/*
The MIT License

Copyright (c) 2009-2010. Carlos Guzmán Álvarez. http://chronoswpf.codeplex.com/

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Markup;
using System.Xml;
using System.Xml.Linq;
using Chronos.Extensions.Windows;
using Chronos.Presentation.Core.Services;
using Chronos.Presentation.Core.Windows;
using Chronos.Presentation.Windows.Controls;
using nRoute.ViewServices;

namespace Chronos.Presentation.Windows
{
    /// <summary>
    /// Desktop serializer for <see cref="E:Chronos.Presentation.Windows.Elements.WidgetElement"/> and 
    /// <see cref="E:Chronos.Presentation.Windows.Elements.ShortcutElement"/> contents.
    /// </summary>
    internal static class DesktopSerializer
    {
        #region · Save/Load Methods ·

        /// <summary>
        /// Loads the contents of the specified filename in the given <see cref="Desktop"/> instance.
        /// </summary>
        /// <param name="desktop">The desktop.</param>
        /// <param name="filename">The filename.</param>
        public static void Load(Desktop desktop, string filename)
        {
            XElement root = LoadFromFile(filename);

            if (root == null)
            {
                return;
            }

            // Widget Deserialization
            IEnumerable<XElement> widgetsXML = root.Elements("WidgetElements").Elements("WidgetElement");

            foreach (XElement widgetXML in widgetsXML)
            {
                Guid id = new Guid(widgetXML.Element("Id").Value);
                WidgetElement item = DeserializeWidget(widgetXML, id, 0, 0);

                desktop.AddElement(item, item.GetPosition());
            }

            // Shortcut Deserialization
            IEnumerable<XElement> shortcutsXML = root.Elements("ShortcutElements").Elements("ShortcutElement");
            int ti = 0;

            foreach (XElement shortcutXML in shortcutsXML)
            {
                Guid id = new Guid(shortcutXML.Element("Id").Value);
                ShortcutElement item = DeserializeShortcut(shortcutXML, id, 0, 0);

                item.TabIndex = ++ti;

                desktop.AddElement(item, item.GetPosition());
            }
        }

        /// <summary>
        /// Saves the contents of the specified <see cref="Desktop"/> instance in the given file.
        /// </summary>
        /// <param name="desktop">The desktop.</param>
        /// <param name="filename">The filename.</param>
        public static void Save(Desktop desktop, string filename)
        {
            IEnumerable<WidgetElement> widgets = desktop.Children.OfType<WidgetElement>();
            IEnumerable<ShortcutElement> shortcuts = desktop.Children.OfType<ShortcutElement>();

            XElement widgetsItemsXML = SerializeWidgets(widgets);
            XElement shortcutsItemsXML = SerializeShortcuts(shortcuts);

            XElement root = new XElement("Root");

            root.Add(widgetsItemsXML);
            root.Add(shortcutsItemsXML);

            SaveFile(filename, root);
        }

        #endregion

        #region · Serialization Methods ·

        private static XElement LoadFromFile(string filename)
        {
            try
            {
                if (File.Exists(filename))
                {
                    return XElement.Load(filename);
                }
            }
            catch (Exception)
            {
                IShowMessageViewService showMessageService = ViewServiceLocator.GetViewService<IShowMessageViewService>();

                showMessageService.ButtonSetup = DialogButton.Ok;
                showMessageService.Caption = "Error loading the desktop";
                showMessageService.Text = "It was not possible to load the desktop.";

                showMessageService.ShowMessage();
            }

            return null;
        }

        private static void SaveFile(string filename, XElement xElement)
        {
            try
            {
                xElement.Save(filename);
            }
            catch (Exception)
            {
                IShowMessageViewService showMessageService = ViewServiceLocator.GetViewService<IShowMessageViewService>();

                showMessageService.ButtonSetup = DialogButton.Ok;
                showMessageService.Caption = "Failed to save your desktop state";
                showMessageService.Text = "Unable to save your desktop state.";

                showMessageService.ShowMessage();
            }
        }

        private static XElement SerializeWidgets(IEnumerable<WidgetElement> widgets)
        {
            XElement serializedItems = new XElement
                ("WidgetElements",
                    from item in widgets
                    select new XElement
                    ("WidgetElement",
                                new XElement("Type", item.GetType().AssemblyQualifiedName),
                                new XElement("Left", Canvas.GetLeft(item)),
                                new XElement("Top", Canvas.GetTop(item)),
                                new XElement("Width", item.Width),
                                new XElement("Height", item.RealHeight),
                                new XElement("Id", item.Id),
                                new XElement("zIndex", Canvas.GetZIndex(item)),
                                new XElement("WidgetState", item.WidgetState),
                                new XElement("ShowMinimizeButton", item.ShowMinimizeButton)
                    )
                );

            return serializedItems;
        }

        private static WidgetElement DeserializeWidget(XElement itemXML, Guid id, double offsetX, double offsetY)
        {
            WidgetElement item = (WidgetElement)Activator.CreateInstance(Type.GetType(itemXML.Element("Type").Value));

            item.ShowMinimizeButton = Boolean.Parse(itemXML.Element("ShowMinimizeButton").Value);
            item.StartupLocation    = StartupPosition.Manual;
            
            item.Move(Double.Parse(itemXML.Element("Left").Value, CultureInfo.InvariantCulture) + offsetX,
                      Double.Parse(itemXML.Element("Top").Value, CultureInfo.InvariantCulture) + offsetY);
            item.SetZIndex(Int32.Parse(itemXML.Element("zIndex").Value));

            WindowState widgetState = (WindowState)Enum.Parse(typeof(WindowState), itemXML.Element("WidgetState").Value as String);

            item.Width      = Double.Parse(itemXML.Element("Width").Value, CultureInfo.InvariantCulture);
            item.Height     = Double.Parse(itemXML.Element("Height").Value, CultureInfo.InvariantCulture);

            if (widgetState == WindowState.Minimized)
            {
                item.WidgetState = widgetState;
            }

            return item;
        }

        private static XElement SerializeShortcuts(IEnumerable<ShortcutElement> shortcuts)
        {
            XElement serializedItems = new XElement("ShortcutElements",
                                       from item in shortcuts
                                       let contentXaml = XamlWriter.Save(((ShortcutElement)item).DataContext)
                                       select new XElement("ShortcutElement",
                                                  new XElement("Left", Canvas.GetLeft(item)),
                                                  new XElement("Top", Canvas.GetTop(item)),
                                                  new XElement("Width", item.Width),
                                                  new XElement("Height", item.Height),
                                                  new XElement("Id", item.Id),
                                                  new XElement("zIndex", Canvas.GetZIndex(item)),
                                                  new XElement("DataContext", contentXaml)
                                              ));

            return serializedItems;
        }

        private static ShortcutElement DeserializeShortcut(XElement itemXML, Guid id, double offsetX, double offsetY)
        {
            ShortcutElement item = new ShortcutElement
            {
                DataContext = XamlReader.Load(XmlReader.Create(new StringReader(itemXML.Element("DataContext").Value))),
                Width       = Double.Parse(itemXML.Element("Width").Value, CultureInfo.InvariantCulture),
                Height      = Double.Parse(itemXML.Element("Height").Value, CultureInfo.InvariantCulture)
            };

            item.StartupLocation = StartupPosition.Manual;
            item.Move(Double.Parse(itemXML.Element("Left").Value, CultureInfo.InvariantCulture) + offsetX,
                      Double.Parse(itemXML.Element("Top").Value, CultureInfo.InvariantCulture) + offsetY);
            item.SetZIndex(Int32.Parse(itemXML.Element("zIndex").Value));

            return item;
        }

        #endregion
    }
}