//
// Copyright (c) Microsoft. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.
//

#nullable disable

using System;

namespace Microsoft.SqlTools.ServiceLayer.QueryExecution
{
    /// <summary>
    /// Class that represents a Special Action which occured by user request during the query 
    /// </summary>
    public class SpecialAction {
        
        #region Private Class variables 

        // Underlying representation as bitwise flags to simplify logic
        [Flags]
        private enum ActionFlags 
        {
            None    = 0,
            // All added options must be powers of 2
            ExpectYukonXmlShowPlan = 1
        }

        private ActionFlags flags; 

        #endregion

        /// <summary>
        /// The type of XML execution plan that is contained with in a result set  
        /// </summary>
        public SpecialAction()
        {
            flags = ActionFlags.None;
        }

        #region Public Functions
        /// <summary>
        /// No Special action performed 
        /// </summary>
        public bool None 
        { 
            get { return flags == ActionFlags.None; } 
            set 
            {
                flags = ActionFlags.None;
            }
        }

        /// <summary>
        /// Contains an XML execution plan result set  
        /// </summary>
        public bool ExpectYukonXMLShowPlan 
        {
            get { return flags.HasFlag(ActionFlags.ExpectYukonXmlShowPlan); }
            set 
            {
                if (value)
                {
                    // OR flags with value to apply 
                    flags |= ActionFlags.ExpectYukonXmlShowPlan;
                } 
                else
                {
                    // AND flags with the inverse of the value we want to remove
                    flags &= ~(ActionFlags.ExpectYukonXmlShowPlan);
                }
            }
        }

        /// <summary>
        /// Aggregate this special action with the input
        /// </summary>
        public void CombineSpecialAction(SpecialAction action)
        {
            flags |= ((action?.flags) ?? ActionFlags.None);
        }
        public override string ToString() => $"ActionFlag:'{flags}', ExpectYukonXMLShowPlan:'{ExpectYukonXMLShowPlan}'";
        #endregion
    };
}