ProfilePicture FirebaseStorage

[DattaKansal]

You are going to allow users to add, delete and update profile pictures. This seems like a trivial task but it is not.

General flow:

• In FireStore, in a user document there will be a field for profile picture. This will contain a link to a picture (not the actual picture). This link points to an image in storage.
• In FirebaseStorage, we will be storing the images.

Whenever you're updating/deleting make sure you're changing the value in FireStore and FirebaseStorage.

Linking some more documentation below to help you get started:

1. Look at "Storage" in Firebase console. All images will go under the "/images" folder
2. If you want to learn more about Storage: https://youtu.be/YgjYVbg1oiA?si=50piLxY9ihtCfCcg
3. Documentation from Firebase: https://firebase.google.com/docs/storage/ios/upload-files and https://firebase.google.com/docs/storage/ios/download-files and https://firebase.google.com/docs/storage/ios/delete-files

For FirebaseStorage your task mainly revolves around storing an image in FirebaseStorage and then returning the URL to the location of that image. You also need to able take a URL (from FireStore) and then return an image. You need to handle cases where a user updates their profile picture and deletes a profile picture

Work in ProfileViewModel()

Adding reference code from past semesters of iOS (reach out if this doesn't make sense)

1. Given a URL getting the image.

func getImageFromURL(urlString: String, completion: @escaping (UIImage?) -> Void) {
    guard let url = URL(string: urlString) else {
            print("Invalid URL string: \(urlString)")
            completion(nil)
            return
        }
        URLSession.shared.dataTask(with: url) { data, response, error in
            DispatchQueue.main.async {
                if let error = error {
                    print("Error loading image from URL: \(error.localizedDescription)")
                    completion(nil)
                } else if let data = data, let image = UIImage(data: data) {
                    completion(image)
                } else {
                    print("Could not load image from URL: \(urlString)")
                    completion(nil)
                }
            }
        }.resume()
    }

2. Storing an image in FirebaseStorage and returning the URL you stored

func storeImageAndReturnURL(image: UIImage, completion: @escaping (URL?) -> Void) {
        guard let imageData = image.jpegData(compressionQuality: 0.8) else {
            completion(nil)
            return
        }
          // create random image path
        let imagePath = "images/\(UUID().uuidString).jpg"
        let storageRef = Storage.storage().reference()
        // create reference to file you want to upload
        let imageRef = storageRef.child(imagePath)
        //upload image
        DispatchQueue.main.async {
            let uploadTask = imageRef.putData(imageData, metadata: nil) { (metadata, error) in
                if let error = error {
                    print("Error uploading image: (error.localizedDescription)")
                    print("GANDEN FUNG BAD")
                    completion(nil)
                } else {
                    // Image successfully uploaded
                    imageRef.downloadURL { url, error in
                        if let downloadURL = url {
                            completion(downloadURL)
                        } else {
                            print("Error getting download URL: (String(describing: error?.localizedDescription))")
                        }
                    }
                }
            }
        }
    }

3. Get and update profile pictures

func updateProfilePic(userID: String, image: UIImage, completion: @escaping (URL) -> Void) {
        storeImageAndReturnURL(image: image) { url in
            guard let imageURL = url else {
               print("Failed to get download URL")
                return
            }
            let userDocument = self.db.collection("USERS").document(userID)
            userDocument.updateData(["profilePicture": imageURL.absoluteString]) { error in
                if let error = error {
                    print("Error updating document: \(error.localizedDescription)")
                    return
                } else {
                    print("Document successfully updated with new profile picture URL")
                    completion(imageURL)
                }
            }
        }
    }

func getProfilePic(userID: String, completion: @escaping (UIImage?) -> Void) {
       let userDocument = db.collection("USERS").document(userID)
       userDocument.getDocument { (document, error) in
           if let document = document, document.exists, let data = document.data(), let urlString = data["profilePicture"] as? String {
               self.getImageFromURL(urlString: urlString) { image in
                   completion(image)
               }
           } else {
               print("Document does not exist or URL could not be retrieved")
               completion(nil)
           }
       }
   }