// ==========================================================================
// 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;

namespace Python.Runtime {

    /// 
    /// Represents a Python tuple object. See the documentation at
    /// http://www.python.org/doc/current/api/tupleObjects.html for details.
    /// 

    public class PyTuple : PySequence {

	/// 
	/// PyTuple Constructor
	/// 
	///
	/// 
	/// Creates a new PyTuple from an existing object reference. Note 
	/// that the instance assumes ownership of the object reference. 
	/// The object reference is not checked for type-correctness. 
	/// 

	public PyTuple(IntPtr ptr) : base(ptr) {}


	/// 
	/// PyTuple Constructor
	/// 
	///
	/// 
	/// Copy constructor - obtain a PyTuple from a generic PyObject. An 
	/// ArgumentException will be thrown if the given object is not a
	/// Python tuple object.
	/// 

	public PyTuple(PyObject o) : base() {
	    if (!IsTupleType(o)) {
		throw new ArgumentException("object is not a tuple");
	    }
	    Runtime.Incref(o.obj);
	    obj = o.obj;
	}


	/// 
	/// PyTuple Constructor
	/// 
	///
	/// 
	/// Creates a new empty PyTuple.
	/// 

	public PyTuple() : base() {
	    obj = Runtime.PyTuple_New(0);
	    if (obj == IntPtr.Zero) {
		throw new PythonException();
	    }
	}
	

	/// 
	/// PyTuple Constructor
	/// 
	///
	/// 
	/// Creates a new PyTuple from an array of PyObject instances.
	/// 

	public PyTuple(PyObject[] items) : base() {
	    int count = items.Length;
	    obj = Runtime.PyTuple_New(count);
	    for (int i = 0; i < count; i++) {
		IntPtr ptr = items[i].obj;
		Runtime.Incref(ptr);
		int r = Runtime.PyTuple_SetItem(obj, i, ptr);
		if (r < 0) {
		    throw new PythonException();
		}
	    }
	}


	/// 
	/// IsTupleType Method
	/// 
	///
	/// 
	/// Returns true if the given object is a Python tuple.
	/// 

	public static bool IsTupleType(PyObject value) {
	    return Runtime.PyTuple_Check(value.obj);
	}


	/// 
	/// AsTuple Method
	/// 
	///
	/// 
	/// Convert a Python object to a Python tuple if possible, raising  
	/// a PythonException if the conversion is not possible. This is
	/// equivalent to the Python expression "tuple(object)".
	/// 

	public static PyTuple AsTuple(PyObject value) {
	    IntPtr op = Runtime.PySequence_Tuple(value.obj);
	    if (op == IntPtr.Zero) {
		throw new PythonException();
	    }
	    return new PyTuple(op);
	}


    }


}