using System.Collections.Generic;
using System.Collections.Immutable;
using System.Net;
using System.Net.Http.Json;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.Extensions.DependencyInjection;
using StellaOps.Scanner.EntryTrace;
using StellaOps.Scanner.EntryTrace.Serialization;
using StellaOps.Scanner.WebService.Contracts;
using StellaOps.Scanner.WebService.Domain;
using StellaOps.Scanner.WebService.Services;
using Xunit;

namespace StellaOps.Scanner.WebService.Tests;

public sealed partial class ScansEndpointsTests
{
    [Fact]
    public async Task SubmitScanValidatesImageDescriptor()
    {
        using var secrets = new TestSurfaceSecretsScope();
        using var factory = new ScannerApplicationFactory();
        using var client = factory.CreateClient();

        var response = await client.PostAsJsonAsync("/api/v1/scans", new
        {
            image = new { reference = string.Empty, digest = string.Empty }
        });

        Assert.Equal(HttpStatusCode.BadRequest, response.StatusCode);
    }

    [Fact]
    public async Task SubmitScanPropagatesRequestAbortedToken()
    {
        using var secrets = new TestSurfaceSecretsScope();
        RecordingCoordinator coordinator = null!;

        using var factory = new ScannerApplicationFactory().WithOverrides(configuration =>
        {
            configuration["scanner:authority:enabled"] = "false";
        }, configureServices: services =>
        {
            services.AddSingleton<IScanCoordinator>(sp =>
            {
                coordinator = new RecordingCoordinator(
                    sp.GetRequiredService<IHttpContextAccessor>(),
                    sp.GetRequiredService<TimeProvider>(),
                    sp.GetRequiredService<IScanProgressPublisher>());
                return coordinator;
            });
        });

        using var client = factory.CreateClient(new WebApplicationFactoryClientOptions
        {
            AllowAutoRedirect = false
        });

        using var cts = new CancellationTokenSource();
        var request = new ScanSubmitRequest
        {
            Image = new ScanImageDescriptor { Reference = "example.com/demo:1.0" }
        };

        var response = await client.PostAsJsonAsync("/api/v1/scans", request, cts.Token);
        Assert.Equal(HttpStatusCode.Accepted, response.StatusCode);
        Assert.NotNull(coordinator);
        Assert.True(coordinator!.TokenMatched);
        Assert.True(coordinator.LastToken.CanBeCanceled);
    }

    [Fact]
    public async Task SubmitScanAddsDeterminismPinsToMetadata()
    {
        using var secrets = new TestSurfaceSecretsScope();
        RecordingCoordinator coordinator = null!;

        using var factory = new ScannerApplicationFactory().WithOverrides(configuration =>
        {
            configuration["scanner:determinism:feedSnapshotId"] = "feed-2025-11-26";
            configuration["scanner:determinism:policySnapshotId"] = "rev-42";
        }, configureServices: services =>
        {
            services.AddSingleton<IScanCoordinator>(sp =>
            {
                coordinator = new RecordingCoordinator(
                    sp.GetRequiredService<IHttpContextAccessor>(),
                    sp.GetRequiredService<TimeProvider>(),
                    sp.GetRequiredService<IScanProgressPublisher>());
                return coordinator;
            });
        });

        using var client = factory.CreateClient();
        var request = new ScanSubmitRequest
        {
            Image = new ScanImageDescriptor { Reference = "example.com/demo:1.0" }
        };

        var response = await client.PostAsJsonAsync("/api/v1/scans", request);

        Assert.Equal(HttpStatusCode.Accepted, response.StatusCode);
        Assert.NotNull(coordinator?.LastSubmission);
        var metadata = coordinator!.LastSubmission!.Metadata;

        Assert.Equal("feed-2025-11-26", metadata["determinism.feed"]);
        Assert.Equal("rev-42", metadata["determinism.policy"]);
    }

    [Fact]
    public async Task GetEntryTraceReturnsStoredResult()
    {
        using var secrets = new TestSurfaceSecretsScope();
        var scanId = $"scan-{Guid.NewGuid():n}";
        var generatedAt = DateTimeOffset.UtcNow;

        var plan = new EntryTracePlan(
            ImmutableArray.Create("/usr/local/bin/app"),
            ImmutableDictionary<string, string>.Empty,
            "/workspace",
            "appuser",
            "/usr/local/bin/app",
            EntryTraceTerminalType.Native,
            "go",
            0.9,
            ImmutableDictionary<string, string>.Empty);

        var terminal = new EntryTraceTerminal(
            "/usr/local/bin/app",
            EntryTraceTerminalType.Native,
            "go",
            0.9,
            ImmutableDictionary<string, string>.Empty,
            "appuser",
            "/workspace",
            ImmutableArray<string>.Empty);

        var graph = new EntryTraceGraph(
            EntryTraceOutcome.Resolved,
            ImmutableArray<EntryTraceNode>.Empty,
            ImmutableArray<EntryTraceEdge>.Empty,
            ImmutableArray<EntryTraceDiagnostic>.Empty,
            ImmutableArray.Create(plan),
            ImmutableArray.Create(terminal));

        var ndjson = EntryTraceNdjsonWriter.Serialize(graph, new EntryTraceNdjsonMetadata(scanId, "sha256:test", generatedAt));
        var storedResult = new EntryTraceResult(scanId, "sha256:test", generatedAt, graph, ndjson);

        using var factory = new ScannerApplicationFactory().WithOverrides(configureServices: services =>
        {
            services.AddSingleton<IEntryTraceResultStore>(new StubEntryTraceResultStore(storedResult));
        });

        using var client = factory.CreateClient();
        var response = await client.GetAsync($"/api/v1/scans/{scanId}/entrytrace");
        Assert.Equal(HttpStatusCode.OK, response.StatusCode);

        var payload = await response.Content.ReadFromJsonAsync<EntryTraceResponse>();
        Assert.NotNull(payload);
        Assert.Equal(storedResult.ScanId, payload!.ScanId);
        Assert.Equal(storedResult.ImageDigest, payload.ImageDigest);
        Assert.Equal(storedResult.Graph.Plans.Length, payload.Graph.Plans.Length);
    }

    [Fact]
    public async Task GetEntryTraceReturnsNotFoundWhenMissing()
    {
        using var secrets = new TestSurfaceSecretsScope();
        using var factory = new ScannerApplicationFactory().WithOverrides(configureServices: services =>
        {
            services.AddSingleton<IEntryTraceResultStore>(new StubEntryTraceResultStore(null));
        });

        using var client = factory.CreateClient();
        var response = await client.GetAsync("/api/v1/scans/scan-missing/entrytrace");
        Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
    }

    private sealed class RecordingCoordinator : IScanCoordinator
    {
        private readonly IHttpContextAccessor _accessor;
        private readonly InMemoryScanCoordinator _inner;

        public RecordingCoordinator(IHttpContextAccessor accessor, TimeProvider timeProvider, IScanProgressPublisher publisher)
        {
            _accessor = accessor;
            _inner = new InMemoryScanCoordinator(timeProvider, publisher);
        }

        public CancellationToken LastToken { get; private set; }
        public bool TokenMatched { get; private set; }
        public ScanSubmission? LastSubmission { get; private set; }

        public async ValueTask<ScanSubmissionResult> SubmitAsync(ScanSubmission submission, CancellationToken cancellationToken)
        {
            LastToken = cancellationToken;
            TokenMatched = _accessor.HttpContext?.RequestAborted.Equals(cancellationToken) ?? false;
            LastSubmission = submission;
            return await _inner.SubmitAsync(submission, cancellationToken);
        }

        public ValueTask<ScanSnapshot?> GetAsync(ScanId scanId, CancellationToken cancellationToken)
            => _inner.GetAsync(scanId, cancellationToken);

        public ValueTask<ScanSnapshot?> TryFindByTargetAsync(string? reference, string? digest, CancellationToken cancellationToken)
            => _inner.TryFindByTargetAsync(reference, digest, cancellationToken);

        public ValueTask<bool> AttachReplayAsync(ScanId scanId, ReplayArtifacts replay, CancellationToken cancellationToken)
            => _inner.AttachReplayAsync(scanId, replay, cancellationToken);

        public ValueTask<bool> AttachEntropyAsync(ScanId scanId, EntropySnapshot entropy, CancellationToken cancellationToken)
            => _inner.AttachEntropyAsync(scanId, entropy, cancellationToken);
    }

    private sealed class StubEntryTraceResultStore : IEntryTraceResultStore
    {
        private readonly EntryTraceResult? _result;

        public StubEntryTraceResultStore(EntryTraceResult? result)
        {
            _result = result;
        }

        public Task<EntryTraceResult?> GetAsync(string scanId, CancellationToken cancellationToken)
        {
            if (_result is not null && string.Equals(_result.ScanId, scanId, StringComparison.Ordinal))
            {
                return Task.FromResult<EntryTraceResult?>(_result);
            }

            return Task.FromResult<EntryTraceResult?>(null);
        }

        public Task StoreAsync(EntryTraceResult result, CancellationToken cancellationToken)
            => Task.CompletedTask;
    }
}