using System;
using System.Collections.Generic;
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 Ical.Net.CalendarComponents;
using Ical.Net.DataTypes;
using Ical.Net.Serialization;
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);
        //I don't understand why the entire .net ecosystem insists on ignoring ToString(). Is it really that much fun writing a serializer factory? ...java programmers.
        private static EventSerializer ser = new EventSerializer();
        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);

            scratch = Scratch.LoadScratch();

            while (true)
            {
                Task.WaitAll(
                    //await and do next calendar task,
                    calendarCheck(),
                    Task.Delay(calendarNaptime)
                    );
            }
        }
        private static async Task calendarCheck()
        {
            try
            {
                lock (scratch)
                {
                    scratch.agenda.Clear();
                }
                Task.WaitAll(
                    checkCalendar(conf.calendar_twitch, "youtube", (ref Schedulable.Schedulable n) =>
                    {
                        n.ScedulableType = Schedulable.ScedulableType.YTRelease;
                    }),
                    checkCalendar(conf.calendar_twitch, "twitch", (ref Schedulable.Schedulable n) =>
                    {
                        n.ScedulableType = Schedulable.ScedulableType.TwitchStream;
                    })
                );
                lock (scratch)
                {
                    scratch.Save();
                }
            }
            catch (Exception e)
            {
                Console.Error.WriteLine(e);
            }
            Console.WriteLine($"calendars pulled, scratch has {scratch.agenda.Count} schedulables.");

            foreach (var s in scratch.agenda)
            {
                if (s.Showtime - DateTime.Now <= calendarNaptime)
                {
                    Console.WriteLine("I'm an item on the agenda and showtime is near!");
                    Console.WriteLine(s.Event);
                }
            }
        }

        private delegate void schedulableCreate(ref Schedulable.Schedulable creating);
        private static async Task checkCalendar(string calendarUri, string calLabel, schedulableCreate createSchedulable)
        {
            //?export is a hack to allow me to access the calendar
            //it likes to throw an error saying "this is the webDAV interface, use webDAV" at my webDAV client, stopping me from using webDAV.
            var calString = await httpClient.GetStringAsync(conf.webdav_uri + calendarUri + "?export");
            var calT = Calendar.Load(calString);
            var knownChecklist = new List<Schedulable.Schedulable>();
            lock (scratch)
            {
                scratch.Calendars[calLabel] = calString;
                foreach (var calOccurrence in calT.GetOccurrences(searchStart, searchEnd))
                {
                    var asEvent = calOccurrence.Source as Ical.Net.CalendarComponents.CalendarEvent;

                    var newSchedulable = new Schedulable.Schedulable()
                    {
                        Event = ser.SerializeToString(asEvent),
                        OccurrenceStart = calOccurrence.Period.StartTime.Date,
                        OccurrenceEnd = calOccurrence.Period.EndTime.Date,
                        Showtime = calOccurrence.Period.StartTime.Date,
                    };
                    createSchedulable(ref newSchedulable);
                    scratch.agenda.Add(newSchedulable);
                }
            }
        }
    }
}