/* ****************************************************************************
 *
 * Copyright (c) Microsoft Corporation. 
 *
 * This source code is subject to terms and conditions of the Microsoft Public License. A 
 * copy of the license can be found in the License.html file at the root of this distribution. If 
 * you cannot locate the  Microsoft Public License, please send an email to 
 * dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound 
 * by the terms of the Microsoft Public License.
 *
 * You must not remove this notice, or any other, from this software.
 *
 *
 * ***************************************************************************/

using System;
using System.Collections.Generic;

using System.Linq.Expressions;
using System.Scripting.Actions;

namespace System.Dynamic
{
    public class DynamicObject : IDynamicObject
    {
        public virtual object GetMember(GetMemberAction info)
        {
            throw new MissingMemberException("Dynamic", info.Name);
        }
        public virtual void SetMember(SetMemberAction info, object value)
        {
            throw new MissingMemberException("Dynamic", info.Name);
        }

        public virtual object Invoke(InvokeAction info, object[] arguments)
        {
            throw new NotImplementedException("Invoke");
        }

        public virtual object InvokeMember(CallAction info, object[] arguments)
        {
            throw new NotImplementedException("InvokeMember");
        }

        public MetaObject GetMetaObject(Expression parameter)
        {
            return new DynamicMetaObject(this, parameter);
        }

        class DynamicMetaObject : MetaObject
        {
            public DynamicMetaObject(DynamicObject v, Expression e) : base(e, Restrictions.Empty, v) { }

            public override MetaObject GetMember(GetMemberAction info, MetaObject[] args)
            {
                var x = this.Expression;
                var test = Expression.TypeIs(x, typeof(DynamicObject));
                var target = Expression.Call(
                                  Expression.Convert(x, typeof(DynamicObject)),
                                  typeof(DynamicObject).GetMethod("GetMember"),
                                  Expression.Constant(info));
                return new MetaObject(target, Restrictions.ExpressionRestriction(test));
            }

            public override MetaObject SetMember(SetMemberAction info, MetaObject[] args)
            {
                var x = this.Expression;
                var y = args[1].Expression;
                var test = Expression.TypeIs(x, typeof(DynamicObject));
                var target = Expression.Call(
                    Expression.Convert(x, typeof(DynamicObject)),
                    typeof(DynamicObject).GetMethod("SetMember"),
                    Expression.Constant(info),
                    Expression.ConvertHelper(y, typeof(object)));
                return new MetaObject(target, Restrictions.ExpressionRestriction(test));
            }

            public override MetaObject Invoke(InvokeAction action, MetaObject[] args)
            {
                var x = this.Expression;
                var test = Expression.TypeIs(x, typeof(DynamicObject));
                var inits = new Expression[args.Length - 1];
                for (int i = 0; i < inits.Length; i++)
                {
                    inits[i] = Expression.ConvertHelper(args[i + 1].Expression, typeof(object));
                }
                var argsArray = Expression.NewArrayHelper(typeof(object), inits);
                var target = Expression.Call(
                    Expression.Convert(x, typeof(DynamicObject)),
                    typeof(DynamicObject).GetMethod("Invoke"),
                    Expression.Constant(action), argsArray);
                return new MetaObject(target, Restrictions.ExpressionRestriction(test));
            }

            public override MetaObject Call(CallAction action, MetaObject[] args)
            {
                var x = this.Expression;
                var test = Expression.TypeIs(x, typeof(DynamicObject));
                var inits = new Expression[args.Length - 1];
                for (int i = 0; i < inits.Length; i++)
                {
                    inits[i] = Expression.ConvertHelper(args[i + 1].Expression, typeof(object));
                }
                var argsArray = Expression.NewArrayHelper(typeof(object), inits);
                var target = Expression.Call(
                    Expression.Convert(x, typeof(DynamicObject)),
                    typeof(DynamicObject).GetMethod("InvokeMember"),
                    Expression.Constant(action), argsArray);
                return new MetaObject(target, Restrictions.ExpressionRestriction(test));
            }
        }
    }
}