feat: add unified Person+User creation backend

src/use-cases/person.use-cases.ts

@@ -1,9 +1,12 @@
 import { Prisma } from "@/generated/prisma/client"
 import prisma from "@/lib/prisma"
+import { getPasswordHash } from "@/lib/security"
 import type {
   CreatePersonFormType,
   UpdatePersonFormType,
 } from "@/schemas/person.schema"
+import type { UnifiedCreateFormType } from "@/schemas/user.schema"
+import { getUserByEmail } from "@/services/user.service"
 import { PersonService } from "@/services/person.service"
 
 type FieldErrors = Record<string, string[]>
@@ -127,3 +130,82 @@ export async function updatePersonUseCase(
     throw error
   }
 }
+
+export async function createPersonUserUseCase(
+  input: UnifiedCreateFormType,
+): Promise<PersonUseCaseResult> {
+  const { firstName, lastName, department, email, phone, role, password, isActive } =
+    input
+
+  try {
+    return await prisma.$transaction(async (tx) => {
+      // Cross-table email uniqueness: check both Person and User tables
+      const existingPersonEmail = await PersonService.findByEmail(email, tx)
+      if (existingPersonEmail) {
+        return personError({ email: ["Email already exists"] })
+      }
+
+      const existingUserEmail = await getUserByEmail(email, tx)
+      if (existingUserEmail) {
+        return personError({ email: ["Email already exists"] })
+      }
+
+      if (role === "NO_USER") {
+        // Person-only creation — no User record
+        await PersonService.create(
+          {
+            firstName,
+            lastName,
+            department,
+            email,
+            phone: phone ?? null,
+          },
+          tx,
+        )
+
+        return { success: true }
+      }
+
+      // Person + User creation
+      const person = await PersonService.create(
+        {
+          firstName,
+          lastName,
+          department,
+          email,
+          phone: phone ?? null,
+        },
+        tx,
+      )
+
+      const userName = `${firstName} ${lastName}`
+      const hashedPassword = await getPasswordHash(password!)
+
+      const user = await tx.user.create({
+        data: {
+          name: userName,
+          email,
+          password: hashedPassword,
+          role,
+          isActive,
+        },
+      })
+
+      await PersonService.update(
+        person.id,
+        { user: { connect: { id: user.id } } },
+        tx,
+      )
+
+      return { success: true }
+    })
+  } catch (error) {
+    const errors = uniqueErrorFor(error)
+
+    if (errors) {
+      return personError(errors)
+    }
+
+    throw error
+  }
+}