Include.cs

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
 
namespace Waher.Security.SPF.Mechanisms
{
    public class Include : MechanismDomainSpec  
    {
        private readonly SpfExpression[] spfExpressions;
 
        public Include(Term Term, SpfQualifier Qualifier, params SpfExpression[] SpfExpressions)
            : base(Term, Qualifier)
        {
            this.spfExpressions = SpfExpressions;
        }
 
        public override async Task<SpfResult> Matches()
        {
            string Bak = this.term.domain;
            this.term.domain = this.Domain;
            try
            {
                KeyValuePair<SpfResult, string> Result = await SpfResolver.CheckHost(this.term, this.spfExpressions);
 
                switch (Result.Key)
                {
                    case SpfResult.Pass:
                        return SpfResult.Pass;
 
                    case SpfResult.Fail:
                    case SpfResult.SoftFail:
                    case SpfResult.Neutral:
                        return SpfResult.Fail;
 
                    case SpfResult.TemporaryError:
                        return SpfResult.TemporaryError;
 
                    case SpfResult.PermanentError:
                    case SpfResult.None:
                    default:
                        return SpfResult.PermanentError;
                }
            }
            finally
            {
                this.term.domain = Bak;
            }
        }
 
    }
}