using System;
namespace Unosquare.Swan.Networking.Ldap {
  /// <summary>
  /// Represents a LDAP Modification Request Message.
  /// </summary>
  /// <seealso cref="Unosquare.Swan.Networking.Ldap.LdapMessage" />
  public sealed class LdapModifyRequest : LdapMessage {
    /// <summary>
    /// Initializes a new instance of the <see cref="LdapModifyRequest"/> class.
    /// </summary>
    /// <param name="dn">The dn.</param>
    /// <param name="modifications">The modifications.</param>
    /// <param name="control">The control.</param>
    public LdapModifyRequest(String dn, LdapModification[] modifications, LdapControl[] control)
        : base(LdapOperation.ModifyRequest, new RfcModifyRequest(dn, EncodeModifications(modifications)), control) {
    }

    /// <summary>
    /// Gets the dn.
    /// </summary>
    /// <value>
    /// The dn.
    /// </value>
    public String DN => this.Asn1Object.RequestDn;

    /// <inheritdoc />
    public override String ToString() => this.Asn1Object.ToString();

    private static Asn1SequenceOf EncodeModifications(LdapModification[] mods) {
      Asn1SequenceOf rfcMods = new Asn1SequenceOf(mods.Length);

      foreach(LdapModification t in mods) {
        LdapAttribute attr = t.Attribute;

        Asn1SetOf vals = new Asn1SetOf(attr.Size());
        if(attr.Size() > 0) {
          foreach(SByte[] val in attr.ByteValueArray) {
            vals.Add(new Asn1OctetString(val));
          }
        }

        Asn1Sequence rfcMod = new Asn1Sequence(2);
        rfcMod.Add(new Asn1Enumerated((Int32)t.Op));
        rfcMod.Add(new RfcAttributeTypeAndValues(attr.Name, vals));

        rfcMods.Add(rfcMod);
      }

      return rfcMods;
    }

    internal class RfcAttributeTypeAndValues : Asn1Sequence {
      public RfcAttributeTypeAndValues(String type, Asn1Object vals)
          : base(2) {
        this.Add(type);
        this.Add(vals);
      }
    }
  }
}