// 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")
  // Nullable FK to PurchaseOrder — see docs/asset-license-management.md's
  // "## PurchaseOrder (gộp Receipt)" Traceability bullet. Semantically the
  // DEMAND side, unlike AssetItem.purchaseOrderId/License.purchaseOrderId
  // (supply-side intake): this records "which approved Request got grouped
  // into this PO", not "which PO did this item come in through". Shape is
  // identical to those two though — nullable FK, set at creation time only,
  // no update endpoint for this field yet, same P2003-on-insert handling.
  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("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[]
  // Back-relation for Assignment.employeeId — an Employee can hold multiple
  // Assignments (assets/licenses) over time, including several active ones
  // at once (e.g. a laptop + a license seat simultaneously).
  assignments            Assignment[]
  // Back-relation for InventoryScan.assignedEmployeeId — see InventoryScan's
  // comment. An Employee can have multiple scanned items (workstation +
  // monitor + controller, etc.) attributed to them from the office-move
  // inventory walk.
  inventoryScans         InventoryScan[]
  createdAt              DateTime        @default(now()) @map("created_at") @db.Timestamptz(6)

  @@map("employees")
}

// Fixed, closed set of 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. `lost` added
// 2026-08-25 (ALTER TYPE ... ADD VALUE, not a table -- see the
// 2026-08-24/25 discussion in CLAUDE.md on why this stays an enum: the
// values are read directly by business logic, e.g. createAssignment()'s
// `status !== "in_stock"` gate, not just display labels). `assigned`
// renamed to `in_use` same day (ALTER TYPE ... RENAME VALUE) -- "assigned"
// implied a specific person always holds it, but createAssignment() only
// requires in_stock -> the enum value itself, and ~158 real-imported items
// have this status with no Assignment row at all (shared/unowned
// equipment) -- "in_use" doesn't carry that false implication.
enum AssetItemStatus {
  in_stock
  in_use
  repair
  retired
  lost
}

// 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.
// `modelId` was a free-text `model` String until the "Cập nhật 2026-08-02
// (2)" retrofit (docs/asset-license-management.md's "Ràng buộc dữ liệu"
// bullet) — same precedent as Request.employeeId/License.vendorId (string
// -> FK once the referenced entity existed). No production `AssetItem` data
// existed at the time of this change, so this was a plain column-type
// migration, not a backfill. Required (not nullable) — every AssetItem must
// belong to a real AssetModel. AssetItem deliberately does NOT carry its own
// `categoryId` — category is derived via `modelId -> AssetModel.categoryId`
// to avoid two sources of truth that could drift apart.
model AssetItem {
  id                 String               @id @default(uuid()) @db.Uuid
  serialNumber       String               @unique @map("serial_number")
  // Company-assigned physical tag (e.g. "DANLAP001", printed on a sticker
  // on the device) -- 2026-08-24, added when bulk-importing the real
  // ServiceNow ITAM export (see docs/asset-license-management.md). Was
  // only on InventoryScan before (the office-move walk feature); this is
  // the same concept but on the actual asset record, not a move-day scan.
  // Nullable (a manually-entered new purchase may not have one yet) but
  // unique when present -- the real export had 613/613 unique, non-null
  // tags, same integrity guarantee as serialNumber.
  assetTag           String?              @unique @map("asset_tag")
  modelId            String               @map("model_id") @db.Uuid
  model              AssetModel           @relation(fields: [modelId], references: [id])
  // Nullable as of 2026-08-24 (was NOT NULL) -- bulk-importing the real
  // ITAM export, some legacy rows have no known purchase date at all (no
  // "Order received" value in the source). Manual /assets create form
  // still requires it (a NEW purchase should always have a known date);
  // this only relaxes the DB/import path for historical data. Also means
  // AssetModel.warrantyMonths auto-fill (see createAssetItem()) can't
  // compute anything for these rows -- warrantyEndDate stays null too.
  purchaseDate       DateTime?            @map("purchase_date") @db.Date
  warrantyEndDate    DateTime?            @map("warranty_end_date") @db.Date
  status             AssetItemStatus      @default(in_stock)
  // Purchase cost, in `costCurrency`'s units -- added 2026-08-24 alongside
  // externalPoNumber for the real ITAM export (very sparse there: 8/613
  // rows had a nonzero cost). Decimal, not Float, for exact money math (no
  // binary-float rounding drift) -- Decimal(14,2) comfortably covers VND
  // amounts in the millions with room to spare.
  cost               Decimal?             @db.Decimal(14, 2)
  costCurrency       String?              @map("cost_currency")
  // Reuses the Area entity built for InventoryScan/the office-move feature
  // (2026-08-25) rather than a free-text location string -- same "share
  // the lookup entity across tables" precedent floated for Department.
  // Nullable: real-world coverage is thin (the ITAM export's own location
  // data was nearly useless -- "Physical location" was the literal string
  // "DAN" for all 613 rows, no per-item detail; only "Stockroom" carried
  // any signal, and only for the ~71 in_stock items -- an in_use item is
  // with a person, not sitting in a stockroom bin, so it has no area here
  // by design, not by data gap).
  areaId             String?              @map("area_id") @db.Uuid
  area               Area?                @relation(fields: [areaId], references: [id], onDelete: SetNull)
  purchaseOrderId    String?              @map("purchase_order_id") @db.Uuid
  purchaseOrder      PurchaseOrder?       @relation(fields: [purchaseOrderId], references: [id])
  // Free-text PO number from an external system (e.g. the real ITAM
  // export's "PO number" column) -- deliberately NOT the same thing as
  // purchaseOrderId above, which is a real FK into this app's own
  // PurchaseOrder table. External exports' PO numbers are messy free text
  // ("Not available", "Pending", or an actual number) with no matching
  // PurchaseOrder row to link to here, so this just preserves the raw
  // value for reference instead of forcing a fake relation.
  externalPoNumber   String?              @map("external_po_number")
  createdAt          DateTime             @default(now()) @map("created_at") @db.Timestamptz(6)
  // Back-relation for Assignment.assetItemId — an AssetItem can have
  // multiple Assignment rows over its lifetime (historical + at most one
  // active, see Assignment model's comment), not built until this task.
  assignments        Assignment[]
  // Back-relation for MaintenanceRecord.assetItemId — an AssetItem can have
  // multiple MaintenanceRecord rows over its lifetime (historical + at most
  // one open, see MaintenanceRecord model's comment), not built until this
  // task.
  maintenanceRecords MaintenanceRecord[]

  @@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)
  // Back-relation for Assignment.licenseId — a License can have multiple
  // Assignment rows (one per seat handed out, plus historical returns), not
  // built until this task.
  assignments     Assignment[]

  @@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[]
  // Back-relation for MaintenanceRecord.vendorId — a Vendor can perform
  // multiple repairs/warranty jobs over time, same reuse rationale as
  // PurchaseOrder.vendorId (see MaintenanceRecord model's comment).
  maintenanceRecords MaintenanceRecord[]

  @@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). `requests` is the back-relation from the
// Request.purchaseOrderId retrofit — the DEMAND side ("which approved
// Request got grouped into this PO"), as opposed to assetItems/licenses
// which are the SUPPLY side (intake traceability) — see Request model's
// comment above for the distinction.
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[]
  requests     Request[]

  @@map("purchase_orders")
}

// Fixed, closed set of 2 values tied to the domain (see docs/
// asset-license-management.md's "## Phân loại tài sản: High-value vs
// Low-value/Consumable" section) — native Postgres enum, same rationale as
// RequestType/AssetItemStatus/LicenseType above. Determines downstream
// rules for entities that will attach to a category later (not built in
// this task): AssetModel.categoryId must point to a `high_value` category,
// ConsumableItem.categoryId must point to a `low_value` category.
enum AssetCategoryValueGroup {
  high_value
  low_value
}

// Asset classification catalog — see docs/asset-license-management.md's
// "## Phân loại tài sản" section and the `AssetCategory` row in the "Data
// model (sơ bộ)" table. Standalone entity, no FKs (same starting shape as
// Vendor before it grew relations) — `AssetModel` and
// `AssetCategoryAttributeDef` will attach to this via `categoryId` in
// later tasks (not this one). IT admin defines the concrete categories
// (e.g. "Laptop", "Cáp HDMI") freely; only `valueGroup` is a fixed 2-value
// set.
model AssetCategory {
  id            String                      @id @default(uuid()) @db.Uuid
  name          String
  valueGroup    AssetCategoryValueGroup     @map("value_group")
  createdAt     DateTime                    @default(now()) @map("created_at") @db.Timestamptz(6)
  attributeDefs AssetCategoryAttributeDef[]
  // Back-relation for AssetModel.categoryId — see "Cập nhật 2026-08-02 (2)"
  // in docs/asset-license-management.md. Only categories with
  // valueGroup=high_value are ever actually referenced by an AssetModel (a
  // business rule enforced in src/lib/asset-models.ts's createAssetModel(),
  // not expressible as a Prisma-level constraint), but the relation itself
  // is not restricted to high_value categories at the schema level.
  assetModels   AssetModel[]
  // Back-relation for InventoryScan.categoryId — see InventoryScan's comment.
  inventoryScans InventoryScan[]

  @@map("asset_categories")
}

// Fixed, closed set of 4 values — a DEV-defined technical set (which Zod
// validator to build dynamically for AssetModel.specs at write time: string
// -> z.string(), number -> z.number(), boolean -> z.boolean(), date ->
// z.coerce.date()). Deliberately a different kind of "fixed set" than
// AssetCategoryValueGroup above: that one is a closed business classification
// IT admins never extend; this one is a closed set of *primitive types* the
// app's dynamic-attribute machinery knows how to handle. Still modeled as a
// native Postgres enum per the same codebase convention (RequestType /
// AssetItemStatus / LicenseType / AssetCategoryValueGroup), not a String +
// hand-rolled check.
enum AssetAttributeDataType {
  string
  number
  boolean
  date
}

// Per-category dynamic attribute definitions — see docs/
// asset-license-management.md's "Cập nhật 2026-08-02 (3): thêm
// AssetCategoryAttributeDef" section and the `AssetCategoryAttributeDef` row
// in the "Data model (sơ bộ)" table. Defines the *shape* of attributes a
// category cares about (e.g. category "Laptop" -> key `ram_gb`, label
// "RAM (GB)", dataType number); the actual *values* live in
// AssetModel.specs (JSONB), not built in this task. Each AssetCategory owns
// its own independent set of attribute defs — deliberately NOT a shared
// attribute library across categories (stakeholder explicitly rejected that
// design to keep things simple at current scale), so the same `key` string
// existing under two different categoryId rows is normal, not a collision —
// only unique *within* a category, hence the composite unique below (not a
// plain @unique on key alone). `sortOrder` is the display order on the
// dynamic form, no uniqueness constraint of its own (ties/gaps are fine,
// it's just a sort key).
model AssetCategoryAttributeDef {
  id         String                 @id @default(uuid()) @db.Uuid
  categoryId String                 @map("category_id") @db.Uuid
  category   AssetCategory          @relation(fields: [categoryId], references: [id])
  key        String
  label      String
  dataType   AssetAttributeDataType @map("data_type")
  required   Boolean
  sortOrder  Int                    @map("sort_order")
  createdAt  DateTime               @default(now()) @map("created_at") @db.Timestamptz(6)

  @@unique([categoryId, key])
  @@map("asset_category_attribute_defs")
}

// Sits between AssetCategory and AssetItem — see docs/
// asset-license-management.md's "Cập nhật 2026-08-02 (2)" section and the
// `AssetModel` row in the "Data model (sơ bộ)" table. 1 AssetModel has many
// AssetItem serials (AssetItem.modelId FK, not built in this task).
// `manufacturer`/`name` are deliberately two separate String fields (not
// merged into one), per the doc, to allow filtering/reporting by
// manufacturer alone (e.g. "Dell") without string-parsing a combined field.
// `categoryId` is a required FK to AssetCategory — the DB layer doesn't
// enforce that the referenced category is `high_value` (Prisma/Postgres FK
// constraints can't express that), that business rule is checked in
// src/lib/asset-models.ts's createAssetModel() via an explicit lookup
// before the create, per the doc's "Ràng buộc dữ liệu" section. `specs` is
// JSONB, defaulting to an empty object — the real per-category dynamic
// attribute *values* (whose *shape* is defined by
// AssetCategoryAttributeDef rows for this model's category). This task
// deliberately does NOT validate specs against the category's attribute
// defs (loose z.record(z.unknown()) validation only, see
// src/lib/asset-models.ts) — that dynamic cross-validation is a separate
// follow-up task per the doc's "Cập nhật 2026-08-02 (3)" section.
model AssetModel {
  id           String        @id @default(uuid()) @db.Uuid
  categoryId   String        @map("category_id") @db.Uuid
  category     AssetCategory @relation(fields: [categoryId], references: [id])
  manufacturer String
  name         String
  specs        Json          @default("{}")
  // Standard manufacturer/vendor warranty length for this model, in months
  // (e.g. Dell Latitude 5420 -> 36). Nullable -- not every model has a known
  // standard term. Used only as a DEFAULT when creating an AssetItem: see
  // src/lib/assets.ts's createAssetItem() -- warrantyEndDate = purchaseDate
  // + warrantyMonths, computed server-side only when the caller doesn't
  // supply warrantyEndDate explicitly (2026-08-21 decision: a specific
  // purchase batch's actual warranty can differ from the model's standard
  // term -- e.g. an extended-warranty deal -- so this must stay an
  // overridable suggestion, not a hard-locked computed column on AssetItem).
  warrantyMonths Int?        @map("warranty_months")
  createdAt    DateTime      @default(now()) @map("created_at") @db.Timestamptz(6)
  // Back-relation for the AssetItem.model -> AssetItem.modelId retrofit —
  // see "Cập nhật 2026-08-02 (2)" in docs/asset-license-management.md.
  assetItems   AssetItem[]
  // Back-relation for InventoryScan.modelId — see InventoryScan's comment.
  inventoryScans InventoryScan[]

  @@map("asset_models")
}

// Assigns an AssetItem (high-value hardware) or a License seat to a specific
// Employee — see docs/asset-license-management.md's "## Assignment (chốt
// 2026-08-02)" section and the `Assignment` row in the "Data model (sơ bộ)"
// table. Exactly one of assetItemId/licenseId must be set (XOR) — enforced
// at the Zod layer (src/lib/assignments.ts's `.refine()`), NOT a DB
// constraint, per the same convention as PurchaseOrder's
// receivedAt/receivedById co-nullability check: Prisma schema can't express
// an XOR between two nullable FKs natively. Both FKs stay plain nullable
// columns here for that reason. `assignedAt` defaults to now() but is a
// real stored column (not derived from createdAt) because a future
// "transfer" operation (out of scope for this task, see doc) will create a
// new Assignment row whose assignedAt should reflect the transfer moment,
// not necessarily row-insert time. `returnedAt` null means still held by
// the employee — this is also what "active assignment" means throughout
// the codebase (see the uniqueness rule below). `signedAt` is deliberately
// just a nullable timestamp marking "handover paperwork signed" — NO file
// upload, stakeholder explicitly decided against storing a scanned file at
// this stage (see doc). No `@@unique` on assetItemId here for "only one
// active assignment at a time" — a plain unique constraint would also
// forbid a *second, already-returned* historical Assignment for the same
// AssetItem (e.g. item reassigned after being returned), which is valid and
// expected. The "at most one ACTIVE (returnedAt IS NULL) assignment per
// AssetItem" invariant is instead enforced in application code
// (src/lib/assignments.ts's createAssignment(), inside the same transaction
// that mutates AssetItem.status/License.seatsUsed) — a partial unique index
// (`WHERE returned_at IS NULL`) would express this at the DB level too, but
// that's raw SQL outside a Prisma-expressible `@@unique`, so deliberately
// not added here; see feature-implementer report for this trade-off.
model Assignment {
  id          String     @id @default(uuid()) @db.Uuid
  employeeId  String     @map("employee_id") @db.Uuid
  employee    Employee   @relation(fields: [employeeId], references: [id])
  assetItemId String?    @map("asset_item_id") @db.Uuid
  assetItem   AssetItem? @relation(fields: [assetItemId], references: [id], onDelete: Restrict)
  licenseId   String?    @map("license_id") @db.Uuid
  license     License?   @relation(fields: [licenseId], references: [id], onDelete: Restrict)
  assignedAt  DateTime   @default(now()) @map("assigned_at") @db.Timestamptz(6)
  returnedAt  DateTime?  @map("returned_at") @db.Timestamptz(6)
  signedAt    DateTime?  @map("signed_at") @db.Timestamptz(6)
  createdAt   DateTime   @default(now()) @map("created_at") @db.Timestamptz(6)

  @@map("assignments")
}

// 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")
}

// Fixed, closed set of 3 values tied to the domain (see docs/
// asset-license-management.md's "## MaintenanceRecord (spec BA + stakeholder,
// chốt 2026-08-04)" section) — native Postgres enum, same rationale as
// RequestType/AssetItemStatus/LicenseType/AssetCategoryValueGroup/
// AssetAttributeDataType above.
enum MaintenanceType {
  repair
  warranty
  preventive
}

// Records a repair/warranty/preventive-maintenance job for a specific
// AssetItem — see docs/asset-license-management.md's "## MaintenanceRecord
// (spec BA + stakeholder, chốt 2026-08-04)" section. Only applies to
// AssetItem (hardware) — License has no physical-repair concept, so unlike
// Assignment there's no XOR here: assetItemId is the single, always-required
// target. `vendorId` reuses the existing Vendor entity (same "external
// counterparty" concept as PurchaseOrder.vendorId) and is nullable — null
// means an internal repair with no outside vendor involved. No `cost` field,
// per the same precedent as PurchaseOrder (stakeholder explicitly said no
// money tracking there). No separate `status` field either — "open" vs
// "done" is derived from `endDate` (null = still being worked on, set = done),
// same precedent as PurchaseOrder.receivedAt not duplicating state. `endDate
// >= startDate` and "at most one OPEN (endDate IS NULL) MaintenanceRecord per
// AssetItem" are both business invariants enforced at the application layer
// (src/lib/maintenance-records.ts, not built in this task) — NOT DB
// constraints, per the same convention as Assignment's XOR / "at most one
// active" invariant (see Assignment model's comment above for the mirrored
// trade-off). No FK to User for "who logged this" — no existing precedent in
// this codebase ties a business entity to User (User is login-only), see
// doc for this explicit call.
model MaintenanceRecord {
  id               String           @id @default(uuid()) @db.Uuid
  assetItemId      String           @map("asset_item_id") @db.Uuid
  assetItem        AssetItem        @relation(fields: [assetItemId], references: [id])
  type             MaintenanceType
  vendorId         String?          @map("vendor_id") @db.Uuid
  vendor           Vendor?          @relation(fields: [vendorId], references: [id])
  issueDescription String           @map("issue_description")
  resolutionNotes  String?          @map("resolution_notes")
  startDate        DateTime         @map("start_date") @db.Date
  endDate          DateTime?        @map("end_date") @db.Date
  createdAt        DateTime         @default(now()) @map("created_at") @db.Timestamptz(6)

  @@map("maintenance_records")
}

// Physical location tag for the office-move inventory walk — see the
// "chia theo area" decision in the inventory-scans project chat. Deliberately
// NOT the pre-existing high-value AssetItem's target ("Seat" tied 1:1 to a
// Employee/team) because that data (the new office seating chart) doesn't
// exist yet at the time this was built — `team` is nullable and gets filled
// in once the seating chart is finalized, no schema change needed then.
// Covers both per-seat locations ("Seat 12") and shared-room locations
// ("Phòng họp A", "Kho tầng 2") with the same flat entity — splitting seat
// vs room into separate types was considered and rejected as premature; add
// a `type` column later if filtering by kind actually becomes necessary.
// `name` is globally unique so the bot's "reuse existing or create new" flow
// (grows the list as the walk progresses, avoids duplicate near-identical
// area names from free-typing) has something to match against.
model Area {
  id             String          @id @default(uuid()) @db.Uuid
  name           String          @unique
  team           String?
  createdAt      DateTime        @default(now()) @map("created_at") @db.Timestamptz(6)
  inventoryScans InventoryScan[]
  // Back-relation for AssetItem.areaId -- see that field's comment.
  assetItems     AssetItem[]

  @@map("areas")
}

// One physical item logged during the office-move inventory walk (bot flow:
// Category -> Model -> [Workstation only: cpu/ram/gpu] -> Area -> assignee ->
// optional photo). Deliberately NOT a row in AssetItem: AssetItem requires a
// unique serialNumber and a purchaseDate, neither of which is known/at-hand
// during a fast walk-and-tap pass — forcing either would either block the
// walk or invent fake placeholder data, which this codebase avoids elsewhere
// (see AssetItem/License/PurchaseOrder comments' "no fake data" precedent).
// InventoryScan is the lightweight capture; promoting a scan to a real
// AssetItem (with a real serial once read off the physical tag) is a manual
// follow-up step done later in the review UI, not built in this task.
// `categoryId`/`modelId` reuse the existing AssetCategory/AssetModel catalog
// (seeded with Controller/Màn hình/Workstation for this task's scope) rather
// than inventing a parallel classification. `areaId` and `assignedEmployeeId`
// are both nullable — plenty of scanned items are shared equipment in a room
// (no single assignee) or not yet placed in a known Area. `specs` is JSONB,
// same shape/rationale as AssetModel.specs — holds the Workstation-only
// cpu/ram/gpu answers; empty object for categories that don't need them.
// `telegramChatId`/`telegramMessageId` are kept for traceability back to the
// original bot conversation (debugging a bad scan, or re-fetching the photo
// from Telegram if `photoPath` is ever lost) — nullable since a scan created
// directly from the review UI later won't have either.
model InventoryScan {
  id                 String         @id @default(uuid()) @db.Uuid
  categoryId         String         @map("category_id") @db.Uuid
  category           AssetCategory  @relation(fields: [categoryId], references: [id])
  modelId            String         @map("model_id") @db.Uuid
  model              AssetModel     @relation(fields: [modelId], references: [id])
  areaId             String?        @map("area_id") @db.Uuid
  area               Area?          @relation(fields: [areaId], references: [id])
  assignedEmployeeId String?        @map("assigned_employee_id") @db.Uuid
  assignedEmployee   Employee?      @relation(fields: [assignedEmployeeId], references: [id])
  // Physical asset tag/barcode label already stuck on the device (see the
  // "Scan QR/barcode đã có sẵn trên thiết bị" scope decision). Free text,
  // typed by the bot operator for now — not yet an actual barcode-image
  // decode. Deliberately NOT unique/required at this table's level (unlike
  // AssetItem.serialNumber): plenty of scanned items have no tag at all
  // (Controllers, Monitors bought without one), and enforcing uniqueness
  // here would block the walk on a typo'd re-entry instead of just letting
  // review-time cleanup catch it, per this model's "don't block the walk"
  // precedent (see AssetItem-vs-InventoryScan comment above).
  assetTag           String?        @map("asset_tag")
  // Manufacturer serial number, read off the same physical tag as
  // assetTag — same "don't block the walk" rationale (nullable, not
  // unique at this table's level; AssetItem.serialNumber is the unique
  // one, enforced only once a scan is promoted). Filled in either by
  // typing, or later by whoever reviews the scan's photo (bot operator or
  // Claude) reading it off the image — no OCR automation built yet, this
  // column is just where that value lands once read.
  serialNumber       String?        @map("serial_number")
  specs              Json           @default("{}")
  // Stores the Telegram file_id (not a local disk path, despite the DB
  // column name) — photos live on Telegram's servers, re-fetched on demand
  // via GET /api/inventory-scans/[id]/photo rather than duplicated onto
  // this app's own disk. Avoids a shared volume mount between this
  // container and the separate inventory-capture bot service.
  photoFileId        String?        @map("photo_path")
  telegramChatId     String?        @map("telegram_chat_id")
  telegramMessageId  Int?           @map("telegram_message_id")
  createdAt          DateTime       @default(now()) @map("created_at") @db.Timestamptz(6)
  // Back-reference for ExpectedAsset.matchedScanId -- set once someone
  // picks this scan's pre-uploaded row via the bot's "🔍 Tìm trong list"
  // step. No @relation attribute needed here; the FK lives on the other
  // side.
  expectedAsset      ExpectedAsset?

  @@map("inventory_scans")
}

// A row from a pre-move Excel/CSV export of known assets (asset tag,
// model, old area/owner), uploaded via POST /api/expected-assets/import
// before an office-move walk starts (2026-08-21 decision -- team decided
// plain manual entry was faster/more reliable than local OCR for ~300-400
// assets, see docs/asset-license-management.md, but typing in a KNOWN
// asset tag from scratch during the walk is still wasted effort when it's
// sitting right here). Purely a lookup/staging table for the bot's "🔍 Tìm
// trong list" picker -- modelText/oldAreaText/oldAssigneeText are free
// text straight from the import file, deliberately NOT FK'd into
// AssetModel/Area/Employee: import-file text won't reliably match this
// app's catalog IDs/spelling, and forcing that match at import time would
// block the whole import on one typo instead of just being a soft
// "here's the old value" suggestion during the walk. Marked matched (via
// matchedScanId) once someone actually picks it while creating a scan, so
// it stops showing up in future searches.
model ExpectedAsset {
  id              String         @id @default(uuid()) @db.Uuid
  assetTag        String?        @map("asset_tag")
  modelText       String         @map("model_text")
  serialNumber    String?        @map("serial_number")
  oldAreaText     String?        @map("old_area_text")
  oldAssigneeText String?        @map("old_assignee_text")
  matchedScanId   String?        @unique @map("matched_scan_id") @db.Uuid
  matchedScan     InventoryScan? @relation(fields: [matchedScanId], references: [id])
  createdAt       DateTime       @default(now()) @map("created_at") @db.Timestamptz(6)

  @@map("expected_assets")
}