extend schema
  @link(url: "https://specs.apollo.dev/federation/v2.3", import: ["@key", "@external"])
  @link(url: "https://specs.graphql-hive.com/hive/v1.0", import: ["@meta"])
  @meta(name: "owner", content: "notifications-team")
  @meta(name: "contact", content: "#notifications-channel")

directive @meta(
  name: String!
  content: String!
) repeatable on SCHEMA | OBJECT | INTERFACE | FIELD_DEFINITION

"""
ISO-8601 formatted date and time string
"""
scalar DateTime

"""
Types of notifications that can be sent to users
"""
enum NotificationType {
  """
  Notification about a product update
  """
  PRODUCT_UPDATE
  """
  Notification when a new review is posted
  """
  REVIEW_POSTED
  """
  Welcome notification for new users
  """
  WELCOME
}

"""
Filter criteria for searching notifications
"""
input NotificationFilterInput {
  """
  Search text to match against notification messages
  """
  searchText: String
  """
  Filter by specific notification types
  """
  types: [NotificationType!]
  """
  Only include notifications from this date onwards
  """
  dateFrom: DateTime
  """
  Only include notifications up to this date
  """
  dateTo: DateTime
}

"""
Base interface for all notification types
"""
interface NotificationItf @meta(name: "domain", content: "notifications") {
  id: ID!
  message: String!
}

"""
Notification sent when a product is updated
"""
type ProductUpdateNotification implements NotificationItf {
  """
  Unique identifier for the notification
  """
  id: ID!
  """
  Human-readable notification message
  """
  message: String!
  """
  The product that was updated
  """
  product: Product!
  """
  Timestamp when the product was updated
  """
  updatedAt: DateTime!
}

"""
Notification sent when a review is posted
"""
type ReviewPostedNotification implements NotificationItf {
  """
  Unique identifier for the notification
  """
  id: ID!
  """
  Human-readable notification message
  """
  message: String!
  """
  The review that was posted
  """
  review: Review!
  """
  Timestamp when the review was posted
  """
  postedAt: DateTime!
}

"""
Welcome notification sent to new users
"""
type WelcomeNotification implements NotificationItf {
  """
  Unique identifier for the notification
  """
  id: ID!
  """
  Human-readable notification message
  """
  message: String!
  """
  Timestamp when the notification was created
  """
  createdAt: DateTime!
}

"""
Union of all possible notification types
"""
union Notification = ProductUpdateNotification | ReviewPostedNotification | WelcomeNotification

extend type User @key(fields: "id") {
  """
  Unique identifier for the user
  """
  id: ID! @external
  """
  List of all notifications for this user
  """
  notifications: [Notification!]!
}

extend type Product @key(fields: "upc") {
  """
  Universal Product Code
  """
  upc: String!
}

"""
Review stub reference (full definition in reviews subgraph)
"""
type Review @key(fields: "id") {
  """
  Unique identifier for the review
  """
  id: ID!
}

extend type Query {
  notification(
    """
    Unique identifier of the notification to retrieve
    """
    id: ID!
  ): Notification
  notifications: [Notification!]!
  searchNotifications(
    """
    Filter criteria including search text, notification types, and date range
    """
    filter: NotificationFilterInput!
  ): [Notification!]!
}