//
//  ManagedObjectExtensions.swift
//  Reader
//
//  Created by Shadowfacts on 12/24/21.
//

import Foundation
import Fervor

extension Group {
    
    func updateFromServer(_ serverGroup: Fervor.Group) {
        guard self.id == nil || self.id == serverGroup.id else { return }
        self.id = serverGroup.id
        self.title = serverGroup.title
        // feeds relationships will be updated after feeds are created in PersistentContainer.sync
    }
    
}

extension Feed {
    
    func updateFromServer(_ serverFeed: Fervor.Feed) {
        guard self.id == nil || self.id == serverFeed.id else { return }
        self.id = serverFeed.id
        self.title = serverFeed.title
        self.url = serverFeed.url
        self.lastUpdated = serverFeed.lastUpdated
        // todo: check this
        self.removeFromGroups(self.groups!.filtered(using: NSPredicate(format: "NOT id IN %@", serverFeed.groupIDs)) as NSSet)
        let groupsToAddReq = Group.fetchRequest()
        groupsToAddReq.predicate = NSPredicate(format: "id IN %@", serverFeed.groupIDs.filter { g in !self.groups!.contains { ($0 as! Group).id == g } })
        let groupsToAdd = try! self.managedObjectContext!.fetch(groupsToAddReq)
        self.addToGroups(NSSet(array: groupsToAdd))
    }
    
}

extension Item {
    
    func updateFromServer(_ serverItem: Fervor.Item) {
        guard self.id == nil || self.id == serverItem.id else { return }
        self.id = serverItem.id
        self.author = serverItem.author
        self.content = serverItem.content
        self.title = serverItem.title
        self.read = serverItem.read ?? false
        self.published = serverItem.published
        self.url = serverItem.url
        if self.feed?.id != serverItem.feedID {
            let feedReq = Feed.fetchRequest()
            feedReq.predicate = NSPredicate(format: "id = %@", serverItem.feedID)
            self.feed = try! self.managedObjectContext!.fetch(feedReq).first!
        }
    }
    
}