// 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 = ["postgresqlExtensions"]
}

datasource db {
  provider   = "postgresql"
  url        = env("DATABASE_URL")
  extensions = [pgvector(map: "vector"), uuidOssp(map: "uuid-ossp")]
}

// ============================================
// User & Authentication
// ============================================

model User {
  id              String   @id @default(uuid())
  supabaseId      String   @unique @map("supabase_id")
  email           String   @unique
  name            String?
  avatarUrl       String?  @map("avatar_url")
  
  // Subscription
  subscriptionTier SubscriptionTier @default(FREE) @map("subscription_tier")
  
  // Timestamps
  createdAt       DateTime @default(now()) @map("created_at")
  updatedAt       DateTime @updatedAt @map("updated_at")
  
  // Role
  role            UserRole         @default(USER)
  
  // Relations
  settings        UserSettings?
  subscription    Subscription?
  courses         Course[]         @relation("AuthoredCourses")
  enrollments     Enrollment[]
  lessonProgress  LessonProgress[]
  purchases       Purchase[]
  reviews         Review[]
  generations     CourseGeneration[]
  groupMembers    GroupMember[]
  groupMessages   GroupMessage[]
  homeworkSubmissions HomeworkSubmission[]
  supportTickets  SupportTicket[]
  ticketMessages  TicketMessage[]
  
  @@map("users")
}

model UserSettings {
  id                String   @id @default(uuid())
  userId            String   @unique @map("user_id")
  
  // AI Settings - user can override default model
  customAiModel     String?  @map("custom_ai_model") // e.g., "qwen/qwen3-coder-next"
  
  // Notification settings
  emailNotifications Boolean @default(true) @map("email_notifications")
  marketingEmails    Boolean @default(false) @map("marketing_emails")
  
  // UI Preferences
  theme             String   @default("system") // "light", "dark", "system"
  language          String   @default("ru")
  
  createdAt         DateTime @default(now()) @map("created_at")
  updatedAt         DateTime @updatedAt @map("updated_at")
  
  // Relations
  user              User     @relation(fields: [userId], references: [id], onDelete: Cascade)
  
  @@map("user_settings")
}

enum UserRole {
  USER
  MODERATOR
  ADMIN
}

// ============================================
// Subscription & Payments
// ============================================

enum SubscriptionTier {
  FREE
  PREMIUM
  PRO
}

model Subscription {
  id                    String           @id @default(uuid())
  userId                String           @unique @map("user_id")
  tier                  SubscriptionTier @default(FREE)
  
  // Stripe
  stripeCustomerId      String?          @unique @map("stripe_customer_id")
  stripeSubscriptionId  String?          @unique @map("stripe_subscription_id")
  stripePriceId         String?          @map("stripe_price_id")
  
  // Billing cycle
  currentPeriodStart    DateTime?        @map("current_period_start")
  currentPeriodEnd      DateTime?        @map("current_period_end")
  cancelAtPeriodEnd     Boolean          @default(false) @map("cancel_at_period_end")
  
  // Usage tracking
  coursesCreatedThisMonth Int            @default(0) @map("courses_created_this_month")
  usageResetDate        DateTime?        @map("usage_reset_date")
  
  // Status
  status                String           @default("active") // active, canceled, past_due, incomplete
  
  createdAt             DateTime         @default(now()) @map("created_at")
  updatedAt             DateTime         @updatedAt @map("updated_at")
  
  // Relations
  user                  User             @relation(fields: [userId], references: [id], onDelete: Cascade)
  
  @@map("subscriptions")
}

// ============================================
// Courses
// ============================================

enum CourseStatus {
  DRAFT
  GENERATING
  PENDING_REVIEW
  PUBLISHED
  REJECTED
  ARCHIVED
}

model Course {
  id              String       @id @default(uuid())
  authorId        String       @map("author_id")
  
  // Basic info
  title           String
  description     String?      @db.Text
  slug            String       @unique
  coverImage      String?      @map("cover_image")
  
  // Status
  status          CourseStatus @default(DRAFT)
  
  // Marketplace
  isPublished     Boolean      @default(false) @map("is_published")
  price           Decimal?     @db.Decimal(10, 2) // null = free course
  currency        String       @default("USD")
  
  // Author verification — author checked the content and vouches for quality
  isVerified      Boolean      @default(false) @map("is_verified")
  
  // Categorization
  categoryId      String?      @map("category_id")
  tags            String[]     @default([])
  difficulty      String?      // "beginner", "intermediate", "advanced"
  estimatedHours  Int?         @map("estimated_hours")
  
  // SEO & metadata
  metaTitle       String?      @map("meta_title")
  metaDescription String?      @map("meta_description")
  
  // Stats
  viewCount       Int          @default(0) @map("view_count")
  enrollmentCount Int          @default(0) @map("enrollment_count")
  averageRating   Float?       @map("average_rating")
  
  // Timestamps
  publishedAt     DateTime?    @map("published_at")
  createdAt       DateTime     @default(now()) @map("created_at")
  updatedAt       DateTime     @updatedAt @map("updated_at")
  
  // Moderation
  moderationNote  String?      @db.Text @map("moderation_note")
  moderatedAt     DateTime?    @map("moderated_at")
  
  // Relations
  author          User         @relation("AuthoredCourses", fields: [authorId], references: [id], onDelete: Cascade)
  category        Category?    @relation(fields: [categoryId], references: [id])
  chapters        Chapter[]
  enrollments     Enrollment[]
  purchases       Purchase[]
  reviews         Review[]
  generation      CourseGeneration?
  groups          CourseGroup[]
  
  // Vector embedding for semantic search
  embedding       Unsupported("vector(1536)")?
  
  @@index([authorId])
  @@index([status])
  @@index([isPublished])
  @@index([categoryId])
  @@map("courses")
}

model Chapter {
  id          String   @id @default(uuid())
  courseId    String   @map("course_id")
  
  title       String
  description String?  @db.Text
  order       Int      @default(0)
  
  // Timestamps
  createdAt   DateTime @default(now()) @map("created_at")
  updatedAt   DateTime @updatedAt @map("updated_at")
  
  // Relations
  course      Course   @relation(fields: [courseId], references: [id], onDelete: Cascade)
  lessons     Lesson[]
  
  @@index([courseId])
  @@map("chapters")
}

model Lesson {
  id          String   @id @default(uuid())
  chapterId   String   @map("chapter_id")
  
  title       String
  content     Json?    // TipTap JSON content
  order       Int      @default(0)
  
  // Duration estimate
  durationMinutes Int? @map("duration_minutes")
  
  // Media
  videoUrl    String?  @map("video_url")
  
  // Timestamps
  createdAt   DateTime @default(now()) @map("created_at")
  updatedAt   DateTime @updatedAt @map("updated_at")
  
  // Relations
  chapter     Chapter  @relation(fields: [chapterId], references: [id], onDelete: Cascade)
  homework    Homework[]
  
  // Vector embedding for semantic search
  embedding   Unsupported("vector(1536)")?
  
  @@index([chapterId])
  @@map("lessons")
}

// ============================================
// AI Course Generation
// ============================================

enum GenerationStatus {
  PENDING
  ANALYZING
  ASKING_QUESTIONS
  WAITING_FOR_ANSWERS
  RESEARCHING
  GENERATING_OUTLINE
  GENERATING_CONTENT
  COMPLETED
  FAILED
  CANCELLED
}

model CourseGeneration {
  id              String           @id @default(uuid())
  userId          String           @map("user_id")
  courseId        String?          @unique @map("course_id")
  
  // Input
  initialPrompt   String           @db.Text @map("initial_prompt")
  
  // AI Configuration
  aiModel         String           @map("ai_model")
  
  // Status & Progress
  status          GenerationStatus @default(PENDING)
  progress        Int              @default(0) // 0-100
  currentStep     String?          @map("current_step")
  
  // Clarifying questions flow
  questions       Json?            // Array of questions to ask
  answers         Json?            // User's answers
  
  // Generated outline (intermediate state)
  generatedOutline Json?           @map("generated_outline")
  
  // Error handling
  errorMessage    String?          @db.Text @map("error_message")
  retryCount      Int              @default(0) @map("retry_count")
  
  // Job tracking
  jobId           String?          @map("job_id") // BullMQ job ID
  
  // Timestamps
  startedAt       DateTime?        @map("started_at")
  completedAt     DateTime?        @map("completed_at")
  createdAt       DateTime         @default(now()) @map("created_at")
  updatedAt       DateTime         @updatedAt @map("updated_at")
  
  // Relations
  user            User             @relation(fields: [userId], references: [id], onDelete: Cascade)
  course          Course?          @relation(fields: [courseId], references: [id], onDelete: SetNull)
  
  @@index([userId])
  @@index([status])
  @@map("course_generations")
}

// ============================================
// Marketplace (Future)
// ============================================

model Category {
  id          String   @id @default(uuid())
  name        String   @unique
  slug        String   @unique
  description String?  @db.Text
  icon        String?
  parentId    String?  @map("parent_id")
  order       Int      @default(0)
  
  createdAt   DateTime @default(now()) @map("created_at")
  updatedAt   DateTime @updatedAt @map("updated_at")
  
  // Relations
  parent      Category?  @relation("CategoryHierarchy", fields: [parentId], references: [id])
  children    Category[] @relation("CategoryHierarchy")
  courses     Course[]
  
  @@map("categories")
}

model Purchase {
  id              String   @id @default(uuid())
  userId          String   @map("user_id")
  courseId        String   @map("course_id")
  
  // Payment details
  amount          Decimal  @db.Decimal(10, 2)
  currency        String   @default("USD")
  stripePaymentId String?  @map("stripe_payment_id")
  
  // Status
  status          String   @default("completed") // pending, completed, refunded
  
  // Access
  accessGrantedAt DateTime @default(now()) @map("access_granted_at")
  accessExpiresAt DateTime? @map("access_expires_at") // null = lifetime access
  
  createdAt       DateTime @default(now()) @map("created_at")
  updatedAt       DateTime @updatedAt @map("updated_at")
  
  // Relations
  user            User     @relation(fields: [userId], references: [id], onDelete: Cascade)
  course          Course   @relation(fields: [courseId], references: [id], onDelete: Cascade)
  
  @@unique([userId, courseId])
  @@index([userId])
  @@index([courseId])
  @@map("purchases")
}

model Review {
  id        String   @id @default(uuid())
  userId    String   @map("user_id")
  courseId  String   @map("course_id")
  
  rating    Int      // 1-5
  title     String?
  content   String?  @db.Text
  
  // Moderation
  isApproved Boolean @default(true) @map("is_approved")
  
  createdAt DateTime @default(now()) @map("created_at")
  updatedAt DateTime @updatedAt @map("updated_at")
  
  // Relations
  user      User     @relation(fields: [userId], references: [id], onDelete: Cascade)
  course    Course   @relation(fields: [courseId], references: [id], onDelete: Cascade)
  
  @@unique([userId, courseId])
  @@index([courseId])
  @@map("reviews")
}

// ============================================
// Enrollment & Progress
// ============================================

model Enrollment {
  id          String    @id @default(uuid())
  userId      String    @map("user_id")
  courseId     String    @map("course_id")
  
  // Progress
  progress    Int       @default(0) // 0-100
  completedAt DateTime? @map("completed_at")
  
  // Certificate
  certificateUrl String? @map("certificate_url")
  
  createdAt   DateTime  @default(now()) @map("created_at")
  updatedAt   DateTime  @updatedAt @map("updated_at")
  
  // Relations
  user        User      @relation(fields: [userId], references: [id], onDelete: Cascade)
  course      Course    @relation(fields: [courseId], references: [id], onDelete: Cascade)
  lessons     LessonProgress[]
  
  @@unique([userId, courseId])
  @@index([userId])
  @@index([courseId])
  @@map("enrollments")
}

model LessonProgress {
  id            String    @id @default(uuid())
  userId        String    @map("user_id")
  enrollmentId  String    @map("enrollment_id")
  lessonId      String    @map("lesson_id")
  
  completedAt   DateTime? @map("completed_at")
  quizScore     Int?      @map("quiz_score") // 0-100
  
  createdAt     DateTime  @default(now()) @map("created_at")
  
  // Relations
  user          User       @relation(fields: [userId], references: [id], onDelete: Cascade)
  enrollment    Enrollment @relation(fields: [enrollmentId], references: [id], onDelete: Cascade)
  
  @@unique([userId, lessonId])
  @@index([enrollmentId])
  @@map("lesson_progress")
}

// ============================================
// Course Groups & Collaboration
// ============================================

model CourseGroup {
  id          String   @id @default(uuid())
  courseId    String   @map("course_id")
  name        String
  description String?  @db.Text
  
  createdAt   DateTime @default(now()) @map("created_at")
  updatedAt   DateTime @updatedAt @map("updated_at")
  
  course      Course   @relation(fields: [courseId], references: [id], onDelete: Cascade)
  members     GroupMember[]
  messages    GroupMessage[]
  
  @@index([courseId])
  @@map("course_groups")
}

model GroupMember {
  id        String   @id @default(uuid())
  groupId   String   @map("group_id")
  userId    String   @map("user_id")
  role      String   @default("student") // "teacher", "student"
  
  joinedAt  DateTime @default(now()) @map("joined_at")
  
  group     CourseGroup @relation(fields: [groupId], references: [id], onDelete: Cascade)
  user      User     @relation(fields: [userId], references: [id], onDelete: Cascade)
  
  @@unique([groupId, userId])
  @@map("group_members")
}

model GroupMessage {
  id        String   @id @default(uuid())
  groupId   String   @map("group_id")
  userId    String   @map("user_id")
  content   String   @db.Text
  
  createdAt DateTime @default(now()) @map("created_at")
  
  group     CourseGroup @relation(fields: [groupId], references: [id], onDelete: Cascade)
  user      User     @relation(fields: [userId], references: [id], onDelete: Cascade)
  
  @@index([groupId])
  @@map("group_messages")
}

// ============================================
// Homework & Assignments
// ============================================

model Homework {
  id              String   @id @default(uuid())
  lessonId        String   @map("lesson_id")
  title           String
  description     String   @db.Text
  dueDate         DateTime? @map("due_date")
  
  createdAt       DateTime @default(now()) @map("created_at")
  updatedAt       DateTime @updatedAt @map("updated_at")
  
  lesson          Lesson   @relation(fields: [lessonId], references: [id], onDelete: Cascade)
  submissions     HomeworkSubmission[]
  
  @@index([lessonId])
  @@map("homework")
}

model HomeworkSubmission {
  id            String   @id @default(uuid())
  homeworkId    String   @map("homework_id")
  userId        String   @map("user_id")
  content       String   @db.Text
  
  // AI grading
  aiScore       Int?     @map("ai_score") // 0-100
  aiFeedback    String?  @db.Text @map("ai_feedback")
  
  // Teacher grading
  teacherScore  Int?     @map("teacher_score") // 0-100
  teacherFeedback String? @db.Text @map("teacher_feedback")
  
  submittedAt   DateTime @default(now()) @map("submitted_at")
  gradedAt      DateTime? @map("graded_at")
  
  homework      Homework @relation(fields: [homeworkId], references: [id], onDelete: Cascade)
  user          User     @relation(fields: [userId], references: [id], onDelete: Cascade)
  
  @@unique([homeworkId, userId])
  @@map("homework_submissions")
}

// ============================================
// Support Tickets
// ============================================

model SupportTicket {
  id          String   @id @default(uuid())
  userId      String   @map("user_id")
  title       String
  status      String   @default("open") // "open", "in_progress", "resolved", "closed"
  priority    String   @default("normal") // "low", "normal", "high"
  
  createdAt   DateTime @default(now()) @map("created_at")
  updatedAt   DateTime @updatedAt @map("updated_at")
  
  user        User     @relation(fields: [userId], references: [id], onDelete: Cascade)
  messages    TicketMessage[]
  
  @@index([userId])
  @@index([status])
  @@map("support_tickets")
}

model TicketMessage {
  id        String   @id @default(uuid())
  ticketId  String   @map("ticket_id")
  userId    String   @map("user_id")
  content   String   @db.Text
  isStaff   Boolean  @default(false) @map("is_staff")
  
  createdAt DateTime @default(now()) @map("created_at")
  
  ticket    SupportTicket @relation(fields: [ticketId], references: [id], onDelete: Cascade)
  user      User     @relation(fields: [userId], references: [id], onDelete: Cascade)
  
  @@index([ticketId])
  @@map("ticket_messages")
}