feat: Reorganizes files.

Sources/App/Controllers/DB/PurchaseOrderDB.swift

@@ -0,0 +1,65 @@
+import Fluent
+import Vapor
+
+// An intermediate between our api and view controllers that interacts with the
+// database.
+struct PurchaseOrderDB {
+
+  func create(
+    _ model: PurchaseOrder.Create,
+    createdById: User.IDValue,
+    on db: any Database
+  ) async throws -> PurchaseOrder.DTO {
+    guard let employee = try await Employee.find(model.createdForID, on: db) else {
+      throw Abort(.notFound, reason: "Employee not found.")
+    }
+
+    guard employee.active else {
+      throw Abort(.badRequest, reason: "Employee is not active, unable to generate a PO for in-active employees")
+    }
+
+    let purchaseOrder = model.toModel(createdByID: createdById)
+    try await purchaseOrder.save(on: db)
+    guard let loaded = try await get(id: purchaseOrder.requireID(), on: db) else {
+      return purchaseOrder.toDTO()
+    }
+    return loaded
+  }
+
+  func fetchAll(on db: any Database) async throws -> [PurchaseOrder.DTO] {
+    try await PurchaseOrder.allQuery(on: db)
+      .sort(\.$id, .descending)
+      .all().map { $0.toDTO() }
+  }
+
+  func fetchPage(_ page: Int, limit: Int, on db: any Database) async throws -> Page<PurchaseOrder.DTO> {
+    try await PurchaseOrder.allQuery(on: db)
+      .sort(\.$id, .descending)
+      .paginate(PageRequest(page: page, per: limit))
+      .map { $0.toDTO() }
+  }
+
+  func get(id: PurchaseOrder.IDValue, on db: any Database) async throws -> PurchaseOrder.DTO? {
+    try await PurchaseOrder.allQuery(on: db)
+      .filter(\.$id == id)
+      .first()?.toDTO()
+  }
+
+  func delete(id: PurchaseOrder.IDValue, on db: any Database) async throws {
+    guard let purchaseOrder = try await PurchaseOrder.find(id, on: db) else {
+      throw Abort(.notFound)
+    }
+    try await purchaseOrder.delete(on: db)
+  }
+}
+
+private extension PurchaseOrder {
+  static func allQuery(on db: any Database) -> QueryBuilder<PurchaseOrder> {
+    PurchaseOrder.query(on: db)
+      .with(\.$createdBy)
+      .with(\.$createdFor)
+      .with(\.$vendorBranch) { branch in
+        branch.with(\.$vendor)
+      }
+  }
+}