// Message model

enum MessageRole {
  user
  assistant
  system
}

model Message {
  id              String      @id @default(uuid())
  role            MessageRole
  content         String
  tokensUsed      Int?
  model           String?
  metadata        Json?
  createdAt       DateTime    @default(now())

  conversationId  String
  conversation    Conversation @relation(fields: [conversationId], references: [id], onDelete: Cascade)

  @@index([conversationId])
  @@index([createdAt])
  @@index([conversationId, createdAt])
}