using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.Linq;
using System.Threading.Tasks;
using Windows.UI.Xaml.Controls;
using GalaSoft.MvvmLight.Views;
using MediatR;
using Microsoft.Extensions.DependencyInjection;
using ModernKeePass.Application.Common.Interfaces;
using ModernKeePass.Application.Database.Commands.SaveDatabase;
using ModernKeePass.Application.Database.Models;
using ModernKeePass.Application.Database.Queries.GetDatabase;
using ModernKeePass.Application.Entry.Models;
using ModernKeePass.Application.Group.Commands.AddEntry;
using ModernKeePass.Application.Group.Commands.AddGroup;
using ModernKeePass.Application.Group.Commands.CreateEntry;
using ModernKeePass.Application.Group.Commands.CreateGroup;
using ModernKeePass.Application.Group.Commands.DeleteGroup;
using ModernKeePass.Application.Group.Commands.MoveEntry;
using ModernKeePass.Application.Group.Commands.RemoveGroup;
using ModernKeePass.Application.Group.Commands.SortEntries;
using ModernKeePass.Application.Group.Commands.SortGroups;
using ModernKeePass.Application.Group.Commands.UpdateGroup;
using ModernKeePass.Application.Group.Models;
using ModernKeePass.Application.Group.Queries.GetGroup;
using ModernKeePass.Application.Group.Queries.SearchEntries;
using ModernKeePass.Common;
using ModernKeePass.Domain.AOP;
using ModernKeePass.Domain.Enums;
using ModernKeePass.Interfaces;
using ModernKeePass.Models;
using RelayCommand = GalaSoft.MvvmLight.Command.RelayCommand;

namespace ModernKeePass.ViewModels
{
    public class GroupDetailVm : NotifyPropertyChangedBase, IVmEntity
    {
        public ObservableCollection<EntryVm> Entries { get; }

        public ObservableCollection<GroupVm> Groups { get; }
        
        public bool IsNotRoot => Database.RootGroupId != _group.Id;

        public IOrderedEnumerable<IGrouping<char, EntryVm>> EntriesZoomedOut => from e in Entries
            group e by e.Title.ToUpper().FirstOrDefault() into grp
            orderby grp.Key
            select grp;

        public string Id => _group.Id;

        public string Title
        {
            get { return _group.Title; }
            set
            {
                _mediator.Send(new UpdateGroupCommand {Group = _group, Title = value, Icon = _group.Icon}).Wait();
                SaveCommand.RaiseCanExecuteChanged();
            }
        }

        public Symbol Icon
        {
            get { return (Symbol) Enum.Parse(typeof(Symbol), _group.Icon.ToString()); }
            set
            {
                _mediator.Send(new UpdateGroupCommand { Group = _group, Title = _group.Title, Icon = (Icon)Enum.Parse(typeof(Icon), value.ToString()) }).Wait();
                SaveCommand.RaiseCanExecuteChanged();
            }
        }
        
        public bool IsEditMode
        {
            get { return _isEditMode; }
            set
            {
                SetProperty(ref _isEditMode, value);
                SortEntriesCommand.RaiseCanExecuteChanged();
                SortGroupsCommand.RaiseCanExecuteChanged();
            }
        }

        public bool IsRecycleOnDelete => Database.IsRecycleBinEnabled && !IsInRecycleBin;

        public bool IsInRecycleBin => _parent != null && _parent.Id == Database.RecycleBinId;

        public IEnumerable<GroupVm> BreadCrumb { get; }

        public RelayCommand SaveCommand { get; }
        public RelayCommand SortEntriesCommand { get; }
        public RelayCommand SortGroupsCommand { get; }
        public RelayCommand MoveCommand { get; }
        public RelayCommand CreateEntryCommand { get; }
        public RelayCommand CreateGroupCommand { get; }
        public RelayCommand DeleteCommand { get; set; }
        public RelayCommand GoBackCommand { get; set; }

        private DatabaseVm Database => _mediator.Send(new GetDatabaseQuery()).GetAwaiter().GetResult();

        private readonly IMediator _mediator;
        private readonly IResourceProxy _resource;
        private readonly INavigationService _navigation;
        private readonly IDialogService _dialog;
        private readonly GroupVm _group;
        private readonly GroupVm _parent;
        private bool _isEditMode;
        private EntryVm _reorderedEntry;

        public GroupDetailVm() {}
        
        internal GroupDetailVm(string groupId) : this(groupId, 
            App.Services.GetRequiredService<IMediator>(), 
            App.Services.GetRequiredService<IResourceProxy>(), 
            App.Services.GetRequiredService<INavigationService>(), 
            App.Services.GetRequiredService<IDialogService>())
        { }

        public GroupDetailVm(string groupId, IMediator mediator, IResourceProxy resource, INavigationService navigation, IDialogService dialog)
        {
            _mediator = mediator;
            _resource = resource;
            _navigation = navigation;
            _dialog = dialog;
            _group = _mediator.Send(new GetGroupQuery { Id = groupId }).GetAwaiter().GetResult();
            if (!string.IsNullOrEmpty(_group.ParentGroupId))
            {
                _parent = _mediator.Send(new GetGroupQuery { Id = _group.ParentGroupId }).GetAwaiter().GetResult();
                BreadCrumb = new List<GroupVm> {_parent};
            }

            SaveCommand = new RelayCommand(async () => await SaveChanges(), () => Database.IsDirty);
            SortEntriesCommand = new RelayCommand(async () => await SortEntriesAsync(), () => IsEditMode);
            SortGroupsCommand = new RelayCommand(async () => await SortGroupsAsync(), () => IsEditMode);
            MoveCommand = new RelayCommand(async () => await Move(_parent), () => IsNotRoot);
            CreateEntryCommand = new RelayCommand(async () => await AddNewEntry(), () => !IsInRecycleBin && Database.RecycleBinId != Id);
            CreateGroupCommand = new RelayCommand(async () => await AddNewGroup(), () => !IsInRecycleBin && Database.RecycleBinId != Id);
            DeleteCommand = new RelayCommand(async () => await AskForDelete());
            GoBackCommand = new RelayCommand(() => _navigation.GoBack());

            Entries = new ObservableCollection<EntryVm>(_group.Entries);
            Entries.CollectionChanged += Entries_CollectionChanged;
            Groups = new ObservableCollection<GroupVm>(_group.SubGroups);
        }

        private async Task AskForDelete()
        {
            var message = IsRecycleOnDelete
                ? _resource.GetResourceValue("GroupRecyclingConfirmation")
                : _resource.GetResourceValue("GroupDeletingConfirmation");

            await _dialog.ShowMessage(message, _resource.GetResourceValue("EntityDeleteTitle"),
                _resource.GetResourceValue("EntityDeleteActionButton"),
                _resource.GetResourceValue("EntityDeleteCancelButton"),
                async isOk =>
                {
                    if (isOk)
                    {
                        var text = IsRecycleOnDelete
                            ? _resource.GetResourceValue("GroupRecycled")
                            : _resource.GetResourceValue("GroupDeleted");
                        //ToastNotificationHelper.ShowMovedToast(Entity, resource.GetResourceValue("EntityDeleting"), text);
                        await _mediator.Send(new DeleteGroupCommand
                        {
                            GroupId = _group.Id, ParentGroupId = _group.ParentGroupId,
                            RecycleBinName = _resource.GetResourceValue("RecycleBinTitle")
                        });
                        _navigation.GoBack();
                    }
                });
        }


        public async Task AddNewGroup(string name = "")
        {
            var group = await _mediator.Send(new CreateGroupCommand {Name = name, ParentGroup = _group});
            _navigation.NavigateTo(Constants.Navigation.GroupPage, new NavigationItem
            {
                Id = group.Id,
                IsNew = true
            });
        }
        
        public async Task AddNewEntry()
        {
            var entry = await _mediator.Send(new CreateEntryCommand { ParentGroup = _group });
            _navigation.NavigateTo(Constants.Navigation.EntryPage, new NavigationItem
            {
                Id = entry.Id,
                IsNew = true
            });
        }
        
        public async Task Move(GroupVm destination)
        {
            await _mediator.Send(new AddGroupCommand {ParentGroup = destination, Group = _group });
            await _mediator.Send(new RemoveGroupCommand {ParentGroup = _parent, Group = _group });
        }

        public async Task<IEnumerable<EntryVm>> Search(string queryText)
        {
            return await _mediator.Send(new SearchEntriesQuery {GroupId = Id, SearchText = queryText});
        }

        private async Task SaveChanges()
        {
            await _mediator.Send(new SaveDatabaseCommand());
            SaveCommand.RaiseCanExecuteChanged();
        }

        private async void Entries_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            switch (e.Action)
            {
                case NotifyCollectionChangedAction.Remove:
                    var oldIndex = e.OldStartingIndex;
                     _reorderedEntry = _group.Entries[oldIndex];
                    break;
                case NotifyCollectionChangedAction.Add:
                    if (_reorderedEntry == null)
                    {
                        var entry = (EntryVm) e.NewItems[0];
                        await _mediator.Send(new AddEntryCommand {Entry = entry, ParentGroup = _group});
                    }
                    else
                    {
                        await _mediator.Send(new MoveEntryCommand {Entry = _reorderedEntry, ParentGroup = _group, Index = e.NewStartingIndex});
                    }
                    break;
            }
            SaveCommand.RaiseCanExecuteChanged();
        }

        private async Task SortEntriesAsync()
        {
            await _mediator.Send(new SortEntriesCommand {Group = _group});
            OnPropertyChanged(nameof(Entries));
            SaveCommand.RaiseCanExecuteChanged();
        }
        
        private async Task SortGroupsAsync()
        {
            await _mediator.Send(new SortGroupsCommand {Group = _group});
            OnPropertyChanged(nameof(Groups));
            SaveCommand.RaiseCanExecuteChanged();
        }
    }
}