// <copyright file="PedigreeBuilderTests.cs" company="StellaOps">
// Copyright (c) StellaOps. Licensed under the AGPL-3.0-or-later.
// </copyright>

using System.Collections.Immutable;
using FluentAssertions;
using Microsoft.Extensions.Time.Testing;
using StellaOps.Scanner.Emit.Pedigree;
using Xunit;

namespace StellaOps.Scanner.Emit.Tests.Pedigree;

/// <summary>
/// Unit tests for pedigree builder classes.
/// Sprint: SPRINT_20260107_005_002 Task PD-011
/// </summary>
[Trait("Category", "Unit")]
public sealed class PedigreeBuilderTests
{
    private static readonly DateTimeOffset FixedTime =
        new(2026, 1, 8, 12, 0, 0, TimeSpan.Zero);

    #region AncestorComponentBuilder Tests

    [Fact]
    public void AncestorBuilder_AddAncestor_CreatesComponent()
    {
        // Arrange
        var builder = new AncestorComponentBuilder();

        // Act
        var ancestors = builder
            .AddAncestor("openssl", "1.1.1n")
            .Build();

        // Assert
        ancestors.Should().HaveCount(1);
        ancestors[0].Name.Should().Be("openssl");
        ancestors[0].Version.Should().Be("1.1.1n");
        ancestors[0].Level.Should().Be(1);
    }

    [Fact]
    public void AncestorBuilder_AddGenericUpstream_CreatesPurl()
    {
        // Arrange
        var builder = new AncestorComponentBuilder();

        // Act
        var ancestors = builder
            .AddGenericUpstream("openssl", "1.1.1n", "https://www.openssl.org")
            .Build();

        // Assert
        ancestors[0].Purl.Should().Be("pkg:generic/openssl@1.1.1n");
        ancestors[0].ProjectUrl.Should().Be("https://www.openssl.org");
    }

    [Fact]
    public void AncestorBuilder_AddGitHubUpstream_CreatesGitHubPurl()
    {
        // Arrange
        var builder = new AncestorComponentBuilder();

        // Act
        var ancestors = builder
            .AddGitHubUpstream("openssl", "openssl", "openssl-3.0.0")
            .Build();

        // Assert
        ancestors[0].Purl.Should().Be("pkg:github/openssl/openssl@openssl-3.0.0");
        ancestors[0].ProjectUrl.Should().Be("https://github.com/openssl/openssl");
    }

    [Fact]
    public void AncestorBuilder_AddAncestryChain_SetsLevels()
    {
        // Arrange
        var builder = new AncestorComponentBuilder();

        // Act
        var ancestors = builder
            .AddAncestryChain(
                ("parent", "2.0", "pkg:generic/parent@2.0"),
                ("grandparent", "1.0", "pkg:generic/grandparent@1.0"))
            .Build();

        // Assert
        ancestors.Should().HaveCount(2);
        ancestors[0].Level.Should().Be(1);
        ancestors[0].Name.Should().Be("parent");
        ancestors[1].Level.Should().Be(2);
        ancestors[1].Name.Should().Be("grandparent");
    }

    #endregion

    #region VariantComponentBuilder Tests

    [Fact]
    public void VariantBuilder_AddDebianPackage_CreatesPurl()
    {
        // Arrange
        var builder = new VariantComponentBuilder();

        // Act
        var variants = builder
            .AddDebianPackage("openssl", "1.1.1n-0+deb11u5", "bullseye", "amd64")
            .Build();

        // Assert
        variants.Should().HaveCount(1);
        variants[0].Distribution.Should().Be("debian");
        variants[0].Release.Should().Be("bullseye");
        variants[0].Purl.Should().Contain("pkg:deb/debian/openssl");
        variants[0].Purl.Should().Contain("distro=debian-bullseye");
        variants[0].Purl.Should().Contain("arch=amd64");
    }

    [Fact]
    public void VariantBuilder_AddRpmPackage_CreatesPurl()
    {
        // Arrange
        var builder = new VariantComponentBuilder();

        // Act
        var variants = builder
            .AddRpmPackage("openssl", "1.1.1k-9.el9", "rhel", "9", "x86_64")
            .Build();

        // Assert
        variants[0].Distribution.Should().Be("rhel");
        variants[0].Purl.Should().Contain("pkg:rpm/rhel/openssl");
    }

    [Fact]
    public void VariantBuilder_AddAlpinePackage_CreatesPurl()
    {
        // Arrange
        var builder = new VariantComponentBuilder();

        // Act
        var variants = builder
            .AddAlpinePackage("openssl", "3.0.12-r4", "3.19")
            .Build();

        // Assert
        variants[0].Distribution.Should().Be("alpine");
        variants[0].Purl.Should().Contain("pkg:apk/alpine/openssl");
    }

    [Fact]
    public void VariantBuilder_MultipleDistros_OrdersByDistribution()
    {
        // Arrange
        var builder = new VariantComponentBuilder();

        // Act
        var variants = builder
            .AddDebianPackage("pkg", "1.0", "bookworm")
            .AddAlpinePackage("pkg", "1.0", "3.19")
            .AddRpmPackage("pkg", "1.0", "rhel", "9")
            .Build();

        // Assert
        variants[0].Distribution.Should().Be("alpine");
        variants[1].Distribution.Should().Be("debian");
        variants[2].Distribution.Should().Be("rhel");
    }

    #endregion

    #region CommitInfoBuilder Tests

    [Fact]
    public void CommitBuilder_AddCommit_CreatesCommitInfo()
    {
        // Arrange
        var builder = new CommitInfoBuilder();

        // Act
        var commits = builder
            .AddCommit("abc123def456", "https://github.com/org/repo/commit/abc123", "Fix bug")
            .Build();

        // Assert
        commits.Should().HaveCount(1);
        commits[0].Uid.Should().Be("abc123def456");
        commits[0].Message.Should().Be("Fix bug");
    }

    [Fact]
    public void CommitBuilder_AddGitHubCommit_GeneratesUrl()
    {
        // Arrange
        var builder = new CommitInfoBuilder();

        // Act
        var commits = builder
            .AddGitHubCommit("openssl", "openssl", "abc123def")
            .Build();

        // Assert
        commits[0].Url.Should().Be("https://github.com/openssl/openssl/commit/abc123def");
    }

    [Fact]
    public void CommitBuilder_AddCommitWithCveExtraction_ExtractsCves()
    {
        // Arrange
        var builder = new CommitInfoBuilder();

        // Act
        var commits = builder
            .AddCommitWithCveExtraction(
                "abc123",
                null,
                "Fix CVE-2024-1234 and CVE-2024-5678")
            .Build();

        // Assert
        commits[0].ResolvesCves.Should().BeEquivalentTo(new[] { "CVE-2024-1234", "CVE-2024-5678" });
    }

    [Fact]
    public void CommitBuilder_NormalizesShaTolowercase()
    {
        // Arrange
        var builder = new CommitInfoBuilder();

        // Act
        var commits = builder
            .AddCommit("ABC123DEF456")
            .Build();

        // Assert
        commits[0].Uid.Should().Be("abc123def456");
    }

    [Fact]
    public void CommitBuilder_TruncatesLongMessage()
    {
        // Arrange
        var builder = new CommitInfoBuilder();
        var longMessage = new string('x', 1000);

        // Act
        var commits = builder
            .AddCommit("abc123", message: longMessage)
            .Build();

        // Assert
        commits[0].Message!.Length.Should().BeLessThan(550);
        commits[0].Message.Should().EndWith("...");
    }

    #endregion

    #region PatchInfoBuilder Tests

    [Fact]
    public void PatchBuilder_AddBackport_CreatesPatchInfo()
    {
        // Arrange
        var builder = new PatchInfoBuilder();

        // Act
        var patches = builder
            .AddBackport(
                diffUrl: "https://patch.url/fix.patch",
                resolvesCves: new[] { "CVE-2024-1234" },
                source: "debian-security")
            .Build();

        // Assert
        patches.Should().HaveCount(1);
        patches[0].Type.Should().Be(PatchType.Backport);
        patches[0].Resolves.Should().ContainSingle(r => r.Id == "CVE-2024-1234");
        patches[0].Source.Should().Be("debian-security");
    }

    [Fact]
    public void PatchBuilder_AddFromFeedserOrigin_MapsTypes()
    {
        // Arrange
        var builder = new PatchInfoBuilder();

        // Act
        var patches = builder
            .AddFromFeedserOrigin("upstream")
            .AddFromFeedserOrigin("distro")
            .AddFromFeedserOrigin("vendor")
            .Build();

        // Assert
        patches[0].Type.Should().Be(PatchType.CherryPick);
        patches[1].Type.Should().Be(PatchType.Backport);
        patches[2].Type.Should().Be(PatchType.Unofficial);
    }

    [Fact]
    public void PatchBuilder_DeterminesSourceName()
    {
        // Arrange
        var builder = new PatchInfoBuilder();

        // Act
        var patches = builder
            .AddBackport(resolvesCves: new[] { "CVE-2024-1234", "GHSA-xxxx-yyyy-zzzz" })
            .Build();

        // Assert
        patches[0].Resolves.Should().Contain(r => r.Id == "CVE-2024-1234" && r.SourceName == "NVD");
        patches[0].Resolves.Should().Contain(r => r.Id == "GHSA-XXXX-YYYY-ZZZZ" && r.SourceName == "GitHub");
    }

    #endregion

    #region PedigreeNotesGenerator Tests

    [Fact]
    public void NotesGenerator_GeneratesBackportSummary()
    {
        // Arrange
        var timeProvider = new FakeTimeProvider(FixedTime);
        var generator = new PedigreeNotesGenerator(timeProvider);
        var data = new PedigreeData
        {
            Patches = new[]
            {
                new PatchInfo { Type = PatchType.Backport },
                new PatchInfo { Type = PatchType.Backport }
            }.ToImmutableArray()
        };

        // Act
        var notes = generator.GenerateNotes(data);

        // Assert
        notes.Should().Contain("2 backports");
    }

    [Fact]
    public void NotesGenerator_IncludesConfidenceAndTier()
    {
        // Arrange
        var timeProvider = new FakeTimeProvider(FixedTime);
        var generator = new PedigreeNotesGenerator(timeProvider);
        var data = new PedigreeData
        {
            Ancestors = new[] { new AncestorComponent { Name = "test", Version = "1.0" } }.ToImmutableArray()
        };

        // Act
        var notes = generator.GenerateNotes(data, confidencePercent: 95, feedserTier: 1);

        // Assert
        notes.Should().Contain("confidence 95%");
        notes.Should().Contain("Tier 1 (exact match)");
    }

    [Fact]
    public void NotesGenerator_GenerateSummaryLine_CreatesConciseSummary()
    {
        // Arrange
        var timeProvider = new FakeTimeProvider(FixedTime);
        var generator = new PedigreeNotesGenerator(timeProvider);
        var data = new PedigreeData
        {
            Patches = new[] { new PatchInfo { Type = PatchType.Backport } }.ToImmutableArray(),
            Ancestors = new[] { new AncestorComponent { Name = "openssl", Version = "1.1.1n" } }.ToImmutableArray()
        };

        // Act
        var summary = generator.GenerateSummaryLine(data);

        // Assert
        summary.Should().Contain("1 backport");
        summary.Should().Contain("from openssl 1.1.1n");
    }

    #endregion
}