using System;
using System.IO;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using StellaOps.Signals.Options;
using StellaOps.Signals.Services;
using Xunit;

namespace StellaOps.Signals.Tests;

public class EdgeBundleIngestionServiceTests
{
    private readonly EdgeBundleIngestionService _service;
    private const string TestTenantId = "test-tenant";
    private const string TestGraphHash = "blake3:abc123def456";

    public EdgeBundleIngestionServiceTests()
    {
        var opts = new SignalsOptions();
        opts.Storage.RootPath = Path.GetTempPath();
        var options = Microsoft.Extensions.Options.Options.Create(opts);
        _service = new EdgeBundleIngestionService(NullLogger<EdgeBundleIngestionService>.Instance, options);
    }

    [Fact]
    public async Task IngestAsync_ParsesBundleAndStoresDocument()
    {
        // Arrange
        var bundle = new
        {
            schema = "edge-bundle-v1",
            bundleId = "bundle:test123",
            graphHash = TestGraphHash,
            bundleReason = "RuntimeHits",
            generatedAt = DateTimeOffset.UtcNow.ToString("O"),
            edges = new[]
            {
                new { from = "func_a", to = "func_b", kind = "call", reason = "RuntimeHit", revoked = false, confidence = 0.9 },
                new { from = "func_b", to = "func_c", kind = "call", reason = "RuntimeHit", revoked = false, confidence = 0.8 }
            }
        };
        var bundleJson = JsonSerializer.Serialize(bundle);
        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(bundleJson));

        // Act
        var result = await _service.IngestAsync(TestTenantId, stream, null);

        // Assert
        Assert.Equal("bundle:test123", result.BundleId);
        Assert.Equal(TestGraphHash, result.GraphHash);
        Assert.Equal("RuntimeHits", result.BundleReason);
        Assert.Equal(2, result.EdgeCount);
        Assert.Equal(0, result.RevokedCount);
        Assert.False(result.Quarantined);
        Assert.Contains("cas://reachability/edges/", result.CasUri);
    }

    [Fact]
    public async Task IngestAsync_TracksRevokedEdgesForQuarantine()
    {
        // Arrange
        var bundle = new
        {
            schema = "edge-bundle-v1",
            bundleId = "bundle:revoked123",
            graphHash = TestGraphHash,
            bundleReason = "Revoked",
            edges = new[]
            {
                new { from = "func_a", to = "func_b", kind = "call", reason = "Revoked", revoked = true, confidence = 1.0 },
                new { from = "func_b", to = "func_c", kind = "call", reason = "TargetRemoved", revoked = true, confidence = 1.0 },
                new { from = "func_c", to = "func_d", kind = "call", reason = "LowConfidence", revoked = false, confidence = 0.3 }
            }
        };
        var bundleJson = JsonSerializer.Serialize(bundle);
        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(bundleJson));

        // Act
        var result = await _service.IngestAsync(TestTenantId, stream, null);

        // Assert
        Assert.Equal(3, result.EdgeCount);
        Assert.Equal(2, result.RevokedCount);
        Assert.True(result.Quarantined);
    }

    [Fact]
    public async Task IsEdgeRevokedAsync_ReturnsTrueForRevokedEdges()
    {
        // Arrange
        var bundle = new
        {
            bundleId = "bundle:revoke-check",
            graphHash = TestGraphHash,
            bundleReason = "Revoked",
            edges = new[]
            {
                new { from = "vuln_func", to = "patched_func", kind = "call", reason = "Revoked", revoked = true, confidence = 1.0 }
            }
        };
        var bundleJson = JsonSerializer.Serialize(bundle);
        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(bundleJson));
        await _service.IngestAsync(TestTenantId, stream, null);

        // Act & Assert
        Assert.True(await _service.IsEdgeRevokedAsync(TestTenantId, TestGraphHash, "vuln_func", "patched_func"));
        Assert.False(await _service.IsEdgeRevokedAsync(TestTenantId, TestGraphHash, "other_func", "some_func"));
    }

    [Fact]
    public async Task GetBundlesForGraphAsync_ReturnsAllBundlesForGraph()
    {
        // Arrange - ingest multiple bundles
        var graphHash = $"blake3:graph_{Guid.NewGuid():N}";

        var bundle1 = new { bundleId = "bundle:1", graphHash, bundleReason = "RuntimeHits", edges = new[] { new { from = "a", to = "b", kind = "call", reason = "RuntimeHit", revoked = false, confidence = 1.0 } } };
        var bundle2 = new { bundleId = "bundle:2", graphHash, bundleReason = "InitArray", edges = new[] { new { from = "c", to = "d", kind = "call", reason = "InitArray", revoked = false, confidence = 1.0 } } };

        using var stream1 = new MemoryStream(Encoding.UTF8.GetBytes(JsonSerializer.Serialize(bundle1)));
        using var stream2 = new MemoryStream(Encoding.UTF8.GetBytes(JsonSerializer.Serialize(bundle2)));

        await _service.IngestAsync(TestTenantId, stream1, null);
        await _service.IngestAsync(TestTenantId, stream2, null);

        // Act
        var bundles = await _service.GetBundlesForGraphAsync(TestTenantId, graphHash);

        // Assert
        Assert.Equal(2, bundles.Length);
        Assert.Contains(bundles, b => b.BundleId == "bundle:1");
        Assert.Contains(bundles, b => b.BundleId == "bundle:2");
    }

    [Fact]
    public async Task GetRevokedEdgesAsync_ReturnsOnlyRevokedEdges()
    {
        // Arrange
        var graphHash = $"blake3:revoked_graph_{Guid.NewGuid():N}";
        var bundle = new
        {
            bundleId = "bundle:mixed",
            graphHash,
            bundleReason = "Revoked",
            edges = new[]
            {
                new { from = "a", to = "b", kind = "call", reason = "Revoked", revoked = true, confidence = 1.0 },
                new { from = "c", to = "d", kind = "call", reason = "RuntimeHit", revoked = false, confidence = 0.9 },
                new { from = "e", to = "f", kind = "call", reason = "Revoked", revoked = true, confidence = 1.0 }
            }
        };
        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(JsonSerializer.Serialize(bundle)));
        await _service.IngestAsync(TestTenantId, stream, null);

        // Act
        var revokedEdges = await _service.GetRevokedEdgesAsync(TestTenantId, graphHash);

        // Assert
        Assert.Equal(2, revokedEdges.Length);
        Assert.All(revokedEdges, e => Assert.True(e.Revoked));
    }

    [Fact]
    public async Task IngestAsync_WithDsseStream_SetsVerifiedAndDsseFields()
    {
        // Arrange
        var bundle = new
        {
            bundleId = "bundle:verified",
            graphHash = TestGraphHash,
            bundleReason = "RuntimeHits",
            edges = new[] { new { from = "a", to = "b", kind = "call", reason = "RuntimeHit", revoked = false, confidence = 1.0 } }
        };
        var dsseEnvelope = new
        {
            payloadType = "application/vnd.stellaops.edgebundle.predicate+json",
            payload = Convert.ToBase64String(Encoding.UTF8.GetBytes("{}")),
            signatures = new[] { new { keyid = "test", sig = "abc123" } }
        };

        using var bundleStream = new MemoryStream(Encoding.UTF8.GetBytes(JsonSerializer.Serialize(bundle)));
        using var dsseStream = new MemoryStream(Encoding.UTF8.GetBytes(JsonSerializer.Serialize(dsseEnvelope)));

        // Act
        var result = await _service.IngestAsync(TestTenantId, bundleStream, dsseStream);

        // Assert
        Assert.NotNull(result.DsseCasUri);
        Assert.EndsWith(".dsse", result.DsseCasUri);
    }

    [Fact]
    public async Task IngestAsync_ThrowsOnMissingGraphHash()
    {
        // Arrange
        var bundle = new
        {
            bundleId = "bundle:no-graph",
            bundleReason = "RuntimeHits",
            edges = Array.Empty<object>()
        };
        using var stream = new MemoryStream(Encoding.UTF8.GetBytes(JsonSerializer.Serialize(bundle)));

        // Act & Assert
        await Assert.ThrowsAsync<InvalidOperationException>(() => _service.IngestAsync(TestTenantId, stream, null));
    }

    [Fact]
    public async Task IngestAsync_UpdatesExistingBundleWithSameId()
    {
        // Arrange
        var graphHash = $"blake3:update_test_{Guid.NewGuid():N}";
        var bundle1 = new
        {
            bundleId = "bundle:same-id",
            graphHash,
            bundleReason = "RuntimeHits",
            edges = new[] { new { from = "a", to = "b", kind = "call", reason = "RuntimeHit", revoked = false, confidence = 0.5 } }
        };
        var bundle2 = new
        {
            bundleId = "bundle:same-id",
            graphHash,
            bundleReason = "RuntimeHits",
            edges = new[]
            {
                new { from = "a", to = "b", kind = "call", reason = "RuntimeHit", revoked = false, confidence = 0.9 },
                new { from = "c", to = "d", kind = "call", reason = "RuntimeHit", revoked = false, confidence = 0.8 }
            }
        };

        using var stream1 = new MemoryStream(Encoding.UTF8.GetBytes(JsonSerializer.Serialize(bundle1)));
        using var stream2 = new MemoryStream(Encoding.UTF8.GetBytes(JsonSerializer.Serialize(bundle2)));

        // Act
        await _service.IngestAsync(TestTenantId, stream1, null);
        await _service.IngestAsync(TestTenantId, stream2, null);

        // Assert
        var bundles = await _service.GetBundlesForGraphAsync(TestTenantId, graphHash);
        Assert.Single(bundles);
        Assert.Equal(2, bundles[0].Edges.Count); // Updated to have 2 edges
    }
}