//
// AddinDescription.cs
//
// Author:
//   Lluis Sanchez Gual
//
// Copyright (C) 2007 Novell, Inc (http://www.novell.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;
using System.Collections.Generic;
using System.IO;
using System.Xml;
using System.Xml.Serialization;
using System.Collections.Specialized;
using Mono.Addins.Serialization;
using Mono.Addins.Database;
using System.Text;

namespace Mono.Addins.Description
{
	/// <summary>
	/// An add-in description
	/// </summary>
	/// <remarks>
	/// This class represent an add-in manifest. It has properties for getting
	/// all information, and methods for loading and saving files.
	///	</remarks>
	public class AddinDescription: IBinaryXmlElement
	{
		XmlDocument configDoc;
		string configFile;
		AddinDatabase ownerDatabase;
		
		string id;
		string name;
		string ns;
		string version;
		string compatVersion;
		string author;
		string url;
		string copyright;
		string description;
		string category;
		string basePath;
		string sourceAddinFile;
		bool isroot;
		bool hasUserId;
		bool canWrite = true;
		bool defaultEnabled = true;
		AddinFlags flags = AddinFlags.None;
		string domain;
				
		ModuleDescription mainModule;
		ModuleCollection optionalModules;
		ExtensionNodeSetCollection nodeSets;
		ConditionTypeDescriptionCollection conditionTypes;
		ExtensionPointCollection extensionPoints;
		ExtensionNodeDescription localizer;
		object[] fileInfo;
		
		AddinPropertyCollectionImpl properties;
		Dictionary<string,string> variables;
		
		internal static BinaryXmlTypeMap typeMap;
		
		static AddinDescription ()
		{
			typeMap = new BinaryXmlTypeMap ();
			typeMap.RegisterType (typeof(AddinDescription), "AddinDescription");
			typeMap.RegisterType (typeof(Extension), "Extension");
			typeMap.RegisterType (typeof(ExtensionNodeDescription), "Node");
			typeMap.RegisterType (typeof(ExtensionNodeSet), "NodeSet");
			typeMap.RegisterType (typeof(ExtensionNodeType), "NodeType");
			typeMap.RegisterType (typeof(ExtensionPoint), "ExtensionPoint");
			typeMap.RegisterType (typeof(ModuleDescription), "ModuleDescription");
			typeMap.RegisterType (typeof(ConditionTypeDescription), "ConditionType");
			typeMap.RegisterType (typeof(Condition), "Condition");
			typeMap.RegisterType (typeof(AddinDependency), "AddinDependency");
			typeMap.RegisterType (typeof(AssemblyDependency), "AssemblyDependency");
			typeMap.RegisterType (typeof(NodeTypeAttribute), "NodeTypeAttribute");
			typeMap.RegisterType (typeof(AddinFileInfo), "FileInfo");
			typeMap.RegisterType (typeof(AddinProperty), "Property");
		}
		
		internal AddinDatabase OwnerDatabase {
			get { return ownerDatabase; }
			set { ownerDatabase = value; }
		}
		
		/// <summary>
		/// Gets or sets the path to the main addin file.
		/// </summary>
		/// <value>
		/// The addin file.
		/// </value>
		/// <remarks>
		/// The add-in file can be either the main assembly of an add-in or an xml manifest.
		/// </remarks>
		public string AddinFile {
			get { return sourceAddinFile; }
			set { sourceAddinFile = value; }
		}
		
		/// <summary>
		/// Gets the addin identifier.
		/// </summary>
		/// <value>
		/// The addin identifier.
		/// </value>
		public string AddinId {
			get { return Addin.GetFullId (Namespace, LocalId, Version); }
		}
		
		/// <summary>
		/// Gets or sets the local identifier.
		/// </summary>
		/// <value>
		/// The local identifier.
		/// </value>
		public string LocalId {
			get { return id != null ? ParseString (id) : string.Empty; }
			set { id = value; hasUserId = true; }
		}

		/// <summary>
		/// Gets or sets the namespace.
		/// </summary>
		/// <value>
		/// The namespace.
		/// </value>
		public string Namespace {
			get { return ns != null ? ParseString (ns) : string.Empty; }
			set { ns = value; }
		}

		/// <summary>
		/// Gets or sets the display name of the add-in.
		/// </summary>
		/// <value>
		/// The name.
		/// </value>
		public string Name {
			get {
				string val = Properties.GetPropertyValue ("Name");
				if (val.Length > 0)
					return val;
				if (name != null && name.Length > 0)
					return ParseString (name);
				if (HasUserId)
					return AddinId;
				else if (sourceAddinFile != null)
					return Path.GetFileNameWithoutExtension (sourceAddinFile);
				else
					return string.Empty;
			}
			set { name = value; }
		}
		
		/// <summary>
		/// Gets or sets the version.
		/// </summary>
		/// <value>
		/// The version.
		/// </value>
		public string Version {
			get { return version != null ? ParseString (version) : string.Empty; }
			set { version = value; }
		}

		/// <summary>
		/// Gets or sets the version of the add-in with which this add-in is backwards compatible.
		/// </summary>
		/// <value>
		/// The compat version.
		/// </value>
		public string CompatVersion {
			get { return compatVersion != null ? ParseString (compatVersion) : string.Empty; }
			set { compatVersion = value; }
		}

		/// <summary>
		/// Gets or sets the author.
		/// </summary>
		/// <value>
		/// The author.
		/// </value>
		public string Author {
			get {
				string val = Properties.GetPropertyValue ("Author");
				if (val.Length > 0)
					return val;
				return ParseString (author) ?? string.Empty; 
			}
			set { author = value; }
		}

		/// <summary>
		/// Gets or sets the Url where more information about the add-in can be found.
		/// </summary>
		/// <value>
		/// The URL.
		/// </value>
		public string Url {
			get {
				string val = Properties.GetPropertyValue ("Url");
				if (val.Length > 0)
					return val;
				return ParseString (url) ?? string.Empty;
			}
			set { url = value; }
		}

		/// <summary>
		/// Gets or sets the copyright.
		/// </summary>
		/// <value>
		/// The copyright.
		/// </value>
		public string Copyright {
			get {
				string val = Properties.GetPropertyValue ("Copyright");
				if (val.Length > 0)
					return val;
				return ParseString (copyright) ?? string.Empty; 
			}
			set { copyright = value; }
		}

		/// <summary>
		/// Gets or sets the description of the add-in.
		/// </summary>
		/// <value>
		/// The description.
		/// </value>
		public string Description {
			get {
				string val = Properties.GetPropertyValue ("Description");
				if (val.Length > 0)
					return val;
				return ParseString (description) ?? string.Empty;
			}
			set { description = value; }
		}

		/// <summary>
		/// Gets or sets the category of the add-in.
		/// </summary>
		/// <value>
		/// The category.
		/// </value>
		public string Category {
			get {
				string val = Properties.GetPropertyValue ("Category");
				if (val.Length > 0)
					return val;
				return ParseString (category) ?? string.Empty;
			}
			set { category = value; }
		}
		
		/// <summary>
		/// Gets the base path for locating external files relative to the add-in.
		/// </summary>
		/// <value>
		/// The base path.
		/// </value>
		public string BasePath {
			get { return basePath != null ? basePath : string.Empty; }
		}
		
		internal void SetBasePath (string path)
		{
			basePath = path;
		}
		
		/// <summary>
		/// Gets or sets a value indicating whether this instance is an add-in root.
		/// </summary>
		/// <value>
		/// <c>true</c> if this instance is an add-in root; otherwise, <c>false</c>.
		/// </value>
		public bool IsRoot {
			get { return isroot; }
			set { isroot = value; }
		}
		
		/// <summary>
		/// Gets or sets a value indicating whether this add-in is enabled by default.
		/// </summary>
		/// <value>
		/// <c>true</c> if enabled by default; otherwise, <c>false</c>.
		/// </value>
		public bool EnabledByDefault {
			get { return defaultEnabled; }
			set { defaultEnabled = value; }
		}
		
		/// <summary>
		/// Gets or sets the add-in flags.
		/// </summary>
		/// <value>
		/// The flags.
		/// </value>
		public AddinFlags Flags {
			get { return flags; }
			set { flags = value; }
		}
		
		internal bool HasUserId {
			get { return hasUserId; }
			set { hasUserId = value; }
		}
		
		/// <summary>
		/// Gets a value indicating whether this add-in can be disabled.
		/// </summary>
		/// <value>
		/// <c>true</c> if this add-in can be disabled; otherwise, <c>false</c>.
		/// </value>
		public bool CanDisable {
			get { return (flags & AddinFlags.CantDisable) == 0 && !IsHidden; }
		}
		
		/// <summary>
		/// Gets a value indicating whether this add-in can be uninstalled.
		/// </summary>
		/// <value>
		/// <c>true</c> if this instance can be uninstalled; otherwise, <c>false</c>.
		/// </value>
		public bool CanUninstall {
			get { return (flags & AddinFlags.CantUninstall) == 0 && !IsHidden; }
		}
		
		/// <summary>
		/// Gets a value indicating whether this add-in is hidden.
		/// </summary>
		/// <value>
		/// <c>true</c> if this add-in is hidden; otherwise, <c>false</c>.
		/// </value>
		public bool IsHidden {
			get { return (flags & AddinFlags.Hidden) != 0; }
		}
		
		internal bool SupportsVersion (string ver)
		{
			return Addin.CompareVersions (ver, Version) >= 0 &&
				   (CompatVersion.Length == 0 || Addin.CompareVersions (ver, CompatVersion) <= 0);
		}
		
		/// <summary>
		/// Gets all external files
		/// </summary>
		/// <value>
		/// All files.
		/// </value>
		/// <remarks>
		/// External files are data files and assemblies explicitly referenced in the Runtime section of the add-in manifest.
		/// </remarks>
		public StringCollection AllFiles {
			get {
				StringCollection col = new StringCollection ();
				foreach (string s in MainModule.AllFiles)
					col.Add (s);

				foreach (ModuleDescription mod in OptionalModules) {
					foreach (string s in mod.AllFiles)
						col.Add (s);
				}
				return col;
			}
		}
		
		/// <summary>
		/// Gets all paths to be ignored by the add-in scanner.
		/// </summary>
		/// <value>
		/// All paths to be ignored.
		/// </value>
		public StringCollection AllIgnorePaths {
			get {
				StringCollection col = new StringCollection ();
				foreach (string s in MainModule.IgnorePaths)
					col.Add (s);

				foreach (ModuleDescription mod in OptionalModules) {
					foreach (string s in mod.IgnorePaths)
						col.Add (s);
				}
				return col;
			}
		}
		
		/// <summary>
		/// Gets the main module.
		/// </summary>
		/// <value>
		/// The main module.
		/// </value>
		public ModuleDescription MainModule {
			get {
				if (mainModule == null) {
					if (RootElement == null)
						mainModule = new ModuleDescription ();
					else
						mainModule = new ModuleDescription (RootElement);
					mainModule.SetParent (this);
				}
				return mainModule;
			}
		}
		
		/// <summary>
		/// Gets the optional modules.
		/// </summary>
		/// <value>
		/// The optional modules.
		/// </value>
		/// <remarks>
		/// Optional modules can be used to declare extensions which will be registered only if some specified
		/// add-in dependencies can be satisfied. Dependencies specified in optional modules are 'soft dependencies',
		/// which means that they don't need to be satisfied in order to load the add-in.
		/// </remarks>
		public ModuleCollection OptionalModules {
			get {
				if (optionalModules == null) {
					optionalModules = new ModuleCollection (this);
					if (RootElement != null) {
						foreach (XmlElement mod in RootElement.SelectNodes ("Module"))
							optionalModules.Add (new ModuleDescription (mod));
					}
				}
				return optionalModules;
			}
		}
		
		/// <summary>
		/// Gets all modules (including the main module and all optional modules)
		/// </summary>
		/// <value>
		/// All modules.
		/// </value>
		public ModuleCollection AllModules {
			get {
				ModuleCollection col = new ModuleCollection (this);
				col.Add (MainModule);
				foreach (ModuleDescription mod in OptionalModules)
					col.Add (mod);
				return col;
			}
		}
		
		/// <summary>
		/// Gets the extension node sets.
		/// </summary>
		/// <value>
		/// The extension node sets.
		/// </value>
		public ExtensionNodeSetCollection ExtensionNodeSets {
			get {
				if (nodeSets == null) {
					nodeSets = new ExtensionNodeSetCollection (this);
					if (RootElement != null) {
						foreach (XmlElement elem in RootElement.SelectNodes ("ExtensionNodeSet"))
							nodeSets.Add (new ExtensionNodeSet (elem));
					}
				}
				return nodeSets;
			}
		}
		
		/// <summary>
		/// Gets the extension points.
		/// </summary>
		/// <value>
		/// The extension points.
		/// </value>
		public ExtensionPointCollection ExtensionPoints {
			get {
				if (extensionPoints == null) {
					extensionPoints = new ExtensionPointCollection (this);
					if (RootElement != null) {
						foreach (XmlElement elem in RootElement.SelectNodes ("ExtensionPoint"))
							extensionPoints.Add (new ExtensionPoint (elem));
					}
				}
				return extensionPoints;
			}
		}
		
		/// <summary>
		/// Gets the condition types.
		/// </summary>
		/// <value>
		/// The condition types.
		/// </value>
		public ConditionTypeDescriptionCollection ConditionTypes {
			get {
				if (conditionTypes == null) {
					conditionTypes = new ConditionTypeDescriptionCollection (this);
					if (RootElement != null) {
						foreach (XmlElement elem in RootElement.SelectNodes ("ConditionType"))
							conditionTypes.Add (new ConditionTypeDescription (elem));
					}
				}
				return conditionTypes;
			}
		}
		
		/// <summary>
		/// Gets or sets the add-in localizer.
		/// </summary>
		/// <value>
		/// The description of the add-in localizer for this add-in.
		/// </value>
		public ExtensionNodeDescription Localizer {
			get { return localizer; }
			set { localizer = value; }
		}
		
		/// <summary>
		/// Custom properties specified in the add-in header
		/// </summary>
		public AddinPropertyCollection Properties {
			get {
				if (properties == null)
					properties = new AddinPropertyCollectionImpl (this);
				return properties;
			}
		}
		
		/// <summary>
		/// Adds an extension point.
		/// </summary>
		/// <returns>
		/// The extension point.
		/// </returns>
		/// <param name='path'>
		/// Path that identifies the new extension point.
		/// </param>
		public ExtensionPoint AddExtensionPoint (string path)
		{
			ExtensionPoint ep = new ExtensionPoint ();
			ep.Path = path;
			ExtensionPoints.Add (ep);
			return ep;
		}
		
		internal ExtensionNodeDescription FindExtensionNode (string path, bool lookInDeps)
		{
			// Look in the extensions of this add-in
			
			foreach (Extension ext in MainModule.Extensions) {
				if (path.StartsWith (ext.Path + "/")) {
					string subp = path.Substring (ext.Path.Length).Trim ('/');
					ExtensionNodeDescriptionCollection nodes = ext.ExtensionNodes;
					ExtensionNodeDescription node = null;
					foreach (string p in subp.Split ('/')) {
						if (p.Length == 0) continue;
						node = nodes [p];
						if (node == null)
							break;
						nodes = node.ChildNodes;
					}
					if (node != null)
						return node;
				}
			}
			
			if (!lookInDeps || OwnerDatabase == null)
				return null;
			
			// Look in dependencies
			
			foreach (Dependency dep in MainModule.Dependencies) {
				AddinDependency adep = dep as AddinDependency;
				if (adep == null) continue;
				Addin ad = OwnerDatabase.GetInstalledAddin (Domain, adep.FullAddinId);
				if (ad != null && ad.Description != null) {
					ExtensionNodeDescription node = ad.Description.FindExtensionNode (path, false);
					if (node != null)
						return node;
				}
			}
			return null;
		}
		
		XmlElement RootElement {
			get {
				if (configDoc != null)
					return configDoc.DocumentElement;
				else
					return null;
			}
		}

		internal void ResetXmlDoc ()
		{
			configDoc = null;
		}
		
		/// <summary>
		/// Gets or sets file where this description is stored
		/// </summary>
		/// <value>
		/// The file path.
		/// </value>
		public string FileName {
			get { return configFile; }
			set { configFile = value; }
		}
		
		internal string Domain {
			get { return domain; }
			set { domain = value; }
		}
		
		internal void StoreFileInfo ()
		{
			var allFiles = AllFiles;
			var list = new List<AddinFileInfo> (allFiles.Count);
			foreach (string f in allFiles) {
				string file = Path.Combine (this.BasePath, f);
				AddinFileInfo fi = new AddinFileInfo ();
				fi.FileName = f;
				fi.Timestamp = File.GetLastWriteTime (file);
				list.Add (fi);
			}
			fileInfo = list.ToArray ();
		}
		
		internal bool FilesChanged ()
		{
			// Checks if the files of the add-in have changed.
			if (fileInfo == null)
				return true;
			
			foreach (AddinFileInfo f in fileInfo) {
				string file = Path.Combine (this.BasePath, f.FileName);
				if (!File.Exists (file))
					return true;
				if (f.Timestamp != File.GetLastWriteTime (file))
					return true;
			}
			
			return false;
		}
		
		void TransferCoreProperties (bool removeProperties)
		{
			if (properties == null)
				return;
			
			string val = properties.ExtractCoreProperty ("Id", removeProperties);
			if (val != null)
				id = val;
			
			val = properties.ExtractCoreProperty ("Namespace", removeProperties);
			if (val != null)
				ns = val;
			
			val = properties.ExtractCoreProperty ("Version", removeProperties);
			if (val != null)
				version = val;
			
			val = properties.ExtractCoreProperty ("CompatVersion", removeProperties);
			if (val != null)
				compatVersion = val;
			
			val = properties.ExtractCoreProperty ("DefaultEnabled", removeProperties);
			if (val != null)
				defaultEnabled = GetBool (val, true);
			
			val = properties.ExtractCoreProperty ("IsRoot", removeProperties);
			if (val != null)
				isroot = GetBool (val, true);
			
			val = properties.ExtractCoreProperty ("Flags", removeProperties);
			if (val != null)
				flags = (AddinFlags) Enum.Parse (typeof(AddinFlags), val);
		}

		bool TryGetVariableValue (string name, out string value)
		{
			if (variables != null && variables.TryGetValue (name, out value))
				return true;
			
			switch (name) {
				case "Id": value = id; return true;
				case "Namespace": value = ns; return true;
				case "Version": value = version; return true;
				case "CompatVersion": value = compatVersion; return true;
				case "DefaultEnabled": value = defaultEnabled.ToString (); return true;
				case "IsRoot": value = isroot.ToString (); return true;
				case "Flags": value = flags.ToString (); return true;
			}
			if (properties != null && properties.HasProperty (name)) {
				value = properties.GetPropertyValue (name);
				return true;
			}
			value = null;
			return false;
		}
		
		/// <summary>
		/// Saves the add-in description.
		/// </summary>
		/// <param name='fileName'>
		/// File name where to save this instance
		/// </param>
		/// <remarks>
		/// Saves the add-in description to the specified file and sets the FileName property.
		/// </remarks>
		public void Save (string fileName)
		{
			configFile = fileName;
			Save ();
		}
		
		/// <summary>
		/// Saves the add-in description.
		/// </summary>
		/// <exception cref='InvalidOperationException'>
		/// It is thrown if FileName is not set
		/// </exception>
		/// <remarks>
		/// The description is saved to the file specified in the FileName property.
		/// </remarks>
		public void Save ()
		{
			if (configFile == null)
				throw new InvalidOperationException ("File name not specified.");
			
			SaveXml ();

			using (StreamWriter sw = new StreamWriter (configFile)) {
				XmlTextWriter tw = new XmlTextWriter (sw);
				tw.Formatting = Formatting.Indented;
				configDoc.Save (tw);
			}
		}
		
		/// <summary>
		/// Generates an XML representation of the add-in description
		/// </summary>
		/// <returns>
		/// An XML manifest.
		/// </returns>
		public XmlDocument SaveToXml ()
		{
			SaveXml ();
			return configDoc;
		}
		
		void SaveXml ()
		{
			if (!canWrite)
				throw new InvalidOperationException ("Can't write incomplete description.");
			
			XmlElement elem;
			
			if (configDoc == null) {
				configDoc = new XmlDocument ();
				configDoc.AppendChild (configDoc.CreateElement ("Addin"));
			}
			
			elem = configDoc.DocumentElement;

			SaveCoreProperty (elem, HasUserId ? id : null, "id", "Id");
			SaveCoreProperty (elem, version, "version", "Version");
			SaveCoreProperty (elem, ns, "namespace", "Namespace");
			SaveCoreProperty (elem, isroot ? "true" : null, "isroot", "IsRoot");
			
			// Name will return the file name when HasUserId=false
			if (!string.IsNullOrEmpty (name))
				elem.SetAttribute ("name", name);
			else
				elem.RemoveAttribute ("name");
				
			SaveCoreProperty (elem, compatVersion, "compatVersion", "CompatVersion");
			SaveCoreProperty (elem, defaultEnabled ? null : "false", "defaultEnabled", "DefaultEnabled");
			SaveCoreProperty (elem, flags != AddinFlags.None ? flags.ToString () : null, "flags", "Flags");
			
			if (author != null && author.Length > 0)
				elem.SetAttribute ("author", author);
			else
				elem.RemoveAttribute ("author");
				
			if (url != null && url.Length > 0)
				elem.SetAttribute ("url", url);
			else
				elem.RemoveAttribute ("url");
				
			if (copyright != null && copyright.Length > 0)
				elem.SetAttribute ("copyright", copyright);
			else
				elem.RemoveAttribute ("copyright");
				
			if (description != null && description.Length > 0)
				elem.SetAttribute ("description", description);
			else
				elem.RemoveAttribute ("description");
				
			if (category != null && category.Length > 0)
				elem.SetAttribute ("category", category);
			else
				elem.RemoveAttribute ("category");
			
			if (localizer == null || localizer.Element == null) {
				// Remove old element if it exists
				XmlElement oldLoc = (XmlElement) elem.SelectSingleNode ("Localizer");
				if (oldLoc != null)
					elem.RemoveChild (oldLoc);
			}
			if (localizer != null)
				localizer.SaveXml (elem);
			
			if (mainModule != null) {
				mainModule.Element = elem;
				mainModule.SaveXml (elem);
			}
				
			if (optionalModules != null)
				optionalModules.SaveXml (elem);
				
			if (nodeSets != null)
				nodeSets.SaveXml (elem);
				
			if (extensionPoints != null)
				extensionPoints.SaveXml (elem);
			
			XmlElement oldHeader = (XmlElement) elem.SelectSingleNode ("Header");
			if (properties == null || properties.Count == 0) {
				if (oldHeader != null)
					elem.RemoveChild (oldHeader);
			} else {
				if (oldHeader == null) {
					oldHeader = elem.OwnerDocument.CreateElement ("Header");
					if (elem.FirstChild != null)
						elem.InsertBefore (oldHeader, elem.FirstChild);
					else
						elem.AppendChild (oldHeader);
				}
				else
					oldHeader.RemoveAll ();
				foreach (var prop in properties) {
					XmlElement propElem = elem.OwnerDocument.CreateElement (prop.Name);
					if (!string.IsNullOrEmpty (prop.Locale))
						propElem.SetAttribute ("locale", prop.Locale);
					propElem.InnerText = prop.Value ?? string.Empty;
					oldHeader.AppendChild (propElem);
				}
			}
			
			XmlElement oldVars = (XmlElement) elem.SelectSingleNode ("Variables");
			if (variables == null || variables.Count == 0) {
				if (oldVars != null)
					elem.RemoveChild (oldVars);
			} else {
				if (oldVars == null) {
					oldVars = elem.OwnerDocument.CreateElement ("Variables");
					if (elem.FirstChild != null)
						elem.InsertBefore (oldVars, elem.FirstChild);
					else
						elem.AppendChild (oldVars);
				}
				else
					oldVars.RemoveAll ();
				foreach (var prop in variables) {
					XmlElement propElem = elem.OwnerDocument.CreateElement (prop.Key);
					propElem.InnerText = prop.Value ?? string.Empty;
					oldVars.AppendChild (propElem);
				}
			}
		}

		public XmlDocument SaveToVsixXml ()
		{
			if (!canWrite)
				throw new InvalidOperationException ("Can't write incomplete description.");

			XmlElement packageManifestEl;

			var vsixDoc = new XmlDocument ();
			vsixDoc.AppendChild (vsixDoc.CreateElement ("PackageManifest"));

			packageManifestEl = vsixDoc.DocumentElement;
			packageManifestEl.SetAttribute ("Version", "2.0.0");
			packageManifestEl.SetAttribute ("xmlns", "http://schemas.microsoft.com/developer/vsx-schema/2011");

			var metadata = vsixDoc.CreateElement ("Metadata");
			var identity = vsixDoc.CreateElement ("Identity");
			identity.SetAttribute ("Language", "en-US");
			identity.SetAttribute ("Id", LocalId);
			identity.SetAttribute ("Version", Version);
			identity.SetAttribute ("Publisher", Properties.GetPropertyValue ("VisualStudio.Publisher"));
			metadata.AppendChild (identity);

			var displayNameEl = vsixDoc.CreateElement ("DisplayName");
			displayNameEl.InnerText = Name;
			metadata.AppendChild (displayNameEl);

			var descriptionEl = vsixDoc.CreateElement ("Description");
			descriptionEl.SetAttribute ("xml:space", "preserve");
			descriptionEl.InnerText = Description;
			metadata.AppendChild (descriptionEl);

			var moreInfoEl = vsixDoc.CreateElement ("MoreInfo");
			moreInfoEl.InnerText = Url;
			metadata.AppendChild (moreInfoEl);

			var tagsEl = vsixDoc.CreateElement ("Tags");
			if (!string.IsNullOrEmpty (Properties.GetPropertyValue ("VisualStudio.Tags")))
				tagsEl.InnerText = Properties.GetPropertyValue ("VisualStudio.Tags");
			metadata.AppendChild (tagsEl);

			var categoriesEl = vsixDoc.CreateElement ("Categories");
			categoriesEl.InnerText = Category;
			metadata.AppendChild (categoriesEl);

			var galleryFlagsEl = vsixDoc.CreateElement ("GalleryFlags");
			var galleryFlags = Properties.GetPropertyValue ("VisualStudio.GalleryFlags");
			if (string.IsNullOrEmpty (galleryFlags))
				galleryFlags = "Public";
			galleryFlagsEl.InnerText = galleryFlags;
			metadata.AppendChild (galleryFlagsEl);

			var badgesEl = vsixDoc.CreateElement ("Badges");
			//TODO:Add Badges support
			metadata.AppendChild (badgesEl);

			var icon = Properties.GetPropertyValue ("Icon32");
			if (!string.IsNullOrEmpty (icon)) {
				var iconEl = vsixDoc.CreateElement ("Icon");
				iconEl.InnerText = icon;
				metadata.AppendChild (iconEl);
			}
			var license = Copyright;
			if (!string.IsNullOrEmpty (license)) {
				var licenseEl = vsixDoc.CreateElement ("License");
				licenseEl.InnerText = license;
				metadata.AppendChild (licenseEl);
			}

			packageManifestEl.AppendChild (metadata);

			var installationEl = vsixDoc.CreateElement ("Installation");
			var installationTargetEl = vsixDoc.CreateElement ("InstallationTarget");
			installationTargetEl.SetAttribute ("Id", "Microsoft.VisualStudio.Mac");
			installationEl.AppendChild (installationTargetEl);
			packageManifestEl.AppendChild (installationEl);

			packageManifestEl.AppendChild (vsixDoc.CreateElement ("Dependencies"));

			var assetsEl = vsixDoc.CreateElement ("Assets");
			var addinInfoAsset = vsixDoc.CreateElement ("Asset");
			addinInfoAsset.SetAttribute ("Type", "Microsoft.VisualStudio.Mac.AddinInfo");
			addinInfoAsset.SetAttribute ("Path", "addin.info");
			addinInfoAsset.SetAttribute ("Addressable", "true");
			assetsEl.AppendChild (addinInfoAsset);

			if (!string.IsNullOrEmpty (icon)) {
				var iconAsset = vsixDoc.CreateElement ("Asset");
				iconAsset.SetAttribute ("Type", "Microsoft.VisualStudio.Services.Icons.Default");
				iconAsset.SetAttribute ("Path", icon);
				iconAsset.SetAttribute ("Addressable", "true");
				assetsEl.AppendChild (iconAsset);
			}

			var propertyToAssetTypeMappings = new Dictionary<string, string>{
				{"VisualStudio.License", "Microsoft.VisualStudio.Services.Content.License"},
				{"VisualStudio.Details", "Microsoft.VisualStudio.Services.Content.Details"},
				{"VisualStudio.Changelog", "Microsoft.VisualStudio.Services.Content.Changelog"},
			};

			foreach (var mapping in propertyToAssetTypeMappings) {
				if (!string.IsNullOrEmpty (Properties.GetPropertyValue (mapping.Key))) {
					var asset = vsixDoc.CreateElement ("Asset");
					asset.SetAttribute ("Type", mapping.Value);
					asset.SetAttribute ("Path", icon);
					asset.SetAttribute ("Addressable", "true");
					assetsEl.AppendChild (asset);
				}
			}

			packageManifestEl.AppendChild (assetsEl);

			return vsixDoc;
		}
		
		void SaveCoreProperty (XmlElement elem, string val, string attr, string prop)
		{
			if (properties != null && properties.HasProperty (prop)) {
				elem.RemoveAttribute (attr);
				if (!string.IsNullOrEmpty (val))
					properties.SetPropertyValue (prop, val);
				else
					properties.RemoveProperty (prop);
			}
			else if (string.IsNullOrEmpty (val))
				elem.RemoveAttribute (attr);
			else
				elem.SetAttribute (attr, val);
		}
		

		/// <summary>
		/// Load an add-in description from a file
		/// </summary>
		/// <param name='configFile'>
		/// The file.
		/// </param>
		public static AddinDescription Read (string configFile)
		{
			AddinDescription config;
			using (Stream s = File.OpenRead (configFile)) {
				config = Read (s, Path.GetDirectoryName (configFile));
			}
			config.configFile = configFile;
			return config;
		}
		
		/// <summary>
		/// Load an add-in description from a stream
		/// </summary>
		/// <param name='stream'>
		/// The stream
		/// </param>
		/// <param name='basePath'>
		/// The path to be used to resolve relative file paths.
		/// </param>
		public static AddinDescription Read (Stream stream, string basePath)
		{
			return Read (new StreamReader (stream), basePath);
		}
		
		/// <summary>
		/// Load an add-in description from a text reader
		/// </summary>
		/// <param name='reader'>
		/// The text reader
		/// </param>
		/// <param name='basePath'>
		/// The path to be used to resolve relative file paths.
		/// </param>
		public static AddinDescription Read (TextReader reader, string basePath)
		{
			AddinDescription config = new AddinDescription ();
			
			try {
				config.configDoc = new XmlDocument ();
				config.configDoc.Load (reader);
			} catch (Exception ex) {
				throw new InvalidOperationException ("The add-in configuration file is invalid: " + ex.Message, ex);
			}

			XmlElement elem = config.configDoc.DocumentElement;
			if (elem.LocalName == "ExtensionModel")
				return config;
			
			XmlElement varsElem = (XmlElement) elem.SelectSingleNode ("Variables");
			if (varsElem != null) {
				foreach (XmlNode node in varsElem.ChildNodes) {
					XmlElement prop = node as XmlElement;
					if (prop == null)
						continue;
					if (config.variables == null)
						config.variables = new Dictionary<string, string> ();
					config.variables [prop.LocalName] = prop.InnerText;
				}
			}

			config.id = elem.GetAttribute ("id");
			config.ns = elem.GetAttribute ("namespace");
			config.name = elem.GetAttribute ("name");
			config.version = elem.GetAttribute ("version");
			config.compatVersion = elem.GetAttribute ("compatVersion");
			config.author = elem.GetAttribute ("author");
			config.url = elem.GetAttribute ("url");
			config.copyright = elem.GetAttribute ("copyright");
			config.description = elem.GetAttribute ("description");
			config.category = elem.GetAttribute ("category");
			config.basePath = elem.GetAttribute ("basePath");
			config.domain = "global";
			
			string s = elem.GetAttribute ("isRoot");
			if (s.Length == 0) s = elem.GetAttribute ("isroot");
			config.isroot = GetBool (s, false);
			
			config.defaultEnabled = GetBool (elem.GetAttribute ("defaultEnabled"), true);
			
			string prot = elem.GetAttribute ("flags");
			if (prot.Length == 0)
				config.flags = AddinFlags.None;
			else
				config.flags = (AddinFlags) Enum.Parse (typeof(AddinFlags), prot);
			
			XmlElement localizerElem = (XmlElement) elem.SelectSingleNode ("Localizer");
			if (localizerElem != null)
				config.localizer = new ExtensionNodeDescription (localizerElem);
			
			XmlElement headerElem = (XmlElement) elem.SelectSingleNode ("Header");
			if (headerElem != null) {
				foreach (XmlNode node in headerElem.ChildNodes) {
					XmlElement prop = node as XmlElement;
					if (prop == null)
						continue;
						config.Properties.SetPropertyValue (prop.LocalName, prop.InnerText, prop.GetAttribute ("locale"));
				}
			}
			
			config.TransferCoreProperties (false);
			
			if (config.id.Length > 0)
				config.hasUserId = true;
			
			return config;
		}

		internal string ParseString (string input)
		{
			if (input == null || input.Length < 4)
				return input;

			int i = input.IndexOf ("$(");
			if (i == -1)
				return input;

			StringBuilder result = new StringBuilder (input.Length);
			result.Append (input, 0, i);

			while (i < input.Length) {
				if (input [i] == '$') {
					i++;
					
					if (i >= input.Length || input[i] != '(') {
						result.Append ('$');
						continue;
					}
					
					i++;
					int start = i;
					while (i < input.Length && input [i] != ')')
						i++;
					
					string tag = input.Substring (start, i - start);

					string tagValue;
					if (TryGetVariableValue (tag, out tagValue))
						result.Append (tagValue);
					else {
						result.Append ('$');
						i = start - 1;
					}
				} else {
					result.Append (input [i]);
				}
				i++;
			}
			return result.ToString ();
		}
		
		static bool GetBool (string s, bool defval)
		{
			if (s.Length == 0)
				return defval;
			else
				return s == "true" || s == "yes";
		}
		
		internal static AddinDescription ReadBinary (FileDatabase fdb, string configFile)
		{
			AddinDescription description = (AddinDescription) fdb.ReadSharedObject (configFile, typeMap);
			if (description != null) {
				description.FileName = configFile;
				description.canWrite = !fdb.IgnoreDescriptionData;
			}
			return description;
		}
		
		internal void SaveBinary (FileDatabase fdb, string file)
		{
			configFile = file;
			SaveBinary (fdb);
		}
		
		internal void SaveBinary (FileDatabase fdb)
		{
			if (!canWrite)
				throw new InvalidOperationException ("Can't write incomplete description.");
			fdb.WriteSharedObject (AddinFile, FileName, typeMap, this);
//			BinaryXmlReader.DumpFile (configFile);
		}
		
		/// <summary>
		/// Verify this instance.
		/// </summary>
		/// <remarks>
		/// This method checks all the definitions in the description and returns a list of errors.
		/// If the returned list is empty, it means that the description is valid.
		/// </remarks>
		public StringCollection Verify ()
		{
			return Verify (new AddinFileSystemExtension ());
		}
		
		internal StringCollection Verify (AddinFileSystemExtension fs)
		{
			StringCollection errors = new StringCollection ();
			
			if (IsRoot) {
				if (OptionalModules.Count > 0)
					errors.Add ("Root add-in hosts can't have optional modules.");
			}
			
			if (AddinId.Length == 0 || Version.Length == 0) {
				if (ExtensionPoints.Count > 0)
					errors.Add ("Add-ins which define new extension points must have an Id and Version.");
			}

			MainModule.Verify ("", errors);
			OptionalModules.Verify ("", errors);
			ExtensionNodeSets.Verify ("", errors);
			ExtensionPoints.Verify ("", errors);
			ConditionTypes.Verify ("", errors);
			
			foreach (ExtensionNodeSet nset in ExtensionNodeSets) {
				if (nset.Id.Length == 0)
					errors.Add ("Attribute 'id' can't be empty for global node sets.");
			}
			
			string bp = null;
			if (BasePath.Length > 0)
				bp = BasePath;
			else if (sourceAddinFile != null && sourceAddinFile.Length > 0)
				bp = Path.GetDirectoryName (AddinFile);
			else if (configFile != null && configFile.Length > 0)
				bp = Path.GetDirectoryName (configFile);
				
			if (bp != null) {
				foreach (string file in AllFiles) {
					string asmFile = Path.Combine (bp, Util.NormalizePath (file));
					if (!fs.FileExists (asmFile))
						errors.Add ("The file '" + asmFile + "' referenced in the manifest could not be found.");
				}
			}
			
			if (localizer != null && localizer.GetAttribute ("type").Length == 0) {
				errors.Add ("The attribute 'type' in the Location element is required.");
			}
			
			// Ensure that there are no duplicated properties
			
			if (properties != null) {
				HashSet<string> props = new HashSet<string> ();
				foreach (var prop in properties) {
					if (!props.Add (prop.Name + " " + prop.Locale))
						errors.Add (string.Format ("Property {0} specified more than once", prop.Name + (prop.Locale != null ? " (" + prop.Locale + ")" : "")));
				}
			}
			
			return errors;
		}
		
		internal void SetExtensionsAddinId (string addinId)
		{
			foreach (ExtensionPoint ep in ExtensionPoints)
				ep.SetExtensionsAddinId (addinId);
				
			foreach (ExtensionNodeSet ns in ExtensionNodeSets)
				ns.SetExtensionsAddinId (addinId);
		}
		
		internal void UnmergeExternalData (Hashtable addins)
		{
			// Removes extension types and extension sets coming from other add-ins.
			foreach (ExtensionPoint ep in ExtensionPoints)
				ep.UnmergeExternalData (AddinId, addins);
				
			foreach (ExtensionNodeSet ns in ExtensionNodeSets)
				ns.UnmergeExternalData (AddinId, addins);
		}
		
		internal void MergeExternalData (AddinDescription other)
		{
			// Removes extension types and extension sets coming from other add-ins.
			foreach (ExtensionPoint ep in other.ExtensionPoints) {
				ExtensionPoint tep = ExtensionPoints [ep.Path];
				if (tep != null)
					tep.MergeWith (AddinId, ep);
			}
				
			foreach (ExtensionNodeSet ns in other.ExtensionNodeSets) {
				ExtensionNodeSet tns = ExtensionNodeSets [ns.Id];
				if (tns != null)
					tns.MergeWith (AddinId, ns);
			}
		}
		
		internal bool IsExtensionModel {
			get { return RootElement.LocalName == "ExtensionModel"; }
		}
		
		internal static AddinDescription Merge (AddinDescription desc1, AddinDescription desc2)
		{
			if (!desc2.IsExtensionModel) {
				AddinDescription tmp = desc1;
				desc1 = desc2; desc2 = tmp;
			}
			((AddinPropertyCollectionImpl)desc1.Properties).AddRange (desc2.Properties);
			desc1.ExtensionPoints.AddRange (desc2.ExtensionPoints);
			desc1.ExtensionNodeSets.AddRange (desc2.ExtensionNodeSets);
			desc1.ConditionTypes.AddRange (desc2.ConditionTypes);
			desc1.OptionalModules.AddRange (desc2.OptionalModules);
			foreach (string s in desc2.MainModule.Assemblies)
				desc1.MainModule.Assemblies.Add (s);
			foreach (string s in desc2.MainModule.DataFiles)
				desc1.MainModule.DataFiles.Add (s);
			desc1.MainModule.MergeWith (desc2.MainModule);
			return desc1;
		}
		
		void IBinaryXmlElement.Write (BinaryXmlWriter writer)
		{
			TransferCoreProperties (true);
			writer.WriteValue ("id", ParseString (id));
			writer.WriteValue ("ns", ParseString (ns));
			writer.WriteValue ("isroot", isroot);
			writer.WriteValue ("name", ParseString (name));
			writer.WriteValue ("version", ParseString (version));
			writer.WriteValue ("compatVersion", ParseString (compatVersion));
			writer.WriteValue ("hasUserId", hasUserId);
			writer.WriteValue ("author", ParseString (author));
			writer.WriteValue ("url", ParseString (url));
			writer.WriteValue ("copyright", ParseString (copyright));
			writer.WriteValue ("description", ParseString (description));
			writer.WriteValue ("category", ParseString (category));
			writer.WriteValue ("basePath", basePath);
			writer.WriteValue ("sourceAddinFile", sourceAddinFile);
			writer.WriteValue ("defaultEnabled", defaultEnabled);
			writer.WriteValue ("domain", domain);
			writer.WriteValue ("MainModule", MainModule);
			writer.WriteValue ("OptionalModules", OptionalModules);
			writer.WriteValue ("NodeSets", ExtensionNodeSets);
			writer.WriteValue ("ExtensionPoints", ExtensionPoints);
			writer.WriteValue ("ConditionTypes", ConditionTypes);
			writer.WriteValue ("FilesInfo", fileInfo);
			writer.WriteValue ("Localizer", localizer);
			writer.WriteValue ("flags", (int)flags);
			writer.WriteValue ("Properties", properties);
		}
		
		void IBinaryXmlElement.Read (BinaryXmlReader reader)
		{
			id = reader.ReadStringValue ("id");
			ns = reader.ReadStringValue ("ns");
			isroot = reader.ReadBooleanValue ("isroot");
			name = reader.ReadStringValue ("name");
			version = reader.ReadStringValue ("version");
			compatVersion = reader.ReadStringValue ("compatVersion");
			hasUserId = reader.ReadBooleanValue ("hasUserId");
			author = reader.ReadStringValue ("author");
			url = reader.ReadStringValue ("url");
			copyright = reader.ReadStringValue ("copyright");
			description = reader.ReadStringValue ("description");
			category = reader.ReadStringValue ("category");
			basePath = reader.ReadStringValue ("basePath");
			sourceAddinFile = reader.ReadStringValue ("sourceAddinFile");
			defaultEnabled = reader.ReadBooleanValue ("defaultEnabled");
			domain = reader.ReadStringValue ("domain");
			mainModule = (ModuleDescription) reader.ReadValue ("MainModule");
			optionalModules = (ModuleCollection) reader.ReadValue ("OptionalModules", new ModuleCollection (this));
			nodeSets = (ExtensionNodeSetCollection) reader.ReadValue ("NodeSets", new ExtensionNodeSetCollection (this));
			extensionPoints = (ExtensionPointCollection) reader.ReadValue ("ExtensionPoints", new ExtensionPointCollection (this));
			conditionTypes = (ConditionTypeDescriptionCollection) reader.ReadValue ("ConditionTypes", new ConditionTypeDescriptionCollection (this));
			fileInfo = (object[]) reader.ReadValue ("FilesInfo", null);
			localizer = (ExtensionNodeDescription) reader.ReadValue ("Localizer");
			flags = (AddinFlags) reader.ReadInt32Value ("flags");
			properties = (AddinPropertyCollectionImpl) reader.ReadValue ("Properties", new AddinPropertyCollectionImpl (this));
			
			if (mainModule != null)
				mainModule.SetParent (this);
		}
	}
	
	class AddinFileInfo: IBinaryXmlElement
	{
		string fileName;
		DateTime timestamp;
		
		public string FileName {
			get {
				return fileName;
			}
			set {
				fileName = value;
			}
		}

		public System.DateTime Timestamp {
			get {
				return timestamp;
			}
			set {
				timestamp = value;
			}
		}
		
		public void Read (BinaryXmlReader reader)
		{
			fileName = reader.ReadStringValue ("fileName");
			timestamp = reader.ReadDateTimeValue ("timestamp");
		}

		public void Write (BinaryXmlWriter writer)
		{
			writer.WriteValue ("fileName", fileName);
			writer.WriteValue ("timestamp", timestamp);
		}
	}
}