using MMoneyCoderSharp.Data;

namespace MBN_STOCK_WEBVIEW.LegacyApplication.Tests;

public sealed class LegacyTabActivationParityTests
{
    [Fact]
    public async Task ThemeEachActivation_LoadsOriginalEmptyQueryOncePerActivation()
    {
        // Original evidence: Control/UC4.cs UC4_Load starts timer1 and its first
        // timer1_Tick calls GetThemeByKeyword with the initially empty txts value.
        var service = new CountingThemeService();
        var controller = new LegacyOperatorController(
            Lookup(),
            themeWorkflow: new LegacyThemeWorkflow(service));

        var first = await controller.SelectTabAsync(LegacyOperatorTabId.Theme);
        Assert.Equal(string.Empty, service.Queries.Single());
        Assert.Single(first.Theme!.SearchResults);

        await controller.SelectTabAsync(LegacyOperatorTabId.Theme);
        Assert.Single(service.Queries);

        await controller.SelectTabAsync(LegacyOperatorTabId.Index);
        var second = await controller.SelectTabAsync(LegacyOperatorTabId.Theme);

        Assert.Collection(
            service.Queries,
            query => Assert.Equal(string.Empty, query),
            query => Assert.Equal(string.Empty, query));
        Assert.Single(second.Theme!.SearchResults);
    }

    [Fact]
    public async Task ExpertEachActivation_LoadsOriginalFullListOncePerActivation()
    {
        // Original evidence: Control/UC6.cs UC6_Load calls Data_Load, whose query
        // reads the complete EXPERT_LIST without a filter.
        var service = new CountingExpertService();
        var controller = new LegacyOperatorController(
            Lookup(),
            expertWorkflow: new LegacyExpertWorkflowController(service));

        var first = await controller.SelectTabAsync(LegacyOperatorTabId.Expert);
        Assert.Equal(string.Empty, service.Queries.Single());
        Assert.Single(first.Expert!.Search.Results);

        await controller.SelectTabAsync(LegacyOperatorTabId.Expert);
        Assert.Single(service.Queries);

        await controller.SelectTabAsync(LegacyOperatorTabId.Index);
        var second = await controller.SelectTabAsync(LegacyOperatorTabId.Expert);

        Assert.Collection(
            service.Queries,
            query => Assert.Equal(string.Empty, query),
            query => Assert.Equal(string.Empty, query));
        Assert.Single(second.Expert!.Search.Results);
    }

    [Fact]
    public async Task DragSwapThatActivatesTheme_UsesTheSameNativeInitialLoad()
    {
        var service = new CountingThemeService();
        var controller = new LegacyOperatorController(
            Lookup(),
            themeWorkflow: new LegacyThemeWorkflow(service));

        var state = await controller.SwapTabsAsync(
            LegacyOperatorTabId.Theme,
            LegacyOperatorTabId.Exchange);

        Assert.Equal(string.Empty, service.Queries.Single());
        Assert.Single(state.Theme!.SearchResults);
        Assert.Equal(
            LegacyOperatorTabId.Theme,
            Assert.Single(state.Tabs!, tab => tab.IsActive).Id);
    }

    [Fact]
    public async Task SupersededThemeActivation_DoesNotCommitAndRetriesWhenNeeded()
    {
        var service = new DelayedThemeService();
        var controller = new LegacyOperatorController(
            Lookup(),
            themeWorkflow: new LegacyThemeWorkflow(service));

        var firstActivation = controller.SelectTabAsync(LegacyOperatorTabId.Theme);
        await service.FirstRequestStarted.Task.WaitAsync(TimeSpan.FromSeconds(5));

        controller.SelectTab(LegacyOperatorTabId.Index);
        service.ReleaseFirstRequest.TrySetResult();
        var superseded = await firstActivation;

        Assert.Equal(
            LegacyOperatorTabId.Index,
            Assert.Single(superseded.Tabs!, tab => tab.IsActive).Id);

        var retried = await controller.SelectTabAsync(LegacyOperatorTabId.Theme);
        Assert.Equal(2, service.CallCount);
        Assert.Single(retried.Theme!.SearchResults);
    }

    private static ILegacyStockLookup Lookup() =>
        new StaticLookup(new LegacyStockSearchData(string.Empty, [], []));

    private sealed class StaticLookup : ILegacyStockLookup
    {
        private readonly LegacyStockSearchData _data;

        public StaticLookup(LegacyStockSearchData data)
        {
            _data = data;
        }

        public Task<LegacyStockSearchData> SearchAsync(
            string text,
            CancellationToken cancellationToken = default) => Task.FromResult(_data);
    }

    private sealed class CountingThemeService : IThemeSelectionService
    {
        private static readonly ThemeSelectionIdentity Identity = new(
            ThemeMarket.Krx,
            ThemeSession.NotApplicable,
            "00000001",
            "Theme A");

        public List<string> Queries { get; } = [];

        public Task<ThemeSearchResult> SearchAsync(
            string query,
            ThemeSession nxtSession,
            int maximumResults = LegacyThemeSelectionService.DefaultMaximumResults,
            CancellationToken cancellationToken = default)
        {
            Queries.Add(query);
            return Task.FromResult(CreateThemeResult(query, nxtSession));
        }

        public Task<ThemePreviewResult> PreviewAsync(
            ThemeSelectionIdentity identity,
            int maximumItems = LegacyThemeSelectionService.DefaultMaximumPreviewItems,
            CancellationToken cancellationToken = default) => Task.FromResult(
                new ThemePreviewResult(identity, DateTimeOffset.UtcNow, [], false));

        public static ThemeSearchResult CreateThemeResult(
            string query,
            ThemeSession nxtSession) => new(
                query,
                nxtSession,
                DateTimeOffset.UtcNow,
                [new ThemeSelectorItem(Identity, DataSourceKind.Oracle)],
                false);
    }

    private sealed class DelayedThemeService : IThemeSelectionService
    {
        private int _callCount;

        public TaskCompletionSource FirstRequestStarted { get; } = new(
            TaskCreationOptions.RunContinuationsAsynchronously);

        public TaskCompletionSource ReleaseFirstRequest { get; } = new(
            TaskCreationOptions.RunContinuationsAsynchronously);

        public int CallCount => Volatile.Read(ref _callCount);

        public async Task<ThemeSearchResult> SearchAsync(
            string query,
            ThemeSession nxtSession,
            int maximumResults = LegacyThemeSelectionService.DefaultMaximumResults,
            CancellationToken cancellationToken = default)
        {
            if (Interlocked.Increment(ref _callCount) == 1)
            {
                FirstRequestStarted.TrySetResult();
                await ReleaseFirstRequest.Task.WaitAsync(cancellationToken);
            }

            return CountingThemeService.CreateThemeResult(query, nxtSession);
        }

        public Task<ThemePreviewResult> PreviewAsync(
            ThemeSelectionIdentity identity,
            int maximumItems = LegacyThemeSelectionService.DefaultMaximumPreviewItems,
            CancellationToken cancellationToken = default) => Task.FromResult(
                new ThemePreviewResult(identity, DateTimeOffset.UtcNow, [], false));
    }

    private sealed class CountingExpertService : IExpertSelectionService
    {
        private static readonly ExpertSelectionIdentity Identity = new("0001", "Expert A");

        public List<string> Queries { get; } = [];

        public Task<ExpertSearchResult> SearchAsync(
            string query = "",
            int maximumResults = LegacyExpertSelectionService.DefaultMaximumResults,
            CancellationToken cancellationToken = default)
        {
            Queries.Add(query);
            return Task.FromResult(new ExpertSearchResult(
                query,
                DateTimeOffset.UtcNow,
                [new ExpertSelectorItem(Identity, DataSourceKind.Oracle)],
                false));
        }

        public Task<ExpertPreviewResult> PreviewAsync(
            ExpertSelectionIdentity identity,
            int maximumItems = LegacyExpertSelectionService.DefaultMaximumPreviewItems,
            CancellationToken cancellationToken = default) => Task.FromResult(
                new ExpertPreviewResult(identity, DateTimeOffset.UtcNow, [], false));
    }
}