// 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.
//
// Copyright (C) 2005, 2006 Novell, Inc (http://www.novell.com)
//

#if CONFIGURATION_DEP
extern alias PrebuiltSystem;
using NameValueCollection = PrebuiltSystem.System.Collections.Specialized.NameValueCollection;
#endif
#if CONFIGURATION_DEP
using System.IO;
using System.Xml.Serialization;
#endif

using System.ComponentModel;
using System.Reflection;
using System.Threading;
using System.Collections.Specialized;

namespace System.Configuration {

	public abstract class ApplicationSettingsBase : SettingsBase, INotifyPropertyChanged
	{
		protected ApplicationSettingsBase ()
		{
			Initialize (Context, Properties, Providers);
		}

		protected ApplicationSettingsBase (IComponent owner)
			: this (owner, String.Empty)
		{
		}
 
		protected ApplicationSettingsBase (string settingsKey)
		{
			this.settingsKey = settingsKey;

			Initialize (Context, Properties, Providers);
		}

		protected ApplicationSettingsBase (IComponent owner, 
						   string settingsKey)
		{
			if (owner == null)
				throw new ArgumentNullException ();

#if (CONFIGURATION_DEP)
			providerService = (ISettingsProviderService)owner.Site.GetService(typeof (ISettingsProviderService));
#endif
			this.settingsKey = settingsKey;

			Initialize (Context, Properties, Providers);
		}

		public event PropertyChangedEventHandler PropertyChanged;
		public event SettingChangingEventHandler SettingChanging;
		public event SettingsLoadedEventHandler SettingsLoaded;
		public event SettingsSavingEventHandler SettingsSaving;

		public object GetPreviousVersion (string propertyName)
		{
			throw new NotImplementedException ();
		}

		public void Reload ()
		{
#if (CONFIGURATION_DEP)
			foreach (SettingsProvider provider in Providers) {
//				IApplicationSettingsProvider iasp = provider as IApplicationSettingsProvider;
				CacheValuesByProvider(provider);
			}
#endif
		}

		public void Reset()
		{
#if (CONFIGURATION_DEP)
			Reload ();
			foreach (SettingsPropertyValue pv in PropertyValues)
				pv.PropertyValue = pv.Reset();
#endif
		}

		public override void Save()
		{
#if (CONFIGURATION_DEP)
			Context.CurrentSettings = this;
			/* ew.. this needs to be more efficient */
			foreach (SettingsProvider provider in Providers) {
				SettingsPropertyValueCollection cache = new SettingsPropertyValueCollection ();

				foreach (SettingsPropertyValue val in PropertyValues) {
					if (val.Property.Provider == provider)
						cache.Add (val);
				}

				if (cache.Count > 0)
					provider.SetPropertyValues (Context, cache);
			}
			Context.CurrentSettings = null;
#endif
		}

		public virtual void Upgrade()
		{
		}

		protected virtual void OnPropertyChanged (object sender, 
							  PropertyChangedEventArgs e)
		{
			if (PropertyChanged != null)
				PropertyChanged (sender, e);
		}

		protected virtual void OnSettingChanging (object sender, 
							  SettingChangingEventArgs e)
		{
			if (SettingChanging != null)
				SettingChanging (sender, e);
		}

		protected virtual void OnSettingsLoaded (object sender, 
							 SettingsLoadedEventArgs e)
		{
			if (SettingsLoaded != null)
				SettingsLoaded (sender, e);
		}

		protected virtual void OnSettingsSaving (object sender, 
							 CancelEventArgs e)
		{
			if (SettingsSaving != null)
				SettingsSaving (sender, e);
		}

		[Browsable (false)]
		public override SettingsContext Context {
			get {
				if (IsSynchronized)
					Monitor.Enter (this);

				try {
					if (context == null) {
						context = new SettingsContext ();
						context ["SettingsKey"] = "";
						Type type = GetType ();
						context ["GroupName"] = type.FullName;
						context ["SettingsClassType"] = type;
					}

					return context;
				} finally {
					if (IsSynchronized)
						Monitor.Exit (this);
				}
			}
		}

		void CacheValuesByProvider (SettingsProvider provider)
		{
			SettingsPropertyCollection col = new SettingsPropertyCollection ();

			foreach (SettingsProperty p in Properties) {
				if (p.Provider == provider)
					col.Add (p);
			}

			if (col.Count > 0) {
				SettingsPropertyValueCollection vals = provider.GetPropertyValues (Context, col);
				foreach (SettingsPropertyValue prop in vals) {
					if (PropertyValues [prop.Name] != null)
						PropertyValues [prop.Name].PropertyValue = prop.PropertyValue;
					else
						PropertyValues.Add (prop);
				}
			}

			OnSettingsLoaded (this, new SettingsLoadedEventArgs (provider));
		}

		void InitializeSettings (SettingsPropertyCollection settings)
		{
		}

		object GetPropertyValue (string propertyName)
		{
			SettingsProperty prop = Properties [ propertyName ];

			if (prop == null)
				throw new SettingsPropertyNotFoundException (propertyName);

			if (propertyValues == null)
				InitializeSettings (Properties);

			if (PropertyValues [ propertyName ] == null)
				CacheValuesByProvider (prop.Provider);

			return PropertyValues [ propertyName ].PropertyValue;
		}

		[MonoTODO]
		public override object this [ string propertyName ] {
			get {
				if (IsSynchronized) {
					lock (this) {
						return GetPropertyValue (propertyName);
					}
				}

				return GetPropertyValue (propertyName);
			}
			set {
				SettingsProperty prop = Properties [ propertyName ];

				if (prop == null)
					throw new SettingsPropertyNotFoundException (propertyName);

				if (prop.IsReadOnly)
					throw new SettingsPropertyIsReadOnlyException (propertyName);

				/* XXX check the type of the property vs the type of @value */
				if (value != null &&
				    !prop.PropertyType.IsAssignableFrom (value.GetType()))
					throw new SettingsPropertyWrongTypeException (propertyName);

				if (PropertyValues [ propertyName ] == null)
					CacheValuesByProvider (prop.Provider);

				SettingChangingEventArgs changing_args = new SettingChangingEventArgs (propertyName,
												       GetType().FullName,
												       settingsKey,
												       value,
												       false);

				OnSettingChanging (this, changing_args);

				if (changing_args.Cancel == false) {
					/* actually set the value */
					PropertyValues [ propertyName ].PropertyValue = value;

					/* then emit PropertyChanged */
					OnPropertyChanged (this, new PropertyChangedEventArgs (propertyName));
				}
			}
		}

#if (CONFIGURATION_DEP)
		[Browsable (false)]
		public override SettingsPropertyCollection Properties {
			get {
				if (IsSynchronized)
					Monitor.Enter (this);

				try {
					if (properties == null) {
						SettingsProvider local_provider = null;

						properties = new SettingsPropertyCollection ();

						Type this_type = GetType();
						SettingsProviderAttribute[] provider_attrs = (SettingsProviderAttribute[])this_type.GetCustomAttributes (typeof (SettingsProviderAttribute), false);;
						if (provider_attrs != null && provider_attrs.Length != 0) {
							Type provider_type = Type.GetType (provider_attrs[0].ProviderTypeName);
							SettingsProvider provider = (SettingsProvider) Activator.CreateInstance (provider_type);
							provider.Initialize (null, null);
							if (provider != null && Providers [provider.Name] == null) {
								Providers.Add (provider);
								local_provider = provider;
							}
						}

						PropertyInfo[] type_props = this_type.GetProperties ();
						foreach (PropertyInfo prop in type_props) { // only public properties
							SettingAttribute[] setting_attrs = (SettingAttribute[])prop.GetCustomAttributes (typeof (SettingAttribute), false);
							if (setting_attrs == null || setting_attrs.Length == 0)
								continue;
							CreateSettingsProperty (prop, properties, ref local_provider);
						}
					}

					return properties;
				} finally {
					if (IsSynchronized)
						Monitor.Exit (this);
				}
			}
		}

		void CreateSettingsProperty (PropertyInfo prop, SettingsPropertyCollection properties, ref SettingsProvider local_provider)
		{
			SettingsAttributeDictionary dict = new SettingsAttributeDictionary ();
			SettingsProvider provider = null;
			object defaultValue = null;
			SettingsSerializeAs serializeAs = SettingsSerializeAs.String;
			bool explicitSerializeAs = false;

			foreach (Attribute a in prop.GetCustomAttributes (false)) {
				/* the attributes we handle natively here */
				if (a is SettingsProviderAttribute) {
					Type provider_type = Type.GetType (((SettingsProviderAttribute)a).ProviderTypeName);
					provider = (SettingsProvider) Activator.CreateInstance (provider_type);
					provider.Initialize (null, null);
				}
				else if (a is DefaultSettingValueAttribute) {
					defaultValue = ((DefaultSettingValueAttribute)a).Value;
				}
				else if (a is SettingsSerializeAsAttribute) {
					serializeAs = ((SettingsSerializeAsAttribute)a).SerializeAs;
					explicitSerializeAs = true;
				}
				else if (a is ApplicationScopedSettingAttribute ||
					 a is UserScopedSettingAttribute) {
					dict.Add (a.GetType(), a);
				}
				else {
					dict.Add (a.GetType(), a);
				}
			}

			if (!explicitSerializeAs) {
				// DefaultValue is a string and if we can't convert from string to the 
				// property type then the only other option left is for the string to 
				// be XML.
				//
				TypeConverter converter = TypeDescriptor.GetConverter (prop.PropertyType);
				if (converter != null && 
				    (!converter.CanConvertFrom (typeof (string)) || 
				     !converter.CanConvertTo (typeof (string))))
					serializeAs = SettingsSerializeAs.Xml;
			}

			SettingsProperty setting =
				new SettingsProperty (prop.Name, prop.PropertyType, provider, false /* XXX */,
						      defaultValue /* XXX always a string? */, serializeAs, dict,
						      false, false);


			if (providerService != null)
				setting.Provider = providerService.GetSettingsProvider (setting);

			if (provider == null) {
				if (local_provider == null) {
					local_provider = new LocalFileSettingsProvider () as SettingsProvider;
					local_provider.Initialize (null, null);
				}
				setting.Provider = local_provider;
				// .NET ends up to set this to providers.
				provider = local_provider;
			}

			if (provider != null) {
				/* make sure we're using the same instance of a
				   given provider across multiple properties */
				SettingsProvider p = Providers[provider.Name];
				if (p != null)
					setting.Provider = p;
			}

			properties.Add (setting);

			if (setting.Provider != null && Providers [setting.Provider.Name] == null)
				Providers.Add (setting.Provider);
		}
#endif

		[Browsable (false)]
		public override SettingsPropertyValueCollection PropertyValues {
			get {
				if (IsSynchronized)
					Monitor.Enter (this);

				try {
					if (propertyValues == null) {
						propertyValues = new SettingsPropertyValueCollection ();
					}

					return propertyValues;
				} finally {
					if (IsSynchronized)
						Monitor.Exit (this);
				}
			}
		}

		[Browsable (false)]
		public override SettingsProviderCollection Providers {
			get {
				if (IsSynchronized)
					Monitor.Enter (this);

				try {
					if (providers == null)
						providers = new SettingsProviderCollection ();

					return providers;
				} finally {
					if (IsSynchronized)
						Monitor.Exit (this);
				}
			}
		}

		[Browsable (false)]
		public string SettingsKey {
			get {
				return settingsKey;
			}
			set {
				settingsKey = value;
			}
		}

		string settingsKey;
		SettingsContext context;
#if (CONFIGURATION_DEP)		
		SettingsPropertyCollection properties;
		ISettingsProviderService providerService;
#endif
		SettingsPropertyValueCollection propertyValues;
		SettingsProviderCollection providers;
        }

}