// 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[]
  // Back-relation for PurchaseOrder.receivedById — an Employee can be the
  // receiver on multiple POs over time.
  purchaseOrdersReceived PurchaseOrder[]
  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 Assignment relation yet — that entity doesn't exist yet (see "Việc còn
// dở" in CLAUDE.md). warrantyEndDate is nullable: not every asset has known
// warranty terms at intake time (smallest sensible assumption — doesn't
// block creation). purchaseOrderId is a nullable FK to PurchaseOrder — see
// docs/asset-license-management.md's "## PurchaseOrder (gộp Receipt)"
// Traceability bullet: supply-side traceability ("which PO did this asset
// item come in through"). Nullable because not every AssetItem goes through
// a formal PO (e.g. historical stock predating the system). Set at
// intake/creation time only — no update endpoint for this field yet, same
// precedent as License.vendorId being set-at-creation with no PATCH.
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)
  purchaseOrderId String?         @map("purchase_order_id") @db.Uuid
  purchaseOrder   PurchaseOrder?  @relation(fields: [purchaseOrderId], references: [id])
  createdAt       DateTime        @default(now()) @map("created_at") @db.Timestamptz(6)

  @@map("asset_items")
}

// Fixed, closed set of 2 values tied to the domain (see docs/
// asset-license-management.md's "Data model (sơ bộ)" table) — native
// Postgres enum, same rationale as RequestType/AssetItemStatus above.
enum LicenseType {
  perpetual
  subscription
}

// Software license inventory — see docs/asset-license-management.md's "Data
// model (sơ bộ)" table (tên, vendor, tổng seat, seat đã dùng, ngày hết hạn,
// loại). `vendorId` was a free-text `vendor` String until the "## Vendor
// (chốt 2026-08-02)" retrofit — same precedent as Request.employeeId
// (string -> FK once Employee existed). No production `License` data
// existed at the time of this change, so this was a plain column-type
// migration, not a backfill. `seatsUsed` is a stored counter (defaults to 0
// at creation), not a computed value — it will only ever be set to 0 here
// since Assignment (the thing that would consume seats) doesn't exist yet.
// `expiryDate` is nullable: perpetual licenses never expire, only
// subscription licenses usually have one. `purchaseOrderId` is a nullable FK
// to PurchaseOrder — see docs/asset-license-management.md's "## PurchaseOrder
// (gộp Receipt)" Traceability bullet: supply-side traceability ("which PO
// did this license come in through"). Nullable because not every License
// goes through a formal PO. Mirrors AssetItem.purchaseOrderId's just-merged
// pattern exactly — same nullable-FK shape, set at creation time only, no
// update endpoint for this field yet.
model License {
  id              String         @id @default(uuid()) @db.Uuid
  name            String
  vendorId        String         @map("vendor_id") @db.Uuid
  vendor          Vendor         @relation(fields: [vendorId], references: [id])
  seatsTotal      Int            @map("seats_total")
  seatsUsed       Int            @default(0) @map("seats_used")
  expiryDate      DateTime?      @map("expiry_date") @db.Date
  licenseType     LicenseType    @map("license_type")
  purchaseOrderId String?        @map("purchase_order_id") @db.Uuid
  purchaseOrder   PurchaseOrder? @relation(fields: [purchaseOrderId], references: [id])
  createdAt       DateTime       @default(now()) @map("created_at") @db.Timestamptz(6)

  @@map("licenses")
}

// Purchasing counterparty — see docs/asset-license-management.md's "## Vendor
// (chốt 2026-08-02)". Deliberately independent of AssetModel.manufacturer
// (OEM, e.g. "Dell") — Vendor is the reseller/distributor actually bought
// from (e.g. "FPT Trading"), a different concept that isn't always the same
// company. `licenses` is the back-relation from the License.vendor ->
// License.vendorId retrofit (same doc section). `purchaseOrders` is the
// back-relation from PurchaseOrder.vendorId (see "## PurchaseOrder (gộp
// Receipt) (chốt 2026-08-02)"). taxCode/notes are nullable — not every
// vendor record has a known VN tax code or extra notes at creation time.
model Vendor {
  id             String          @id @default(uuid()) @db.Uuid
  name           String
  contactEmail   String          @map("contact_email")
  contactPhone   String          @map("contact_phone")
  address        String
  taxCode        String?         @map("tax_code")
  notes          String?
  createdAt      DateTime        @default(now()) @map("created_at") @db.Timestamptz(6)
  licenses       License[]
  purchaseOrders PurchaseOrder[]

  @@map("vendors")
}

// Purchasing document — see docs/asset-license-management.md's "##
// PurchaseOrder (gộp Receipt) (chốt 2026-08-02)". Deliberately absorbs what
// would otherwise be a separate `Receipt` entity: receiving is just part of
// this row's own state (`receivedAt`/`receivedBy`), not a separate table to
// reconcile against. No `status` field — status is inferred from linked
// `Request`s (Ordered -> Received -> Delivered), not stored here, to avoid
// two sources of truth. No cost/price fields — stakeholder said explicitly
// PurchaseOrder doesn't need to track money, only "which asset/license
// belongs to which PO". Receiving is all-or-nothing per PO (no partial
// receipt tracking) — a deliberate simplification, see doc for the
// stakeholder-accepted tradeoff. `receivedAt`/`receivedBy` are both
// nullable and must be co-null/co-set together (both-null = not yet
// received) — enforced at the Zod layer (src/lib/purchase-orders.ts), not a
// DB constraint, same approach as other cross-field invariants in this
// codebase (e.g. Assignment's assetItemId/licenseId XOR, not built yet).
// `assetItems` is the back-relation from the AssetItem.purchaseOrderId
// retrofit (supply-side traceability, same doc section). `licenses` is the
// back-relation from the License.purchaseOrderId retrofit (same doc
// section, same rationale). Request back-references are NOT part of this
// change — out of scope for this task.
model PurchaseOrder {
  id           String      @id @default(uuid()) @db.Uuid
  vendorId     String      @map("vendor_id") @db.Uuid
  vendor       Vendor      @relation(fields: [vendorId], references: [id])
  orderDate    DateTime    @map("order_date") @db.Timestamptz(6)
  expectedDate DateTime    @map("expected_date") @db.Timestamptz(6)
  receivedAt   DateTime?   @map("received_at") @db.Timestamptz(6)
  receivedById String?     @map("received_by") @db.Uuid
  receivedBy   Employee?   @relation(fields: [receivedById], references: [id])
  createdAt    DateTime    @default(now()) @map("created_at") @db.Timestamptz(6)
  assetItems   AssetItem[]
  licenses     License[]

  @@map("purchase_orders")
}

// 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")
}