using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Web.Mvc;

using BeWoPlanerMobil.Models;
using BeWoPlanerMobil.Service;
using BS.Shared.DataContracts;
using BS.Shared.DataContracts.Compact;
using BS.Shared.Extensions;

using DevExpress.XtraScheduler;
using DevExpress.XtraScheduler.Compatibility;
using static BeWoPlanerMobil.Util.MobileUtils;

namespace BeWoPlanerMobil.Controllers
{
    public class SchedulerController : AbstractBaseController
    {
        private const string SchedulerModelSessionKey = "SchedulerModel";

        private SchedulerModel _Model;
        public SchedulerModel Model
        {
            get
            {
                if (!MobileSessionFacade.IsUserLoggedIn())
                {
                    RedirectToActionPermanent("Index", "Login");
                    return null;
                }

                if (((SchedulerModel) Session[SchedulerModelSessionKey])?.Employee == null)
                {
                    _Model = new SchedulerModel { Employee = MobileSessionFacade.LoggedInEmployee };
                    Session[SchedulerModelSessionKey] = _Model;
                }
                else
                {
                    _Model = (SchedulerModel) Session[SchedulerModelSessionKey];
                }

                return _Model;
            }
        }


        [Authorize]
        public ActionResult Scheduler()
        {
            if (!MobileSessionFacade.IsUserLoggedIn() || Request.Browser.Browser.Equals("InternetExplorer") || !AbstractModel.IsAllowedToSeeScheduler)
            {
                return RedirectToActionPermanent("Index", "Login");
            }

            LoadAppointmentsForDate();

            return View(Model);
        }

        private void LoadAppointmentsForDate()
        {
            if(Model?.Employee.EmployeeOid == null)
            {
                return;
            }

            var date = Model.SelectedDate;

            var appointments = KalenderService.LoadFilteredAppointmentsMitAufgaben(AbstractModel.HasRightToSeeAllEmployeeAppointments, Model.Employee.EmployeeOid.Value, date.Date, date.Date.AddDays(1), new List<long>(), new List<long>(), new List<long>(), false, false, false, false, true, true).ToList();

            var tasks = appointments.Where(w => w.IsTask).ToList();

            var zuErledigen = tasks.Where(t => t.DueDate.HasValue && t.DueDate.Value.Date >= DateTime.Today);

            // Nur eigene Kliententermine ansehen
            if(!AbstractModel.HasRightToSeeAllCustomerAppointments)
            {
                appointments = appointments.Where(a => a.CustomerList.All(c => MobileSessionFacade.LoggedInEmployee.RelatedCustomers.Any(rc => rc.Customer.Equals(c)))).ToList();
            }

            if(!AbstractModel.HasRightToSeeAllResourceAppointments)
            {
                appointments = appointments.Where(a => a.ResourceList.Count == 0).ToList();
            }

            if(!AbstractModel.IsAllowedToSeeCustomers)
            {
                appointments = appointments.Where(a => a.CustomerList.Count == 0).ToList();
            }

            var holySweetFlyingFuck = appointments.Where(w =>
                w.StartDate.HasValue && w.EndDate.HasValue &&
                ((date.InBetween(w.StartDate.Value, w.EndDate.Value, false) ||
                  date.CompareShortDates(w.StartDate.Value)) && w.RecurrenceInfo == null ||
                 w.RecurrenceInfo != null && (w.Type == 3 || w.Type == 4) &&
                 (date.InBetween(w.StartDate.Value, w.EndDate.Value, false) ||
                  date.CompareShortDates(w.StartDate.Value)))).ToList();

            var deletedOccurrences = holySweetFlyingFuck.Where(w => w.Type == 4).Select(s => GetOccurrenceId(s.RecurrenceInfo)).ToList();
            var changedOccurrences = holySweetFlyingFuck.Where(w => w.Type == 3).Select(s => GetOccurrenceId(s.RecurrenceInfo)).ToList();

            holySweetFlyingFuck = holySweetFlyingFuck.Where(w => w.Type != 4).ToList();

            foreach(var appointment in appointments)
            {
                if(appointment.RecurrenceInfo != null && appointment.Type == 1)
                {
                    var recurrenceInfo = new RecurrenceInfo();
                    recurrenceInfo.FromXml(appointment.RecurrenceInfo);
                    var occurrenceCalculator = OccurrenceCalculator.CreateInstance(recurrenceInfo);

                    var pattern = StaticAppointmentFactory.CreateAppointment(AppointmentType.Pattern);
                    pattern.RecurrenceInfo.FromXml(appointment.RecurrenceInfo);
                    pattern.Start = pattern.RecurrenceInfo.Start;
                    pattern.End = pattern.RecurrenceInfo.End;
                    var patternId = pattern.RecurrenceInfo.Id.ToString();

                    var interval = new TimeInterval(date, date.AddDays(1));

                    var occurrences = occurrenceCalculator.CalcOccurrences(interval, pattern);

                    if(occurrences.Count > 0)
                    {
                        foreach(var termin in occurrences.GetAppointments(interval))
                        {
                            var index = termin.RecurrenceIndex;

                            var duration = (appointment.EndDate.Value - appointment.StartDate.Value).TotalMinutes;

                            if(!date.InBetween(termin.Start.GetShortDateTime(), termin.Start.AddMinutes(duration),
                                    true) || changedOccurrences.Any(a =>
                                    a.PatternId.Equals(patternId) && a.Index == index) ||
                                deletedOccurrences.Any(a => a.PatternId.Equals(patternId) && a.Index == index))
                            {
                                continue;
                            }

                            holySweetFlyingFuck.AddIfNotIn(new SchedulerAppointmentDC
                            {
                                AllDay = appointment.AllDay,
                                CustomerList = appointment.CustomerList,
                                Description = appointment.Description,
                                EmployeeList = appointment.EmployeeList,
                                EndDate = termin.Start.AddMinutes(duration),
                                FormerBookingSequenceOid = appointment.FormerBookingSequenceOid,
                                IsPrivate = appointment.IsPrivate,
                                LabelId = appointment.LabelId,
                                Location = appointment.Location,
                                Originator = appointment.Originator,
                                RecurrenceInfo = termin.RecurrenceInfo.ToXml(),
                                ReminderInfo = appointment.ReminderInfo,
                                ResourceList = appointment.ResourceList,
                                StartDate = termin.Start,
                                Subject = appointment.Subject ?? "",
                                Type = appointment.Type
                            });
                        }
                    }
                }
            }

            holySweetFlyingFuck.AddRange(zuErledigen);

            Model.Appointments = holySweetFlyingFuck;
        }

        [Authorize]
        [HttpPost]
        public ActionResult InsertOrUpdateAppointment(FormCollection formCollection)
        {
            try
            {
                if (Model == null)
                {
                    RedirectToActionPermanent("Index", "Login");
                }

                var rawStartDate = formCollection["StartDate"];
                var rawEndDate   = formCollection["EndDate"];
                var rawStartTime = formCollection["StartTime"];
                var rawEndTime   = formCollection["EndTime"];
                var subject      = formCollection["Subject"];
                var location     = formCollection["Location"];
                var notice       = formCollection["Notice"];

                var isSuccessfulStartDate = DateTime.TryParseExact(rawStartDate, "dd.MM.yyyy", null, DateTimeStyles.None, out var startDate);
                var isSuccessfulStartTime = DateTime.TryParseExact(rawStartTime, "HH:mm", null, DateTimeStyles.None, out var startTime);
                var isSuccessfulEndDate   = DateTime.TryParseExact(rawEndDate, "dd.MM.yyyy", null, DateTimeStyles.None, out var endDate);
                var isSuccessfulEndTime   = DateTime.TryParseExact(rawEndTime, "HH:mm", null, DateTimeStyles.None, out var endTime);

                if (isSuccessfulStartDate && isSuccessfulStartTime && isSuccessfulEndDate && isSuccessfulEndTime)
                {
                    startDate = startDate.MergeDatesByDate(startTime);
                    endDate = endDate.MergeDatesByDate(endTime);

                    var appointmentToInsert = Model.SelectedAppointment ?? new SchedulerAppointmentDC();

                    appointmentToInsert.EmployeeList       = new List<Employee2SchedulerAppointmentDC>();
                    appointmentToInsert.CustomerList       = new List<CompactCustomerDC>();
                    appointmentToInsert.ResourceList       = new List<ResourceDC>();
                    appointmentToInsert.SupportConceptList = new List<CompactSupportConceptDC>();
                    appointmentToInsert.EndDate            = endDate;
                    appointmentToInsert.StartDate          = startDate;
                    appointmentToInsert.Subject            = subject;
                    appointmentToInsert.Description        = notice;
                    appointmentToInsert.Originator         = MobileSessionFacade.LoggedInCompactEmployee;
                    appointmentToInsert.Location           = location;

                    if (appointmentToInsert.SchedulerAppointmentOid.HasValue)
                    {
                        KalenderService.UpdateSchedulerAppointments(new List<SchedulerAppointmentDC> {appointmentToInsert});
                    }
                    else
                    {
                        KalenderService.InsertSchedulerAppointments(new List<SchedulerAppointmentDC> {appointmentToInsert});
                    }
                }
            }
            catch (Exception exception)
            {
                Log.Error(exception.Message, exception);
            }
            finally
            {
                if (Model != null)
                {
                    Model.SelectedAppointment = null;
                }
            }
            
            return RedirectToActionPermanent("Scheduler");
        }

        [Authorize]
        [HttpPost]
        public ActionResult NavigateToPreviousDate()
        {
            if (Model == null)
            {
                RedirectToActionPermanent("Index", "Login");
            }

            Model.SelectedDate = Model.SelectedDate.AddDays(-1);

            if(Model != null)
            {
                Model.SelectedAppointment = null;
            }

            return RedirectToActionPermanent("Scheduler");
        }

        [Authorize]
        [HttpPost]
        public ActionResult NavigateToNextDate()
        {
            if(Model == null)
            {
                RedirectToActionPermanent("Index", "Login");
            }

            Model.SelectedDate = Model.SelectedDate.AddDays(1);

            if(Model != null)
            {
                Model.SelectedAppointment = null;
            }

            return RedirectToActionPermanent("Scheduler");
        }

        [Authorize]
        [HttpPost]
        public ActionResult SelectSchedulerDate(FormCollection formCollection) {
            if (Model == null)
            {
                RedirectToActionPermanent("Index", "Login");
            }

            var rawSchedulerDate = formCollection["SchedulerDate"];

            var schedulerDate = DateTime.ParseExact(rawSchedulerDate, "dd.MM.yyyy", null);

            Model.SelectedDate = schedulerDate;

            if(Model != null)
            {
                Model.SelectedAppointment = null;
            }

            return RedirectToActionPermanent("Scheduler");
        }

        [Authorize]
        [HttpPost]
        public ActionResult SelectAppointmentToEdit(FormCollection formCollection)
        {
            var rawOid = formCollection["scheduler-oid-holder"];

            var isSuccessful = long.TryParse(rawOid, out var appointmentOid);

            if (isSuccessful)
            {
                Model.SelectedAppointment = Model.Appointments.FirstOrDefault(app => app.SchedulerAppointmentOid.HasValue && app.SchedulerAppointmentOid.Value == appointmentOid);
            }

            return RedirectToActionPermanent("Scheduler");
        }

        [Authorize]
        public JsonResult ResetSelectedAppointment()
        {
            if (Model != null)
            {
                Model.SelectedAppointment = null;
            }

            return Json(null, JsonRequestBehavior.AllowGet);
        }

        [Authorize]
        public JsonResult CheckForOverlappingAppointments(string startDateRaw, string endDateRaw, string startTimeRaw, string endTimeRaw)
        {
            if (Model == null)
            {
                return null;
            }

            var isOverlapping = false;
            var oid = Model.SelectedAppointment?.SchedulerAppointmentOid;

            var isSuccessfulStartDate = DateTime.TryParseExact(startDateRaw, "dd.MM.yyyy", null, DateTimeStyles.None, out var startDate);
            var isSuccessfulStartTime = DateTime.TryParseExact(startTimeRaw, "HH:mm", null, DateTimeStyles.None, out var startTime);
            var isSuccessfulEndDate = DateTime.TryParseExact(endDateRaw, "dd.MM.yyyy", null, DateTimeStyles.None, out var endDate);
            var isSuccessfulEndTime = DateTime.TryParseExact(endTimeRaw, "HH:mm", null, DateTimeStyles.None, out var endTime);

            if (isSuccessfulStartDate && isSuccessfulStartTime && isSuccessfulEndDate && isSuccessfulEndTime)
            {
                startDate = startDate.MergeDatesByDate(startTime);
                endDate = endDate.MergeDatesByDate(endTime);

                var customerList = Model.SelectedAppointment?.CustomerList?.Select(customer => customer.CustomerOid).ToList() ?? new List<long>();
                var employeeList = Model.SelectedAppointment?.EmployeeList?.Select(employee2Appointment => employee2Appointment.Employee.EmployeeOid).ToList() ?? new List<long>();
                var resourceList = Model.SelectedAppointment?.ResourceList?.Select(resource => resource.ResourceOid.Value).ToList() ?? new List<long>();

                var originator = Model.SelectedAppointment?.Originator ?? MobileSessionFacade.LoggedInCompactEmployee;

                var recurrenceId = Model.SelectedAppointment?.RecurrenceId ?? string.Empty;
                var recurrenceIndex = Model.SelectedAppointment?.RecurrenceIndex ?? 0;

                isOverlapping = KalenderService.OverlappingAppointmentsExist(startDate, endDate, employeeList, customerList, resourceList, originator.EmployeeOid, oid, recurrenceId, recurrenceIndex);
            }

            return Json(isOverlapping, JsonRequestBehavior.AllowGet);
        }
    }
}