SimpleX-Chat/apps/ios/Shared/Views/ChatList/UserPicker.swift

//
// Created by Avently on 16.01.2023.
// Copyright (c) 2023 SimpleX Chat. All rights reserved.
//

import SwiftUI
import SimpleXChat

private let fillColorDark = Color(uiColor: UIColor(red: 0.11, green: 0.11, blue: 0.11, alpha: 255))
private let fillColorLight = Color(uiColor: UIColor(red: 0.99, green: 0.99, blue: 0.99, alpha: 255))

struct UserPicker: View {
    @EnvironmentObject var chatModel: ChatModel
    @Environment(\.colorScheme) var colorScheme
    @Binding var showSettings: Bool
    @Binding var userPickerVisible: Bool
    var manageUsers: () -> Void = {}
    @State var scrollViewContentSize: CGSize = .zero
    @State var disableScrolling: Bool = true
    private let menuButtonHeight: CGFloat = 68
    @State var chatViewNameWidth: CGFloat = 0

    var fillColor: Color {
        colorScheme == .dark ? fillColorDark : fillColorLight
    }

    var body: some View {
        VStack {
            Spacer().frame(height: 1)
            VStack(spacing: 0) {
                ScrollView {
                    ScrollViewReader { sp in
                        VStack(spacing: 0) {
                            ForEach(Array(chatModel.users.enumerated()), id: \.0) { i, userInfo in
                                Button(action: {
                                    if !userInfo.user.activeUser {
                                        chatModel.changeActiveUser(userInfo.user.userId)
                                        userPickerVisible = false
                                    }
                                }, label: {
                                    HStack(spacing: 0) {
                                        ProfileImage(imageStr: userInfo.user.image)
                                        .frame(width: 44, height: 44)
                                        .padding(.trailing, 12)
                                        Text(userInfo.user.chatViewName)
                                        .fontWeight(i == 0 ? .medium : .regular)
                                        .foregroundColor(.primary)
                                        .overlay(DetermineWidth())
                                        Spacer()
                                        if i == 0 {
                                            Image(systemName: "checkmark")
                                        } else if userInfo.unreadCount > 0 {
                                            unreadCounter(userInfo.unreadCount)
                                        }
                                    }
                                    .padding(.trailing)
                                    .padding([.leading, .vertical], 12)
                                })
                                .buttonStyle(PressedButtonStyle(defaultColor: fillColor, pressedColor: Color(uiColor: .secondarySystemFill)))
                                if i < chatModel.users.count - 1 {
                                    Divider()
                                }
                            }
                        }
                        .overlay {
                            GeometryReader { geo -> Color in
                                DispatchQueue.main.async {
                                    scrollViewContentSize = geo.size
                                    let scenes = UIApplication.shared.connectedScenes
                                    if let windowScene = scenes.first as? UIWindowScene {
                                        let layoutFrame = windowScene.windows[0].safeAreaLayoutGuide.layoutFrame
                                        disableScrolling = scrollViewContentSize.height + menuButtonHeight * 2 + 10 < layoutFrame.height
                                    }
                                }
                                return Color.clear
                            }
                        }
                        .onChange(of: userPickerVisible) { visible in
                            if visible {
                                sp.scrollTo(0)
                            }
                        }
                    }
                }
                .simultaneousGesture(DragGesture(minimumDistance: disableScrolling ? 0 : 10000000))
                .frame(maxHeight: scrollViewContentSize.height)

                Divider()
                menuButton("Your user profiles", icon: "pencil") {
                    manageUsers()
                }
                Divider()
                menuButton("Settings", icon: "gearshape") {
                    showSettings = true
                    withAnimation {
                        userPickerVisible.toggle()
                    }
                }
            }
        }
        .clipShape(RoundedRectangle(cornerRadius: 16))
        .background(
            Rectangle()
                .fill(fillColor)
                .cornerRadius(16)
                .shadow(color: .black.opacity(0.12), radius: 24, x: 0, y: 0)
        )
        .onPreferenceChange(DetermineWidth.Key.self) { chatViewNameWidth = $0 }
        .frame(maxWidth: chatViewNameWidth > 0 ? min(300, chatViewNameWidth + 130) : 300)
        .padding(8)
        .onChange(of: [chatModel.currentUser?.chatViewName, chatModel.currentUser?.image] ) { _ in
            reloadCurrentUser()
        }
        .opacity(userPickerVisible ? 1.0 : 0.0)
        .onAppear {
            reloadUsers()
        }
    }

    private func reloadCurrentUser() {
        if let updatedUser = chatModel.currentUser, let index = chatModel.users.firstIndex(where: { $0.user.userId == updatedUser.userId }) {
            var users = chatModel.users
            users[index] = UserInfo(user: updatedUser, unreadCount: users[index].unreadCount)
            chatModel.updateUsers(users)
        }
    }

    private func reloadUsers() {
        Task {
            chatModel.updateUsers(listUsers())
        }
    }

    private func menuButton(_ title: LocalizedStringKey, icon: String, action: @escaping () -> Void) -> some View {
        Button(action: action) {
            HStack(spacing: 0) {
                Text(title)
                    .overlay(DetermineWidth())
                Spacer()
                Image(systemName: icon)
//                    .frame(width: 24, alignment: .center)
            }
            .padding(.horizontal)
            .padding(.vertical, 22)
            .frame(height: menuButtonHeight)
        }
        .buttonStyle(PressedButtonStyle(defaultColor: fillColor, pressedColor: Color(uiColor: .secondarySystemFill)))
    }
}

func unreadCounter(_ unread: Int64) -> some View {
    unreadCountText(Int(truncatingIfNeeded: unread))
    .font(.caption)
    .foregroundColor(.white)
    .padding(.horizontal, 4)
    .frame(minWidth: 18, minHeight: 18)
    .background(Color.accentColor)
    .cornerRadius(10)
}

struct UserPicker_Previews: PreviewProvider {
    static var previews: some View {
        let m = ChatModel()
        m.updateUsers([UserInfo.sampleData, UserInfo.sampleData])
        return UserPicker(
            showSettings: Binding.constant(false),
            userPickerVisible: Binding.constant(true)
        )
        .environmentObject(m)
    }
}