using System;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
using franz;
using Ical.Net;
using Newtonsoft.Json;

namespace director
{
    class Program
    {
        //private static Telefranz tf;
        public static Config conf;
        private static TimeSpan calendarNaptime = TimeSpan.FromHours(1);
        private static Scratch scratch;
        private static HttpClient httpClient;
        private static DateTime searchStart = DateTime.Now; //is it slower to just call datetime.now every time? /shrug
        private static DateTime searchEnd = DateTime.Now.AddDays(7);
        static void Main(string[] args)
        {
            if (!File.Exists("appsettings.json"))
            {
                Console.Error.WriteLine("appsettings.json was not found!");
                return;
            }
            conf = JsonConvert.DeserializeObject<Config>(File.ReadAllText("appsettings.json"));
            httpClient = new HttpClient();
            httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(
                System.Text.Encoding.ASCII.GetBytes($"{conf.webdav_username}:{conf.webdav_password}")));
            //tf = new Telefranz("scheduler", conf.kafka_bootstrap);
            //todo: subscribe to event appears message - you don't need to respond to an event disappearing message
            
            //todo: talk to dave. What's coming up in the next short timeframe?
            
            scratch = Scratch.LoadScratch();
            
            while (true)
            {
                Task.WaitAll(
                    //await and do next calendar task,
                    calendarCheck(),
                    Task.Delay(calendarNaptime)
                    );
            }
        }
        private static async Task calendarCheck()
        {
            //pull calendar ics's
            try
            {
                Task.WaitAll(
                    checkYoutube(),
                    checkTwitch()
                );
            }
            catch (Exception e)
            {
                Console.Error.WriteLine("sure would be nice if it threw an error");
                Console.Error.WriteLine(e);
            }
            Console.WriteLine("k.");
            lock (scratch)
            {
                //verify against existing copy, react to changes
                //put in scratch
            }
        }
        private static async Task checkTwitch()
        {
            var calString = await httpClient.GetStringAsync(conf.webdav_uri + conf.calendar_twitch + "?export");
            lock(scratch)
            {
                scratch.Calendars["twitch"] = calString;
            }
            var calT = Calendar.Load(calString);
            Console.WriteLine($"calendar name: {calT.Name}");
            foreach(var evt in calT.Events){
                var upcoming = evt.GetOccurrences(searchStart, searchEnd)?.FirstOrDefault();
                if(upcoming != null){
                    Console.WriteLine($"[twitch] event {evt.Summary} has an occurence: {upcoming.Period.StartTime}");
                }
                
            }
        }
        private static async Task checkYoutube()
        {
            var calString = await httpClient.GetStringAsync(conf.webdav_uri + conf.calendar_youtube + "?export");
            lock(scratch)
            {
                scratch.Calendars["youtube"] = calString;
            }
            var calYT = Calendar.Load(calString);
            Console.WriteLine($"calendar name: {calYT.Name}");
            foreach(var evt in calYT.Events){
                var upcoming = evt.GetOccurrences(searchStart, searchEnd)?.FirstOrDefault();
                if(upcoming != null){
                    Console.WriteLine($"[youtube] event {evt.Summary} has an occurence: {upcoming.Period.StartTime}");
                }
                
            }
        }
    }
}