using FastEndpoints;

namespace Shared.Problems;

public static class KbxFastEndpoints
{
    public static void ConfigureErrors(Config config)
    {
        config.Errors.ProducesMetadataType = typeof(KbxValidationProblem);
        config.Errors.ResponseBuilder = (failures, _, _) =>
            KbxValidationProblem.Create(failures.Select(f => new KbxValidationError(
                Field: ToCamelCase(f.PropertyName),
                RowKey: null,
                Code: string.IsNullOrWhiteSpace(f.ErrorCode) ? "VALIDATION_ERROR" : f.ErrorCode,
                Message: f.ErrorMessage)).ToArray());
    }

    private static string? ToCamelCase(string? value)
    {
        if (string.IsNullOrWhiteSpace(value)) return value;
        return char.ToLowerInvariant(value[0]) + value[1..];
    }
}