// Builder.custom - customizations to Gtk.Builder
//
// Authors: Stephane Delcroix  <stephane@delcroix.org>
// The biggest part of this code is adapted from glade#, by
//	Ricardo Fernández Pascual <ric@users.sourceforge.net>
//	Rachel Hestilow <hestilow@ximian.com>
//
// Copyright (c) 2008, 2009 Novell, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of version 2 of the Lesser GNU General
// Public License as published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this program; if not, write to the
// Free Software Foundation, Inc., 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.

[System.Serializable]
public class HandlerNotFoundException : SystemException
{
	string handler_name;
	string signal_name;
	System.Reflection.EventInfo evnt;
	Type delegate_type;

	public HandlerNotFoundException (string handler_name, string signal_name,
					 System.Reflection.EventInfo evnt, Type delegate_type)
		: this (handler_name, signal_name, evnt, delegate_type, null)
	{
	}

	public HandlerNotFoundException (string handler_name, string signal_name,
					 System.Reflection.EventInfo evnt, Type delegate_type, Exception inner)
		: base ("No handler " + handler_name + " found for signal " + signal_name,
			inner)
	{
		this.handler_name = handler_name;
		this.signal_name = signal_name;
		this.evnt = evnt;
		this.delegate_type = delegate_type;
	}

	public HandlerNotFoundException (string message, string handler_name, string signal_name,
					 System.Reflection.EventInfo evnt, Type delegate_type)
		: base ((message != null) ? message : "No handler " + handler_name + " found for signal " + signal_name,
			null)
	{
		this.handler_name = handler_name;
		this.signal_name = signal_name;
		this.evnt = evnt;
		this.delegate_type = delegate_type;
	}

	protected HandlerNotFoundException (System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
		: base (info, context)
	{
		handler_name = info.GetString ("HandlerName");
		signal_name = info.GetString ("SignalName");
		evnt = info.GetValue ("Event", typeof (System.Reflection.EventInfo)) as System.Reflection.EventInfo;
		delegate_type = info.GetValue ("DelegateType", typeof (Type)) as Type;
	}

	public string HandlerName
	{
		get {
			return handler_name;
		}
	}

	public string SignalName
	{
		get {
			return signal_name;
		}
	}

	public System.Reflection.EventInfo Event
	{
		get {
			return evnt;
		}
	}

	public Type DelegateType
	{
		get {
			return delegate_type;
		}
	}

	public override void GetObjectData (System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
	{
		base.GetObjectData (info, context);
		info.AddValue ("HandlerName", handler_name);
		info.AddValue ("SignalName", signal_name);
		info.AddValue ("Event", evnt);
		info.AddValue ("DelegateType", delegate_type);
	}
}


[AttributeUsage (AttributeTargets.Field)]
public class ObjectAttribute : Attribute
{
	private string name;
	private bool specified;

	public ObjectAttribute (string name)
	{
		specified = true;
		this.name = name;
	}

	public ObjectAttribute ()
	{
		specified = false;
	}

	public string Name
	{
		get { return name; }
	}

	public bool Specified
	{
		get { return specified; }
	}
}

public IntPtr GetRawObject(string name) {
	IntPtr native_name = GLib.Marshaller.StringToPtrGStrdup (name);
	IntPtr raw_ret = gtk_builder_get_object(Handle, native_name);
	GLib.Marshaller.Free (native_name);
	return raw_ret;
}

public Builder (System.IO.Stream s) : this (s, null)
{
}

public Builder (System.IO.Stream s, string translation_domain)
{
	if (s == null)
		throw new ArgumentNullException ("s");

	int size = (int) s.Length;
	byte[] buffer = new byte[size];
	s.Read (buffer, 0, size);
	s.Close ();

	AddFromString(System.Text.Encoding.UTF8.GetString (buffer));

	TranslationDomain = translation_domain;
}

public Builder (string resource_name) : this (resource_name, null)
{
}

public Builder (string resource_name, string translation_domain) : this (System.Reflection.Assembly.GetEntryAssembly (), resource_name, translation_domain)
{
}

public Builder (System.Reflection.Assembly assembly, string resource_name, string translation_domain) : this ()
{
	if (GetType() != typeof (Builder))
		throw new InvalidOperationException ("Cannot chain to this constructor from subclasses.");

	if (assembly == null)
		assembly = System.Reflection.Assembly.GetCallingAssembly ();

	System.IO.Stream s = assembly.GetManifestResourceStream (resource_name);
	if (s == null)
		throw new ArgumentException ("Cannot get resource file '" + resource_name + "'",
					     "resource_name");

	int size = (int) s.Length;
	byte[] buffer = new byte[size];
	s.Read (buffer, 0, size);
	s.Close ();

	AddFromString(System.Text.Encoding.UTF8.GetString (buffer));

	TranslationDomain = translation_domain;
}

public void Autoconnect (object handler)
{
	BindFields (handler);
	(new SignalConnector (this, handler)).ConnectSignals ();
}

public void Autoconnect (Type handler_class)
{
	BindFields (handler_class);
	(new SignalConnector (this, handler_class)).ConnectSignals ();
}

class SignalConnector
{
	Builder builder;
	Type handler_type;
	object handler;

	public SignalConnector (Builder builder, object handler)
	{
		this.builder = builder;
		this.handler = handler;
		handler_type = handler.GetType ();
	}

	public SignalConnector (Builder builder, Type handler_type)
	{
		this.builder = builder;
		this.handler = null;
		this.handler_type = handler_type;		
	}

	[DllImport("libgtk-win32-2.0-0.dll")]
	static extern void gtk_builder_connect_signals_full(IntPtr raw, GtkBeansSharp.BuilderConnectFuncNative func, IntPtr user_data);

	public void ConnectSignals() {
		GtkBeansSharp.BuilderConnectFuncWrapper func_wrapper = new GtkBeansSharp.BuilderConnectFuncWrapper (new GtkBeans.BuilderConnectFunc (ConnectFunc));
		gtk_builder_connect_signals_full(builder.Handle, func_wrapper.NativeDelegate, IntPtr.Zero);
	}

	public void ConnectFunc (Builder builder, GLib.Object objekt, string signal_name, string handler_name, GLib.Object connect_object, GLib.ConnectFlags flags)
	{
		/* search for the event to connect */
		System.Reflection.MemberInfo[] evnts = objekt.GetType ().
			FindMembers (System.Reflection.MemberTypes.Event,
			     System.Reflection.BindingFlags.Instance
			     | System.Reflection.BindingFlags.Static
			     | System.Reflection.BindingFlags.Public
			     | System.Reflection.BindingFlags.NonPublic,
			     new System.Reflection.MemberFilter (SignalFilter), signal_name);
		foreach (System.Reflection.EventInfo ei in evnts) {
			bool connected = false;
			System.Reflection.MethodInfo add = ei.GetAddMethod ();
			System.Reflection.ParameterInfo[] addpi = add.GetParameters ();
			if (addpi.Length == 1) { /* this should be always true, unless there's something broken */
				Type delegate_type = addpi[0].ParameterType;

				/* look for an instance method */
				if (connect_object != null || handler != null)
					try {
						Delegate d = Delegate.CreateDelegate (delegate_type, connect_object != null ? connect_object : handler, handler_name);
						add.Invoke (objekt, new object[] { d } );
						connected = true;
					} catch (ArgumentException) { /* ignore if there is not such instance method */
					}

				/* look for a static method if no instance method has been found */
				if (!connected && handler_type != null)
					try  {
						Delegate d = Delegate.CreateDelegate (delegate_type, handler_type, handler_name);
						add.Invoke (objekt, new object[] { d } );
						connected = true;
					} catch (ArgumentException) { /* ignore if there is not such static method */
					}

				if (!connected) {
					string msg = ExplainError (ei.Name, delegate_type, handler_type, handler_name);
					throw new HandlerNotFoundException (msg, handler_name, signal_name, ei, delegate_type);
				}
			}
		}
	}

	static bool SignalFilter (System.Reflection.MemberInfo m, object filterCriteria)
	{
		string signame = (filterCriteria as string);
		object[] attrs = m.GetCustomAttributes (typeof (GLib.SignalAttribute), false);
		if (attrs.Length > 0)
		{
			foreach (GLib.SignalAttribute a in attrs)
			{
				if (signame == a.CName)
				{
					return true;
				}
			}
			return false;
		}
		else
		{
			/* this tries to match the names when no attibutes are present.
			   It is only a fallback. */
			signame = signame.ToLower ().Replace ("_", "");
			string evname = m.Name.ToLower ();
			return signame == evname;
		}
	}

	static string GetSignature (System.Reflection.MethodInfo method)
	{
		if (method == null)
			return null;

		System.Reflection.ParameterInfo [] parameters = method.GetParameters ();
		System.Text.StringBuilder sb = new System.Text.StringBuilder ();
		sb.Append ('(');
		foreach (System.Reflection.ParameterInfo info in parameters) {
			sb.Append (info.ParameterType.ToString ());
			sb.Append (',');
		}
		if (sb.Length != 0)
			sb.Length--;

		sb.Append (')');
		return sb.ToString ();
	}

	static string GetSignature (Type delegate_type)
	{
		System.Reflection.MethodInfo method = delegate_type.GetMethod ("Invoke");
		return GetSignature (method);
	}

	const System.Reflection.BindingFlags flags = System.Reflection.BindingFlags.NonPublic |
					System.Reflection.BindingFlags.Public |
					System.Reflection.BindingFlags.Static |
					System.Reflection.BindingFlags.Instance;
	static string GetSignature (Type klass, string method_name)
	{
		try {
			System.Reflection.MethodInfo method = klass.GetMethod (method_name, flags);
			return GetSignature (method);
		} catch {
			// May be more than one method with that name and none matches
			return null;
		}
	}


	static string ExplainError (string event_name, Type deleg, Type klass, string method)
	{
		if (deleg == null || klass == null || method == null)
			return null;

		System.Text.StringBuilder sb = new System.Text.StringBuilder ();
		string expected = GetSignature (deleg);
		string actual = GetSignature (klass, method);
		if (actual == null)
			return null;
			sb.AppendFormat ("The handler for the event {0} should take '{1}', " +
				"but the signature of the provided handler ('{2}') is '{3}'\n",
				event_name, expected, method, actual);
		return sb.ToString ();
	}

}


void BindFields (object target)
{
	BindFields (target, target.GetType ());
}

void BindFields (Type type)
{
	BindFields (null, type);
}

void BindFields (object target, Type type)
{
	System.Reflection.BindingFlags flags = System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.DeclaredOnly;
	if (target != null)
		flags |= System.Reflection.BindingFlags.Instance;
	else
		flags |= System.Reflection.BindingFlags.Static;

	do {
		System.Reflection.FieldInfo[] fields = type.GetFields (flags);
		if (fields == null)
			return;

		foreach (System.Reflection.FieldInfo field in fields)
		{
			object[] attrs = field.GetCustomAttributes (typeof (ObjectAttribute), false);
			if (attrs == null || attrs.Length == 0)
				continue;
			// The widget to field binding must be 1:1, so only check
			// the first attribute.
			ObjectAttribute attr = (ObjectAttribute) attrs[0];
			GLib.Object gobject;
			if (attr.Specified)
				gobject = GetObject (attr.Name);
			else
				gobject = GetObject (field.Name);

			if (gobject != null)
				try {
					field.SetValue (target, gobject, flags, null, null);
				} catch (Exception e) {
					Console.WriteLine ("Unable to set value for field " + field.Name);
					throw e;
				}
		}
		type = type.BaseType;
	}
	while (type != typeof(object) && type != null);
}