Architettura e API

// Schema dati target del portale B2B Valkiria Fluidodinamica S.r.l. (azienda fittizia).
// Documentazione architetturale: nella sandbox pubblica i dati vivono in memoria,
// in produzione questo schema è applicato a PostgreSQL 16 tramite Prisma Migrate.

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

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

enum Role {
  BUYER
  TIER1
  AGENT
  ADMIN
}

enum ContractTier {
  OFFERTA_BASE
  CONTRATTO_QUADRO
}

enum OrderStatus {
  DRAFT
  SUBMITTED
  PAID
  INVOICED
  CANCELLED
}

enum VatRegime {
  ORDINARIA
  ESENTE_ART8
}

enum WebhookOutcome {
  PROCESSED
  DUPLICATE_IGNORED
  SIGNATURE_INVALID
}

model Company {
  id                         String        @id @default(cuid())
  legalName                  String
  vatNumber                  String        @unique @db.VarChar(13)
  sdiRecipientCode           String        @db.Char(7)
  pec                        String
  priceListTierId            String
  priceListTier              PriceListTier @relation(fields: [priceListTierId], references: [id])
  freeShippingThresholdCents Int
  intentDeclarationProtocol  String?       @db.VarChar(32)
  stripeCustomerId           String?       @unique
  users                      User[]
  orders                     B2BOrder[]
  createdAt                  DateTime      @default(now())
  updatedAt                  DateTime      @updatedAt

  @@index([priceListTierId])
}

model User {
  id        String   @id @default(cuid())
  email     String   @unique
  fullName  String
  role      Role
  companyId String?
  company   Company? @relation(fields: [companyId], references: [id])
  orders    B2BOrder[]
  createdAt DateTime @default(now())

  @@index([companyId, role])
}

model PriceListTier {
  id                 String       @id @default(cuid())
  tier               ContractTier @unique
  contractCode       String       @unique
  contractDiscountBp Int
  /// Scaglioni volume serializzati: [{ minQty, maxQty, discountBp }]
  volumeTiers        Json
  validFrom          DateTime
  validTo            DateTime?
  companies          Company[]
}

model Product {
  sku                 String      @id @db.VarChar(32)
  name                String
  category            String
  maxPressureBar      Int
  flowLpm             Int?
  tempMinC            Int
  tempMaxC            Int
  weightGrams         Int
  listPriceCents      Int
  industrialCostCents Int
  leadTimeDays        Int
  stockBergamo        Int         @default(0)
  stockBrescia        Int         @default(0)
  /// Optimistic locking: ogni decremento giacenza incrementa la versione.
  version             Int         @default(0)
  orderLines          OrderLine[]
  updatedAt           DateTime    @updatedAt

  @@index([category])
}

model B2BOrder {
  id              String      @id @default(cuid())
  orderCode       String      @unique
  /// Chiave di idempotenza inviata dal client: impedisce doppie emissioni.
  idempotencyKey  String      @unique
  companyId       String
  company         Company     @relation(fields: [companyId], references: [id])
  createdById     String
  createdBy       User        @relation(fields: [createdById], references: [id])
  status          OrderStatus @default(SUBMITTED)
  vatRegime       VatRegime
  paymentMethod   String
  taxableCents    Int
  shippingCents   Int
  vatCents        Int
  stampDutyCents  Int         @default(0)
  totalCents      Int
  stripeSessionId String?     @unique
  invoiceNumber   String?     @unique
  sdiIdentifier   String?
  lines           OrderLine[]
  webhookLogs     WebhookLog[]
  createdAt       DateTime    @default(now())

  @@index([companyId, createdAt(sort: Desc)])
  @@index([status])
}

model OrderLine {
  id                 String   @id @default(cuid())
  orderId            String
  order              B2BOrder @relation(fields: [orderId], references: [id], onDelete: Cascade)
  sku                String
  product            Product  @relation(fields: [sku], references: [sku])
  quantity           Int
  listUnitCents      Int
  netUnitCents       Int
  volumeTierLabel    String
  overrideDiscountBp Int      @default(0)
  lineNetCents       Int
  fromBergamo        Int
  fromBrescia        Int
  backorder          Int

  @@unique([orderId, sku])
  @@index([sku])
}

/// Ogni consegna (anche duplicata o con firma non valida) viene registrata.
model WebhookLog {
  id                String         @id @default(cuid())
  stripeEventId     String
  type              String
  orderId           String?
  order             B2BOrder?      @relation(fields: [orderId], references: [id])
  signatureVerified Boolean
  outcome           WebhookOutcome
  payload           Json
  receivedAt        DateTime       @default(now())

  @@index([stripeEventId])
  @@index([orderId])
  @@index([type, receivedAt(sort: Desc)])
}

/// Deduplica: un evento Stripe produce effetti di dominio al più una volta.
/// L'INSERT avviene nella stessa transazione dell'effetto; la violazione della
/// chiave primaria segnala un duplicato → risposta 200 con outcome DUPLICATE_IGNORED.
model ProcessedStripeEvent {
  eventId     String   @id
  type        String
  processedAt DateTime @default(now())
}