using System.Collections.Immutable;
using System.Text.Json.Nodes;
using StellaOps.Graph.Indexer.Documents;
using StellaOps.Graph.Indexer.Ingestion.Sbom;
using StellaOps.Graph.Indexer.Schema;
using StellaOps.TestKit;

namespace StellaOps.Graph.Indexer.Tests;

public sealed class SbomSnapshotExporterTests
{
    [Trait("Category", TestCategories.Unit)]
        [Fact]
    public async Task ExportAsync_WritesCanonicalFilesWithStableHash()
    {
        var snapshot = new SbomSnapshot
        {
            Tenant = "tenant-c",
            ArtifactDigest = "sha256:artifact-c",
            SbomDigest = "sha256:sbom-c",
            BaseArtifacts = Array.Empty<SbomBaseArtifact>()
        };

        var nodes = new[]
        {
            CreateArtifactNode("art", snapshot.ArtifactDigest, snapshot.SbomDigest),
            CreateComponentNode("comp", "pkg:npm/test@1.0.0")
        }.ToImmutableArray();

        var edges = new[]
        {
            CreateEdge("edge-1", source: "art", target: "comp")
        }.ToImmutableArray();

        var batch = new GraphBuildBatch(nodes, edges);
        var exporter = new SbomSnapshotExporter(new GraphSnapshotBuilder(), new FileSystemSnapshotFileWriter(_tempRoot));

        await exporter.ExportAsync(snapshot, batch, CancellationToken.None);

        var manifestPath = Path.Combine(_tempRoot, "manifest.json");
        var manifestJson = JsonNode.Parse(await File.ReadAllTextAsync(manifestPath))!.AsObject();

        // Hash in manifest should equal recomputed canonical hash.
        var computed = GraphIdentity.ComputeDocumentHash(manifestJson);
        Assert.Equal(computed, manifestJson["hash"]!.GetValue<string>());

        // Adjacency should contain both nodes and edges, deterministic ids.
        var adjacency = JsonNode.Parse(await File.ReadAllTextAsync(Path.Combine(_tempRoot, "adjacency.json")))!.AsObject();
        var nodesArray = adjacency["nodes"]!.AsArray();
        Assert.Equal(2, nodesArray.Count);
        Assert.Equal("art", nodesArray[0]! ["node_id"]!.GetValue<string>());

        // nodes.jsonl and edges.jsonl should both exist and be non-empty.
        Assert.True(new FileInfo(Path.Combine(_tempRoot, "nodes.jsonl")).Length > 0);
        Assert.True(new FileInfo(Path.Combine(_tempRoot, "edges.jsonl")).Length > 0);
    }

    public SbomSnapshotExporterTests()
    {
        _tempRoot = Path.Combine(Path.GetTempPath(), "graph-snapshot-tests", Guid.NewGuid().ToString("n"));
        Directory.CreateDirectory(_tempRoot);
    }

    public void Dispose()
    {
        try { Directory.Delete(_tempRoot, recursive: true); } catch { /* ignore */ }
    }

    private readonly string _tempRoot;

    private static JsonObject CreateArtifactNode(string id, string artifactDigest, string sbomDigest)
    {
        var attributes = new JsonObject
        {
            ["artifact_digest"] = artifactDigest,
            ["sbom_digest"] = sbomDigest
        };

        return new JsonObject
        {
            ["id"] = id,
            ["kind"] = "artifact",
            ["attributes"] = attributes
        };
    }

    private static JsonObject CreateComponentNode(string id, string purl)
    {
        var attributes = new JsonObject
        {
            ["purl"] = purl
        };

        return new JsonObject
        {
            ["id"] = id,
            ["kind"] = "component",
            ["attributes"] = attributes
        };
    }

    private static JsonObject CreateEdge(string id, string source, string target)
    {
        return new JsonObject
        {
            ["id"] = id,
            ["source"] = source,
            ["target"] = target
        };
    }
}