//
//  Persistence.swift
//  CoreDataSample
//
//  Created by Garth Vander Houwen on 11/28/21.
//

import CoreData

class PersistenceController {

	static let shared = PersistenceController()

	static var preview: PersistenceController = {
		let result = PersistenceController(inMemory: false)
		let viewContext = result.container.viewContext
		for _ in 0..<10 {
			let newItem = NodeInfoEntity(context: viewContext)
			newItem.lastHeard = Date()
		}
		do {
			try viewContext.save()
		} catch {
			// 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.
			let nsError = error as NSError
			fatalError("Unresolved error \(nsError), \(nsError.userInfo)")
		}
		return result
	}()

	let container: NSPersistentContainer

	init(inMemory: Bool = false) {
		container = NSPersistentContainer(name: "Meshtastic")
		if inMemory {
			container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
		}
		container.loadPersistentStores(completionHandler: { (_, error) in
			// Merge policy that favors in memory data over data in the db
			self.container.viewContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
			
			
			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.

				/*
				Typical reasons for an error here include:
				* The parent directory does not exist, cannot be created, or disallows writing.
				* The persistent store is not accessible, due to permissions or data protection when the device is locked.
				* The device is out of space.
				* The store could not be migrated to the current model version.
				Check the error message to determine what the actual problem was.
				*/
				
				let firstStoreURL = self.container.persistentStoreCoordinator.persistentStores.first?.url
				
				do {
					
					try self.container.persistentStoreCoordinator.destroyPersistentStore(at: firstStoreURL!, type: .sqlite, options: nil)
					
					print("💥 Something went terribly wrong, CoreData database truncated.  All app data is lost.")
					
				} catch {
					print("💣 Failed to destroy broken CoreData database, delete the app.")
				}
			
				print("💣💥 Unresolved error \(error), \(error.userInfo)")
			}
		})
	}
}