using System.Text.Json.Serialization;

namespace StellaOps.Findings.Ledger.Domain;

/// <summary>
/// Immutable decision event per advisory §11.
/// </summary>
public sealed class DecisionEvent
{
    /// <summary>
    /// Unique identifier for this decision event.
    /// </summary>
    public string Id { get; init; } = Guid.NewGuid().ToString("N");

    /// <summary>
    /// Alert identifier.
    /// </summary>
    public required string AlertId { get; init; }

    /// <summary>
    /// Artifact identifier (image digest/commit hash).
    /// </summary>
    public required string ArtifactId { get; init; }

    /// <summary>
    /// Actor who made the decision.
    /// </summary>
    public required string ActorId { get; init; }

    /// <summary>
    /// When the decision was recorded (UTC).
    /// </summary>
    public required DateTimeOffset Timestamp { get; init; }

    /// <summary>
    /// Decision status: affected, not_affected, under_investigation.
    /// </summary>
    public required string DecisionStatus { get; init; }

    /// <summary>
    /// Preset reason code.
    /// </summary>
    public required string ReasonCode { get; init; }

    /// <summary>
    /// Custom reason text.
    /// </summary>
    public string? ReasonText { get; init; }

    /// <summary>
    /// Content-addressed evidence hashes.
    /// </summary>
    public required List<string> EvidenceHashes { get; init; }

    /// <summary>
    /// Policy context (ruleset version, policy id).
    /// </summary>
    public string? PolicyContext { get; init; }

    /// <summary>
    /// Deterministic replay token for reproducibility.
    /// </summary>
    public required string ReplayToken { get; init; }
}

/// <summary>
/// Alert entity for triage.
/// </summary>
public sealed class Alert
{
    /// <summary>
    /// Unique alert identifier.
    /// </summary>
    public required string AlertId { get; init; }

    /// <summary>
    /// Tenant identifier.
    /// </summary>
    public required string TenantId { get; init; }

    /// <summary>
    /// Artifact identifier (image digest/commit hash).
    /// </summary>
    public required string ArtifactId { get; init; }

    /// <summary>
    /// Vulnerability identifier.
    /// </summary>
    public required string VulnId { get; init; }

    /// <summary>
    /// Affected component PURL.
    /// </summary>
    public string? ComponentPurl { get; init; }

    /// <summary>
    /// Severity level (critical, high, medium, low).
    /// </summary>
    public required string Severity { get; init; }

    /// <summary>
    /// Triage band (hot, warm, cold).
    /// </summary>
    public required string Band { get; init; }

    /// <summary>
    /// Alert status (open, in_review, decided, closed).
    /// </summary>
    public required string Status { get; init; }

    /// <summary>
    /// Composite triage score.
    /// </summary>
    public double Score { get; init; }

    /// <summary>
    /// When the alert was created.
    /// </summary>
    public required DateTimeOffset CreatedAt { get; init; }

    /// <summary>
    /// When the alert was last updated.
    /// </summary>
    public DateTimeOffset? UpdatedAt { get; init; }

    /// <summary>
    /// Number of decisions recorded for this alert.
    /// </summary>
    public int DecisionCount { get; init; }
}

/// <summary>
/// Evidence bundle for an alert.
/// </summary>
public sealed class EvidenceBundle
{
    /// <summary>
    /// Alert identifier.
    /// </summary>
    public required string AlertId { get; init; }

    /// <summary>
    /// Reachability evidence.
    /// </summary>
    public EvidenceSection? Reachability { get; init; }

    /// <summary>
    /// Call stack evidence.
    /// </summary>
    public EvidenceSection? CallStack { get; init; }

    /// <summary>
    /// Provenance evidence.
    /// </summary>
    public EvidenceSection? Provenance { get; init; }

    /// <summary>
    /// VEX status evidence.
    /// </summary>
    public VexStatusEvidence? VexStatus { get; init; }

    /// <summary>
    /// Content-addressed hashes for all evidence.
    /// </summary>
    public required EvidenceHashes Hashes { get; init; }

    /// <summary>
    /// When the bundle was computed.
    /// </summary>
    public required DateTimeOffset ComputedAt { get; init; }
}

/// <summary>
/// Evidence section with status and proof.
/// </summary>
public sealed class EvidenceSection
{
    /// <summary>
    /// Status: available, loading, unavailable, error.
    /// </summary>
    public required string Status { get; init; }

    /// <summary>
    /// Content hash for this evidence.
    /// </summary>
    public string? Hash { get; init; }

    /// <summary>
    /// Proof data (type-specific).
    /// </summary>
    public object? Proof { get; init; }
}

/// <summary>
/// VEX status evidence with history.
/// </summary>
public sealed class VexStatusEvidence
{
    /// <summary>
    /// Status: available, unavailable.
    /// </summary>
    public required string Status { get; init; }

    /// <summary>
    /// Current VEX statement.
    /// </summary>
    public VexStatement? Current { get; init; }

    /// <summary>
    /// Historical VEX statements.
    /// </summary>
    public IReadOnlyList<VexStatement>? History { get; init; }
}

/// <summary>
/// VEX statement summary.
/// </summary>
public sealed class VexStatement
{
    /// <summary>
    /// Statement identifier.
    /// </summary>
    public required string StatementId { get; init; }

    /// <summary>
    /// VEX status.
    /// </summary>
    public required string Status { get; init; }

    /// <summary>
    /// Justification code.
    /// </summary>
    public string? Justification { get; init; }

    /// <summary>
    /// Impact statement.
    /// </summary>
    public string? ImpactStatement { get; init; }

    /// <summary>
    /// When the statement was issued.
    /// </summary>
    public required DateTimeOffset Timestamp { get; init; }

    /// <summary>
    /// Statement issuer.
    /// </summary>
    public string? Issuer { get; init; }
}

/// <summary>
/// Content-addressed hashes for evidence bundle.
/// </summary>
public sealed class EvidenceHashes
{
    /// <summary>
    /// All hashes for the bundle.
    /// </summary>
    public required IReadOnlyList<string> Hashes { get; init; }
}

/// <summary>
/// Audit timeline for an alert.
/// </summary>
public sealed class AuditTimeline
{
    /// <summary>
    /// Alert identifier.
    /// </summary>
    public required string AlertId { get; init; }

    /// <summary>
    /// List of audit events.
    /// </summary>
    public required IReadOnlyList<AuditEvent> Events { get; init; }

    /// <summary>
    /// Total count of events.
    /// </summary>
    public int TotalCount { get; init; }
}

/// <summary>
/// Single audit event.
/// </summary>
public sealed class AuditEvent
{
    /// <summary>
    /// Event identifier.
    /// </summary>
    public required string EventId { get; init; }

    /// <summary>
    /// Type of audit event.
    /// </summary>
    public required string EventType { get; init; }

    /// <summary>
    /// Actor who triggered the event.
    /// </summary>
    public required string ActorId { get; init; }

    /// <summary>
    /// When the event occurred.
    /// </summary>
    public required DateTimeOffset Timestamp { get; init; }

    /// <summary>
    /// Event-specific details.
    /// </summary>
    public object? Details { get; init; }

    /// <summary>
    /// Replay token if applicable.
    /// </summary>
    public string? ReplayToken { get; init; }
}

/// <summary>
/// Alert diff result.
/// </summary>
public sealed class AlertDiff
{
    /// <summary>
    /// Alert identifier.
    /// </summary>
    public required string AlertId { get; init; }

    /// <summary>
    /// Baseline scan identifier.
    /// </summary>
    public string? BaselineScanId { get; init; }

    /// <summary>
    /// Current scan identifier.
    /// </summary>
    public required string CurrentScanId { get; init; }

    /// <summary>
    /// SBOM diff summary.
    /// </summary>
    public SbomDiff? SbomDiff { get; init; }

    /// <summary>
    /// VEX diff summary.
    /// </summary>
    public VexDiff? VexDiff { get; init; }

    /// <summary>
    /// When the diff was computed.
    /// </summary>
    public required DateTimeOffset ComputedAt { get; init; }
}

/// <summary>
/// SBOM diff summary.
/// </summary>
public sealed class SbomDiff
{
    /// <summary>
    /// Number of added components.
    /// </summary>
    public int AddedComponents { get; init; }

    /// <summary>
    /// Number of removed components.
    /// </summary>
    public int RemovedComponents { get; init; }

    /// <summary>
    /// Number of changed components.
    /// </summary>
    public int ChangedComponents { get; init; }

    /// <summary>
    /// Detailed changes.
    /// </summary>
    public IReadOnlyList<ComponentDiff>? Changes { get; init; }
}

/// <summary>
/// Single component diff.
/// </summary>
public sealed class ComponentDiff
{
    /// <summary>
    /// Component PURL.
    /// </summary>
    public required string Purl { get; init; }

    /// <summary>
    /// Type of change: added, removed, changed.
    /// </summary>
    public required string ChangeType { get; init; }

    /// <summary>
    /// Old version if changed/removed.
    /// </summary>
    public string? OldVersion { get; init; }

    /// <summary>
    /// New version if changed/added.
    /// </summary>
    public string? NewVersion { get; init; }
}

/// <summary>
/// VEX diff summary.
/// </summary>
public sealed class VexDiff
{
    /// <summary>
    /// Number of status changes.
    /// </summary>
    public int StatusChanges { get; init; }

    /// <summary>
    /// Number of new statements.
    /// </summary>
    public int NewStatements { get; init; }

    /// <summary>
    /// Detailed changes.
    /// </summary>
    public IReadOnlyList<VexStatusDiff>? Changes { get; init; }
}

/// <summary>
/// Single VEX status diff.
/// </summary>
public sealed class VexStatusDiff
{
    /// <summary>
    /// Vulnerability identifier.
    /// </summary>
    public required string VulnId { get; init; }

    /// <summary>
    /// Old status.
    /// </summary>
    public string? OldStatus { get; init; }

    /// <summary>
    /// New status.
    /// </summary>
    public required string NewStatus { get; init; }

    /// <summary>
    /// When the change occurred.
    /// </summary>
    public required DateTimeOffset Timestamp { get; init; }
}