using General_Ledger_Service.Exceptions;
using General_Ledger_Service.Interfaces.Repositories;

namespace General_Ledger_Service.Services
{
    // Shared "resulting depth must not exceed the configured max" check, used by every
    // recursive-entity Service (Account, CostCenter, and any future one — see
    // 01_Full_Development_Plan.md Section 4.2). Not a generic base class (CLAUDE.md Rule 2) —
    // just the repeated system_config lookup + comparison + BadRequestException, extracted once.
    internal static class DepthGuard
    {
        public static async Task EnsureWithinMaxDepthAsync(
            ISystemConfigRepository systemConfigRepository,
            string maxDepthConfigKey,
            string? enforceConfigKey,
            int resultingDepth,
            string exceededMessage)
        {
            if (enforceConfigKey != null)
            {
                var enforceConfig = await systemConfigRepository.GetByKeyAsync(enforceConfigKey);
                if (enforceConfig?.ConfigValue != "TRUE")
                {
                    return;
                }
            }

            var maxDepthConfig = await systemConfigRepository.GetByKeyAsync(maxDepthConfigKey)
                ?? throw new NotFoundException($"System config '{maxDepthConfigKey}' not found");
            var maxDepth = int.Parse(maxDepthConfig.ConfigValue);

            if (resultingDepth > maxDepth)
            {
                throw new BadRequestException(exceededMessage);
            }
        }
    }
}