using System.Collections.Immutable;
using System.Globalization;
using System.Text.Json.Nodes;
using StellaOps.Concelier.Models.Observations;
using StellaOps.Concelier.RawModels;
using StellaOps.Concelier.WebService.Services;
using Xunit;

namespace StellaOps.Concelier.WebService.Tests;

public class AdvisoryChunkCacheKeyTests
{
    [Fact]
    public void Create_NormalizesObservationOrdering()
    {
        var options = new AdvisoryChunkBuildOptions(
            "CVE-2025-0001",
            "fp",
            10,
            10,
            ImmutableHashSet.Create("workaround"),
            ImmutableHashSet<string>.Empty,
            8);

        var first = BuildObservation("obs-1", "sha256:one", "2025-11-18T00:00:00Z");
        var second = BuildObservation("obs-2", "sha256:two", "2025-11-18T00:05:00Z");

        var ordered = AdvisoryChunkCacheKey.Create("tenant-a", "CVE-2025-0001", options, new[] { first, second }, "fp");
        var reversed = AdvisoryChunkCacheKey.Create("tenant-a", "CVE-2025-0001", options, new[] { second, first }, "fp");

        Assert.Equal(ordered.Value, reversed.Value);
    }

    [Fact]
    public void Create_NormalizesFilterCasing()
    {
        var optionsLower = new AdvisoryChunkBuildOptions(
            "CVE-2025-0002",
            "fp",
            5,
            5,
            ImmutableHashSet.Create("workaround", "fix"),
            ImmutableHashSet.Create("ndjson"),
            1);

        var optionsUpper = new AdvisoryChunkBuildOptions(
            "CVE-2025-0002",
            "fp",
            5,
            5,
            ImmutableHashSet.Create("WorkAround", "FIX"),
            ImmutableHashSet.Create("NDJSON"),
            1);

        var observation = BuildObservation("obs-3", "sha256:three", "2025-11-18T00:10:00Z");

        var lower = AdvisoryChunkCacheKey.Create("tenant-a", "CVE-2025-0002", optionsLower, new[] { observation }, "fp");
        var upper = AdvisoryChunkCacheKey.Create("tenant-a", "CVE-2025-0002", optionsUpper, new[] { observation }, "fp");

        Assert.Equal(lower.Value, upper.Value);
    }

    [Fact]
    public void Create_ChangesWhenContentHashDiffers()
    {
        var options = new AdvisoryChunkBuildOptions(
            "CVE-2025-0003",
            "fp",
            5,
            5,
            ImmutableHashSet<string>.Empty,
            ImmutableHashSet<string>.Empty,
            1);

        var original = BuildObservation("obs-4", "sha256:orig", "2025-11-18T00:15:00Z");
        var mutated = BuildObservation("obs-4", "sha256:mut", "2025-11-18T00:15:00Z");

        var originalKey = AdvisoryChunkCacheKey.Create("tenant-a", "CVE-2025-0003", options, new[] { original }, "fp");
        var mutatedKey = AdvisoryChunkCacheKey.Create("tenant-a", "CVE-2025-0003", options, new[] { mutated }, "fp");

        Assert.NotEqual(originalKey.Value, mutatedKey.Value);
    }

    private static AdvisoryObservation BuildObservation(string id, string contentHash, string timestamp)
    {
        var createdAt = DateTimeOffset.Parse(timestamp, CultureInfo.InvariantCulture);

        return new AdvisoryObservation(
            id,
            tenant: "tenant-a",
            source: new AdvisoryObservationSource("nvd", "stream", "api"),
            upstream: new AdvisoryObservationUpstream(
                upstreamId: id,
                documentVersion: "1",
                fetchedAt: createdAt,
                receivedAt: createdAt,
                contentHash: contentHash,
                signature: new AdvisoryObservationSignature(false, null, null, null)),
            content: new AdvisoryObservationContent("csaf", "2.0", JsonNode.Parse("{}")!),
            linkset: new AdvisoryObservationLinkset(Array.Empty<string>(), Array.Empty<string>(), Array.Empty<string>(), Array.Empty<AdvisoryObservationReference>()),
            rawLinkset: new RawLinkset(),
            createdAt: createdAt);
    }
}