// Prisma schema — source of truth for the DB schema going forward,
// replacing the hand-written `CREATE TABLE IF NOT EXISTS` migration that
// used to live in src/lib/db.ts. Only the Request entity (Draft state only)
// exists so far — see ../processes/asset-license-management.md for the full
// data model / state machine this will grow into.

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

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

// Fixed, closed set of 2 values tied to the domain (asset vs license
// request) — a native Postgres enum is the idiomatic Prisma mapping here.
// This replaces the old `type TEXT NOT NULL CHECK (type IN ('asset',
// 'license'))` column with `type "RequestType" NOT NULL` backed by a
// `CREATE TYPE "RequestType" AS ENUM ('asset', 'license')`. Same validation
// guarantee (only these two values are ever storable), different mechanism.
// See feature-implementer report for the enum-vs-TEXT+CHECK trade-off.
enum RequestType {
  asset
  license
}

model Request {
  id         String      @id @default(uuid()) @db.Uuid
  // Was a free-text String with no referential integrity — retrofitted to a
  // real FK once Employee records existed to point to (see Employee model
  // above). No production data existed at the time of this change (`requests`
  // table was empty), so this was a plain column-type migration, not a
  // backfill.
  employeeId String      @map("employee_id") @db.Uuid
  employee   Employee    @relation(fields: [employeeId], references: [id])
  type       RequestType
  reason     String
  // Only the 'Draft' state is implemented so far. Deliberately kept as a
  // plain string (not an enum) until more states exist — see
  // src/lib/requests.ts's RequestStatus type.
  status     String      @default("Draft")
  createdAt  DateTime    @default(now()) @map("created_at") @db.Timestamptz(6)

  @@map("requests")
}

// Employee directory — see docs/asset-license-management.md's "Data model
// (sơ bộ)" table (id, tên, phòng ban, manager). `department` is deliberately
// a plain String for now, not a separate Department entity — that's a
// possible future normalization, not built yet. `managerId` is a nullable
// self-relation: top-level employees (no manager) have `managerId = null`.
model Employee {
  id         String     @id @default(uuid()) @db.Uuid
  name       String
  department String
  managerId  String?    @map("manager_id") @db.Uuid
  manager    Employee?  @relation("EmployeeManager", fields: [managerId], references: [id])
  reports    Employee[] @relation("EmployeeManager")
  requests   Request[]
  createdAt  DateTime   @default(now()) @map("created_at") @db.Timestamptz(6)

  @@map("employees")
}

// Fixed, closed set of 4 values tied to the domain (see docs/
// asset-license-management.md's "Data model (sơ bộ)" table) — native
// Postgres enum, same rationale as RequestType above.
enum AssetItemStatus {
  in_stock
  assigned
  repair
  retired
}

// Hardware inventory — see docs/asset-license-management.md's "Data model
// (sơ bộ)" table (serial number, model, ngày mua, bảo hành, trạng thái).
// No Vendor/Assignment relation yet — those entities don't exist yet
// (see "Việc còn dở" in CLAUDE.md), so this is a standalone entity for now,
// same starting shape as Employee before Request grew an FK to it.
// warrantyEndDate is nullable: not every asset has known warranty terms at
// intake time (smallest sensible assumption — doesn't block creation).
model AssetItem {
  id              String          @id @default(uuid()) @db.Uuid
  serialNumber    String          @unique @map("serial_number")
  model           String
  purchaseDate    DateTime        @map("purchase_date") @db.Date
  warrantyEndDate DateTime?       @map("warranty_end_date") @db.Date
  status          AssetItemStatus @default(in_stock)
  createdAt       DateTime        @default(now()) @map("created_at") @db.Timestamptz(6)

  @@map("asset_items")
}

// Minimal internal auth accounts — NOT company SSO (deliberately ruled out,
// see CLAUDE.md / auth decision notes). A handful of trusted IT staff
// accounts, created by hand via scripts/create-user.ts, no self-registration.
// Auth.js v5 Credentials provider + JWT session strategy is used, so this is
// intentionally just a plain user table — no `Account`/`Session`/
// `VerificationToken` models, those exist for OAuth account linking / DB
// session strategy, neither of which applies here. No `role` field either:
// permission model is flat for now (any logged-in user can do anything).
model User {
  id           String   @id @default(uuid()) @db.Uuid
  email        String   @unique
  passwordHash String   @map("password_hash")
  name         String
  createdAt    DateTime @default(now()) @map("created_at") @db.Timestamptz(6)

  @@map("users")
}