admin/src/Oms.Application/Shared/MarketingCouponScope.cs

using System.Text.Json;
using System.Text.Json.Serialization;

namespace Oms.Application.Shared;

public class CouponApplyScope
{
    [JsonPropertyName("countryCodes")]
    public List<string>? CountryCodes { get; set; }
}

public static class MarketingCouponScope
{
    public static bool Matches(string? applyScopeJson, string? destinationCountry)
    {
        var codes = ParseCountryCodes(applyScopeJson);
        if (codes.Count == 0)
        {
            return true;
        }

        if (string.IsNullOrWhiteSpace(destinationCountry))
        {
            return false;
        }

        var dest = destinationCountry.Trim();
        return codes.Any(x => string.Equals(x, dest, StringComparison.OrdinalIgnoreCase));
    }

    public static IReadOnlyList<string> ParseCountryCodes(string? applyScopeJson)
    {
        if (string.IsNullOrWhiteSpace(applyScopeJson))
        {
            return [];
        }

        try
        {
            var scope = JsonSerializer.Deserialize<CouponApplyScope>(applyScopeJson);
            return (scope?.CountryCodes ?? [])
                .Where(x => !string.IsNullOrWhiteSpace(x))
                .Select(x => x.Trim())
                .Distinct(StringComparer.OrdinalIgnoreCase)
                .ToList();
        }
        catch (JsonException)
        {
            return [];
        }
    }
}