using AS1024.GeoFeed.Interfaces;
using Microsoft.Extensions.Caching.Memory;

namespace AS1024.GeoFeed.GeoFeedBuilder
{
    public class PreLoadGeoFeed : IHostedService
    {
        private readonly ILogger<PreLoadGeoFeed> logger;
        private readonly IGeoFeedProvider provider;
        private readonly IMemoryCache memoryCache;
        private const string GeoFeedCacheKey = "GeoFeedData";

        public PreLoadGeoFeed(ILogger<PreLoadGeoFeed> logger,
            IGeoFeedProvider provider,
            IMemoryCache memoryCache)
        {
            this.logger = logger;
            this.provider = provider;
            this.memoryCache = memoryCache;
        }

        async Task IHostedService.StartAsync(CancellationToken cancellationToken)
        {
            logger.LogInformation("Preloading GeoFeed data in memory...");
            var feed = await provider.GetGeoFeedData();
            var cacheEntryOptions = new MemoryCacheEntryOptions().SetAbsoluteExpiration(TimeSpan.FromHours(1));
            memoryCache.Set(GeoFeedCacheKey, feed, cacheEntryOptions);
        }

        Task IHostedService.StopAsync(CancellationToken cancellationToken)
        {
            return Task.CompletedTask;
        }
    }
}