/*

Copyright (C) 2017 Apple Inc. All Rights Reserved.

See LICENSE.txt for this sample’s licensing information

Abstract:

Object to describe a photo in this app: a wrapper for CKRecord and useful for Cocoa Bindings.

*/

import Foundation

import CloudKit

class CloudPhoto : NSObject {

    var cloudRecord : CKRecord

    var isMyPhoto : Bool = false

    var distanceFromUser : Double = -1  // in kilometers

    init(record : CKRecord) {

        cloudRecord = record

        // Used for Cocoa bindings, when the filterPredicate of the array controller filters by "Mine".

        isMyPhoto = (CloudManager.isMyRecord(cloudRecord.creatorUserRecordID))

        super.init()

    }

    class func keyPathsForValuesAffectingIsPhotoNearMe() -> Set<String> {

        // "isPhotoNearMe" key path depends on "distanceFromUser" for it's value

        return NSSet(objects:"distanceFromUser") as! Set<String>

    }

    /**

    Used for Cocoa bindings, when the filterPredicate of the array controller filters by "Near Me"

    returns true if the given photo is within kNearMeDistance or the user's current location.

    */

    var isPhotoNearMe : Bool {

        get {

            // return yes if the distance is within kNearMeDistance of the user

            return distanceFromUser < kNearMeDistance && distanceFromUser != -1

        }

    }

    /// Used for Cocoa bindings, when the filterPredicate of the array controller filters by "Recent".

    var isRecentPhoto : Bool {

        get {

            let calendar: Calendar = Calendar.current

            let date1 = Date()

            let date2 = calendar.startOfDay(for: photoDate!)

            let components = calendar.dateComponents([Calendar.Component.day], from: date2, to: date1)

            return components.day! <= 5  // recent within last 5 days

        }

    }

    // TITLE

    /// Returns the name or title of this CloudPhoto object.

    var photoTitle : String {

        get {

            return cloudRecord[APLCloudManager.photoTitleAttribute()] as! String

        }

        set(title) {

            cloudRecord[APLCloudManager.photoTitleAttribute()] = title as CKRecordValue

        }

    }

    // DATE

    /// Returns the date when this CloudPhoto object was created. (optional as some photos may not have a mod date)

    var photoDate : Date? {

        get {

            return cloudRecord[APLCloudManager.photoDateAttribute()] as? Date

        }

        set(date) {

            cloudRecord[APLCloudManager.photoDateAttribute()] = date as? CKRecordValue

        }

    }

    // LOCATION

    /// Returns the CLLocation (geo tagged location) of this CloudPhoto object. (optional as some photos may not have a location)

    var photoLocation : CLLocation? {

        get {

            return cloudRecord[APLCloudManager.photoLocationAttribute()] as? CLLocation

        }

        set(location) {

            cloudRecord[APLCloudManager.photoLocationAttribute()] = location as? CKRecordValue

        }

    }

    func record() -> CKRecord {

        return cloudRecord

    }

    // IMAGE

    /// Returns the NSImage of this CloudPhoto object.

    var photoImage : NSImage? {

        get {

            guard let photoAsset = cloudRecord[APLCloudManager.photoAssetAttribute()] as? CKAsset,

                photoAsset.fileURL.path.characters.count > 0 else { return nil }

            let imageData = NSImage(contentsOfFile: photoAsset.fileURL.path)!

            return imageData

        }

        set {

            cloudRecord[APLCloudManager.photoAssetAttribute()] = nil

        }

    }

    func setPhotoImageURL(_ imageURL: URL) {

        let asset = CKAsset(fileURL:imageURL)

        cloudRecord[APLCloudManager.photoAssetAttribute()] = asset

    }

    // OWNER

    /**

    Returns the owner of this CloudPhoto object; asynchronously fetches the owner of a given photo,

    and uses the completion handler to return it back.

    */

    func photoOwner(_ completionHandler: @escaping (String?) -> Void) {

        CloudManager.fetchUserName(from: cloudRecord.creatorUserRecordID) { (familyName) in

            completionHandler(familyName)

        }

    }

}