// ==========================================================================
// This software is subject to the provisions of the Zope Public License,
// Version 2.0 (ZPL).  A copy of the ZPL should accompany this distribution.
// THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
// WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
// FOR A PARTICULAR PURPOSE.
// ==========================================================================

using System;
using System.Reflection;

namespace Python.Runtime {

    //========================================================================
    // A ConstructorBinder encapsulates information about one or more managed
    // constructors, and is responsible for selecting the right constructor
    // given a set of Python arguments. This is slightly different than the
    // standard MethodBinder because of a difference in invoking constructors
    // using reflection (which is seems to be a CLR bug).
    //========================================================================

    internal class ConstructorBinder : MethodBinder {

	internal ConstructorBinder () : base() {}

	//====================================================================
	// Constructors get invoked when an instance of a wrapped managed
	// class or a subclass of a managed class is created. This differs
	// from the MethodBinder implementation in that we return the raw
	// result of the constructor rather than wrapping it as a Python 
	// object - the reason is that only the caller knows the correct
	// Python type to use when wrapping the result (may be a subclass).
	//====================================================================

 	internal object InvokeRaw(IntPtr inst, IntPtr args, IntPtr kw) {
	    return this.InvokeRaw(inst, args, kw, null);
	}

	internal object InvokeRaw(IntPtr inst, IntPtr args, IntPtr kw,
				  MethodBase info) {
	    Binding binding = this.Bind(inst, args, kw);
	    Object result;

	    if (binding == null) {
		Exceptions.SetError(Exceptions.TypeError, 
				    "no constructor matches given arguments"
				    );
		return null;
	    }

	    // Object construction is presumed to be non-blocking and fast
	    // enough that we shouldn't really need to release the GIL.

	    ConstructorInfo ci = (ConstructorInfo)binding.info;
	    try {
		result = ci.Invoke(binding.args);
	    }
	    catch (Exception e) {
		if (e.InnerException != null) {
		    e = e.InnerException;
		}
		Exceptions.SetError(e);
		return null;
	    }

	    return result;
	}


    }


}