// P4 EntityLink (AK-P4b) — Gate W1 deliverable.
//
// AD-21: one self-contained schema file per module. `tenantId` /
// `createdByUserId` are intentionally BARE String scalars (no `@relation`).
//
// Generic, fully polymorphic link between any two entities. Both sides
// (source + target) are polymorphic so every later module docks onto this one
// table instead of building its own link table. Reusable cross-cutting
// primitive: R-P6 ff. attach Task<->CRM, File<->CRM (beyond FileEntityLink),
// and any future relation here.
//
// Note: `FileEntityLink` (files.prisma) predates this table and stays as-is for
// the file-specific upload flow; new generic links use `EntityLink`.

enum LinkableEntityType {
  contact
  company
  lead
  deal
  project
  task
  file
  user
  order
  appointment
  form_submission
}

/// A directed, role-labelled link from one entity to another, scoped per tenant.
/// Idempotent on the unique tuple (upsert in entityLinkService).
model EntityLink {
  id              String             @id @default(cuid())
  createdAt       DateTime           @default(now())
  tenantId        String
  createdByUserId String
  sourceType      LinkableEntityType
  sourceId        String
  targetType      LinkableEntityType
  targetId        String
  linkRole        String? // optional role label (e.g. "depends-on", "reference")

  @@unique([tenantId, sourceType, sourceId, targetType, targetId])
  @@index([tenantId, targetType, targetId])
  @@index([tenantId, sourceType, sourceId])
}