using System.Collections.Immutable;
using System.Linq;
using Microsoft.Extensions.Logging.Abstractions;
using StellaOps.Concelier.Core.Linksets;
using StellaOps.Scanner.Surface.Env;
using StellaOps.Scanner.WebService.Contracts;
using StellaOps.Scanner.WebService.Services;

namespace StellaOps.Scanner.WebService.Tests;

public sealed class LinksetResolverTests
{
    [Fact]
    public async Task ResolveAsync_MapsSeveritiesAndConflicts()
    {
        var linkset = new AdvisoryLinkset(
            TenantId: "tenant-a",
            Source: "osv",
            AdvisoryId: "CVE-2025-0001",
            ObservationIds: ImmutableArray<string>.Empty,
            Normalized: new AdvisoryLinksetNormalized(
                Purls: new[] { "pkg:npm/demo@1.0.0" },
                Cpes: Array.Empty<string>(),
                Versions: Array.Empty<string>(),
                Ranges: Array.Empty<Dictionary<string, object?>>(),
                Severities: new[]
                {
                    new Dictionary<string, object?>(StringComparer.Ordinal)
                    {
                        ["source"] = "nvd",
                        ["type"] = "cvssv3",
                        ["score"] = 9.8,
                        ["vector"] = "AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                        ["labels"] = new Dictionary<string, object?> { ["preferred"] = "true" }
                    }
                }),
            Provenance: null,
            Confidence: 0.91,
            Conflicts: new[] { new AdvisoryLinksetConflict("severity", "disagree", new[] { "cvssv2", "cvssv3" }) },
            CreatedAt: DateTimeOffset.UtcNow,
            BuiltByJobId: "job-1");

        var resolver = new LinksetResolver(
            new FakeLinksetQueryService(linkset),
            new FakeSurfaceEnvironment(),
            NullLogger<LinksetResolver>.Instance);

        var result = await resolver.ResolveAsync(new[]
        {
            new PolicyPreviewFindingDto { Id = "CVE-2025-0001" }
        }, CancellationToken.None);

        var summary = Assert.Single(result);
        Assert.Equal("CVE-2025-0001", summary.AdvisoryId);
        Assert.Equal("osv", summary.Source);
        Assert.Equal(0.91, summary.Confidence);

        var severity = Assert.Single(summary.Severities!);
        Assert.Equal("nvd", severity.Source);
        Assert.Equal("cvssv3", severity.Type);
        Assert.Equal(9.8, severity.Score);
        Assert.Equal("AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", severity.Vector);
        Assert.NotNull(severity.Labels);

        var conflict = Assert.Single(summary.Conflicts!);
        Assert.Equal("severity", conflict.Field);
        Assert.Equal("disagree", conflict.Reason);
    }

    [Fact]
    public async Task ResolveAsync_ReturnsEmptyWhenNoIds()
    {
        var resolver = new LinksetResolver(
            new FakeLinksetQueryService(),
            new FakeSurfaceEnvironment(),
            NullLogger<LinksetResolver>.Instance);

        var result = await resolver.ResolveAsync(Array.Empty<PolicyPreviewFindingDto>(), CancellationToken.None);
        Assert.Empty(result);
    }

    private sealed class FakeLinksetQueryService : IAdvisoryLinksetQueryService
    {
        private readonly AdvisoryLinkset[] _linksets;

        public FakeLinksetQueryService(params AdvisoryLinkset[] linksets)
        {
            _linksets = linksets;
        }

        public Task<AdvisoryLinksetQueryResult> QueryAsync(AdvisoryLinksetQueryOptions options, CancellationToken cancellationToken)
        {
            var matched = _linksets
                .Where(ls => options.AdvisoryIds?.Contains(ls.AdvisoryId, StringComparer.OrdinalIgnoreCase) == true)
                .ToImmutableArray();
            return Task.FromResult(new AdvisoryLinksetQueryResult(matched, null, false));
        }
    }

    private sealed class FakeSurfaceEnvironment : ISurfaceEnvironment
    {
        public SurfaceEnvironmentSettings Settings { get; } = new()
        {
            Tenant = "tenant-a"
        };

        public IReadOnlyDictionary<string, string> RawVariables { get; } = new Dictionary<string, string>(StringComparer.Ordinal)
        {
            ["SCANNER__TENANT"] = "tenant-a"
        };
    }
}