using System.Reflection;
using AcDream.App.Rendering;
using AcDream.App.Net;
using AcDream.Core.Net;
using AcDream.Runtime;
using AcDream.Runtime.Session;

namespace AcDream.App.Tests.Net;

public sealed class GameWindowLiveSessionOwnershipTests
{
    private const BindingFlags PrivateInstance =
        BindingFlags.Instance | BindingFlags.NonPublic;

    [Fact]
    public void GameWindowRetainsCanonicalRuntimeAndFocusedHostButNoMirroredSession()
    {
        FieldInfo[] fields = typeof(GameWindow).GetFields(PrivateInstance);

        Assert.Contains(
            fields,
            field => field.Name == "_runtime"
                && field.FieldType == typeof(GameRuntime));
        Assert.Contains(
            fields,
            field => field.Name == "_liveSessionHost"
                && field.FieldType == typeof(LiveSessionHost));
        Assert.DoesNotContain(
            fields,
            field => field.Name == "_liveSessionController"
                || field.FieldType == typeof(LiveSessionController));
        Assert.DoesNotContain(fields, field => field.Name == "_liveSession");
        Assert.DoesNotContain(fields, field => field.FieldType == typeof(WorldSession));
        Assert.DoesNotContain(fields, field => field.FieldType == typeof(LiveSessionResetPlan));
        Assert.DoesNotContain(fields, field => field.Name == "_liveSessionEvents");
        Assert.DoesNotContain(fields, field => field.Name == "_liveSessionCommands");
    }

    [Fact]
    public void GraphicalSessionSourceBorrowsCanonicalRuntimeState()
    {
        FieldInfo[] fields = typeof(LiveSessionAppSource).GetFields(PrivateInstance);

        Assert.Equal(2, fields.Length);
        Assert.Contains(
            fields,
            field => field.Name == "_session"
                && field.FieldType == typeof(LiveSessionController));
        Assert.Contains(
            fields,
            field => field.Name == "_commands"
                && field.FieldType == typeof(LiveSessionCommandSurface));
        Assert.DoesNotContain(fields, field => field.FieldType == typeof(WorldSession));
        Assert.DoesNotContain(fields, field => field.FieldType == typeof(bool));
        Assert.DoesNotContain(
            fields,
            field => field.FieldType == typeof(RuntimeGenerationToken)
                || field.FieldType == typeof(ulong));
    }

    [Fact]
    public void ProductionWindowConstructsOnlyTheCanonicalRuntimeRoot()
    {
        string root = FindRepositoryRoot();
        string source = File.ReadAllText(Path.Combine(
            root,
            "src",
            "AcDream.App",
            "Rendering",
            "GameWindow.cs"));

        Assert.Equal(
            1,
            CountOccurrences(source, "new GameRuntime("));
        Assert.Contains(
            "private readonly GameRuntime _runtime;",
            source,
            StringComparison.Ordinal);
        Assert.Contains(
            "_runtimeHostLease = _runtime.AcquireHostLease(",
            source,
            StringComparison.Ordinal);
        string[] forbidden =
        [
            "new RuntimeEntityObjectLifetime(",
            "new RuntimeInventoryState(",
            "new RuntimeCharacterState(",
            "new RuntimeCommunicationState(",
            "new RuntimeActionState(",
            "new RuntimeLocalPlayerMovementState(",
            "new RuntimeWorldTransitState(",
            "new LiveSessionController(",
            "new GameRuntimeClock(",
        ];
        Assert.All(
            forbidden,
            value => Assert.DoesNotContain(
                value,
                source,
                StringComparison.Ordinal));
    }

    [Fact]
    public void ProductionSourceConstructsOnlyOneLiveSessionCommandSurface()
    {
        // CH3 review S5(b): LiveSessionCommandSurface has no dependencies of
        // its own — CH3 deliberately hoisted its single construction site
        // (SessionPlayerComposition.cs) so RuntimeSettingsTargets and the
        // retained UI's chat/inventory panels share the SAME generation-
        // gated command route. A second construction site anywhere under
        // src/AcDream.App would silently split that route into two, each
        // with its own activation/dispose lifecycle.
        string root = FindRepositoryRoot();
        string appRoot = Path.Combine(root, "src", "AcDream.App");

        int total = Directory
            .EnumerateFiles(appRoot, "*.cs", SearchOption.AllDirectories)
            .Sum(path => CountOccurrences(
                File.ReadAllText(path),
                "new LiveSessionCommandSurface("));

        Assert.Equal(1, total);
    }

    [Theory]
    [InlineData("TryStartLiveSession")]
    [InlineData("ClearInboundEntityState")]
    [InlineData("WireLiveSessionEvents")]
    [InlineData("DisposeLiveSessionRouting")]
    [InlineData("CreateLiveSessionBinding")]
    [InlineData("ApplyLiveSessionSelection")]
    [InlineData("ApplyLiveSessionEnteredWorld")]
    public void DisplacedLifecycleBodiesAreAbsent(string methodName)
    {
        Assert.Null(typeof(GameWindow).GetMethod(methodName, PrivateInstance));
    }

    /// <summary>
    /// Campaign CC CC7 review-fix round, F5 (2026-08-16): the reviewer
    /// found that deleting the <c>CharacterCreated</c>/<c>CreationFailed</c>
    /// delegate assignments from <see cref="AcDream.App.Net.LiveSessionRuntimeFactory"/>
    /// (the App-layer wiring that forwards those two Runtime events to
    /// <c>SessionStatusWriter</c>, feeding the launcher's status-payload
    /// cycle) leaves every test suite green. <c>LiveSessionRuntimeFactory</c>
    /// has exactly one production construction site
    /// (<c>SessionPlayerComposition.cs</c>), buried inside the full
    /// <c>GameWindow</c> composition graph, and no test in this repository
    /// constructs it directly — there is no practical seam to exercise the
    /// wiring behaviorally without a <see cref="GameWindow"/>. This test
    /// follows the SAME source-text-pin pattern the rest of this file
    /// already uses for wiring that can't otherwise be unit-tested
    /// (<see cref="ProductionWindowConstructsOnlyTheCanonicalRuntimeRoot"/>,
    /// <see cref="DisplacedLifecycleBodiesAreAbsent"/>): it fails if either
    /// delegate assignment is removed or its argument mapping changes. The
    /// exact PAYLOAD shape these calls must produce is pinned separately,
    /// at <c>SessionStatusWriterTests.CharacterCreatedAndCreationFailed_WriteThePinnedShape</c>
    /// (<c>tests/AcDream.Runtime.Tests/Session/SessionStatusWriterTests.cs</c>)
    /// — together the two tests cover "the delegates are bound" (here) and
    /// "they produce §LA1's exact payload" (there).
    /// </summary>
    [Fact]
    public void LiveSessionRuntimeFactoryBindsCharacterCreatedAndCreationFailedToTheStatusWriter()
    {
        string root = FindRepositoryRoot();
        string source = File.ReadAllText(Path.Combine(
            root,
            "src",
            "AcDream.App",
            "Net",
            "LiveSessionRuntimeFactory.cs"));

        Assert.Contains(
            "CharacterCreated: identity => _statusWriter.CharacterCreated(",
            source,
            StringComparison.Ordinal);
        Assert.Contains(
            "identity.Guid,",
            source,
            StringComparison.Ordinal);
        Assert.Contains(
            "identity.Name),",
            source,
            StringComparison.Ordinal);
        Assert.Contains(
            "CreationFailed: rejection => _statusWriter.CreationFailed(",
            source,
            StringComparison.Ordinal);
        Assert.Contains(
            "rejection.RawCode,",
            source,
            StringComparison.Ordinal);
        Assert.Contains(
            "rejection.Reason,",
            source,
            StringComparison.Ordinal);
        Assert.Contains(
            "rejection.AttemptedName)),",
            source,
            StringComparison.Ordinal);
    }

    private static int CountOccurrences(string source, string value)
    {
        int count = 0;
        int cursor = 0;
        while ((cursor = source.IndexOf(
                   value,
                   cursor,
                   StringComparison.Ordinal)) >= 0)
        {
            count++;
            cursor += value.Length;
        }
        return count;
    }

    private static string FindRepositoryRoot()
    {
        var current = new DirectoryInfo(AppContext.BaseDirectory);
        while (current is not null)
        {
            if (File.Exists(Path.Combine(current.FullName, "AcDream.slnx")))
                return current.FullName;
            current = current.Parent;
        }

        throw new DirectoryNotFoundException("AcDream.slnx was not found.");
    }
}