//
// CSharpInvokeMemberBinder.cs
//
// Authors:
//	Marek Safar  <marek.safar@gmail.com>
//
// Copyright (C) 2009 Novell, Inc (http://www.novell.com)
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.Dynamic;
using System.Collections.Generic;
using System.Linq;
using Compiler = Mono.CSharp;
using SLE = System.Linq.Expressions;

namespace Microsoft.CSharp.RuntimeBinder
{
	class CSharpInvokeMemberBinder : InvokeMemberBinder
	{
		//
		// A custom runtime invocation is needed to deal with member invocation which
		// is not real member invocation but invocation on invocalble member.
		//
		// An example:
		// class C {
		//		dynamic f;
		//		void Foo ()
		//		{
		//			dynamic d = new C ();
		//			d.f.M ();
		//		}
		//
		// The runtime value of `f' can be a delegate in which case we are invoking result
		// of member invocation, this is already handled by DoResolveDynamic but we need
		// more runtime dependencies which require Microsoft.CSharp assembly reference or
		// a lot of reflection calls
		//
		class Invocation : Compiler.Invocation
		{
			sealed class RuntimeDynamicInvocation : Compiler.ShimExpression
			{
				Invocation invoke;

				public RuntimeDynamicInvocation (Invocation invoke, Compiler.Expression memberExpr)
					: base (memberExpr)
				{
					this.invoke = invoke;
				}

				protected override Compiler.Expression DoResolve (Compiler.ResolveContext rc)
				{
					type = expr.Type;
					eclass = Compiler.ExprClass.Value;
					return this;
				}

				//
				// Creates an invoke call on invocable expression
				//
				public override System.Linq.Expressions.Expression MakeExpression (Compiler.BuilderContext ctx)
				{
					var invokeBinder = invoke.invokeBinder;
					var binder = Binder.Invoke (invokeBinder.flags, invokeBinder.callingContext, invokeBinder.argumentInfo);

					var args = invoke.Arguments;
					var args_expr = new SLE.Expression[invokeBinder.argumentInfo.Count];

					var types = new Type [args_expr.Length + 2];

					// Required by MakeDynamic
					types[0] = typeof (System.Runtime.CompilerServices.CallSite);
					types[1] = expr.Type.GetMetaInfo ();

					args_expr[0] = expr.MakeExpression (ctx);

					for (int i = 0; i < args.Count; ++i) {
						args_expr[i + 1] = args[i].Expr.MakeExpression (ctx);

						int type_index = i + 2;
						types[type_index] = args[i].Type.GetMetaInfo ();
						if (args[i].IsByRef)
							types[type_index] = types[type_index].MakeByRefType ();
					}

					// Return type goes last
					bool void_result = (invokeBinder.flags & CSharpBinderFlags.ResultDiscarded) != 0;
					types[types.Length - 1] = void_result ? typeof (void) : invokeBinder.ReturnType;

					//
					// Much easier to use Expression.Dynamic cannot be used because it ignores ByRef arguments
					// and it always generates either Func or Action and any value type argument is lost
					//
					Type delegateType = SLE.Expression.GetDelegateType (types);
					return SLE.Expression.MakeDynamic (delegateType, binder, args_expr);
				}
			}

			readonly CSharpInvokeMemberBinder invokeBinder;

			public Invocation (Compiler.Expression expr, Compiler.Arguments arguments, CSharpInvokeMemberBinder invokeBinder)
				: base (expr, arguments)
			{
				this.invokeBinder = invokeBinder;
			}

			protected override Compiler.Expression DoResolveDynamic (Compiler.ResolveContext ec, Compiler.Expression memberExpr)
			{
				return new RuntimeDynamicInvocation (this, memberExpr).Resolve (ec);
			}
		}

		readonly CSharpBinderFlags flags;
		IList<CSharpArgumentInfo> argumentInfo;
		IList<Type> typeArguments;
		Type callingContext;
		
		public CSharpInvokeMemberBinder (CSharpBinderFlags flags, string name, Type callingContext, IEnumerable<Type> typeArguments, IEnumerable<CSharpArgumentInfo> argumentInfo)
			: base (name, false, CSharpArgumentInfo.CreateCallInfo (argumentInfo, 1))
		{
			this.flags = flags;
			this.callingContext = callingContext;
			this.argumentInfo = argumentInfo.ToReadOnly ();
			this.typeArguments = typeArguments.ToReadOnly ();
		}
		
		public override DynamicMetaObject FallbackInvoke (DynamicMetaObject target, DynamicMetaObject[] args, DynamicMetaObject errorSuggestion)
		{
			var b = new CSharpInvokeBinder (flags, callingContext, argumentInfo);
			
			// TODO: Is errorSuggestion ever used?
			return b.Defer (target, args);
		}
		
		public override DynamicMetaObject FallbackInvokeMember (DynamicMetaObject target, DynamicMetaObject[] args, DynamicMetaObject errorSuggestion)
		{
			var ctx = DynamicContext.Create ();
			var c_args = ctx.CreateCompilerArguments (argumentInfo.Skip (1), args);
			var t_args = typeArguments == null ?
				null :
				new Compiler.TypeArguments (typeArguments.Select (l => new Compiler.TypeExpression (ctx.ImportType (l), Compiler.Location.Null)).ToArray ());

			var expr = ctx.CreateCompilerExpression (argumentInfo[0], target);

			//
			// Simple name invocation is actually member access invocation
 			// to capture original this argument. This  brings problem when
			// simple name is resolved as a static invocation and member access
			// has to be reduced back to simple name without reporting an error
			//
			if ((flags & CSharpBinderFlags.InvokeSimpleName) != 0) {
				var value = expr as Compiler.RuntimeValueExpression;
				if (value != null)
					value.IsSuggestionOnly = true;
			}

			expr = new Compiler.MemberAccess (expr, Name, t_args, Compiler.Location.Null);
			expr = new Invocation (expr, c_args, this);

			if ((flags & CSharpBinderFlags.ResultDiscarded) == 0)
				expr = new Compiler.Cast (new Compiler.TypeExpression (ctx.ImportType (ReturnType), Compiler.Location.Null), expr, Compiler.Location.Null);
			else
				expr = new Compiler.DynamicResultCast (ctx.ImportType (ReturnType), expr);

			var binder = new CSharpBinder (this, expr, errorSuggestion);
			binder.AddRestrictions (target);
			binder.AddRestrictions (args);

			if ((flags & CSharpBinderFlags.InvokeSpecialName) != 0)
				binder.ResolveOptions |= Compiler.ResolveContext.Options.InvokeSpecialName;

			return binder.Bind (ctx, callingContext);
		}
	}
}