GoogleSignIn-iOS/Samples/Swift/DaysUntilBirthday/Shared/Services/UserProfileImageLoader.swift

/*
 * Copyright 2021 Google LLC
 *
 * 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.
 */

#if os(iOS)
typealias GIDImage = UIImage
#elseif os(macOS)
typealias GIDImage = NSImage
#endif

import Combine
import SwiftUI
@preconcurrency import GoogleSignIn

/// An observable class for loading the current user's profile image.
@MainActor final class UserProfileImageLoader: ObservableObject {
  private let userProfile: GIDProfileData
  private var imageLoadingTask: Task<Void, Never>?
  /// A `UIImage` property containing the current user's profile image.
  /// - note: This will default to a placeholder, and updates will be published to subscribers.
  @Published var image = GIDImage(named: "PlaceholderAvatar")!

  /// Creates an instance of this loader with provided user profile.
  /// - note: The instance will asynchronously fetch the image data upon creation.
    init(userProfile: GIDProfileData) {
        self.userProfile = userProfile
        guard userProfile.hasImage else {
            return
        }
        imageLoadingTask = Task {
            await loadProfileImage()
        }
    }

    private func loadProfileImage() async {
    #if os(iOS)
        let dimension = 45 * UIScreen.main.scale
    #elseif os(macOS)
        let dimension = 120
    #endif

        guard let url = userProfile.imageURL(withDimension: UInt(dimension)) else {
            return
        }

        do {
            let (imageData, _) = try await URLSession.shared.data(from: url)
            if let image = GIDImage(data: imageData) {
                self.image = image
            }
        } catch {
            print("Image download failed:", error)
        }
    }

    deinit {
        imageLoadingTask?.cancel()
    }
}