using DocumentService.Application.Common.DTOs;

namespace DocumentService.Client.Models.Results;

/// <summary>
/// Combined result of a PDF validation followed by a Swiss QR Code extraction.
/// Both operations are always executed; <see cref="QrCode"/> is <c>null</c> when
/// the document fails validation.
/// </summary>
/// <param name="QrCode">
/// Extracted Swiss QR Code data, or <c>null</c> if the PDF was invalid or did not
/// contain a recognisable Swiss QR Code.
/// </param>
/// <param name="Validation">
/// PDF validation result. Always populated regardless of whether extraction succeeded.
/// Use <see cref="PdfValidationResult.IsValid"/>
/// to determine whether the extraction was attempted.
/// </param>
public record SwissQrCodeResult(
    SwissQrCodeExtractionResult? QrCode,
    PdfValidationResult Validation)
{
    /// <summary>
    /// Optional convenience method for code readability. Follows the standard
    /// <c>TryXxx</c> pattern (e.g. <see cref="int.TryParse(string, out int)"/>,
    /// <see cref="Dictionary{TKey,TValue}.TryGetValue"/>).
    /// Use it when you prefer an <c>if/else</c> branch over a null-check on <see cref="QrCode"/>;
    /// it is not required – both approaches are equivalent.
    /// </summary>
    /// <param name="qrCode">
    /// When this method returns <c>true</c>, contains the extracted QR Code data.
    /// When this method returns <c>false</c>, this value is <c>null</c> and must not be used.
    /// </param>
    /// <returns>
    /// <c>true</c> if the PDF was valid and a Swiss QR Code was successfully extracted;
    /// <c>false</c> otherwise.
    /// </returns>
    public bool TryExtract(out SwissQrCodeExtractionResult qrCode)
    {
        qrCode = QrCode ?? null!;
        return Validation.IsValid && QrCode is not null;
    }
}