// This file is auto-generated by alef — DO NOT EDIT.
// alef:hash:4e15143f4af1ae8bafbdb1506ef057da924484c66a19483966333558ad437e75
// To regenerate: alef generate
// To verify freshness: alef verify --exit-code
// Issues & docs: https://github.com/kreuzberg-dev/alef
#nullable enable

using System;
using System.Collections.Generic;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace Kreuzberg;

/// <summary>
/// A single contiguous hunk in a unified diff.
/// </summary>
public sealed record DiffHunk
{
    /// <summary>
    /// Starting line number in the old content (0-indexed).
    /// </summary>
    [JsonPropertyName("from_line")]
    public ulong FromLine { get; init; } = 0;

    /// <summary>
    /// Number of lines from the old content in this hunk.
    /// </summary>
    [JsonPropertyName("from_count")]
    public ulong FromCount { get; init; } = 0;

    /// <summary>
    /// Starting line number in the new content (0-indexed).
    /// </summary>
    [JsonPropertyName("to_line")]
    public ulong ToLine { get; init; } = 0;

    /// <summary>
    /// Number of lines from the new content in this hunk.
    /// </summary>
    [JsonPropertyName("to_count")]
    public ulong ToCount { get; init; } = 0;

    /// <summary>
    /// Lines that make up this hunk.
    /// </summary>
    [JsonPropertyName("lines")]
    public List<DiffLine> Lines { get; init; } = [];


    /// <summary>
    /// Parse a <see cref="DiffHunk"/> from a JSON string.
    /// </summary>
    /// <exception cref="KreuzbergException">When the JSON cannot be deserialised.</exception>
    public static DiffHunk FromJson(string json)
    {
        try
        {
            return JsonSerializer.Deserialize<DiffHunk>(json, JsonOptions)
                ?? throw new KreuzbergException($"Failed to parse DiffHunk from JSON: deserializer returned null");
        }
        catch (KreuzbergException)
        {
            throw;
        }
        catch (Exception e)
        {
            throw new KreuzbergException($"Failed to parse DiffHunk from JSON: {e.Message}", e);
        }
    }

    private static readonly JsonSerializerOptions JsonOptions = new()
    {
        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingDefault,
        Converters = { new JsonStringEnumConverter(JsonNamingPolicy.SnakeCaseLower) },
    };

    /// <summary>Options for serializing config/input objects to FFI. Strips nulls
    /// (nullable C# fields default to null and would override required Rust fields with
    /// non-deserialisable nulls) but preserves explicit false/0 so caller intent is kept.</summary>
    private static readonly JsonSerializerOptions JsonSerializationOptions = new()
    {
        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull,
        Converters = { new JsonStringEnumConverter(JsonNamingPolicy.SnakeCaseLower) },
    };
}
