using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Erp.Languages.Entities;
using Volo.Abp.Caching;
using Volo.Abp.DependencyInjection;
using Volo.Abp.Domain.Repositories;
using Volo.Abp.Localization;

namespace Erp.Languages.Localization;

[Dependency(ReplaceServices = true)]
public class DatabaseLanguageProvider : ILanguageProvider, ITransientDependency
{
    private readonly IReadOnlyBasicRepository<Language, Guid> languageRepository;
    private readonly IDistributedCache<LanguageListCacheItem> cache;

    public const string CacheKey = "Languages";

    public DatabaseLanguageProvider(
        IReadOnlyBasicRepository<Language, Guid> languageRepository,
        IDistributedCache<LanguageListCacheItem> cache)
    {
        this.languageRepository = languageRepository;
        this.cache = cache;
    }

    public async Task<IReadOnlyList<LanguageInfo>> GetLanguagesAsync()
    {
        var langs = await cache.GetOrAddAsync(CacheKey, GetLanguagesFromDB);
        return langs.Languages;
    }

    private async Task<LanguageListCacheItem> GetLanguagesFromDB()
    {
        var langs = await languageRepository.GetListAsync();
        return new LanguageListCacheItem
        {
            Languages = langs.OrderBy(o => o.DisplayName)
                            .Select(a => new LanguageInfo(a.CultureName, a.UiCultureName, a.DisplayName))
                            .ToList()
        };
    }
}