// 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>
/// Layout detection configuration.
///
/// Controls layout detection behavior in the extraction pipeline.
/// When set on `ExtractionConfig`(super.ExtractionConfig), layout detection
/// is enabled for PDF extraction.
/// </summary>
public sealed record LayoutDetectionConfig
{
    /// <summary>
    /// Confidence threshold override (null = use model default).
    /// </summary>
    [JsonPropertyName("confidence_threshold")]
    public float? ConfidenceThreshold { get; init; } = null;

    /// <summary>
    /// Whether to apply postprocessing heuristics (default: true).
    /// </summary>
    [JsonPropertyName("apply_heuristics")]
    public bool ApplyHeuristics { get; init; } = true;

    /// <summary>
    /// Table structure recognition model.
    ///
    /// Controls which model is used for table cell detection within layout-detected
    /// table regions. Defaults to `TableModel.Tatr`.
    /// </summary>
    [JsonPropertyName("table_model")]
    public TableModel? TableModel { get; init; } = null;

    /// <summary>
    /// Hardware acceleration for ONNX models (layout detection + table structure).
    ///
    /// When set, controls which execution provider (CPU, CUDA, CoreML, TensorRT)
    /// is used for inference. Defaults to `None` (auto-select per platform).
    /// </summary>
    [JsonPropertyName("acceleration")]
    public AccelerationConfig? Acceleration { get; init; } = null;


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

    public static LayoutDetectionConfig Default()
    {
        var nativeResult = NativeMethods.LayoutDetectionConfigDefault();
        var jsonPtr = NativeMethods.LayoutDetectionConfigToJson(nativeResult);
        var json = global::System.Runtime.InteropServices.Marshal.PtrToStringUTF8(jsonPtr);
        NativeMethods.FreeString(jsonPtr);
        NativeMethods.LayoutDetectionConfigFree(nativeResult);
        return JsonSerializer.Deserialize<LayoutDetectionConfig>(json ?? "null", JsonOptions)!;
    }
}
