using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using InABox.Clients;
using InABox.Core;

namespace Comal.Classes
{
    public class KanbanSubscriberSet
    {
        private readonly List<KanbanSubscriber> _subscribers = new List<KanbanSubscriber>();

        public KanbanSubscriberSet(IEnumerable<Guid> kanbanids)
        {
            _subscribers.Clear();
            var result = new Client<KanbanSubscriber>().Query(
                new Filter<KanbanSubscriber>(x => x.Kanban.ID).InList(kanbanids.ToArray()),
                new Columns<KanbanSubscriber>(x => x.ID).Add(x => x.Kanban.ID).Add(x => x.Employee.ID).Add(x => x.Assignee).Add(x => x.Manager)
                    .Add(x => x.Observer));
            if (result.Rows.Any())
                _subscribers.AddRange(result.Rows.Select(x => x.ToObject<KanbanSubscriber>()));
        }

        public void Save(bool wait = true)
        {
            var update = Task.Run(() =>
            {
                var updates = _subscribers.Where(x => (x.Manager || x.Assignee || x.Observer) && (x.IsChanged() || Equals(x.ID, Guid.Empty)));
                new Client<KanbanSubscriber>().Save(updates, "");
            });
            var delete = Task.Run(() =>
            {
                var deletes = _subscribers.Where(x => !x.Manager && !x.Assignee && !x.Observer).ToArray();
                new Client<KanbanSubscriber>().Delete(deletes, "");
            });
            if (wait)
                Task.WaitAll(update, delete);
        }

        private KanbanSubscriber EnsureSubscriber(Guid kanbanid, Guid employeeid)
        {
            var subscriber = _subscribers.FirstOrDefault(x => Equals(x.Kanban.ID, kanbanid) && Equals(x.Employee.ID, employeeid));
            if (subscriber == null)
            {
                subscriber = new KanbanSubscriber();
                subscriber.Kanban.ID = kanbanid;
                subscriber.Employee.ID = employeeid;
                _subscribers.Add(subscriber);
            }

            return subscriber;
        }

        public void EnsureManager(Guid kanbanid, Guid employeeid)
        {
            var manager = EnsureSubscriber(kanbanid, employeeid);

            // No-one else can be a manager
            var others = _subscribers.Where(x => Equals(x.Kanban.ID, kanbanid)).ToArray();
            foreach (var other in others)
                other.Manager = false;

            // only this one!
            manager.Manager = true;
        }

        public void EnsureAssignee(Guid kanbanid, Guid employeeid)
        {
            var assignee = EnsureSubscriber(kanbanid, employeeid);

            // No-one else can be a assignee
            var others = _subscribers.Where(x => Equals(x.Kanban.ID, kanbanid)).ToArray();
            foreach (var other in others)
                other.Assignee = false;

            // only this one!
            assignee.Assignee = true;
        }

        public void EnsureObserver(Guid kanbanid, Guid employeeid)
        {
            var observer = EnsureSubscriber(kanbanid, employeeid);

            // Employee can only be an observer once
            var subscribers = _subscribers.Where(x => Equals(x.Kanban.ID, kanbanid) && Equals(x.Employee.ID, employeeid)).ToArray();
            foreach (var subscriber in subscribers)
                subscriber.Observer = false;

            observer.Observer = true;
        }
    }
}