// ==========================================================================
// 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.Collections;
using System.Reflection;
using System.Runtime.InteropServices;

namespace Python.Runtime {

    /// 
    /// Implements a Python type for managed arrays. This type is essentially
    /// the same as a ClassObject, except that it provides sequence semantics 
    /// to support natural array usage (indexing) from Python.
    /// 

    internal class ArrayObject : ClassBase {

	internal ArrayObject(Type tp) : base(tp) {}

	internal override bool CanSubclass() {
	    return false;
	}

	[CallConvCdecl()]
	public static IntPtr tp_new(IntPtr tp, IntPtr args, IntPtr kw) {
	    ArrayObject self = GetManagedObject(tp) as ArrayObject;
	    if (Runtime.PyTuple_Size(args) != 1) {
		return Exceptions.RaiseTypeError("array expects 1 argument");
	    }
	    IntPtr op = Runtime.PyTuple_GetItem(args, 0);
	    Object result;

	    if (!Converter.ToManaged(op, self.type, out result, true)) {
		return IntPtr.Zero;
	    }
	    return CLRObject.GetInstHandle(result, tp);
	    string message = "cannot instantiate array wrapper";
	    return Exceptions.RaiseTypeError(message);
	}


	//====================================================================
	// Implements __getitem__ for array types.
	//====================================================================

	[CallConvCdecl()]
	public static IntPtr mp_subscript(IntPtr ob, IntPtr idx) {
	    CLRObject obj = (CLRObject)ManagedType.GetManagedObject(ob);
	    Array items = obj.inst as Array;
	    Type itemType = obj.inst.GetType().GetElementType();
	    int rank = items.Rank;
	    int index = 0;
	    object value;

	    // Note that CLR 1.0 only supports int indexes - methods to
	    // support long indices were introduced in 1.1. We could
	    // support long indices automatically, but given that long
	    // indices are not backward compatible and a relative edge 
	    // case, we won't bother for now.

	    // Single-dimensional arrays are the most common case and are
	    // cheaper to deal with than multi-dimensional, so check first.

	    if (rank == 1) {
		index = (int)Runtime.PyInt_AsLong(idx);

		if (Exceptions.ErrorOccurred()) {
		    return Exceptions.RaiseTypeError("invalid index value");
		}

		if (index < 0) {
		    index = items.Length + index;
		}

		try {
		    value = items.GetValue(index);
		}
		catch (IndexOutOfRangeException) {
		    Exceptions.SetError(Exceptions.IndexError,
					"array index out of range"
					);
		    return IntPtr.Zero; 
		}

		return Converter.ToPython(items.GetValue(index), itemType);
	    }

	    // Multi-dimensional arrays can be indexed a la: list[1, 2, 3].

	    if (!Runtime.PyTuple_Check(idx)) {
		Exceptions.SetError(Exceptions.TypeError,
				    "invalid index value"
				    );
		return IntPtr.Zero;
	    }

	    int count = Runtime.PyTuple_Size(idx);

	    Array args = Array.CreateInstance(typeof(Int32), count);

	    for (int i = 0; i < count; i++) {
		IntPtr op = Runtime.PyTuple_GetItem(idx, i);
		index = (int)Runtime.PyInt_AsLong(op);

		if (Exceptions.ErrorOccurred()) {
		    return Exceptions.RaiseTypeError("invalid index value");
		}

		if (index < 0) {
		    index = items.GetLength(i) + index;
		}

		args.SetValue(index, i);
	    }

	    try {
		value = items.GetValue((int[]) args);
	    }
	    catch (IndexOutOfRangeException) {
		Exceptions.SetError(Exceptions.IndexError,
				    "array index out of range"
				    );
		return IntPtr.Zero; 
	    }

	    return Converter.ToPython(value, itemType);
	}


	//====================================================================
	// Implements __setitem__ for array types.
	//====================================================================

	[CallConvCdecl()]
	public static int mp_ass_subscript(IntPtr ob, IntPtr idx, IntPtr v) {
	    CLRObject obj = (CLRObject)ManagedType.GetManagedObject(ob);
	    Array items = obj.inst as Array;
	    Type itemType = obj.inst.GetType().GetElementType();
	    int rank = items.Rank;
	    int index = 0;
	    object value;

	    if (items.IsReadOnly) {
		Exceptions.RaiseTypeError("array is read-only");
		return -1;
	    }

	    if (!Converter.ToManaged(v, itemType, out value, true)) {
		return -1;
	    }

	    if (rank == 1) {
		index = (int)Runtime.PyInt_AsLong(idx);

		if (Exceptions.ErrorOccurred()) {
		    Exceptions.RaiseTypeError("invalid index value");
		    return -1;
		}

		if (index < 0) {
		    index = items.Length + index;
		}

		try {
		    items.SetValue(value, index);
		}
		catch (IndexOutOfRangeException) {
		    Exceptions.SetError(Exceptions.IndexError,
					"array index out of range"
					);
		    return -1; 
		}

		return 0;
	    }

	    if (!Runtime.PyTuple_Check(idx)) {
		Exceptions.RaiseTypeError("invalid index value");
		return -1;
	    }

	    int count = Runtime.PyTuple_Size(idx);

	    Array args = Array.CreateInstance(typeof(Int32), count);

	    for (int i = 0; i < count; i++) {
		IntPtr op = Runtime.PyTuple_GetItem(idx, i);
		index = (int)Runtime.PyInt_AsLong(op);

		if (Exceptions.ErrorOccurred()) {
		    Exceptions.RaiseTypeError("invalid index value");
		    return -1;
		}

		if (index < 0) {
		    index = items.GetLength(i) + index;
		}

		args.SetValue(index, i);
	    }

	    try {
		items.SetValue(value, (int[])args);
	    }
	    catch (IndexOutOfRangeException) {
		Exceptions.SetError(Exceptions.IndexError,
				    "array index out of range"
				    );
		return -1;
	    }

	    return 0;
	}


	//====================================================================
	// Implements __contains__ for array types.
	//====================================================================

	[CallConvCdecl()]
	public static int sq_contains(IntPtr ob, IntPtr v) {
	    CLRObject obj = (CLRObject)ManagedType.GetManagedObject(ob);
	    Type itemType = obj.inst.GetType().GetElementType();
	    IList items = obj.inst as IList;
	    object value;

	    if (!Converter.ToManaged(v, itemType, out value, false)) {
		return 0;
	    }

	    if (items.Contains(value)) {
		return 1;
	    }

	    return 0;
	}


	//====================================================================
	// Implements __len__ for array types.
	//====================================================================

	[CallConvCdecl()]
	public static int mp_length(IntPtr ob) {
	    CLRObject self = (CLRObject)ManagedType.GetManagedObject(ob);
	    Array items = self.inst as Array;
	    return items.Length;
	}


    }	

}