// ==++==
// 
//   Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// ==--==
//
// <OWNER>GPaperin</OWNER>
// <OWNER>Microsoft</OWNER>
 
using System;
using System.Runtime;
using System.Security;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics.Contracts;
using System.Runtime.InteropServices;
using System.Runtime.CompilerServices;
 
namespace System.Runtime.InteropServices.WindowsRuntime
{
    // This is a set of stub methods implementing the support for the IList interface on WinRT
    // objects that support IBindableVector. Used by the interop mashaling infrastructure.
    //
    // The methods on this class must be written VERY carefully to avoid introducing security holes.
    // That's because they are invoked with special "this"! The "this" object
    // for all of these methods are not BindableVectorToListAdapter objects. Rather, they are
    // of type IBindableVector. No actual BindableVectorToListAdapter object is ever instantiated.
    // Thus, you will see a lot of expressions that cast "this" to "IBindableVector".
    internal sealed class BindableVectorToListAdapter
    {
        private BindableVectorToListAdapter()
        {
            Contract.Assert(false, "This class is never instantiated");
        }
 
        // object this[int index] { get }
        [SecurityCritical]
        internal object Indexer_Get(int index)
        {
            if (index < 0)
                throw new ArgumentOutOfRangeException("index");
 
            IBindableVector _this = JitHelpers.UnsafeCast<IBindableVector>(this);
            return GetAt(_this, (uint)index);
        }
 
        // object this[int index] { set }
        [SecurityCritical]
        internal void Indexer_Set(int index, object value)
        {
            if (index < 0)
                throw new ArgumentOutOfRangeException("index");
 
            IBindableVector _this = JitHelpers.UnsafeCast<IBindableVector>(this);
            SetAt(_this, (uint)index, value);
        }
 
        // int Add(object value)
        [SecurityCritical]
        internal int Add(object value)
        {
            IBindableVector _this = JitHelpers.UnsafeCast<IBindableVector>(this);
            _this.Append(value);
 
            uint size = _this.Size;
            if (((uint)Int32.MaxValue) < size)
            {
                throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_CollectionBackingListTooLarge"));
            }
 
            return (int)(size - 1);
        }
 
        // bool Contains(object item)
        [SecurityCritical]
        internal bool Contains(object item)
        {
            IBindableVector _this = JitHelpers.UnsafeCast<IBindableVector>(this);
 
            uint index;
            return _this.IndexOf(item, out index);
        }
 
        // void Clear()
        [SecurityCritical]
        internal void Clear()
        {
            IBindableVector _this = JitHelpers.UnsafeCast<IBindableVector>(this);
            _this.Clear();
        }
 
        // bool IsFixedSize { get }
        [Pure]
        [SecurityCritical]
        internal bool IsFixedSize()
        {
            return false;
        }
 
        // bool IsReadOnly { get }
        [Pure]
        [SecurityCritical]
        internal bool IsReadOnly()
        {
            return false;
        }
 
        // int IndexOf(object item)
        [SecurityCritical]
        internal int IndexOf(object item)
        {
            IBindableVector _this = JitHelpers.UnsafeCast<IBindableVector>(this);
 
            uint index;
            bool exists = _this.IndexOf(item, out index);
 
            if (!exists)
                return -1;
 
            if (((uint)Int32.MaxValue) < index)
            {
                throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_CollectionBackingListTooLarge"));
            }
 
            return (int)index;
        }
 
        // void Insert(int index, object item)
        [SecurityCritical]
        internal void Insert(int index, object item)
        {
            if (index < 0)
                throw new ArgumentOutOfRangeException("index");
 
            IBindableVector _this = JitHelpers.UnsafeCast<IBindableVector>(this);
            InsertAtHelper(_this, (uint)index, item);
        }
 
        // bool Remove(object item)
        [SecurityCritical]
        internal void Remove(object item)
        {
            IBindableVector _this = JitHelpers.UnsafeCast<IBindableVector>(this);
 
            uint index;
            bool exists = _this.IndexOf(item, out index);
 
            if (exists)
            {
                if (((uint)Int32.MaxValue) < index)
                {
                    throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_CollectionBackingListTooLarge"));
                }
 
                RemoveAtHelper(_this, index);
            }
        }
 
        // void RemoveAt(int index)
        [SecurityCritical]
        internal void RemoveAt(int index)
        {
            if (index < 0)
                throw new ArgumentOutOfRangeException("index");
 
            IBindableVector _this = JitHelpers.UnsafeCast<IBindableVector>(this);
            RemoveAtHelper(_this, (uint)index);
        }
 
        // Helpers:
 
        private static object GetAt(IBindableVector _this, uint index)
        {
            try
            {
                return _this.GetAt(index);
 
                // We delegate bounds checking to the underlying collection and if it detected a fault,
                // we translate it to the right exception:
            }
            catch (Exception ex)
            {
                if (__HResults.E_BOUNDS == ex._HResult)
                    throw new ArgumentOutOfRangeException("index");
 
                throw;
            }
        }
 
        private static void SetAt(IBindableVector _this, uint index, object value)
        {
            try
            {
                _this.SetAt(index, value);
 
                // We delegate bounds checking to the underlying collection and if it detected a fault,
                // we translate it to the right exception:
            }
            catch (Exception ex)
            {
                if (__HResults.E_BOUNDS == ex._HResult)
                    throw new ArgumentOutOfRangeException("index");
 
                throw;
            }
        }
 
        private static void InsertAtHelper(IBindableVector _this, uint index, object item)
        {
            try
            {
                _this.InsertAt(index, item);
 
                // We delegate bounds checking to the underlying collection and if it detected a fault,
                // we translate it to the right exception:
            }
            catch (Exception ex)
            {
                if (__HResults.E_BOUNDS == ex._HResult)
                    throw new ArgumentOutOfRangeException("index");
 
                throw;
            }
        }
 
        private static void RemoveAtHelper(IBindableVector _this, uint index)
        {
            try
            {
                _this.RemoveAt(index);
 
                // We delegate bounds checking to the underlying collection and if it detected a fault,
                // we translate it to the right exception:
            }
            catch (Exception ex)
            {
                if (__HResults.E_BOUNDS == ex._HResult)
                    throw new ArgumentOutOfRangeException("index");
 
                throw;
            }
        }
    }
}