//
// Copyright 2022-2024 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 XCTest

@testable import ElementX

@MainActor
class CreateRoomScreenViewModelTests: XCTestCase {
    var viewModel: CreateRoomViewModelProtocol!
    var clientProxy: ClientProxyMock!
    var userSession: UserSessionMock!
    
    private let usersSubject = CurrentValueSubject<[UserProfileProxy], Never>([])
    private var cancellables = Set<AnyCancellable>()
    
    var context: CreateRoomViewModel.Context {
        viewModel.context
    }
    
    override func setUpWithError() throws {
        cancellables.removeAll()
        clientProxy = ClientProxyMock(.init(userIDServerName: "matrix.org", userID: "@a:b.com"))
        userSession = UserSessionMock(.init(clientProxy: clientProxy))
        let parameters = CreateRoomFlowParameters()
        usersSubject.send([.mockAlice, .mockBob, .mockCharlie])
        ServiceLocator.shared.settings.knockingEnabled = true
        let viewModel = CreateRoomViewModel(userSession: userSession,
                                            createRoomParameters: .init(parameters),
                                            selectedUsers: usersSubject.asCurrentValuePublisher(),
                                            analytics: ServiceLocator.shared.analytics,
                                            userIndicatorController: UserIndicatorControllerMock(),
                                            appSettings: ServiceLocator.shared.settings)
        self.viewModel = viewModel
        
        viewModel.actions.sink { [weak self] action in
            guard let self else { return }
            switch action {
            case .deselectUser(let user):
                var selectedUsers = usersSubject.value
                if let index = selectedUsers.firstIndex(where: { $0.userID == user.userID }) {
                    selectedUsers.remove(at: index)
                }
                usersSubject.send(selectedUsers)
            default:
                break
            }
        }
        .store(in: &cancellables)
    }
    
    func testDeselectUser() {
        XCTAssertFalse(context.viewState.selectedUsers.isEmpty)
        XCTAssertEqual(context.viewState.selectedUsers.count, 3)
        XCTAssertEqual(context.viewState.selectedUsers.first?.userID, UserProfileProxy.mockAlice.userID)
        context.send(viewAction: .deselectUser(.mockAlice))
        XCTAssertNotEqual(context.viewState.selectedUsers.first?.userID, UserProfileProxy.mockAlice.userID)
    }
    
    func testDefaultSecurity() {
        XCTAssertTrue(context.viewState.bindings.isRoomPrivate)
    }
    
    func testCreateRoomRequirements() {
        XCTAssertFalse(context.viewState.canCreateRoom)
        context.send(viewAction: .updateRoomName("A"))
        XCTAssertTrue(context.viewState.canCreateRoom)
    }
    
    func testCreateRoom() async throws {
        // Given a form with a blank topic.
        context.send(viewAction: .updateRoomName("A"))
        context.roomTopic = ""
        context.isRoomPrivate = false
        XCTAssertTrue(context.viewState.canCreateRoom)
        
        // When creating the room.
        clientProxy.createRoomNameTopicIsRoomPrivateIsKnockingOnlyUserIDsAvatarURLAliasLocalPartReturnValue = .success("1")
        let deferred = deferFulfillment(viewModel.actions) { action in
            guard case .openRoom("1") = action else { return false }
            return true
        }
        context.send(viewAction: .createRoom)
        try await deferred.fulfill()
        
        // Then the room should be created and a topic should not be set.
        XCTAssertTrue(clientProxy.createRoomNameTopicIsRoomPrivateIsKnockingOnlyUserIDsAvatarURLAliasLocalPartCalled)
        XCTAssertEqual(clientProxy.createRoomNameTopicIsRoomPrivateIsKnockingOnlyUserIDsAvatarURLAliasLocalPartReceivedArguments?.name, "A")
        XCTAssertNil(clientProxy.createRoomNameTopicIsRoomPrivateIsKnockingOnlyUserIDsAvatarURLAliasLocalPartReceivedArguments?.topic,
                     "The topic should be sent as nil when it is empty.")
    }
    
    func testCreateKnockingRoom() async {
        context.send(viewAction: .updateRoomName("A"))
        context.roomTopic = "B"
        context.isRoomPrivate = false
        // When setting the room as private we always reset the knocking state to the default value of false
        // so we need to wait a main actor cycle to ensure the view state is updated
        await Task.yield()
        context.isKnockingOnly = true
        XCTAssertTrue(context.viewState.canCreateRoom)
        
        let expectation = expectation(description: "Wait for the room to be created")
        clientProxy.createRoomNameTopicIsRoomPrivateIsKnockingOnlyUserIDsAvatarURLAliasLocalPartClosure = { _, _, isPrivate, isKnockingOnly, _, _, localAliasPart in
            XCTAssertTrue(isKnockingOnly)
            XCTAssertFalse(isPrivate)
            XCTAssertEqual(localAliasPart, "a")
            defer { expectation.fulfill() }
            return .success("")
        }
        context.send(viewAction: .createRoom)
        await fulfillment(of: [expectation])
    }
    
    func testCreatePublicRoomFailsForInvalidAlias() async throws {
        context.send(viewAction: .updateRoomName("A"))
        context.roomTopic = "B"
        context.isRoomPrivate = false
        // When setting the room as private we always reset the alias
        // so we need to wait a main actor cycle to ensure the view state is updated
        await Task.yield()
        
        // we wait for the debounce to show the error
        let deferred = deferFulfillment(context.$viewState) { viewState in
            viewState.aliasErrors.contains(.invalidSymbols) && !viewState.canCreateRoom
        }
        context.send(viewAction: .updateAliasLocalPart("#:"))
        try await deferred.fulfill()
        
        // We also want to force the room creation in case the user may tap the button before the debounce
        // blocked it
        context.send(viewAction: .createRoom)
        await Task.yield()
        XCTAssertFalse(clientProxy.createRoomNameTopicIsRoomPrivateIsKnockingOnlyUserIDsAvatarURLAliasLocalPartCalled)
    }
    
    func testCreatePublicRoomFailsForExistingAlias() async throws {
        clientProxy.isAliasAvailableReturnValue = .success(false)
        context.send(viewAction: .updateRoomName("A"))
        context.roomTopic = "B"
        context.isRoomPrivate = false
        // When setting the room as private we always reset the alias
        // so we need to wait a main actor cycle to ensure the view state is updated
        await Task.yield()
        
        // we wait for the debounce to show the error
        let deferred = deferFulfillment(context.$viewState) { viewState in
            viewState.aliasErrors.contains(.alreadyExists) && !viewState.canCreateRoom
        }
        context.send(viewAction: .updateAliasLocalPart("abc"))
        try await deferred.fulfill()
        
        // We also want to force the room creation in case the user may tap the button before the debounce
        // blocked it
        let expectation = expectation(description: "Wait for the alias to be checked again")
        clientProxy.isAliasAvailableClosure = { _ in
            defer {
                expectation.fulfill()
            }
            return .success(false)
        }
        context.send(viewAction: .createRoom)
        await fulfillment(of: [expectation])
        XCTAssertEqual(clientProxy.isAliasAvailableCallsCount, 2)
        XCTAssertFalse(clientProxy.createRoomNameTopicIsRoomPrivateIsKnockingOnlyUserIDsAvatarURLAliasLocalPartCalled)
    }
    
    func testCreatePrivateRoomCantHaveKnockRule() async {
        context.send(viewAction: .updateRoomName("A"))
        context.roomTopic = "B"
        context.isRoomPrivate = true
        context.isKnockingOnly = true
        context.send(viewAction: .createRoom)
        let expectation = expectation(description: "Wait for the room to be created")
        clientProxy.createRoomNameTopicIsRoomPrivateIsKnockingOnlyUserIDsAvatarURLAliasLocalPartClosure = { _, _, isPrivate, isKnockingOnly, _, _, _ in
            XCTAssertFalse(isKnockingOnly)
            XCTAssertTrue(isPrivate)
            expectation.fulfill()
            return .success("")
        }
        await fulfillment(of: [expectation])
    }
    
    func testNameAndAddressSync() async {
        context.isRoomPrivate = true
        await Task.yield()
        context.send(viewAction: .updateRoomName("abc"))
        XCTAssertEqual(context.viewState.aliasLocalPart, "abc")
        XCTAssertEqual(context.viewState.roomName, "abc")
        context.send(viewAction: .updateRoomName("DEF"))
        XCTAssertEqual(context.viewState.roomName, "DEF")
        XCTAssertEqual(context.viewState.aliasLocalPart, "def")
        context.send(viewAction: .updateRoomName("a  b c"))
        XCTAssertEqual(context.viewState.aliasLocalPart, "a-b-c")
        XCTAssertEqual(context.viewState.roomName, "a  b c")
        context.send(viewAction: .updateAliasLocalPart("hello-world"))
        // This removes the sync
        XCTAssertEqual(context.viewState.aliasLocalPart, "hello-world")
        XCTAssertEqual(context.viewState.roomName, "a  b c")
        
        context.send(viewAction: .updateRoomName("Hello Matrix!"))
        XCTAssertEqual(context.viewState.aliasLocalPart, "hello-world")
        XCTAssertEqual(context.viewState.roomName, "Hello Matrix!")
        
        // Deleting the whole name will restore the sync
        context.send(viewAction: .updateRoomName(""))
        XCTAssertEqual(context.viewState.aliasLocalPart, "")
        XCTAssertEqual(context.viewState.roomName, "")
        
        context.send(viewAction: .updateRoomName("Hello# Matrix!"))
        XCTAssertEqual(context.viewState.aliasLocalPart, "hello-matrix!")
        XCTAssertEqual(context.viewState.roomName, "Hello# Matrix!")
    }
}