using OsmSharp.Streams;
using System;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Threading.Tasks;

namespace Sample.CompleteStream
{
    class Program
    {
        /// <summary>
        /// Downloads a file if it doesn't exist yet.
        /// </summary>
        public static async Task ToFile(string url, string filename)
        {
            if (!File.Exists(filename))
            {
                var client = new HttpClient();
                using (var stream = await client.GetStreamAsync(url))
                using (var outputStream = File.OpenWrite(filename))
                {
                    stream.CopyTo(outputStream);
                }
            }
        }

        static void Main(string[] args)
        {
            ToFile("http://download.openstreetmap.fr/extracts/europe/ukraine//kiev.osm.pbf", "kiev.osm.pbf").Wait();

            using (var fileStream = File.OpenRead("kiev.osm.pbf"))
            {
                // create source stream.
                var source = new PBFOsmStreamSource(fileStream);

                var complete = source.Where(_ => true).ToComplete();

                var counted = complete.GroupBy(osmGeo => osmGeo.Type).Select(group => (group.Key, group.Count()));
                foreach (var (k, v) in counted)
                {
                    Console.WriteLine($"{k}={v}");
                }
            }
        }
    }
}