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//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License, version 2.0, as
// published by the Free Software Foundation.
//
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// with the separately licensed software that they have included with
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//
// Without limiting anything contained in the foregoing, this file,
// which is part of MySQL Connector/NET, is also subject to the
// Universal FOSS Exception, version 1.0, a copy of which can be found at
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//
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// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// See the GNU General Public License, version 2.0, for more details.
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using System.Collections.Generic;
using Ubiety.Dns.Core.Records;

namespace MySql.Data.Common
{
    /// <summary>
    /// Class that represents a DNS SRV record.
    /// RFC 2782 (https://tools.ietf.org/html/rfc2782)
    /// </summary>
    internal class DnsSrvRecord : IComparer<DnsSrvRecord>
    {
        /// <summary>
        /// Gets the port.
        /// </summary>
        internal int Port { get; }

        /// <summary>
        /// Gets the priority.
        /// </summary>
        internal int Priority { get; }

        /// <summary>
        /// Gets the target domain name.
        /// </summary>
        internal string Target { get; }

        /// <summary>
        /// Gets the weight.
        /// </summary>
        internal int Weight { get; }

        /// <summary>
        /// Initializes a new instance of <see cref="DnsSrvRecord"/> class.
        /// </summary>
        /// <param name="port">The port.</param>
        /// <param name="priority">The priority.</param>
        /// <param name="target">The target.</param>
        /// <param name="weight">The weight.</param>
        internal DnsSrvRecord(int port, int priority, string target, int weight)
        {
            this.Port = port;
            this.Priority = priority;
            this.Target = target;
            this.Weight = weight;
        }

        internal DnsSrvRecord() { }

        /// <summary>
        /// Initializes a new instance of <see cref="DnsSrvRecord"/> class.
        /// </summary>
        /// <param name="recordSRV">The DNS SRV record.</param>
        internal DnsSrvRecord(RecordSrv recordSRV)
          : this(recordSRV.Port, recordSRV.Priority, recordSRV.Target, recordSRV.Weight)
        { }

        /// <summary>
        /// Compare two <see cref="DnsSrvRecord"/> objects. First, using their priority and
        /// if both have the same, then using their weights.
        /// </summary>
        /// <param name="x">A <see cref="DnsSrvRecord"/> to compare.</param>
        /// <param name="y">A <see cref="DnsSrvRecord"/> to compare.</param>
        /// <returns></returns>
        public int Compare(DnsSrvRecord x, DnsSrvRecord y)
        {
            int priorityDiff = x.Priority.CompareTo(y.Priority);
            return priorityDiff == 0 ? y.Weight.CompareTo(x.Weight) : priorityDiff;
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="DnsSrvRecord"/> class from a <see cref="RecordSrv"/>.
        /// </summary>
        /// <param name="recordSRV">The DNS SRV record.</param>
        public static implicit operator DnsSrvRecord(RecordSrv recordSRV)
        {
            if (recordSRV == null)
            {
                return null;
            }

            recordSRV.Target = recordSRV.Target.TrimEnd('.');

            return new DnsSrvRecord(recordSRV);
        }
    }
}