// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: MIT-0

import Amplify
import Combine
import Foundation
import SwiftUI

struct ContentView: View {
    @EnvironmentObject var auth: AuthService

    @State var users = [User]()
    @State var postsSubscription: AnyCancellable?

    var body: some View {
        VStack {
            List {
                ForEach(users) { user in
                    VStack {
                        Spacer()
                        HStack {
                            Spacer()
                            Text(user.username)
                                .font(.system(size: 50))
                                .foregroundColor(Color.white)
                            Spacer()
                        }
                        .frame(
                            minWidth: 0,
                            maxWidth: .infinity,
                            minHeight: 180,
                            maxHeight: 180,
                            alignment: .center
                        )
                        .background(user.isSafe! ? Color.green : Color.red)
                        Spacer()
                    }
                }
            }
            Spacer()
            Button("Sign Out", action: auth.signOut)
        }.onAppear {
            observeUsers()
            queryUsers()
        }
    }

    func queryUsers() {
        let u = User.keys
        Amplify.DataStore.query(User.self) {
            result in
            switch result {
            case let .success(users):
                self.users = users
            case let .failure(error):
                print(error)
            }
        }
    }

    func observeUsers() {
        postsSubscription = Amplify.DataStore.publisher(for: User.self)
            .sink {
                if case let .failure(error) = $0 {
                    print("Subscription received error - \(error.localizedDescription)")
                }
            }
        receiveValue: { changes in
            // handle incoming changes
            print("Subscription received mutation: \(changes)")
            queryUsers()
        }
    }
}