// <copyright file="IPedigreeDataProvider.cs" company="StellaOps">
// Copyright (c) StellaOps. Licensed under the BUSL-1.1.
// </copyright>

using System.Collections.Immutable;

namespace StellaOps.Scanner.Emit.Pedigree;

/// <summary>
/// Provider interface for retrieving component pedigree data from Feedser.
/// Sprint: SPRINT_20260107_005_002 Task PD-001
/// </summary>
public interface IPedigreeDataProvider
{
    /// <summary>
    /// Retrieves pedigree data for a component identified by its PURL.
    /// </summary>
    /// <param name="purl">Package URL identifying the component.</param>
    /// <param name="cancellationToken">Cancellation token.</param>
    /// <returns>Pedigree data if available, null otherwise.</returns>
    Task<PedigreeData?> GetPedigreeAsync(
        string purl,
        CancellationToken cancellationToken = default);

    /// <summary>
    /// Retrieves pedigree data for multiple components.
    /// </summary>
    /// <param name="purls">Package URLs identifying the components.</param>
    /// <param name="cancellationToken">Cancellation token.</param>
    /// <returns>Dictionary of PURL to pedigree data (missing components not included).</returns>
    Task<IReadOnlyDictionary<string, PedigreeData>> GetPedigreesBatchAsync(
        IEnumerable<string> purls,
        CancellationToken cancellationToken = default);
}

/// <summary>
/// Aggregate of pedigree information for a component.
/// </summary>
public sealed record PedigreeData
{
    /// <summary>
    /// Gets the ancestor components (upstream sources).
    /// </summary>
    public ImmutableArray<AncestorComponent> Ancestors { get; init; } = ImmutableArray<AncestorComponent>.Empty;

    /// <summary>
    /// Gets the variant components (distro-specific packages derived from same source).
    /// </summary>
    public ImmutableArray<VariantComponent> Variants { get; init; } = ImmutableArray<VariantComponent>.Empty;

    /// <summary>
    /// Gets the relevant commits (security fixes, backports).
    /// </summary>
    public ImmutableArray<CommitInfo> Commits { get; init; } = ImmutableArray<CommitInfo>.Empty;

    /// <summary>
    /// Gets the patches applied to the component.
    /// </summary>
    public ImmutableArray<PatchInfo> Patches { get; init; } = ImmutableArray<PatchInfo>.Empty;

    /// <summary>
    /// Gets optional notes about the pedigree (e.g., backport explanation).
    /// </summary>
    public string? Notes { get; init; }

    /// <summary>
    /// Gets whether any pedigree data is present.
    /// </summary>
    public bool HasData =>
        !Ancestors.IsDefaultOrEmpty ||
        !Variants.IsDefaultOrEmpty ||
        !Commits.IsDefaultOrEmpty ||
        !Patches.IsDefaultOrEmpty ||
        Notes is not null;
}

/// <summary>
/// Represents an upstream ancestor component.
/// </summary>
public sealed record AncestorComponent
{
    /// <summary>
    /// Gets the component type (e.g., "library", "application").
    /// </summary>
    public string Type { get; init; } = "library";

    /// <summary>
    /// Gets the component name.
    /// </summary>
    public required string Name { get; init; }

    /// <summary>
    /// Gets the upstream version.
    /// </summary>
    public required string Version { get; init; }

    /// <summary>
    /// Gets the Package URL for the ancestor.
    /// </summary>
    public string? Purl { get; init; }

    /// <summary>
    /// Gets the URL to the upstream project.
    /// </summary>
    public string? ProjectUrl { get; init; }

    /// <summary>
    /// Gets the relationship level (1 = direct parent, 2 = grandparent, etc.).
    /// </summary>
    public int Level { get; init; } = 1;
}

/// <summary>
/// Represents a variant component (distro-specific package).
/// </summary>
public sealed record VariantComponent
{
    /// <summary>
    /// Gets the component type.
    /// </summary>
    public string Type { get; init; } = "library";

    /// <summary>
    /// Gets the package name in the distribution.
    /// </summary>
    public required string Name { get; init; }

    /// <summary>
    /// Gets the distribution-specific version.
    /// </summary>
    public required string Version { get; init; }

    /// <summary>
    /// Gets the Package URL for the variant.
    /// </summary>
    public required string Purl { get; init; }

    /// <summary>
    /// Gets the distribution name (e.g., "debian", "rhel", "alpine").
    /// </summary>
    public string? Distribution { get; init; }

    /// <summary>
    /// Gets the distribution release (e.g., "bookworm", "9.3").
    /// </summary>
    public string? Release { get; init; }
}

/// <summary>
/// Represents commit information for a security fix or backport.
/// </summary>
public sealed record CommitInfo
{
    /// <summary>
    /// Gets the commit SHA (full or abbreviated).
    /// </summary>
    public required string Uid { get; init; }

    /// <summary>
    /// Gets the URL to view the commit.
    /// </summary>
    public string? Url { get; init; }

    /// <summary>
    /// Gets the commit message (may be truncated).
    /// </summary>
    public string? Message { get; init; }

    /// <summary>
    /// Gets the author information.
    /// </summary>
    public CommitActor? Author { get; init; }

    /// <summary>
    /// Gets the committer information.
    /// </summary>
    public CommitActor? Committer { get; init; }

    /// <summary>
    /// Gets the CVE IDs resolved by this commit, if known.
    /// </summary>
    public ImmutableArray<string> ResolvesCves { get; init; } = ImmutableArray<string>.Empty;
}

/// <summary>
/// Represents an actor (author or committer) in a commit.
/// </summary>
public sealed record CommitActor
{
    /// <summary>
    /// Gets the actor's name.
    /// </summary>
    public string? Name { get; init; }

    /// <summary>
    /// Gets the actor's email.
    /// </summary>
    public string? Email { get; init; }

    /// <summary>
    /// Gets the timestamp of the action.
    /// </summary>
    public DateTimeOffset? Timestamp { get; init; }
}

/// <summary>
/// Represents a patch applied to the component.
/// </summary>
public sealed record PatchInfo
{
    /// <summary>
    /// Gets the patch type.
    /// </summary>
    public PatchType Type { get; init; } = PatchType.Backport;

    /// <summary>
    /// Gets the URL to the patch file.
    /// </summary>
    public string? DiffUrl { get; init; }

    /// <summary>
    /// Gets the patch diff content (optional, may be truncated).
    /// </summary>
    public string? DiffText { get; init; }

    /// <summary>
    /// Gets the CVE IDs resolved by this patch.
    /// </summary>
    public ImmutableArray<PatchResolution> Resolves { get; init; } = ImmutableArray<PatchResolution>.Empty;

    /// <summary>
    /// Gets the functions affected by this patch.
    /// </summary>
    public ImmutableArray<string> AffectedFunctions { get; init; } = ImmutableArray<string>.Empty;

    /// <summary>
    /// Gets the source of the patch (e.g., "debian-security").
    /// </summary>
    public string? Source { get; init; }
}

/// <summary>
/// Patch type enumeration per CycloneDX 1.7 specification.
/// </summary>
public enum PatchType
{
    /// <summary>Informal patch not associated with upstream.</summary>
    Unofficial,

    /// <summary>A patch that is a bugfix or security fix that does not change feature.</summary>
    Monkey,

    /// <summary>A patch that is a backport of a fix from a later version.</summary>
    Backport,

    /// <summary>A cherry-picked commit from upstream.</summary>
    CherryPick
}

/// <summary>
/// Represents a vulnerability resolved by a patch.
/// </summary>
public sealed record PatchResolution
{
    /// <summary>
    /// Gets the vulnerability ID (e.g., "CVE-2024-1234").
    /// </summary>
    public required string Id { get; init; }

    /// <summary>
    /// Gets the source of the vulnerability reference.
    /// </summary>
    public string? SourceName { get; init; }

    /// <summary>
    /// Gets the URL to the vulnerability reference.
    /// </summary>
    public string? SourceUrl { get; init; }
}