using System.Text.Json.Serialization;

namespace StellaOps.Scanner.ChangeTrace.Models;

/// <summary>
/// Byte-level change delta (rolling hash window granularity).
/// </summary>
public sealed record ByteDelta
{
    /// <summary>
    /// Scope of this delta: always "byte" for byte deltas.
    /// </summary>
    [JsonPropertyName("scope")]
    public string Scope { get; init; } = "byte";

    /// <summary>
    /// Byte offset where the change begins.
    /// </summary>
    [JsonPropertyName("offset")]
    public required long Offset { get; init; }

    /// <summary>
    /// Size of the changed region in bytes.
    /// </summary>
    [JsonPropertyName("size")]
    public required int Size { get; init; }

    /// <summary>
    /// Rolling hash of the "before" bytes.
    /// </summary>
    [JsonPropertyName("fromHash")]
    public required string FromHash { get; init; }

    /// <summary>
    /// Rolling hash of the "after" bytes.
    /// </summary>
    [JsonPropertyName("toHash")]
    public required string ToHash { get; init; }

    /// <summary>
    /// Binary section containing this change (e.g., ".text", ".data").
    /// </summary>
    [JsonPropertyName("section")]
    public string? Section { get; init; }

    /// <summary>
    /// Optional context description for this change.
    /// </summary>
    [JsonPropertyName("context")]
    public string? Context { get; init; }
}