// 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 unified OCR element representing detected text with full metadata.
///
/// This is the primary type for structured OCR output, preserving all information
/// from both Tesseract and PaddleOCR backends.
/// </summary>
public sealed record OcrElement
{
    /// <summary>
    /// The recognized text content.
    /// </summary>
    [JsonPropertyName("text")]
    public string Text { get; init; } = "";

    /// <summary>
    /// Bounding geometry (rectangle or quadrilateral).
    /// </summary>
    [JsonPropertyName("geometry")]
    public OcrBoundingGeometry? Geometry { get; init; } = null;

    /// <summary>
    /// Confidence scores for detection and recognition.
    /// </summary>
    [JsonPropertyName("confidence")]
    public OcrConfidence Confidence { get; init; } = default!;

    /// <summary>
    /// Hierarchical level (word, line, block, page).
    /// </summary>
    [JsonPropertyName("level")]
    public OcrElementLevel? Level { get; init; } = null;

    /// <summary>
    /// Rotation information (if detected).
    /// </summary>
    [JsonPropertyName("rotation")]
    public OcrRotation? Rotation { get; init; } = null;

    /// <summary>
    /// Page number (1-indexed).
    /// </summary>
    [JsonPropertyName("page_number")]
    public uint PageNumber { get; init; } = 0;

    /// <summary>
    /// Parent element ID for hierarchical relationships.
    ///
    /// Only used for Tesseract output which has word -&gt; line -&gt; block hierarchy.
    /// </summary>
    [JsonPropertyName("parent_id")]
    public string? ParentId { get; init; } = null;

    /// <summary>
    /// Backend-specific metadata that doesn't fit the unified schema.
    /// </summary>
    [JsonPropertyName("backend_metadata")]
    public Dictionary<string, string> BackendMetadata { get; init; } = new Dictionary<string, string>();


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