using System;
using System.Collections.Generic;

namespace BLToolkit.Mapping
{

    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property, Inherited = true, AllowMultiple = false)]
    public sealed class RelationAttribute : Attribute
    {
        #region Constructors

        public RelationAttribute()
        {
        }

        public RelationAttribute(Type destination)
        {
            _destination = destination;
        }

        public RelationAttribute(string slaveIndex)
        {
            SlaveIndex1 = slaveIndex;
        }

        public RelationAttribute(string slaveIndex, string masterIndex)
            : this(slaveIndex)
        {
            MasterIndex1 = masterIndex;
        }

        public RelationAttribute(Type destination, string slaveIndex)
            : this(destination)
        {
            SlaveIndex1 = slaveIndex;
        }

        public RelationAttribute(Type destination, string slaveIndex, string masterIndex)
            : this(destination)
        {
            SlaveIndex1 = slaveIndex;
            MasterIndex1 = masterIndex;
        }

        #endregion

        private Type _destination;
        public  Type Destination { get { return _destination; } }

        private string _masterIndex1;
        public  string MasterIndex1 { get { return _masterIndex1; } set { _masterIndex1 = value; } }
        
        private string _masterIndex2;
        public  string MasterIndex2 { get { return _masterIndex2; } set { _masterIndex2 = value; } }
        
        private string _masterIndex3;
        public  string MasterIndex3 { get { return _masterIndex3; } set { _masterIndex3 = value; } }

        private string _slaveIndex1;
        public  string SlaveIndex1 { get { return _slaveIndex1; } set { _slaveIndex1 = value; } }
        
        private string _slaveIndex2;
        public  string SlaveIndex2 { get { return _slaveIndex2; } set { _slaveIndex2 = value; } }
        
        private string _slaveIndex3;
        public  string SlaveIndex3 { get { return _slaveIndex3; } set { _slaveIndex3 = value; } }

        public MapIndex MasterIndex
        {
            get
            {
                List<String> index = new List<string>();

                AddIndex(index, MasterIndex1);
                AddIndex(index, MasterIndex2);
                AddIndex(index, MasterIndex3);

                if (index.Count == 0)
                    return null;

                return new MapIndex(index.ToArray());
            }
        }

        public MapIndex SlaveIndex
        {
            get
            {
                List<String> index = new List<string>();

                AddIndex(index, SlaveIndex1);
                AddIndex(index, SlaveIndex2);
                AddIndex(index, SlaveIndex3);

                if (index.Count == 0)
                    return null;

                return new MapIndex(index.ToArray());
            }
        }

        private void AddIndex(List<string> index, string field)
        {
            if (!string.IsNullOrEmpty(field))
                index.Add(field);
        }
    }
}