// This is your Prisma schema file,
// learn more about it in the docs: https://pris.ly/d/prisma-schema

// Looking for ways to speed up your queries, or scale easily with your serverless or edge functions?
// Try Prisma Accelerate: https://pris.ly/cli/accelerate-init

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

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

/* ──────────────────────────────────────────
   Rollen / Rechte
   ────────────────────────────────────────── */

model User {
  id        String      @id @default(cuid())
  email     String      @unique
  username  String      @unique
  name      String?
  passwordHash String

  roles     UserRole[]

  // Audit-Relations
  devicesCreated Device[]       @relation("DeviceCreatedBy")
  devicesUpdated Device[]       @relation("DeviceUpdatedBy")
  historyEntries DeviceHistory[] @relation("DeviceHistoryChangedBy")

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

model Role {
  id    String     @id @default(cuid())
  name  String     @unique      // z.B. "ADMIN", "INVENTUR", "READONLY"
  users UserRole[]
}

// Join-Tabelle User <-> Role (Many-to-Many)
model UserRole {
  user   User @relation(fields: [userId], references: [id])
  userId String

  role   Role @relation(fields: [roleId], references: [id])
  roleId String

  assignedAt DateTime @default(now())

  @@id([userId, roleId])
}

/* ──────────────────────────────────────────
   Stammdaten: Gruppen & Standorte
   ────────────────────────────────────────── */

model DeviceGroup {
  id      String   @id @default(cuid())
  name    String   @unique
  devices Device[]
}

model Location {
  id      String   @id @default(cuid())
  name    String   // z.B. "Raum 1.12", "Lager Keller"
  devices Device[]
}

/* ──────────────────────────────────────────
   Geräte / Inventar
   ────────────────────────────────────────── */

model Device {
  id              String   @id @default(cuid())

  // Fachliche Felder
  name            String               // Anzeigename / Bezeichnung des Geräts
  manufacturer    String               // Hersteller
  model           String               // Modellbezeichnung
  inventoryNumber String   @unique     // Inventar-Nummer
  serialNumber    String?              // Seriennummer
  productNumber   String?              // Produktnummer
  comment         String?

  ipv4Address     String?  @unique     // IPv4-Adresse
  ipv6Address     String?  @unique     // IPv6-Adresse
  macAddress      String?  @unique     // MAC-Adresse
  username        String?  @unique     // Benutzername
  passwordHash    String?  @unique     // Passwort

  // Beziehungen
  group     DeviceGroup? @relation(fields: [groupId], references: [id])
  groupId   String?

  location  Location?    @relation(fields: [locationId], references: [id])
  locationId String?

  // Audit-Felder
  createdAt DateTime @default(now())
  updatedAt DateTime @updatedAt

  createdBy   User?  @relation("DeviceCreatedBy", fields: [createdById], references: [id])
  createdById String?

  updatedBy   User?  @relation("DeviceUpdatedBy", fields: [updatedById], references: [id])
  updatedById String?

  // Historie
  history DeviceHistory[]

  @@index([inventoryNumber])
  @@index([groupId])
  @@index([locationId])
}

/* ──────────────────────────────────────────
   History / Änderungsverlauf
   ────────────────────────────────────────── */

enum DeviceChangeType {
  CREATED
  UPDATED
  DELETED
}

model DeviceHistory {
  id         String           @id @default(cuid())

  device     Device           @relation(fields: [deviceId], references: [id])
  deviceId   String

  changeType DeviceChangeType

  // Snapshot der Gerätedaten zum Zeitpunkt der Änderung
  // z.B. { inventoryNumber, serialNumber, productNumber, groupId, locationId, comment, ... }
  snapshot   Json

  changedAt  DateTime         @default(now())

  changedBy   User?           @relation("DeviceHistoryChangedBy", fields: [changedById], references: [id])
  changedById String?

  @@index([deviceId, changedAt])
}