//
// 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 XCTest

@testable import ElementX

@MainActor
class RoomChangeRolesScreenViewModelTests: XCTestCase {
    var viewModel: RoomChangeRolesScreenViewModelProtocol!
    var roomProxy: JoinedRoomProxyMock!
    
    var context: RoomChangeRolesScreenViewModelType.Context {
        viewModel.context
    }

    func testInitialStateAdministrators() {
        setupViewModel(mode: .administrator)
        XCTAssertEqual(context.viewState.membersToPromote, [])
        XCTAssertEqual(context.viewState.membersToDemote, [])
        XCTAssertEqual(context.viewState.administrators, context.viewState.visibleAdministrators)
        XCTAssertEqual(context.viewState.moderators, context.viewState.visibleModerators)
        XCTAssertEqual(context.viewState.users, context.viewState.visibleUsers)
        XCTAssertEqual(context.viewState.membersWithRole.count, 2)
        XCTAssertEqual(context.viewState.membersWithRole.first?.id, RoomMemberProxyMock.mockAdmin.userID)
        XCTAssertFalse(context.viewState.hasChanges)
        XCTAssertFalse(context.viewState.isSearching)
    }

    func testInitialStateModerators() {
        setupViewModel(mode: .moderator)
        XCTAssertEqual(context.viewState.membersToPromote, [])
        XCTAssertEqual(context.viewState.membersToDemote, [])
        XCTAssertEqual(context.viewState.administrators, context.viewState.visibleAdministrators)
        XCTAssertEqual(context.viewState.moderators, context.viewState.visibleModerators)
        XCTAssertEqual(context.viewState.users, context.viewState.visibleUsers)
        XCTAssertEqual(context.viewState.membersWithRole.count, 1)
        XCTAssertEqual(context.viewState.membersWithRole.first?.id, RoomMemberProxyMock.mockModerator.userID)
        XCTAssertFalse(context.viewState.hasChanges)
        XCTAssertFalse(context.viewState.isSearching)
    }
    
    func testToggleUserOn() {
        testInitialStateModerators()
        guard let firstUser = context.viewState.users.first(where: { !context.viewState.isMemberSelected($0) }) else {
            XCTFail("There should be a regular user available to promote.")
            return
        }
        
        context.send(viewAction: .toggleMember(firstUser))
        
        XCTAssertEqual(context.viewState.membersToPromote, [firstUser])
        XCTAssertEqual(context.viewState.membersToDemote, [])
        XCTAssertEqual(context.viewState.membersWithRole.count, 2)
        XCTAssertTrue(context.viewState.membersWithRole.contains(firstUser))
        XCTAssertTrue(context.viewState.hasChanges)
    }
    
    func testToggleUserOff() {
        testToggleUserOn()
        guard let firstUser = context.viewState.membersToPromote.first else {
            XCTFail("There should be a promoted member before we begin.")
            return
        }
        
        context.send(viewAction: .toggleMember(firstUser))
        
        XCTAssertEqual(context.viewState.membersToPromote, [])
        XCTAssertEqual(context.viewState.membersToDemote, [])
        XCTAssertEqual(context.viewState.membersWithRole.count, 1)
        XCTAssertFalse(context.viewState.membersWithRole.contains(firstUser))
        XCTAssertFalse(context.viewState.hasChanges)
    }
    
    func testDemoteToggledUser() {
        testToggleUserOn()
        guard let firstUser = context.viewState.membersToPromote.first else {
            XCTFail("There should be a promoted member before we begin.")
            return
        }
        
        context.send(viewAction: .demoteMember(firstUser))
        
        XCTAssertEqual(context.viewState.membersToPromote, [])
        XCTAssertEqual(context.viewState.membersToDemote, [])
        XCTAssertEqual(context.viewState.membersWithRole.count, 1)
        XCTAssertFalse(context.viewState.membersWithRole.contains(firstUser))
        XCTAssertFalse(context.viewState.hasChanges)
    }
    
    func testToggleModeratorOff() {
        testInitialStateModerators()
        guard let existingModerator = context.viewState.membersWithRole.first else {
            XCTFail("There should be a member with the role before we begin.")
            return
        }
        
        context.send(viewAction: .toggleMember(existingModerator))
        
        XCTAssertEqual(context.viewState.membersToPromote, [])
        XCTAssertEqual(context.viewState.membersToDemote, [existingModerator])
        XCTAssertEqual(context.viewState.membersWithRole.count, 0)
        XCTAssertFalse(context.viewState.membersWithRole.contains(existingModerator))
        XCTAssertTrue(context.viewState.hasChanges)
    }
    
    func testToggleModeratorOn() {
        testToggleModeratorOff()
        
        guard let demotedMember = context.viewState.membersToDemote.first else {
            XCTFail("There should be a member selected to demote before we begin.")
            return
        }
        
        context.send(viewAction: .toggleMember(demotedMember))
        
        XCTAssertEqual(context.viewState.membersToPromote, [])
        XCTAssertEqual(context.viewState.membersToDemote, [])
        XCTAssertEqual(context.viewState.membersWithRole.count, 1)
        XCTAssertTrue(context.viewState.membersWithRole.contains(demotedMember))
        XCTAssertFalse(context.viewState.hasChanges)
    }
    
    func testDemoteModerator() {
        testInitialStateModerators()
        guard let existingModerator = context.viewState.membersWithRole.first else {
            XCTFail("There should be a member with the role before we begin.")
            return
        }
        
        context.send(viewAction: .demoteMember(existingModerator))
        
        XCTAssertEqual(context.viewState.membersToPromote, [])
        XCTAssertEqual(context.viewState.membersToDemote, [existingModerator])
        XCTAssertEqual(context.viewState.membersWithRole.count, 0)
        XCTAssertFalse(context.viewState.membersWithRole.contains(existingModerator))
        XCTAssertTrue(context.viewState.hasChanges)
    }
    
    func testSaveModeratorChanges() async throws {
        // Given the change roles view model for moderators.
        setupViewModel(mode: .moderator)
        
        guard let firstUser = context.viewState.users.first(where: { !context.viewState.isMemberSelected($0) }),
              let existingModerator = context.viewState.membersWithRole.first else {
            XCTFail("There should be a regular user and a moderator to begin with.")
            return
        }
        
        // When promoting a regular user and demoting a moderator.
        context.send(viewAction: .toggleMember(firstUser))
        context.send(viewAction: .toggleMember(existingModerator))
        context.send(viewAction: .save)
        
        try await Task.sleep(for: .milliseconds(100))
        
        // Then no warning should be shown, and the call to update the users should be made straight away.
        XCTAssertTrue(roomProxy.updatePowerLevelsForUsersCalled)
        XCTAssertEqual(roomProxy.updatePowerLevelsForUsersReceivedUpdates?.count, 2)
        XCTAssertEqual(roomProxy.updatePowerLevelsForUsersReceivedUpdates?.contains { $0.userID == existingModerator.id && $0.powerLevel == 0 }, true)
        XCTAssertEqual(roomProxy.updatePowerLevelsForUsersReceivedUpdates?.contains { $0.userID == firstUser.id && $0.powerLevel == 50 }, true)
    }
    
    func testSavePromotedAdministrator() async throws {
        // Given the change roles view model for administrators.
        setupViewModel(mode: .administrator)
        XCTAssertNil(context.alertInfo)
        
        guard let firstUser = context.viewState.users.first(where: { !context.viewState.isMemberSelected($0) }) else {
            XCTFail("There should be a regular user to begin with.")
            return
        }
        
        // When saving changes to promote a user to an administrator.
        context.send(viewAction: .toggleMember(firstUser))
        context.send(viewAction: .save)
        
        // Then an alert should be shown to warn the action cannot be undone.
        XCTAssertNotNil(context.alertInfo)
        
        // When confirming the prompt
        context.alertInfo?.primaryButton.action?()
        try await Task.sleep(for: .milliseconds(100))
        
        // Then the user should be made into an administrator.
        XCTAssertTrue(roomProxy.updatePowerLevelsForUsersCalled)
        XCTAssertEqual(roomProxy.updatePowerLevelsForUsersReceivedUpdates?.count, 1)
        XCTAssertEqual(roomProxy.updatePowerLevelsForUsersReceivedUpdates?.contains { $0.userID == firstUser.id && $0.powerLevel == 100 }, true)
    }
    
    private func setupViewModel(mode: RoomMemberDetails.Role) {
        roomProxy = JoinedRoomProxyMock(.init(members: .allMembersAsAdmin))
        viewModel = RoomChangeRolesScreenViewModel(mode: mode,
                                                   roomProxy: roomProxy,
                                                   mediaProvider: MediaProviderMock(configuration: .init()),
                                                   userIndicatorController: UserIndicatorControllerMock(),
                                                   analytics: ServiceLocator.shared.analytics)
    }
}