//
// Copyright (c) 2015 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

import UIKit
import Firebase

@objc(PostTableViewCell)
class PostTableViewCell: UITableViewCell {
 @IBOutlet weak var authorImage: UIImageView!
 @IBOutlet weak var authorLabel: UILabel!
 @IBOutlet weak var starButton: UIButton!
 @IBOutlet weak var numStarsLabel: UILabel!
 @IBOutlet weak var postTitle: UILabel!
 @IBOutlet weak var postBody: UITextView!
 var postKey: String?
 var postRef: DatabaseReference!

 @IBAction func didTapStarButton(_ sender: AnyObject) {
 if let postKey = postKey {
 postRef = Database.database().reference().child("posts").child(postKey)
 incrementStars(forRef: postRef)
 postRef.observeSingleEvent(of: .value, with: { (snapshot) in
 let value = snapshot.value as? NSDictionary
 if let uid = value?["uid"] as? String {
 let userPostRef = Database.database().reference()
 .child("user-posts")
 .child(uid)
 .child(postKey)
 self.incrementStars(forRef: userPostRef)
 }
 })
 }
 }

 func incrementStars(forRef ref: DatabaseReference) {
 // [START post_stars_transaction]
 ref.runTransactionBlock({ (currentData: MutableData) -> TransactionResult in
 if var post = currentData.value as? [String : AnyObject], let uid = Auth.auth().currentUser?.uid {
 var stars: Dictionary<String, Bool>
 stars = post["stars"] as? [String : Bool] ?? [:]
 var starCount = post["starCount"] as? Int ?? 0
 if let _ = stars[uid] {
 // Unstar the post and remove self from stars
 starCount -= 1
 stars.removeValue(forKey: uid)
 } else {
 // Star the post and add self to stars
 starCount += 1
 stars[uid] = true
 }
 post["starCount"] = starCount as AnyObject?
 post["stars"] = stars as AnyObject?

 // Set value and report transaction success
 currentData.value = post

 return TransactionResult.success(withValue: currentData)
 }
 return TransactionResult.success(withValue: currentData)
 }) { (error, committed, snapshot) in
 if let error = error {
 print(error.localizedDescription)
 }
 }
 // [END post_stars_transaction]
 }
}