// 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>
/// Image preprocessing metadata.
///
/// Tracks the transformations applied to an image during OCR preprocessing,
/// including DPI normalization, resizing, and resampling.
/// </summary>
public sealed record ImagePreprocessingMetadata
{
    /// <summary>
    /// Original image dimensions (width, height) in pixels
    /// </summary>
    [JsonPropertyName("original_dimensions")]
    public List<ulong> OriginalDimensions { get; init; } = [];

    /// <summary>
    /// Original image DPI (horizontal, vertical)
    /// </summary>
    [JsonPropertyName("original_dpi")]
    public List<double> OriginalDpi { get; init; } = [];

    /// <summary>
    /// Target DPI from configuration
    /// </summary>
    [JsonPropertyName("target_dpi")]
    public int TargetDpi { get; init; } = 0;

    /// <summary>
    /// Scaling factor applied to the image
    /// </summary>
    [JsonPropertyName("scale_factor")]
    public double ScaleFactor { get; init; } = 0.0;

    /// <summary>
    /// Whether DPI was auto-adjusted based on content
    /// </summary>
    [JsonPropertyName("auto_adjusted")]
    public bool AutoAdjusted { get; init; } = false;

    /// <summary>
    /// Final DPI after processing
    /// </summary>
    [JsonPropertyName("final_dpi")]
    public int FinalDpi { get; init; } = 0;

    /// <summary>
    /// New dimensions after resizing (if resized)
    /// </summary>
    [JsonPropertyName("new_dimensions")]
    public List<ulong>? NewDimensions { get; init; } = null;

    /// <summary>
    /// Resampling algorithm used ("LANCZOS3", "CATMULLROM", etc.)
    /// </summary>
    [JsonPropertyName("resample_method")]
    public required string ResampleMethod { get; init; }

    /// <summary>
    /// Whether dimensions were clamped to max_image_dimension
    /// </summary>
    [JsonPropertyName("dimension_clamped")]
    public bool DimensionClamped { get; init; } = false;

    /// <summary>
    /// Calculated optimal DPI (if auto_adjust_dpi enabled)
    /// </summary>
    [JsonPropertyName("calculated_dpi")]
    public int? CalculatedDpi { get; init; } = null;

    /// <summary>
    /// Whether resize was skipped (dimensions already optimal)
    /// </summary>
    [JsonPropertyName("skipped_resize")]
    public bool SkippedResize { get; init; } = false;

    /// <summary>
    /// Error message if resize failed
    /// </summary>
    [JsonPropertyName("resize_error")]
    public string? ResizeError { get; init; } = null;


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