using Microsoft.AspNetCore.Mvc;
using AS1024.GeoFeed.Interfaces;
using AS1024.GeoFeed.GeoFeedBuilder;
using Microsoft.Extensions.Caching.Memory;
using AS1024.GeoFeed.Models;
using System.Text;

namespace AS1024.GeoFeed.Controllers
{
    [ApiController]
    [Route("[controller]")]
    [Route("[controller].csv")]

    public class GeofeedController : ControllerBase
    {
        private readonly IGeoFeedProvider builder;
        private readonly IMemoryCache memoryCache;
        private const string GeoFeedCacheKey = "GeoFeedData";

        public GeofeedController(IGeoFeedProvider builder,
            IMemoryCache memoryCache) {
            this.builder = builder;
            this.memoryCache = memoryCache;
        }

        [HttpGet]
        [Route("")]
        public async Task<IActionResult> Get()
        {
            if (!memoryCache.TryGetValue(GeoFeedCacheKey, out List<IPGeoFeed>? feed))
            {
                feed = await builder.GetGeoFeedData();
                var cacheEntryOptions = new MemoryCacheEntryOptions()
                    .SetAbsoluteExpiration(TimeSpan.FromHours(1));
                memoryCache.Set(GeoFeedCacheKey, feed, cacheEntryOptions);
            }

            var csvContent = feed.ToGeoFeedCsv(); // Assuming ToGeoFeedCsv() returns a string in CSV format.
            var contentBytes = Encoding.UTF8.GetBytes(csvContent);
            var contentType = "text/csv";

            return new FileContentResult(contentBytes, contentType)
            {
                FileDownloadName = "geofeed.csv"
            };
        }
    }
}