId       Int?
  problem         Problem?    @relation(fields: [problemId], references: [id], onDelete: SetNull)

  title           String
  difficulty      Float
  baseCorrectRate Float?
  result          StudyResult
  memo            String?     @db.Text
  studiedAt       DateTime    @default(now())
  timeSpent       Int?

  reviewSchedules ReviewSchedule[]

  @@index([userId, studiedAt])
  @@index([subjectId])
  @@index([tagId])
  @@index([problemId])
  @@map("study_logs")
}

model ReviewSchedule {
  id          Int          @id @default(autoincrement())
  userId      Int
  user        User         @relation(fields: [userId], references: [id], onDelete: Cascade)
  studyLogId  Int
  studyLog    StudyLog     @relation(fields: [studyLogId], references: [id], onDelete: Cascade)

  scheduledAt DateTime
  reviewedAt  DateTime?
  result      StudyResult?
  iteration   Int          @default(0)
  predictedP  Float?
  status      ReviewStatus @default(pending)

  createdAt   DateTime @default(now())
  updatedAt   DateTime @updatedAt

  @@index([userId, status, scheduledAt])
  @@index([studyLogId])
  @@map("review_schedules")
}

/// 평가원/수능/모의평가 등 공개 기출 문제를 담는 컨테이너.
/// Subject 와 별개로 존재 — 모든 사용자가 공유하며 읽기 전용.
model ProblemSet {
  id          Int      @id @default(autoincrement())
  title       String
  /// examType 허용값: "sat" | "mock-june" | "mock-sept" | "academy"
  examType    String
  year        Int
  subjectName String
  sourceUrl   String?
  /// 영어 과목의 듣기 음원 파일 경로 배열 (data/kice/ 상대경로).
  /// 예: ["2026/영어/영어영역듣기평가음원/01_문제 01.mp3", ...]
  audioUrls   Json?
  createdAt   DateTime @default(now())

  problems    Problem[]
  passages    Passage[]

  @@unique([year, examType, subjectName])
  @@map("problem_sets")
}

model Problem {
  id              Int        @id @default(autoincrement())
  problemSetId    Int
  problemSet      ProblemSet @relation(fields: [problemSetId], references: [id], onDelete: Cascade)
  number          Int
  title           String
  difficulty      Float
  baseCorrectRate Float?
  topic           String?
  /// KICE 파싱 결과 — 본문 텍스트 (선택지 제외)
  bodyText        String?    @db.Text
  /// KICE 파싱 결과 — 선택지 객체 { "1": "...", "2": "...", "3": "...", "4": "...", "5": "..." }
  choices         Json?
  /// KICE 파싱 결과 — 정답 번호 1..5
  answerNumber    Int?
  /// 공통 지문 FK (국어 독서/문학, 영어 지문, 사탐 자료 등)
  passageId       Int?
  passage         Passage?   @relation(fields: [passageId], references: [id], onDelete: SetNull)
  /// 파싱 엣지케이스 플래그 — 수동 보정 대상
  needsReview     Boolean    @default(false)
  createdAt       DateTime   @default(now())

  studyLogs       StudyLog[]

  @@unique([problemSetId, number])
  @@index([problemSetId])
  @@index([passageId])
  @@map("problems")
}

/// 평가원 기출의 [N~M] 공통 지문을 담는 컨테이너.
/// 여러 Problem 이 같은 Passage 를 공유할 수 있음.
model Passage {
  id            Int        @id @default(autoincrement())
  problemSetId  Int
  problemSet    ProblemSet @relation(fields: [problemSetId], references: [id], onDelete: Cascade)
  startNumber   Int
  endNumber     Int
  bodyText      String     @db.Text
  createdAt     DateTime   @default(now())

  problems      Problem[]

  @@index([problemSetId])
  @@map("passages")
}

model SkillSnapshot {
  id            Int      @id @default(autoincrement())
  userId        Int
  user          User     @relation(fields: [userId], references: [id], onDelete: Cascade)
  tagId         Int?
  tag           Tag?     @relation(fields: [tagId], references: [id], onDelete: SetNull)

  s0            Float
  lastUpdatedAt DateTime @default(now())
  sampleCount   Int      @default(0)

  @@unique([userId, tagId])
  @@index([userId])
  @@map("skill_snapshots")
}