//
// Copyright 2022 New Vector Ltd
//
// 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.
//

import Combine
import XCTest

@testable import ElementX

@MainActor
class InviteUsersScreenViewModelTests: XCTestCase {
    var viewModel: InviteUsersScreenViewModelProtocol!
    var clientProxy: MockClientProxy!
    var userDiscoveryService: UserDiscoveryServiceMock!
    
    private let usersSubject = CurrentValueSubject<[UserProfile], Never>([])
    private var cancellables: Set<AnyCancellable> = []
    
    var context: InviteUsersScreenViewModel.Context {
        viewModel.context
    }
    
    override func setUpWithError() throws {
        clientProxy = .init(userID: "")
        userDiscoveryService = UserDiscoveryServiceMock()
        userDiscoveryService.fetchSuggestionsReturnValue = .success([])
        userDiscoveryService.searchProfilesWithReturnValue = .success([])
        let userSession = MockUserSession(clientProxy: clientProxy, mediaProvider: MockMediaProvider())
        usersSubject.send([])
        let viewModel = InviteUsersScreenViewModel(selectedUsers: usersSubject.asCurrentValuePublisher(), userSession: userSession, userDiscoveryService: userDiscoveryService)
        viewModel.state.usersSection = .init(type: .suggestions, users: [.mockAlice, .mockBob, .mockCharlie])
        self.viewModel = viewModel
        
        viewModel.actions.sink { [weak self] action in
            guard let self else { return }
            switch action {
            case .toggleUser(let user):
                var selectedUsers = usersSubject.value
                if let index = selectedUsers.firstIndex(where: { $0.userID == user.userID }) {
                    selectedUsers.remove(at: index)
                } else {
                    selectedUsers.append(user)
                }
                usersSubject.send(selectedUsers)
            default:
                break
            }
        }
        .store(in: &cancellables)
    }
    
    func testSelectUser() {
        XCTAssertTrue(context.viewState.selectedUsers.isEmpty)
        context.send(viewAction: .toggleUser(.mockAlice))
        XCTAssertTrue(context.viewState.selectedUsers.count == 1)
        XCTAssertEqual(context.viewState.selectedUsers.first?.userID, UserProfile.mockAlice.userID)
    }
    
    func testReselectUser() {
        XCTAssertTrue(context.viewState.selectedUsers.isEmpty)
        context.send(viewAction: .toggleUser(.mockAlice))
        XCTAssertEqual(context.viewState.selectedUsers.count, 1)
        XCTAssertEqual(context.viewState.selectedUsers.first?.userID, UserProfile.mockAlice.userID)
        context.send(viewAction: .toggleUser(.mockAlice))
        XCTAssertTrue(context.viewState.selectedUsers.isEmpty)
    }
    
    func testDeselectUser() {
        XCTAssertTrue(context.viewState.selectedUsers.isEmpty)
        context.send(viewAction: .toggleUser(.mockAlice))
        XCTAssertEqual(context.viewState.selectedUsers.count, 1)
        XCTAssertEqual(context.viewState.selectedUsers.first?.userID, UserProfile.mockAlice.userID)
        context.send(viewAction: .toggleUser(.mockAlice))
        XCTAssertTrue(context.viewState.selectedUsers.isEmpty)
    }
}