using StackExchange.Redis;
using Telegram.Bot.Types;

namespace nsszcontactbot;

public class PhotosManager(ConnectionMultiplexer redis, string PhotoBasePath)
{
    private readonly IDatabase _redisDb = redis.GetDatabase();
    private readonly string _basePath = PhotoBasePath;
    private const string Key = "cache:photos";
    private const string DefaultPhotoFileId = "AgACAgIAAxkDAAIDTWgtK4jsuoRTb7C4p0uhfVAOvWy2AAK1-TEb3cloSdmbxB-nuRFCAQADAgADcwADNgQ";

    public async Task CacheEmployeePhotoAsync(Employee employee, string fileId, TimeSpan ttl = default)
    {
        string entryName = GetEntryName(employee);
        _redisDb.HashSetAsync(Key, [new(entryName, fileId)]).ConfigureAwait(false);
        ttl = ttl == default ? TimeSpan.FromDays(30) : ttl;
        _redisDb.HashFieldExpireAsync(Key, [new(entryName)], ttl).ConfigureAwait(false);
    }

    public async Task<InputFile?> GetEmployeePhotoAsync(Employee employee)
    {
        string entryName = GetEntryName(employee);
        var val = await _redisDb.HashGetAsync(Key, entryName);
        if (val != RedisValue.Null && val.HasValue)
        {
            return InputFile.FromFileId(val!);
        }
        else
        {
            string photoPath = Path.Combine(_basePath, $"{employee.Id}.jpg");
            photoPath = File.Exists(photoPath) ? photoPath : Path.Combine(_basePath, $"{employee.FullName}.jpg");

            if (File.Exists(photoPath))
            {
                var fileStream = new FileStream(
                    photoPath,
                    FileMode.Open,
                    FileAccess.Read
                );
                return InputFile.FromStream(fileStream);
            }
            return InputFile.FromFileId(DefaultPhotoFileId);;
        }
    }

    private static string GetEntryName(Employee employee) => $"employee:{employee.Id}:fileid";
}