using System;
using System.IO;
using System.IO.IsolatedStorage;
using System.Text;
using System.Windows;
using System.Xml;
using System.Xml.Linq;

namespace Xunit.Runner.Wpf.Persistence
{
    internal static partial class Storage
    {
        private const string WindowLayoutFileName = "window_layout.xml";

        private static string GetWindowLayoutFileName(Window window) => $"{window.Name}_{WindowLayoutFileName}";

        private static IsolatedStorageFile GetStorageFile() => IsolatedStorageFile.GetUserStoreForDomain();

        public static XmlTextReader OpenXmlFile(string fileName)
        {
            var storage = GetStorageFile();
            if (!storage.FileExists(fileName))
            {
                return null;
            }

            var fileStream = storage.OpenFile(fileName, FileMode.Open, FileAccess.Read);
            var reader = new XmlTextReader(fileStream);
            reader.WhitespaceHandling = WhitespaceHandling.None;

            return reader;
        }

        public static XmlTextWriter CreateXmlFile(string fileName)
        {
            var storage = GetStorageFile();
            var fileStream = storage.CreateFile(fileName);
            var writer = new XmlTextWriter(fileStream, Encoding.UTF8);
            writer.Formatting = Formatting.Indented;

            return writer;
        }

        public static void RestoreWindowLayout(Window window)
        {
            if (window == null)
            {
                throw new ArgumentNullException(nameof(window));
            }

            if (string.IsNullOrWhiteSpace(window.Name))
            {
                throw new ArgumentException("Name is not set.", nameof(window));
            }

            using (var windowLayoutReader = OpenXmlFile(GetWindowLayoutFileName(window)))
            {
                if (windowLayoutReader != null)
                {
                    windowLayoutReader.MoveToContent();
                    var xml = XElement.Load(windowLayoutReader);
                    WindowPlacement.Restore(window, xml);
                }
            }
        }

        public static void SaveWindowLayout(Window window)
        {
            if (window == null)
            {
                throw new ArgumentNullException(nameof(window));
            }

            if (string.IsNullOrWhiteSpace(window.Name))
            {
                throw new ArgumentException("Name is not set.", nameof(window));
            }

            using (var windowLayoutWriter = CreateXmlFile(GetWindowLayoutFileName(window)))
            {
                var xml = WindowPlacement.Save(window);
                xml.Save(windowLayoutWriter);
            }
        }
    }
}