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 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(14);
        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()
        {
            //pull calendar ics's
            try
            {
                Task.WaitAll(
                    checkYoutube(),
                    checkTwitch()
                );
                //await checkTwitch();
            }
            catch (Exception e)
            {
                Console.Error.WriteLine("sure would be nice if it threw an error");
                Console.Error.WriteLine(e);
            }
            Console.WriteLine("k.");
        }

        private delegate Schedulable.Schedulable schedulableCreate(CalendarEvent evt);
        private delegate void schedulableUpdate(Schedulable.Schedulable old, CalendarEvent evt);
        private delegate void schedulableRemove(Schedulable.Schedulable removed);
        private static async Task checkCalendar(string calendarUri, string calLabel,
            schedulableCreate createSchedulable,
            schedulableUpdate updateSchedulable,
            schedulableRemove removeSchedulable)
        {
            //?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.
            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 s in scratch.agenda)
                {
                    if (s.Event.Calendar == calT)
                    {
                        knownChecklist.Add(s);
                    }
                }
                foreach (var evt in calT.Events)
                {

                    if(evt.Start.Value >= searchStart && evt.End.Value <= searchEnd)
                    {
                        Console.WriteLine($"[{calLabel}] hi im an event in the search space, {evt.Summary} on {evt.Start}");
                    }
                }
                foreach(var calOccurrence in calT.GetOccurrences(searchStart, searchEnd))
                {
                    var asEvent = calOccurrence.Source as Ical.Net.CalendarComponents.CalendarEvent;
                    Console.WriteLine($"[{calLabel}] hi im an occurence in the search space, {asEvent.Summary} on {calOccurrence.Period.StartTime}");
                    Console.WriteLine($"{asEvent.Uid}");
                }
                
                // foreach (var evt in calT.Events)
                // {
                //     var foundInRange = evt.GetOccurrences(searchStart, searchEnd);
                //     if (foundInRange?.Count > 0)
                //     {
                //         Console.WriteLine($"[{calLabel}] event {evt.Summary} has {foundInRange.Count} occurences");
                //         foreach (var upcoming in foundInRange)
                //         {

                //             if (upcoming != null)
                //             {
                //                 Console.WriteLine($"[{calLabel}] event {evt.Summary} has an occurence: {upcoming.Period.StartTime.Date.ToShortDateString()}; uid: {evt.Uid}");
                //                 Console.WriteLine($"Description: {evt.Description}");
                //                 Console.WriteLine($"Calendar: {evt.Calendar}");
                //                 Console.WriteLine($"Children: {evt.Children.Count}");
                //                 Console.WriteLine($"Class: {evt.Class}");
                //                 Console.WriteLine($"stamp: {evt.DtStamp} created: {evt.Created} start: {evt.DtStart} end: {evt.DtEnd}");
                //                 // Console.WriteLine($"Name: {evt.Name}");
                //                 // Console.WriteLine($"Parent: {evt.Parent}");
                //                 // Console.WriteLine($"Properties: {evt.Properties.Count}");
                //                 // if (evt.Properties.Count > 0)
                //                 // {
                //                 //     foreach (var thing in evt.Properties)
                //                 //     {
                //                 //         Console.WriteLine($"{thing.Name}: {thing.Value}");
                //                 //     }
                //                 // }
                //                 Console.WriteLine($"RecurrenceRules: {evt.RecurrenceRules.Count}");
                //                 // var existing = scratch.agenda.FirstOrDefault(s => s.Event.Uid == upcoming);
                //                 // if(existing == null)
                //                 // {
                //                 //     scratch.agenda.Add(createSchedulable(upcoming));
                //                 // }
                //                 // else
                //                 // {
                //                 //     knownChecklist.Remove(existing);
                //                 //     if(existing.Event != upcoming)
                //                 //     {
                //                 //         Console.WriteLine("existing event != new event, but has same uid");
                //                 //         updateSchedulable(existing, upcoming);
                //                 //         existing.Event = upcoming;
                //                 //     }
                //                 // }
                //             }
                //         }
                //     }
                // }
                if (knownChecklist.Count > 0)
                {
                    foreach (var removed in knownChecklist)
                    {
                        scratch.agenda.Remove(removed);
                        removeSchedulable(removed);
                    }
                }
            }
        }
        private static async Task checkTwitch()
        {
            await checkCalendar(conf.calendar_twitch, "twitch",
                (e) => { return new Schedulable.Schedulable() { Event = e }; },
                (o, e) => { },
                (o) => { }
                );
        }
        private static async Task checkYoutube()
        {
            await checkCalendar(conf.calendar_youtube, "youtube",
                (e) => { return new Schedulable.Schedulable() { Event = e }; },
                (o, e) => { },
                (o) => { }
                );
        }
    }
}