// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information.

using md = System.Data.Entity.Core.Metadata.Edm;
using cqt = System.Data.Entity.Core.Common.CommandTrees;

//using System.Diagnostics; // Please use PlanCompiler.Assert instead of Debug.Assert in this class...

// It is fine to use Debug.Assert in cases where you assert an obvious thing that is supposed
// to prevent from simple mistakes during development (e.g. method argument validation 
// in cases where it was you who created the variables or the variables had already been validated or 
// in "else" clauses where due to code changes (e.g. adding a new value to an enum type) the default 
// "else" block is chosen why the new condition should be treated separately). This kind of asserts are 
// (can be) helpful when developing new code to avoid simple mistakes but have no or little value in 
// the shipped product. 
// PlanCompiler.Assert *MUST* be used to verify conditions in the trees. These would be assumptions 
// about how the tree was built etc. - in these cases we probably want to throw an exception (this is
// what PlanCompiler.Assert does when the condition is not met) if either the assumption is not correct 
// or the tree was built/rewritten not the way we thought it was.
// Use your judgment - if you rather remove an assert than ship it use Debug.Assert otherwise use
// PlanCompiler.Assert.

//
// A CommandPlan represents the plan for a query.
//

namespace System.Data.Entity.Core.Query.PlanCompiler
{

    #region CommandInfo

    // <summary>
    // Captures information about a single provider command
    // </summary>
    internal sealed class ProviderCommandInfo
    {
        #region public apis

        // <summary>
        // Internal methods to get the command tree
        // </summary>
        internal cqt.DbCommandTree CommandTree
        {
            get { return _commandTree; }
        }

        #endregion

        #region private state

        private readonly cqt.DbCommandTree _commandTree;

        #endregion

        #region constructors

        // <summary>
        // Internal constructor for a ProviderCommandInfo object
        // </summary>
        // <param name="commandTree"> command tree for the provider command </param>
        internal ProviderCommandInfo(cqt.DbCommandTree commandTree)
        {
            _commandTree = commandTree;
        }

        #endregion
    }

    #endregion
}
