using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Components;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using Remotely.Server.Enums;
using Remotely.Server.Hubs;
using Remotely.Server.Models;
using Remotely.Server.Services;
using Remotely.Shared.Attributes;
using Remotely.Shared.Models;
using Remotely.Shared.Utilities;
using System;
using System.Collections;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Reflection;
using System.Threading.Tasks;

namespace Remotely.Server.Components.Devices
{
    [Authorize]
    public partial class DevicesFrame : AuthComponentBase, IDisposable
    {
        private readonly List<Device> _allDevices = new();
        private readonly string _deviceGroupAll = Guid.NewGuid().ToString();
        private readonly string _deviceGroupNone = Guid.NewGuid().ToString();
        private readonly List<DeviceGroup> _deviceGroups = new();
        private readonly List<Device> _devicesForPage = new();
        private readonly object _devicesLock = new();
        private readonly List<Device> _filteredDevices = new();
        private readonly List<PropertyInfo> _sortableProperties = new();
        private int _currentPage = 1;
        private int _devicesPerPage = 25;
        private string _filter;
        private bool _hideOfflineDevices = true;
        private string _selectedGroupId;
        private string _selectedSortProperty = "DeviceName";
        private ListSortDirection _sortDirection;

        [Inject]
        private IClientAppState AppState { get; set; }

        [Inject]
        private ICircuitConnection CircuitConnection { get; set; }

        [Inject]
        private IDataService DataService { get; set; }

        [Inject]
        private IJsInterop JsInterop { get; set; }

        [Inject]
        private ILogger<DevicesFrame> Logger { get; set; }

        [Inject]
        private IToastService ToastService { get; set; }

        private int TotalPages => (int)Math.Max(1, Math.Ceiling((decimal)_filteredDevices.Count / _devicesPerPage));

        public void Dispose()
        {
            CircuitConnection.MessageReceived -= CircuitConnection_MessageReceived;
            AppState.PropertyChanged -= AppState_PropertyChanged;
            GC.SuppressFinalize(this);
        }

        public void Refresh()
        {
            LoadDevices();
            InvokeAsync(StateHasChanged);
        }

        protected override async Task OnInitializedAsync()
        {
            await base.OnInitializedAsync();

            CircuitConnection.MessageReceived += CircuitConnection_MessageReceived;
            AppState.PropertyChanged += AppState_PropertyChanged;

            _deviceGroups.Clear();

            _deviceGroups.AddRange(DataService.GetDeviceGroups(User.UserName));

            _selectedGroupId = _deviceGroupAll;

            var sortableProperties = typeof(Device)
                .GetProperties()
                .Where(x => x.CustomAttributes.Any(x => x.AttributeType == typeof(SortableAttribute)));

            _sortableProperties.AddRange(sortableProperties);

            LoadDevices();
        }

        protected override bool ShouldRender()
        {
            var shouldRender = base.ShouldRender();
            if (shouldRender)
            {
                FilterDevices();
            }
            return shouldRender;
        }

        private void AddScriptResult(ScriptResult result)
        {
            var device = DataService.GetDevice(result.DeviceID);
            AppState.AddTerminalLine($"{device?.DeviceName} @ {result.TimeStamp}", "font-weight-bold");

            foreach (var line in result.StandardOutput)
            {
                AppState.AddTerminalLine(line, "text-info");
            }
            foreach (var line in result.ErrorOutput)
            {
                AppState.AddTerminalLine(line, "text-danger");
            }
            AppState.InvokePropertyChanged(nameof(AppState.TerminalLines));
        }

        private void AppState_PropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            if (e.PropertyName == nameof(AppState.DevicesFrameFocusedCardState) ||
                e.PropertyName == nameof(AppState.DevicesFrameFocusedDevice) ||
                e.PropertyName == nameof(AppState.DevicesFrameSelectedDevices))
            {
                InvokeAsync(StateHasChanged);
            }
        }

        private void CircuitConnection_MessageReceived(object sender, CircuitEvent args)
        {
            switch (args.EventName)
            {
                case CircuitEventName.DeviceUpdate:
                case CircuitEventName.DeviceWentOffline:
                    {
                        if (args.Params?.FirstOrDefault() is Device device)
                        {
                            lock (_devicesLock)
                            {
                                var index = _allDevices.FindIndex(x => x.ID == device.ID);
                                if (index > -1)
                                {
                                    _allDevices[index] = device;
                                }

                                index = _devicesForPage.FindIndex(x => x.ID == device.ID);
                                if (index > -1)
                                {
                                    _devicesForPage[index] = device;
                                }
                            }
                            Debouncer.Debounce(TimeSpan.FromSeconds(2), Refresh);
                        }
                        break;
                    }
                case CircuitEventName.DisplayMessage:
                    {
                        var terminalMessage = (string)args.Params[0];
                        var toastMessage = (string)args.Params[1];
                        var className = (string)args.Params[2];
                        AppState.AddTerminalLine(terminalMessage);
                        ToastService.ShowToast(toastMessage, classString: className);
                        InvokeAsync(StateHasChanged);
                    }
                    break;
                case CircuitEventName.ScriptResult:
                    {
                        var result = (ScriptResult)args.Params[0];
                        AddScriptResult(result);
                    }
                    break;
                default:
                    break;
            }
        }

        private void ClearSelectedCard()
        {
            AppState.DevicesFrameFocusedDevice = null;
            AppState.DevicesFrameFocusedCardState = DeviceCardState.Normal;
        }

        private void FilterDevices()
        {
            lock (_devicesLock)
            {
                _filteredDevices.Clear();
                var appendDevices = new List<Device>();

                foreach (var device in _allDevices)
                {
                    if (AppState.DevicesFrameSelectedDevices.Contains(device.ID))
                    {
                        appendDevices.Add(device);
                    }

                    if (!device.IsOnline && _hideOfflineDevices)
                    {
                        continue;
                    }

                    if (!string.IsNullOrWhiteSpace(_filter) &&
                            device.Alias?.Contains(_filter, StringComparison.OrdinalIgnoreCase) != true &&
                            device.CurrentUser?.Contains(_filter, StringComparison.OrdinalIgnoreCase) != true &&
                            device.DeviceName?.Contains(_filter, StringComparison.OrdinalIgnoreCase) != true &&
                            device.Notes?.Contains(_filter, StringComparison.OrdinalIgnoreCase) != true &&
                            device.Platform?.Contains(_filter, StringComparison.OrdinalIgnoreCase) != true &&
                            device.Tags?.Contains(_filter, StringComparison.OrdinalIgnoreCase) != true)
                    {
                        continue;
                    }

                    if (_selectedGroupId == _deviceGroupAll ||
                        _selectedGroupId == device.DeviceGroupID ||
                        (
                            _selectedGroupId == _deviceGroupNone && 
                            string.IsNullOrWhiteSpace(device.DeviceGroupID
                        )))
                    {
                        _filteredDevices.Add(device);
                    }
                }

                if (!string.IsNullOrWhiteSpace(_selectedSortProperty))
                {
                    var direction = _sortDirection == ListSortDirection.Ascending ? 1 : -1;
                    _filteredDevices.Sort((a, b) =>
                    {
                        if (a.IsOnline != b.IsOnline)
                        {
                            return b.IsOnline.CompareTo(a.IsOnline);
                        }

                        var propInfo = _sortableProperties.Find(x => x.Name == _selectedSortProperty);

                        var valueA = propInfo.GetValue(a);
                        var valueB = propInfo.GetValue(b);

                        return Comparer.Default.Compare(valueA, valueB) * direction;
                    });
                }

                var skipCount = (_currentPage - 1) * _devicesPerPage;
                var devicesForPage = _filteredDevices
                    .Except(appendDevices)
                    .Skip(skipCount)
                    .Take(_devicesPerPage);

                _devicesForPage.Clear();
                _devicesForPage.AddRange(appendDevices.Concat(devicesForPage));
            }

        }

        private string GetDisplayName(PropertyInfo propInfo)
        {
            return propInfo.GetCustomAttribute<DisplayAttribute>()?.Name ?? propInfo.Name;
        }

        private string GetSortIcon()
        {
            return $"oi-sort-{_sortDirection.ToString().ToLower()}";
        }

        private void HandleRefreshClicked()
        {
            Refresh();
            ToastService.ShowToast("Devices refreshed.");
        }

        private void LoadDevices()
        {
            lock (_devicesLock)
            {
                _allDevices.Clear();

                var devices = DataService.GetDevicesForUser(Username)
                    .OrderByDescending(x => x.IsOnline)
                    .ToList();

                _allDevices.AddRange(devices);
            }

            FilterDevices();
        }
        private void PageDown()
        {
            if (_currentPage > 1)
            {
                _currentPage--;
            }
        }

        private void PageUp()
        {
            if (_currentPage < TotalPages)
            {
                _currentPage++;
            }
        }

        private void SelectAllCards()
        {
            if (AppState.DevicesFrameSelectedDevices.Any())
            {
                AppState.DevicesFrameSelectedDevices.Clear();
            }
            else
            {
                foreach (var device in _filteredDevices)
                {
                    if (!AppState.DevicesFrameSelectedDevices.Contains(device.ID))
                    {
                        AppState.DevicesFrameSelectedDevices.Add(device.ID);
                    }
                };
            }

            AppState.InvokePropertyChanged(nameof(AppState.DevicesFrameSelectedDevices));
        }

        private void ToggleSortDirection()
        {
            if (_sortDirection == ListSortDirection.Ascending)
            {
                _sortDirection = ListSortDirection.Descending;
            }
            else
            {
                _sortDirection = ListSortDirection.Ascending;
            }
        }
    }
}