element-x-ios/ElementX/Sources/Screens/UserProfileScreen/UserProfileScreenViewModel.swift

//
// Copyright 2025 Element Creations Ltd.
// Copyright 2022-2025 New Vector Ltd.
//
// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
// Please see LICENSE files in the repository root for full details.
//

import Combine
import MatrixRustSDK
import SwiftUI

typealias UserProfileScreenViewModelType = StateStoreViewModelV2<UserProfileScreenViewState, UserProfileScreenViewAction>

class UserProfileScreenViewModel: UserProfileScreenViewModelType, UserProfileScreenViewModelProtocol {
    private let userSession: UserSessionProtocol
    private let analytics: AnalyticsServiceProtocol
    private let userIndicatorController: UserIndicatorControllerProtocol
    
    private var actionsSubject: PassthroughSubject<UserProfileScreenViewModelAction, Never> = .init()
    var actionsPublisher: AnyPublisher<UserProfileScreenViewModelAction, Never> {
        actionsSubject.eraseToAnyPublisher()
    }
    
    init(userID: String,
         isPresentedModally: Bool,
         userSession: UserSessionProtocol,
         analytics: AnalyticsServiceProtocol,
         userIndicatorController: UserIndicatorControllerProtocol) {
        self.userSession = userSession
        self.analytics = analytics
        self.userIndicatorController = userIndicatorController
        
        let initialViewState = UserProfileScreenViewState(userID: userID,
                                                          isOwnUser: userID == userSession.clientProxy.userID,
                                                          isPresentedModally: isPresentedModally,
                                                          appHooks: appHooks,
                                                          bindings: .init())
        
        super.init(initialViewState: userSession.userHooks.userProfileScreenHook.update(initialViewState),
                   mediaProvider: userSession.mediaProvider)
        
        showLoadingIndicator(allowsInteraction: true)
        Task {
            await loadProfile()
            hideLoadingIndicator()
        }
    }
    
    // MARK: - Public
    
    func stop() {
        // Work around QLPreviewController dismissal issues, see the InteractiveQuickLookModifier.
        state.bindings.mediaPreviewItem = nil
        
        hideLoadingIndicator()
    }
    
    override func process(viewAction: UserProfileScreenViewAction) {
        switch viewAction {
        case .displayAvatar(let url):
            Task { await displayFullScreenAvatar(url) }
        case .openDirectChat:
            openDirectChat()
        case .createDirectChat:
            Task { await createDirectChat() }
        case .startCall(let roomID, let isVoiceCall):
            Task { await startCall(roomID: roomID, isVoiceCall: isVoiceCall) }
        case .dismiss:
            actionsSubject.send(.dismiss)
        }
    }
    
    // MARK: - Private
    
    // The proxies aren't Sendable, fetch through these helpers so that
    // they never leave the main actor when running calls in parallel.
    
    private func fetchProfile() async -> Result<UserProfile, ClientProxyError> {
        await userSession.clientProxy.profile(for: state.userID)
    }
    
    private func fetchUserIdentity() async -> Result<UserIdentityProxyProtocol?, ClientProxyError> {
        await userSession.clientProxy.userIdentity(for: state.userID, fallBackToServer: true)
    }
    
    private func loadProfile() async {
        async let profileResult = fetchProfile()
        async let identityResult = fetchUserIdentity()
        
        switch await profileResult {
        case .success(let userProfile):
            state.userProfile = userProfile
            state.permalink = (try? matrixToUserPermalink(userId: state.userID)).flatMap(URL.init(string:))
            
            switch userSession.clientProxy.directRoomForUserID(userProfile.id) {
            case .success(let roomID):
                state.dmRoomID = roomID
            case .failure:
                break
            }
        case .failure(let error):
            state.bindings.alertInfo = .init(id: .unknown)
            MXLog.error("Failed to find user profile: \(error)")
        }
        
        if case let .success(.some(identity)) = await identityResult {
            state.isIdentityKnown = true
            state.isVerified = identity.verificationState == .verified
        } else {
            state.isIdentityKnown = false
            MXLog.error("Failed to find the user's identity.")
        }
    }
    
    private func displayFullScreenAvatar(_ url: URL) async {
        guard let userProfile = state.userProfile else { fatalError() }
        
        showLoadingIndicator(allowsInteraction: false)
        defer { hideLoadingIndicator() }
        
        state.bindings.mediaPreviewItem = await MediaPreviewItem.load(from: url, title: userProfile.displayName, using: userSession.mediaProvider)
    }
    
    private func openDirectChat() {
        guard let userProfile = state.userProfile else { fatalError() }
        
        showLoadingIndicator(allowsInteraction: false)
        defer { hideLoadingIndicator() }
        
        switch userSession.clientProxy.directRoomForUserID(userProfile.id) {
        case .success(let roomID):
            if let roomID {
                actionsSubject.send(.openDirectChat(roomID: roomID))
            } else {
                Task {
                    let isUnknown = if case let .success(identity) = await userSession.clientProxy.userIdentity(for: userProfile.id, fallBackToServer: false) {
                        identity == nil
                    } else {
                        true
                    }
                    state.bindings.inviteConfirmationUser = .init(user: userProfile, isUnknown: isUnknown)
                }
            }
        case .failure:
            state.bindings.alertInfo = .init(id: .failedOpeningDirectChat)
        }
    }
    
    private func createDirectChat() async {
        guard let userProfile = state.userProfile else { fatalError() }
        
        showLoadingIndicator(allowsInteraction: false)
        defer { hideLoadingIndicator() }
        
        switch await userSession.clientProxy.createDirectRoom(with: userProfile.id, expectedRoomName: userProfile.displayName) {
        case .success(let roomID):
            analytics.trackCreatedRoom(isDM: true)
            actionsSubject.send(.openDirectChat(roomID: roomID))
        case .failure:
            state.bindings.alertInfo = .init(id: .failedOpeningDirectChat)
        }
    }
    
    private func startCall(roomID: String, isVoiceCall: Bool) async {
        guard case let .joined(roomProxy) = await userSession.clientProxy.roomForIdentifier(roomID) else {
            showErrorIndicator()
            return
        }
        actionsSubject.send(.startCall(roomProxy: roomProxy, isVoiceCall: isVoiceCall))
    }
    
    // MARK: User Indicators
    
    private var loadingIndicatorIdentifier: String {
        "\(Self.self)-Loading"
    }
    
    private var statusIndicatorIdentifier: String {
        "\(Self.self)-Status"
    }
    
    private func showLoadingIndicator(allowsInteraction: Bool) {
        userIndicatorController.submitIndicator(UserIndicator(id: loadingIndicatorIdentifier,
                                                              type: .modal(progress: .indeterminate, interactiveDismissDisabled: false, allowsInteraction: allowsInteraction),
                                                              title: L10n.commonLoading,
                                                              persistent: true),
                                                delay: .milliseconds(100))
    }
    
    private func hideLoadingIndicator() {
        userIndicatorController.retractIndicatorWithId(loadingIndicatorIdentifier)
    }
    
    private func showErrorIndicator() {
        userIndicatorController.submitIndicator(UserIndicator(id: statusIndicatorIdentifier,
                                                              type: .toast,
                                                              title: L10n.errorUnknown,
                                                              icon: \.close))
    }
}