using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using Bit.App.Abstractions;
using Bit.App.Resources;
using Bit.Core;
using Bit.Core.Abstractions;
using Bit.Core.Enums;
using Bit.iOS.Core.Views;
using CoreGraphics;
using Foundation;
using MobileCoreServices;
using Photos;
using UIKit;

namespace Bit.iOS.Services
{
    public class DeviceActionService : IDeviceActionService
    {
        private readonly IStorageService _storageService;
        private readonly IMessagingService _messagingService;
        private Toast _toast;
        private UIAlertController _progressAlert;

        public DeviceActionService(
            IStorageService storageService,
            IMessagingService messagingService)
        {
            _storageService = storageService;
            _messagingService = messagingService;
        }

        public DeviceType DeviceType => DeviceType.iOS;

        public bool LaunchApp(string appName)
        {
            throw new NotImplementedException();
        }

        public void Toast(string text, bool longDuration = false)
        {
            if(!_toast?.Dismissed ?? false)
            {
                _toast.Dismiss(false);
            }
            _toast = new Toast(text)
            {
                Duration = TimeSpan.FromSeconds(longDuration ? 5 : 3)
            };
            if(TabBarVisible())
            {
                _toast.BottomMargin = 55;
            }
            _toast.Show();
            _toast.DismissCallback = () =>
            {
                _toast?.Dispose();
                _toast = null;
            };
        }

        public Task ShowLoadingAsync(string text)
        {
            if(_progressAlert != null)
            {
                HideLoadingAsync().GetAwaiter().GetResult();
            }

            var result = new TaskCompletionSource<int>();

            var loadingIndicator = new UIActivityIndicatorView(new CGRect(10, 5, 50, 50));
            loadingIndicator.HidesWhenStopped = true;
            loadingIndicator.ActivityIndicatorViewStyle = UIActivityIndicatorViewStyle.Gray;
            loadingIndicator.StartAnimating();

            _progressAlert = UIAlertController.Create(null, text, UIAlertControllerStyle.Alert);
            _progressAlert.View.TintColor = UIColor.Black;
            _progressAlert.View.Add(loadingIndicator);

            var vc = GetPresentedViewController();
            vc?.PresentViewController(_progressAlert, false, () => result.TrySetResult(0));
            return result.Task;
        }

        public Task HideLoadingAsync()
        {
            var result = new TaskCompletionSource<int>();
            if(_progressAlert == null)
            {
                result.TrySetResult(0);
            }
            _progressAlert.DismissViewController(false, () => result.TrySetResult(0));
            _progressAlert.Dispose();
            _progressAlert = null;
            return result.Task;
        }

        public bool OpenFile(byte[] fileData, string id, string fileName)
        {
            var filePath = Path.Combine(GetTempPath(), fileName);
            File.WriteAllBytes(filePath, fileData);
            var url = NSUrl.FromFilename(filePath);
            var viewer = UIDocumentInteractionController.FromUrl(url);
            var controller = GetVisibleViewController();
            var rect = UIDevice.CurrentDevice.UserInterfaceIdiom == UIUserInterfaceIdiom.Pad ?
                new CGRect(100, 5, 320, 320) : controller.View.Frame;
            return viewer.PresentOpenInMenu(rect, controller.View, true);
        }

        public bool CanOpenFile(string fileName)
        {
            // Not sure of a way to check this ahead of time on iOS
            return true;
        }

        public async Task ClearCacheAsync()
        {
            var url = new NSUrl(GetTempPath());
            var tmpFiles = NSFileManager.DefaultManager.GetDirectoryContent(url, null,
                NSDirectoryEnumerationOptions.SkipsHiddenFiles, out NSError error);
            if(error == null && tmpFiles.Length > 0)
            {
                foreach(var item in tmpFiles)
                {
                    NSFileManager.DefaultManager.Remove(item, out NSError itemError);
                }
            }
            await _storageService.SaveAsync(Constants.LastFileCacheClearKey, DateTime.UtcNow);
        }

        public Task SelectFileAsync()
        {
            var controller = GetVisibleViewController();
            var picker = new UIDocumentMenuViewController(new string[] { UTType.Data }, UIDocumentPickerMode.Import);
            picker.AddOption(AppResources.Camera, UIImage.FromBundle("camera"), UIDocumentMenuOrder.First, () =>
            {
                var imagePicker = new UIImagePickerController
                {
                    SourceType = UIImagePickerControllerSourceType.Camera
                };
                imagePicker.FinishedPickingMedia += ImagePicker_FinishedPickingMedia;
                imagePicker.Canceled += ImagePicker_Canceled;
                controller.PresentModalViewController(imagePicker, true);
            });
            picker.AddOption(AppResources.Photos, UIImage.FromBundle("photo"), UIDocumentMenuOrder.First, () =>
            {
                var imagePicker = new UIImagePickerController
                {
                    SourceType = UIImagePickerControllerSourceType.PhotoLibrary
                };
                imagePicker.FinishedPickingMedia += ImagePicker_FinishedPickingMedia;
                imagePicker.Canceled += ImagePicker_Canceled;
                controller.PresentModalViewController(imagePicker, true);
            });
            picker.DidPickDocumentPicker += (sender, e) =>
            {
                controller.PresentViewController(e.DocumentPicker, true, null);
                e.DocumentPicker.DidPickDocument += DocumentPicker_DidPickDocument;
            };
            var root = UIApplication.SharedApplication.KeyWindow.RootViewController;
            if(picker.PopoverPresentationController != null && root != null)
            {
                picker.PopoverPresentationController.SourceView = root.View;
                picker.PopoverPresentationController.SourceRect = root.View.Bounds;
            }
            controller.PresentViewController(picker, true, null);
            return Task.FromResult(0);
        }

        public Task<string> DisplayPromptAync(string title = null, string description = null,
            string text = null, string okButtonText = null, string cancelButtonText = null)
        {
            var result = new TaskCompletionSource<string>();
            var alert = UIAlertController.Create(title ?? string.Empty, description, UIAlertControllerStyle.Alert);
            UITextField input = null;
            okButtonText = okButtonText ?? AppResources.Ok;
            cancelButtonText = cancelButtonText ?? AppResources.Cancel;
            alert.AddAction(UIAlertAction.Create(cancelButtonText, UIAlertActionStyle.Cancel, x =>
            {
                result.TrySetResult(null);
            }));
            alert.AddAction(UIAlertAction.Create(okButtonText, UIAlertActionStyle.Default, x =>
            {
                result.TrySetResult(input.Text ?? string.Empty);
            }));
            alert.AddTextField(x =>
            {
                input = x;
                input.Text = text ?? string.Empty;
            });
            var vc = GetPresentedViewController();
            vc?.PresentViewController(alert, true, null);
            return result.Task;
        }

        private void ImagePicker_FinishedPickingMedia(object sender, UIImagePickerMediaPickedEventArgs e)
        {
            if(sender is UIImagePickerController picker)
            {
                string fileName = null;
                if(e.Info.TryGetValue(UIImagePickerController.ReferenceUrl, out NSObject urlObj))
                {
                    var result = PHAsset.FetchAssets(new NSUrl[] { (urlObj as NSUrl) }, null);
                    fileName = result?.firstObject?.ValueForKey(new NSString("filename"))?.ToString();
                }
                fileName = fileName ?? $"photo_{DateTime.UtcNow.ToString("yyyyMMddHHmmss")}.jpg";
                var lowerFilename = fileName?.ToLowerInvariant();
                byte[] data;
                if(lowerFilename != null && (lowerFilename.EndsWith(".jpg") || lowerFilename.EndsWith(".jpeg")))
                {
                    using(var imageData = e.OriginalImage.AsJPEG())
                    {
                        data = new byte[imageData.Length];
                        System.Runtime.InteropServices.Marshal.Copy(imageData.Bytes, data, 0,
                            Convert.ToInt32(imageData.Length));
                    }
                }
                else
                {
                    using(var imageData = e.OriginalImage.AsPNG())
                    {
                        data = new byte[imageData.Length];
                        System.Runtime.InteropServices.Marshal.Copy(imageData.Bytes, data, 0,
                            Convert.ToInt32(imageData.Length));
                    }
                }
                SelectFileResult(data, fileName);
                picker.DismissViewController(true, null);
            }
        }

        private void ImagePicker_Canceled(object sender, EventArgs e)
        {
            if(sender is UIImagePickerController picker)
            {
                picker.DismissViewController(true, null);
            }
        }

        private void DocumentPicker_DidPickDocument(object sender, UIDocumentPickedEventArgs e)
        {
            e.Url.StartAccessingSecurityScopedResource();
            var doc = new UIDocument(e.Url);
            var fileName = doc.LocalizedName;
            if(string.IsNullOrWhiteSpace(fileName))
            {
                var path = doc.FileUrl?.ToString();
                if(path != null)
                {
                    path = WebUtility.UrlDecode(path);
                    var split = path.LastIndexOf('/');
                    fileName = path.Substring(split + 1);
                }
            }
            var fileCoordinator = new NSFileCoordinator();
            fileCoordinator.CoordinateRead(e.Url, NSFileCoordinatorReadingOptions.WithoutChanges,
                out NSError error, (url) =>
                 {
                     var data = NSData.FromUrl(url).ToArray();
                     SelectFileResult(data, fileName ?? "unknown_file_name");
                 });
            e.Url.StopAccessingSecurityScopedResource();
        }

        private void SelectFileResult(byte[] data, string fileName)
        {
            _messagingService.Send("selectFileResult", new Tuple<byte[], string>(data, fileName));
        }

        private UIViewController GetVisibleViewController(UIViewController controller = null)
        {
            controller = controller ?? UIApplication.SharedApplication.KeyWindow.RootViewController;
            if(controller.PresentedViewController == null)
            {
                return controller;
            }
            if(controller.PresentedViewController is UINavigationController)
            {
                return ((UINavigationController)controller.PresentedViewController).VisibleViewController;
            }
            if(controller.PresentedViewController is UITabBarController)
            {
                return ((UITabBarController)controller.PresentedViewController).SelectedViewController;
            }
            return GetVisibleViewController(controller.PresentedViewController);
        }

        private UIViewController GetPresentedViewController()
        {
            var window = UIApplication.SharedApplication.KeyWindow;
            var vc = window.RootViewController;
            while(vc.PresentedViewController != null)
            {
                vc = vc.PresentedViewController;
            }
            return vc;
        }

        private bool TabBarVisible()
        {
            var vc = GetPresentedViewController();
            return vc != null && (vc is UITabBarController ||
                (vc.ChildViewControllers?.Any(c => c is UITabBarController) ?? false));
        }

        // ref:  //https://developer.xamarin.com/guides/ios/application_fundamentals/working_with_the_file_system/
        public string GetTempPath()
        {
            var documents = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
            return Path.Combine(documents, "..", "tmp");
        }
    }
}