Refactor Notifications structure

src/helpers/NotificationsHelper.ts

@@ -1,5 +1,5 @@
 import { DatabaseHelper } from "./DatabaseHelper";
-import { Notif, NotifElemType, NotifEventVisibility } from "../entities/Notification";
+import { Notif, NotifElemType, NotifEventVisibility, NotifEventType } from "../entities/Notification";
 import { time } from "../utils/DateUtils";
 import { PostsHelper } from "./PostsHelper";
 import { PostPageKind, PostVisibilityLevel } from "../entities/Post";
@@ -17,6 +17,79 @@ const NOTIFICATIONS_TABLE = "comunic_notifications";
 
 export class NotificationsHelper {
 	
+	/**
+	 * Create a notification about a post
+	 * 
+	 * @param fromUser Source user ID
+	 * @param postID Target post ID
+	 * @param action Action to notify
+	 */
+	public static async CreatePostNotification(fromUser: number, postID: number, action: NotifEventType) {
+		await this.Push(new Notif({
+			timeCreate: time(),
+			fromUserID: fromUser,
+			onElemID: postID,
+			onElemType: NotifElemType.POST,
+			type: action
+		}));
+	}
+
+
+	/**
+	 * Create & push friendship request notification
+	 * 
+	 * @param fromUser Source user ID
+	 * @param destUser Destination user ID
+	 * @param action The kind of action
+	 */
+	public static async CreateFriendsNotifications(fromUser: number, destUser: number, action: NotifEventType) {
+		await this.DeleteNotificationsFrienshipRequest(fromUser, destUser);
+
+		// Push the notification
+		await this.Push(new Notif({
+			fromUserID: fromUser,
+			destUserID: destUser,
+			onElemID: fromUser, // Same as fromUser
+			onElemType: NotifElemType.FRIENDSHIP_REQUEST,
+			type: action
+		}));
+	}
+
+
+	/**
+	 * Create & push a group membership notification
+	 * 
+	 * @param userID The ID of the target user for the membership
+	 * @param moderatorID The ID of the moderator creating the notification (0 if it is the user)
+	 * @param groupID The ID of the target group
+	 * @param kind The kind of notification to create
+	 */
+	public static async CreateGroupMembershipNotification(userID: number, moderatorID: number, groupID: number, kind: NotifEventType) {
+		await this.DeleteNotificationsGroupsMembership(userID, groupID);
+
+		const n = new Notif({
+			onElemID: groupID,
+			onElemType: NotifElemType.GROUP_MEMBERSHIP,
+			type: kind
+		});
+
+
+		// The notification must be sent to all the moderators of the group
+		if(moderatorID < 1) {
+			n.fromUserID = userID;
+			n.destUserID = -1;
+		}
+
+		// We specify both the source and the destination of the notification
+		// not to broadcast the notification to all the group members
+		else {
+			n.fromUserID = moderatorID;
+			n.destUserID = userID;
+		}
+
+		await this.Push(n);
+	}
+
 	/**
 	 * Push a new notification
 	 * 
@@ -309,6 +382,51 @@ export class NotificationsHelper {
 		}));
 	}
 
+	/**
+	 * Delete all the notifications related to a friendship request between two users
+	 * 
+	 * @param userOne First user
+	 * @param userTwo Second user
+	 */
+	public static async DeleteNotificationsFrienshipRequest(userOne: number, userTwo: number) {
+		
+		// Delete notifications in two ways
+		await this.Delete(new Notif({
+			onElemType: NotifElemType.FRIENDSHIP_REQUEST,
+			destUserID: userOne,
+			fromUserID: userTwo,
+		}));
+
+		await this.Delete(new Notif({
+			onElemType: NotifElemType.FRIENDSHIP_REQUEST,
+			destUserID: userTwo,
+			fromUserID: userOne,
+		}));
+	}
+
+	/**
+	 * Delete all the notifications related to a specific group membership
+	 * 
+	 * @param userID Target user
+	 * @param groupID The ID of the target group
+	 */
+	public static async DeleteNotificationsGroupsMembership(userID: number, groupID: number) {
+		
+		const n = new Notif({
+			onElemType: NotifElemType.GROUP_MEMBERSHIP,
+			onElemID: groupID
+		});
+
+		n.destUserID = userID;
+		n.fromUserID = -1;
+		await this.Delete(n);
+
+		n.destUserID = -1;
+		n.fromUserID = userID;
+		await this.Delete(n);
+
+	}
+
 	/**
 	 * Count the number of unread notifications of a user
 	 *