import Foundation
import CoreData

class CoreDataStack: NSObject {
    let moduleName = "not"
    let appGroup = "group.com.etherpunk.NotI"
    let databaseName = "NotI"

    func saveToMainContext() { // Just a helper method for removing boilerplate code when you want to save. Remember this will be done on the main thread if called.
        if objectContext.hasChanges {
            do {
                try objectContext.save()
            } catch {
                print("Error saving main ManagedObjectContext: \(error)")
            }
        }
    }

    lazy var persistentContainer: NSPersistentContainer = {
        let persistentContainer = NSPersistentContainer(name: moduleName)
        let storeURL = URL.storeURL(for: appGroup, databaseName: databaseName)
        let storeDescription = NSPersistentStoreDescription(url: storeURL)
        persistentContainer.persistentStoreDescriptions = [storeDescription]
        persistentContainer.loadPersistentStores(completionHandler: { (storeDescription, error) in
            if let error = error as NSError? {
                // Replace this implementation with code to handle the error appropriately.
                // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.

                fatalError("Unresolved error \(error), \(error.userInfo)")
            }
        })

        return persistentContainer
    }()


    lazy var objectContext: NSManagedObjectContext = {
        //let context = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType) // As stated in the documentation change this depending on your need, but i recommend sticking to main thread if possible. Do I realllly need to do this thought? Probably. Need to figure this out.

        let context = self.persistentContainer.viewContext
        return context
    }()
}

public extension URL {
    static func storeURL(for appGroup: String, databaseName: String) -> URL {
        guard let fileContainer = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: appGroup) else {
            fatalError("Shared file container could not be created.")
        }

        return fileContainer.appendingPathComponent("\(databaseName).sqlite")
    }
}