// src/Webshop.Application/Services/Admin/AdminSettingService.cs
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Webshop.Application;
using Webshop.Application.DTOs.Settings;
using Webshop.Application.Services.Admin.Interfaces;
using Webshop.Domain.Interfaces;

namespace Webshop.Application.Services.Admin
{
    public class AdminSettingService : IAdminSettingService
    {
        private readonly ISettingRepository _settingRepository;

        public AdminSettingService(ISettingRepository settingRepository)
        {
            _settingRepository = settingRepository;
        }

        public async Task<ServiceResult<Dictionary<string, List<SettingDto>>>> GetAllGroupedAsync()
        {
            var settings = await _settingRepository.GetAllAsync();

            var groupedSettings = settings
                .GroupBy(s => s.Group ?? "Uncategorized")
                .ToDictionary(
                    g => g.Key,
                    g => g.Select(s => new SettingDto
                    {
                        Key = s.Key,
                        Value = s.Value,
                        Description = s.Description,
                        IsActive = s.IsActive,
                        Group = s.Group
                    }).ToList()
                );

            return ServiceResult.Ok(groupedSettings);
        }

        public async Task<ServiceResult> UpdateSettingsAsync(List<SettingDto> settings)
        {
            var existingSettings = await _settingRepository.GetAllAsync();
            var existingKeys = existingSettings.Select(s => s.Key).ToHashSet();

            var invalidKeys = settings.Where(s => !existingKeys.Contains(s.Key)).Select(s => s.Key).ToList();
            if (invalidKeys.Any())
            {
                return ServiceResult.Fail(ServiceResultType.InvalidInput, $"Die folgenden Einstellungsschlüssel wurden nicht gefunden: {string.Join(", ", invalidKeys)}");
            }

            // Umwandlung in ein Dictionary für effizienten Zugriff
            var settingsDict = existingSettings.ToDictionary(s => s.Key);

            foreach (var settingDto in settings)
            {
                if (settingsDict.TryGetValue(settingDto.Key, out var setting))
                {
                    setting.Value = settingDto.Value;
                    setting.IsActive = settingDto.IsActive;
                    await _settingRepository.UpdateAsync(setting);
                }
            }

            return ServiceResult.Ok();
        }
    }
}