using StellaOps.Scanner.Contracts;
using System.Collections.Immutable;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace StellaOps.Scanner.ReachabilityDrift;

public sealed record CodeChangeFact
{
    [JsonPropertyName("id")]
    public required Guid Id { get; init; }

    [JsonPropertyName("scanId")]
    public required string ScanId { get; init; }

    [JsonPropertyName("baseScanId")]
    public required string BaseScanId { get; init; }

    [JsonPropertyName("language")]
    public required string Language { get; init; }

    [JsonPropertyName("nodeId")]
    public string? NodeId { get; init; }

    [JsonPropertyName("file")]
    public required string File { get; init; }

    [JsonPropertyName("symbol")]
    public required string Symbol { get; init; }

    [JsonPropertyName("kind")]
    public required CodeChangeKind Kind { get; init; }

    [JsonPropertyName("details")]
    public JsonElement? Details { get; init; }

    [JsonPropertyName("detectedAt")]
    public required DateTimeOffset DetectedAt { get; init; }
}

[JsonConverter(typeof(JsonStringEnumConverter<CodeChangeKind>))]
public enum CodeChangeKind
{
    [JsonStringEnumMemberName("added")]
    Added,

    [JsonStringEnumMemberName("removed")]
    Removed,

    [JsonStringEnumMemberName("signature_changed")]
    SignatureChanged,

    [JsonStringEnumMemberName("guard_changed")]
    GuardChanged,

    [JsonStringEnumMemberName("dependency_changed")]
    DependencyChanged,

    [JsonStringEnumMemberName("visibility_changed")]
    VisibilityChanged
}

public sealed record ReachabilityDriftResult
{
    [JsonPropertyName("id")]
    public required Guid Id { get; init; }

    [JsonPropertyName("baseScanId")]
    public required string BaseScanId { get; init; }

    [JsonPropertyName("headScanId")]
    public required string HeadScanId { get; init; }

    [JsonPropertyName("language")]
    public required string Language { get; init; }

    [JsonPropertyName("detectedAt")]
    public required DateTimeOffset DetectedAt { get; init; }

    [JsonPropertyName("newlyReachable")]
    public required ImmutableArray<DriftedSink> NewlyReachable { get; init; }

    [JsonPropertyName("newlyUnreachable")]
    public required ImmutableArray<DriftedSink> NewlyUnreachable { get; init; }

    [JsonPropertyName("resultDigest")]
    public required string ResultDigest { get; init; }

    [JsonPropertyName("totalDriftCount")]
    public int TotalDriftCount => NewlyReachable.Length + NewlyUnreachable.Length;

    [JsonPropertyName("hasMaterialDrift")]
    public bool HasMaterialDrift => NewlyReachable.Length > 0;
}

public sealed record DriftedSink
{
    [JsonPropertyName("id")]
    public required Guid Id { get; init; }

    [JsonPropertyName("sinkNodeId")]
    public required string SinkNodeId { get; init; }

    [JsonPropertyName("symbol")]
    public required string Symbol { get; init; }

    [JsonPropertyName("sinkCategory")]
    public required SinkCategory SinkCategory { get; init; }

    [JsonPropertyName("direction")]
    public required DriftDirection Direction { get; init; }

    [JsonPropertyName("cause")]
    public required DriftCause Cause { get; init; }

    [JsonPropertyName("path")]
    public required CompressedPath Path { get; init; }

    [JsonPropertyName("associatedVulns")]
    public ImmutableArray<AssociatedVuln> AssociatedVulns { get; init; } = ImmutableArray<AssociatedVuln>.Empty;
}

[JsonConverter(typeof(JsonStringEnumConverter<DriftDirection>))]
public enum DriftDirection
{
    [JsonStringEnumMemberName("became_reachable")]
    BecameReachable,

    [JsonStringEnumMemberName("became_unreachable")]
    BecameUnreachable
}

public sealed record DriftCause
{
    [JsonPropertyName("kind")]
    public required DriftCauseKind Kind { get; init; }

    [JsonPropertyName("description")]
    public required string Description { get; init; }

    [JsonPropertyName("changedSymbol")]
    public string? ChangedSymbol { get; init; }

    [JsonPropertyName("changedFile")]
    public string? ChangedFile { get; init; }

    [JsonPropertyName("changedLine")]
    public int? ChangedLine { get; init; }

    [JsonPropertyName("codeChangeId")]
    public Guid? CodeChangeId { get; init; }

    public static DriftCause GuardRemoved(string symbol) =>
        new()
        {
            Kind = DriftCauseKind.GuardRemoved,
            Description = $"Guard condition removed in {symbol}",
            ChangedSymbol = symbol
        };

    public static DriftCause NewPublicRoute(string symbol) =>
        new()
        {
            Kind = DriftCauseKind.NewPublicRoute,
            Description = $"New public entrypoint: {symbol}",
            ChangedSymbol = symbol
        };

    public static DriftCause VisibilityEscalated(string symbol) =>
        new()
        {
            Kind = DriftCauseKind.VisibilityEscalated,
            Description = $"Visibility escalated to public: {symbol}",
            ChangedSymbol = symbol
        };

    public static DriftCause DependencyUpgraded(string package, string? fromVersion, string? toVersion) =>
        new()
        {
            Kind = DriftCauseKind.DependencyUpgraded,
            Description = $"Dependency changed: {package} {fromVersion ?? "?"} -> {toVersion ?? "?"}",
            ChangedSymbol = package
        };

    public static DriftCause GuardAdded(string symbol) =>
        new()
        {
            Kind = DriftCauseKind.GuardAdded,
            Description = $"Guard condition added in {symbol}",
            ChangedSymbol = symbol
        };

    public static DriftCause SymbolRemoved(string symbol) =>
        new()
        {
            Kind = DriftCauseKind.SymbolRemoved,
            Description = $"Symbol removed: {symbol}",
            ChangedSymbol = symbol
        };

    public static DriftCause Unknown() =>
        new()
        {
            Kind = DriftCauseKind.Unknown,
            Description = "Cause could not be determined"
        };
}

[JsonConverter(typeof(JsonStringEnumConverter<DriftCauseKind>))]
public enum DriftCauseKind
{
    [JsonStringEnumMemberName("guard_removed")]
    GuardRemoved,

    [JsonStringEnumMemberName("guard_added")]
    GuardAdded,

    [JsonStringEnumMemberName("new_public_route")]
    NewPublicRoute,

    [JsonStringEnumMemberName("visibility_escalated")]
    VisibilityEscalated,

    [JsonStringEnumMemberName("dependency_upgraded")]
    DependencyUpgraded,

    [JsonStringEnumMemberName("symbol_removed")]
    SymbolRemoved,

    [JsonStringEnumMemberName("unknown")]
    Unknown
}

public sealed record CompressedPath
{
    [JsonPropertyName("entrypoint")]
    public required PathNode Entrypoint { get; init; }

    [JsonPropertyName("sink")]
    public required PathNode Sink { get; init; }

    [JsonPropertyName("intermediateCount")]
    public required int IntermediateCount { get; init; }

    [JsonPropertyName("keyNodes")]
    public required ImmutableArray<PathNode> KeyNodes { get; init; }

    [JsonPropertyName("fullPath")]
    public ImmutableArray<string>? FullPath { get; init; }
}

public sealed record PathNode
{
    [JsonPropertyName("nodeId")]
    public required string NodeId { get; init; }

    [JsonPropertyName("symbol")]
    public required string Symbol { get; init; }

    [JsonPropertyName("file")]
    public string? File { get; init; }

    [JsonPropertyName("line")]
    public int? Line { get; init; }

    [JsonPropertyName("package")]
    public string? Package { get; init; }

    [JsonPropertyName("isChanged")]
    public bool IsChanged { get; init; }

    [JsonPropertyName("changeKind")]
    public CodeChangeKind? ChangeKind { get; init; }
}

public sealed record AssociatedVuln
{
    [JsonPropertyName("cveId")]
    public required string CveId { get; init; }

    [JsonPropertyName("epss")]
    public double? Epss { get; init; }

    [JsonPropertyName("cvss")]
    public double? Cvss { get; init; }

    [JsonPropertyName("vexStatus")]
    public string? VexStatus { get; init; }

    [JsonPropertyName("packagePurl")]
    public string? PackagePurl { get; init; }
}