Can delete a member of a group

src/controllers/GroupsController.ts

@@ -387,6 +387,43 @@ export class GroupsController {
 		h.success("The request has been successfully cancelled!");
 	}
 
+	/**
+	 * Delete a member from a group (as a moderator or an admin)
+	 * 
+	 * @param h Request handler
+	 */
+	public static async DeleteMember(h: RequestHandler) {
+		const groupID = await h.postGroupIDWithAccess("groupID", GroupsAccessLevel.MODERATOR_ACCESS);
+		
+		// Get the membership of the user making the request
+		const currUserMembership = await GroupsHelper.GetMembershipInfo(groupID, h.getUserId());
+
+		// Get the ID of the member to delete
+		const userID = await h.postUserId("userID");
+		const membership = await GroupsHelper.GetMembershipInfo(groupID, userID);
+
+		if(membership == null)
+			h.error(404, "Membership not found!");
+
+		// If the user is an admin, he must not be the last admin of the group
+		if(userID == h.getUserId() && currUserMembership.level == GroupMembershipLevels.ADMINISTRATOR
+			&& await GroupsHelper.CountMembersAtLevel(groupID, GroupMembershipLevels.ADMINISTRATOR) == 1)
+			h.error(401, "You are the last administrator of this group!");
+		
+		
+		// TODO : validate this check
+		// Only administrator can delete members that are more than member (moderators & administrators)
+		if(membership.level < GroupMembershipLevels.MEMBER && currUserMembership.level != GroupMembershipLevels.ADMINISTRATOR)
+			h.error(401, "Only an administrator can delete this membership!");
+		
+		// Delete the membership
+		await GroupsHelper.DeleteMember(groupID, userID);
+
+		// TODO : delete any group membership notifications
+
+		h.success("Membership of the user has been successfully deleted!");
+	}
+
 	/**
 	 * Turn a GroupInfo object into a valid API object
 	 * 

src/controllers/Routes.ts

@@ -114,4 +114,6 @@ export const Routes : Route[] = [
 	{path: "/groups/send_request", cb: (h) => GroupsController.SendRequest(h)},
 
 	{path: "/groups/cancel_request", cb: (h) => GroupsController.CancelRequest(h)},
+
+	{path: "/groups/delete_member", cb: (h) => GroupsController.DeleteMember(h)},
 ]

src/helpers/GroupsHelper.ts

@@ -405,6 +405,21 @@ export class GroupsHelper {
 		});
 	}
 
+	/**
+	 * Count the number of members of a group at a specific member
+	 * @param groupID Target group ID
+	 * @param level The level to check
+	 */
+	public static async CountMembersAtLevel(groupID: number, level: GroupMembershipLevels) : Promise<number> {
+		return await DatabaseHelper.Count({
+			table: GROUPS_MEMBERS_TABLE,
+			where: {
+				groups_id: groupID,
+				level: level
+			}
+		});
+	}
+
 	/**
 	 * Turn a database row into a {GroupInfo} object
 	 *