using System.Collections.Immutable;
using System.Net;
using System.Net.Http.Json;
using System.Text.Json;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using StellaOps.Scanner.SmartDiff.Detection;
using StellaOps.Scanner.WebService.Services;
using StellaOps.TestKit;

namespace StellaOps.Scanner.WebService.Tests;

[Trait("Category", TestCategories.Integration)]
public sealed class SmartDiffEndpointsTests
{
    private const string BasePath = "/api/v1/smart-diff";
    private static readonly DateTimeOffset FixedNow = new(2026, 2, 12, 8, 0, 0, TimeSpan.Zero);

    [Fact]
    public async Task GetScanScopedVexCandidates_ReturnsCandidatesForResolvedTargetDigest()
    {
        var imageDigest = "sha256:target-123";
        var candidate = CreateCandidate("candidate-1", imageDigest, requiresReview: true);
        var candidateStore = new InMemoryVexCandidateStore();
        await candidateStore.StoreCandidatesAsync([candidate], TestContext.Current.CancellationToken);

        var metadataRepository = new StubScanMetadataRepository();
        metadataRepository.Set("scan-1", new ScanMetadata(null, imageDigest, FixedNow));

        await using var factory = CreateFactory(candidateStore, metadataRepository);
        await factory.InitializeAsync();
        using var client = factory.CreateClient();

        var response = await client.GetAsync($"{BasePath}/scan-1/vex-candidates", TestContext.Current.CancellationToken);

        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
        using var payload = await JsonDocument.ParseAsync(await response.Content.ReadAsStreamAsync(TestContext.Current.CancellationToken), cancellationToken: TestContext.Current.CancellationToken);
        Assert.Equal(imageDigest, payload.RootElement.GetProperty("imageDigest").GetString());
        Assert.Equal(1, payload.RootElement.GetProperty("totalCandidates").GetInt32());

        var first = payload.RootElement.GetProperty("candidates")[0];
        Assert.Equal("candidate-1", first.GetProperty("candidateId").GetString());
        Assert.Equal("CVE-2026-0001", first.GetProperty("vulnId").GetString());
        Assert.Equal("vulnerable_code_not_in_execute_path", first.GetProperty("justification").GetString());
        Assert.True(first.GetProperty("requiresReview").GetBoolean());
        Assert.Equal("delta", first.GetProperty("evidenceLinks")[0].GetProperty("type").GetString());
    }

    [Fact]
    public async Task ReviewScanScopedCandidate_UpdatesCandidateReviewState()
    {
        var imageDigest = "sha256:target-456";
        var candidateStore = new InMemoryVexCandidateStore();
        await candidateStore.StoreCandidatesAsync(
            [CreateCandidate("candidate-2", imageDigest, requiresReview: true)],
            TestContext.Current.CancellationToken);

        var metadataRepository = new StubScanMetadataRepository();
        metadataRepository.Set("scan-2", new ScanMetadata(null, imageDigest, FixedNow));

        await using var factory = CreateFactory(candidateStore, metadataRepository);
        await factory.InitializeAsync();
        using var client = factory.CreateClient();

        var reviewResponse = await client.PostAsJsonAsync(
            $"{BasePath}/scan-2/vex-candidates/review",
            new ScanReviewRequestDto("candidate-2", "accept", "verified"),
            TestContext.Current.CancellationToken);

        Assert.Equal(HttpStatusCode.OK, reviewResponse.StatusCode);

        var candidateResponse = await client.GetAsync($"{BasePath}/candidates/candidate-2", TestContext.Current.CancellationToken);
        Assert.Equal(HttpStatusCode.OK, candidateResponse.StatusCode);

        using var payload = await JsonDocument.ParseAsync(await candidateResponse.Content.ReadAsStreamAsync(TestContext.Current.CancellationToken), cancellationToken: TestContext.Current.CancellationToken);
        var candidate = payload.RootElement.GetProperty("candidate");
        Assert.False(candidate.GetProperty("requiresReview").GetBoolean());
    }

    [Fact]
    public async Task GetScanSarif_EmbedsVexCandidateResults()
    {
        var imageDigest = "sha256:target-789";
        var candidateStore = new InMemoryVexCandidateStore();
        await candidateStore.StoreCandidatesAsync(
            [CreateCandidate("candidate-3", imageDigest, requiresReview: false)],
            TestContext.Current.CancellationToken);

        var metadataRepository = new StubScanMetadataRepository();
        metadataRepository.Set("scan-3", new ScanMetadata("sha256:base-111", imageDigest, FixedNow));

        await using var factory = CreateFactory(candidateStore, metadataRepository);
        await factory.InitializeAsync();
        using var client = factory.CreateClient();

        var response = await client.GetAsync($"{BasePath}/scans/scan-3/sarif", TestContext.Current.CancellationToken);

        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
        var body = await response.Content.ReadAsStringAsync(TestContext.Current.CancellationToken);

        Assert.Contains("\"ruleId\":\"SDIFF003\"", body, StringComparison.Ordinal);
        Assert.Contains("CVE-2026-0001", body, StringComparison.Ordinal);
        Assert.Contains("pkg:npm/test-component@1.0.0", body, StringComparison.Ordinal);
    }

    private static ScannerApplicationFactory CreateFactory(
        IVexCandidateStore candidateStore,
        IScanMetadataRepository metadataRepository)
    {
        return ScannerApplicationFactory.CreateLightweight()
            .WithOverrides(configureServices: services =>
            {
                services.RemoveAll<IVexCandidateStore>();
                services.RemoveAll<IMaterialRiskChangeRepository>();
                services.RemoveAll<IScanMetadataRepository>();

                services.AddSingleton(candidateStore);
                services.AddSingleton<IMaterialRiskChangeRepository, StubMaterialRiskChangeRepository>();
                services.AddSingleton(metadataRepository);
            });
    }

    private static VexCandidate CreateCandidate(string candidateId, string imageDigest, bool requiresReview)
    {
        return new VexCandidate(
            CandidateId: candidateId,
            FindingKey: new FindingKey("CVE-2026-0001", "pkg:npm/test-component@1.0.0"),
            SuggestedStatus: VexStatusType.NotAffected,
            Justification: VexJustification.VulnerableCodeNotInExecutePath,
            Rationale: "Reachability evidence shows vulnerable APIs are not reachable.",
            EvidenceLinks: ImmutableArray.Create(new EvidenceLink("delta", "oci://scanner/delta/scan-1", "sha256:evidence")),
            Confidence: 0.97,
            ImageDigest: imageDigest,
            GeneratedAt: FixedNow,
            ExpiresAt: FixedNow.AddDays(30),
            RequiresReview: requiresReview);
    }

    private sealed record ScanReviewRequestDto(string CandidateId, string Action, string? Comment);

    private sealed class StubScanMetadataRepository : IScanMetadataRepository
    {
        private readonly Dictionary<string, ScanMetadata> _metadataByScanId = new(StringComparer.OrdinalIgnoreCase);

        public void Set(string scanId, ScanMetadata metadata)
        {
            _metadataByScanId[scanId] = metadata;
        }

        public Task<ScanMetadata?> GetScanMetadataAsync(string scanId, CancellationToken cancellationToken = default)
        {
            cancellationToken.ThrowIfCancellationRequested();
            return Task.FromResult(_metadataByScanId.TryGetValue(scanId, out var metadata) ? metadata : null);
        }
    }

    private sealed class StubMaterialRiskChangeRepository : IMaterialRiskChangeRepository
    {
        public Task StoreChangeAsync(MaterialRiskChangeResult change, string scanId, CancellationToken ct = default) => Task.CompletedTask;

        public Task StoreChangesAsync(IReadOnlyList<MaterialRiskChangeResult> changes, string scanId, CancellationToken ct = default) => Task.CompletedTask;

        public Task<IReadOnlyList<MaterialRiskChangeResult>> GetChangesForScanAsync(string scanId, CancellationToken ct = default) =>
            Task.FromResult<IReadOnlyList<MaterialRiskChangeResult>>(Array.Empty<MaterialRiskChangeResult>());

        public Task<IReadOnlyList<MaterialRiskChangeResult>> GetChangesForFindingAsync(FindingKey findingKey, int limit = 10, CancellationToken ct = default) =>
            Task.FromResult<IReadOnlyList<MaterialRiskChangeResult>>(Array.Empty<MaterialRiskChangeResult>());

        public Task<MaterialRiskChangeQueryResult> QueryChangesAsync(MaterialRiskChangeQuery query, CancellationToken ct = default) =>
            Task.FromResult(new MaterialRiskChangeQueryResult(ImmutableArray<MaterialRiskChangeResult>.Empty, 0, query.Offset, query.Limit));
    }
}