//
// LocalVariableValueBatch.cs
//
// Author: Jeffrey Stedfast <jeff@xamarin.com>
//
// Copyright (c) 2014 Xamarin Inc. (www.xamarin.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 Mono.Debugger.Soft;

namespace Mono.Debugging.Soft
{
	public class LocalVariableBatch
	{
		readonly LocalVariable[] variables;
		Value[] values;
		int version;

		public LocalVariableBatch (LocalVariable[] variables)
		{
			this.variables = variables;
		}

		public Value GetValue (SoftEvaluationContext ctx, LocalVariable variable)
		{
			if (variable == null)
				throw new ArgumentNullException ("variable");

			if (values == null || version != ctx.Session.StackVersion) {
				values = ctx.Frame.GetValues (variables);
				version = ctx.Session.StackVersion;
			}

			for (int i = 0; i < variables.Length; i++) {
				if (variable == variables[i])
					return values[i];
			}

			throw new ArgumentOutOfRangeException ("variable");
		}

		public void SetValue (SoftEvaluationContext ctx, LocalVariable variable, Value value)
		{
			var canUpdateCache = values != null && version == ctx.Session.StackVersion;

			ctx.Frame.SetValue (variable, value);
			ctx.Session.StackVersion++;

			if (canUpdateCache) {
				for (int i = 0; i < variables.Length; i++) {
					if (variable == variables[i]) {
						values[i] = value;
						break;
					}
				}

				version = ctx.Session.StackVersion;
			} else {
				values = null;
				version = 0;
			}
		}
	}
}