//
// 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
@testable import ElementX
import MatrixRustSDKMocks
import Testing

@MainActor
struct MessageForwardingScreenViewModelTests {
    let forwardingPayload = MessageForwardingPayload(ids: [.event(uniqueID: .init("t1"), eventOrTransactionID: .eventID("t1")),
                                                           .event(uniqueID: .init("t2"), eventOrTransactionID: .eventID("t2"))],
                                                     roomID: "1",
                                                     contents: [RoomMessageEventContentWithoutRelationSDKMock(),
                                                                RoomMessageEventContentWithoutRelationSDKMock()])
    var viewModel: MessageForwardingScreenViewModelProtocol!
    var context: MessageForwardingScreenViewModelType.Context!
    
    init() {
        let clientProxy = ClientProxyMock(.init())
        clientProxy.roomForIdentifierClosure = { .joined(JoinedRoomProxyMock(.init(id: $0))) }
        
        viewModel = MessageForwardingScreenViewModel(forwardingPayload: forwardingPayload,
                                                     userSession: UserSessionMock(.init(clientProxy: clientProxy)),
                                                     roomSummaryProvider: RoomSummaryProviderMock(.init(state: .loaded(.mockRooms))),
                                                     userIndicatorController: UserIndicatorControllerMock())
        context = viewModel.context
    }
    
    @Test
    func initialState() {
        #expect(!context.viewState.rooms.contains { $0.id == forwardingPayload.roomID }, "The source room ID shouldn't be shown")
        #expect(!context.viewState.rooms.contains { $0.id == "7" }, "Upgraded rooms shouldn't be shown")
    }
    
    @Test
    mutating func suggestionsShowRecentlyVisitedRooms() async throws {
        viewModel = makeViewModel(recentlyVisitedRoomIDs: ["3", "5", "2"])
        context = viewModel.context
        
        let deferred = deferFulfillment(context.$viewState) { !$0.suggestedRooms.isEmpty }
        try await deferred.fulfill()
        
        #expect(context.viewState.suggestedRooms.map(\.id) == ["3", "5", "2"])
    }
    
    @Test
    mutating func suggestionsOnlyIncludeRoomsThatCanBeForwardedTo() async throws {
        viewModel = makeViewModel(recentlyVisitedRoomIDs: [forwardingPayload.roomID, "space", "7", "someAwesomeRoomId1", "left", "!unknown:matrix.org", "2"])
        context = viewModel.context
        
        let deferred = deferFulfillment(context.$viewState) { !$0.suggestedRooms.isEmpty }
        try await deferred.fulfill()
        
        #expect(context.viewState.suggestedRooms.map(\.id) == ["2"])
    }
    
    @Test
    mutating func suggestionsAreLimitedToFiveRooms() async throws {
        viewModel = makeViewModel(recentlyVisitedRoomIDs: [forwardingPayload.roomID, "7", "someAwesomeRoomId1", "2", "3", "4", "5", "6", "0"])
        context = viewModel.context
        
        let deferred = deferFulfillment(context.$viewState) { !$0.suggestedRooms.isEmpty }
        try await deferred.fulfill()
        
        #expect(context.viewState.suggestedRooms.map(\.id) == ["2", "3", "4", "5", "6"])
    }
    
    @Test
    mutating func suggestedRoomsAreNotListedInChats() async throws {
        viewModel = makeViewModel(recentlyVisitedRoomIDs: ["2", "5"])
        context = viewModel.context
        
        let deferred = deferFulfillment(context.$viewState) { !$0.suggestedRooms.isEmpty }
        try await deferred.fulfill()
        
        let chatIDs = context.viewState.chats.map(\.id)
        #expect(!chatIDs.contains("2") && !chatIDs.contains("5"))
        #expect(chatIDs.contains("3"))
    }
    
    @Test
    mutating func searchingListsSuggestedRoomsInChats() async throws {
        viewModel = makeViewModel(recentlyVisitedRoomIDs: ["2"])
        context = viewModel.context
        
        let deferredSuggestions = deferFulfillment(context.$viewState) { !$0.suggestedRooms.isEmpty }
        try await deferredSuggestions.fulfill()
        
        let deferredSearch = deferFulfillment(context.$viewState) { $0.rooms.count == 1 }
        context.searchQuery = "Empire"
        try await deferredSearch.fulfill()
        
        #expect(context.viewState.chats.map(\.id) == ["2"])
    }
    
    @Test
    mutating func searchingHidesTheSuggestions() async throws {
        viewModel = makeViewModel(recentlyVisitedRoomIDs: ["2"])
        context = viewModel.context
        
        let deferredSuggestions = deferFulfillment(context.$viewState) { !$0.suggestedRooms.isEmpty }
        try await deferredSuggestions.fulfill()
        #expect(context.viewState.showsSuggestions)
        
        let deferredSearch = deferFulfillment(context.$viewState) { $0.rooms.count == 1 }
        context.searchQuery = "Second"
        try await deferredSearch.fulfill()
        #expect(!context.viewState.showsSuggestions)
        #expect(context.viewState.suggestedRooms.map(\.id) == ["2"], "The suggestions shouldn't be searched")
        
        context.searchQuery = ""
        #expect(context.viewState.showsSuggestions)
    }
    
    @Test
    mutating func noSuggestionsAreShownWhenNoRecentRoomCanBeSuggested() async throws {
        viewModel = makeViewModel(recentlyVisitedRoomIDs: [forwardingPayload.roomID, "7"])
        context = viewModel.context
        
        let deferred = deferFailure(context.$viewState.map(\.showsSuggestions), timeout: .seconds(1)) { $0 }
        try await deferred.fulfill()
    }
    
    @Test
    mutating func noSuggestionsAreShownWhenRecentRoomsFailToLoad() async throws {
        let clientProxy = ClientProxyMock(.init())
        clientProxy.recentlyVisitedRoomIDsReturnValue = .failure(.sdkError(ClientProxyMockError.generic))
        viewModel = MessageForwardingScreenViewModel(forwardingPayload: forwardingPayload,
                                                     userSession: UserSessionMock(.init(clientProxy: clientProxy)),
                                                     roomSummaryProvider: RoomSummaryProviderMock(.init(state: .loaded(.mockRooms))),
                                                     userIndicatorController: UserIndicatorControllerMock())
        context = viewModel.context
        
        let deferred = deferFailure(context.$viewState.map(\.showsSuggestions), timeout: .seconds(1)) { $0 }
        try await deferred.fulfill()
    }
    
    @Test
    mutating func roomSelection() {
        context.send(viewAction: .selectRoom(roomID: "2"))
        #expect(context.viewState.selectedRoomIDs == ["2"])
    }
    
    @Test
    mutating func searching() async throws {
        let deferred = deferFulfillment(context.$viewState) { state in
            state.rooms.count == 1
        }
        
        context.searchQuery = "Second"
        
        try await deferred.fulfill()
    }
    
    @Test
    mutating func forwarding() async throws {
        context.send(viewAction: .selectRoom(roomID: "2"))
        #expect(context.viewState.selectedRoomIDs == ["2"])
        
        let deferred = deferFulfillment(viewModel.actions) { action in
            switch action {
            case .sent(let roomIDs):
                return roomIDs == ["2"]
            default:
                return false
            }
        }
        
        context.send(viewAction: .send)
        
        try await deferred.fulfill()
    }
    
    @Test
    mutating func forwardingSendsEveryMessageToEveryRoomInOrder() async throws {
        let clientProxy = ClientProxyMock(.init())
        var roomProxies = [String: JoinedRoomProxyMock]()
        clientProxy.roomForIdentifierClosure = { roomID in
            let roomProxy = JoinedRoomProxyMock(.init(id: roomID))
            roomProxies[roomID] = roomProxy
            return .joined(roomProxy)
        }
        viewModel = MessageForwardingScreenViewModel(forwardingPayload: forwardingPayload,
                                                     userSession: UserSessionMock(.init(clientProxy: clientProxy)),
                                                     roomSummaryProvider: RoomSummaryProviderMock(.init(state: .loaded(.mockRooms))),
                                                     userIndicatorController: UserIndicatorControllerMock())
        context = viewModel.context
        
        context.send(viewAction: .selectRoom(roomID: "2"))
        context.send(viewAction: .selectRoom(roomID: "3"))
        
        let deferred = deferFulfillment(viewModel.actions) { action in
            if case .sent(let roomIDs) = action {
                return Set(roomIDs) == ["2", "3"]
            }
            return false
        }
        context.send(viewAction: .send)
        try await deferred.fulfill()
        
        let expectedContents = forwardingPayload.contents.map { ObjectIdentifier($0) }
        for roomID in ["2", "3"] {
            let timeline = try #require(roomProxies[roomID]?.timeline as? TimelineProxyMock)
            let sentContents = timeline.sendMessageEventContentReceivedInvocations.map { ObjectIdentifier($0) }
            #expect(sentContents == expectedContents)
        }
    }
    
    @Test
    mutating func forwardingToSeveralRoomsShowsAToast() async throws {
        let userIndicatorController = UserIndicatorControllerMock()
        viewModel = makeViewModel(userIndicatorController: userIndicatorController)
        context = viewModel.context
        
        context.send(viewAction: .selectRoom(roomID: "2"))
        context.send(viewAction: .selectRoom(roomID: "3"))
        
        let deferred = deferFulfillment(viewModel.actions) { action in
            if case .sent = action {
                return true
            }
            return false
        }
        context.send(viewAction: .send)
        try await deferred.fulfill()
        
        let titles = userIndicatorController.submitIndicatorDelayReceivedInvocations.map(\.indicator.title)
        #expect(titles == [L10n.screenRoomMessagesForwarded(2)])
    }
    
    @Test
    mutating func forwardingToOneRoomDoesNotShowAToast() async throws {
        let userIndicatorController = UserIndicatorControllerMock()
        viewModel = makeViewModel(userIndicatorController: userIndicatorController)
        context = viewModel.context
        
        context.send(viewAction: .selectRoom(roomID: "2"))
        
        let deferred = deferFulfillment(viewModel.actions) { action in
            if case .sent = action {
                return true
            }
            return false
        }
        context.send(viewAction: .send)
        try await deferred.fulfill()
        
        // The flow opens the room instead.
        #expect(userIndicatorController.submitIndicatorDelayCallsCount == 0)
    }
    
    @Test
    mutating func forwardingReportsRoomsThatCouldNotBeReached() async throws {
        let clientProxy = ClientProxyMock(.init())
        clientProxy.roomForIdentifierClosure = { roomID in
            roomID == "3" ? nil : .joined(JoinedRoomProxyMock(.init(id: roomID)))
        }
        let userIndicatorController = UserIndicatorControllerMock()
        viewModel = MessageForwardingScreenViewModel(forwardingPayload: forwardingPayload,
                                                     userSession: UserSessionMock(.init(clientProxy: clientProxy)),
                                                     roomSummaryProvider: RoomSummaryProviderMock(.init(state: .loaded(.mockRooms))),
                                                     userIndicatorController: userIndicatorController)
        context = viewModel.context
        
        context.send(viewAction: .selectRoom(roomID: "2"))
        context.send(viewAction: .selectRoom(roomID: "3"))
        
        let deferred = deferFulfillment(viewModel.actions) { action in
            if case .sent(let roomIDs) = action {
                return roomIDs == ["2"]
            }
            return false
        }
        context.send(viewAction: .send)
        try await deferred.fulfill()
        
        #expect(userIndicatorController.submitIndicatorDelayCallsCount == 1)
    }
    
    // MARK: - Helpers
    
    private func makeViewModel(recentlyVisitedRoomIDs: [String] = [],
                               userIndicatorController: UserIndicatorControllerProtocol = UserIndicatorControllerMock()) -> MessageForwardingScreenViewModelProtocol {
        let clientProxy = ClientProxyMock(.init())
        clientProxy.roomForIdentifierClosure = { .joined(JoinedRoomProxyMock(.init(id: $0))) }
        clientProxy.recentlyVisitedRoomIDsReturnValue = .success(recentlyVisitedRoomIDs)
        let knownRooms: [RoomSummary] = .mockRooms + .mockInvites + [.mock(id: "space", name: "Space", isSpace: true),
                                                                     .mock(id: "left", name: "Left", isJoined: false)]
        clientProxy.roomSummaryForIdentifierClosure = { roomID in knownRooms.first { $0.id == roomID } }
        
        return MessageForwardingScreenViewModel(forwardingPayload: forwardingPayload,
                                                userSession: UserSessionMock(.init(clientProxy: clientProxy)),
                                                roomSummaryProvider: RoomSummaryProviderMock(.init(state: .loaded(.mockRooms))),
                                                userIndicatorController: userIndicatorController)
    }
}