/src/FluentNHibernate/Mapping/NaturalIdPart.cs

using System;

using System.Collections.Generic;

using System.Diagnostics;

using System.Linq.Expressions;

using FluentNHibernate.Mapping.Providers;

using FluentNHibernate.MappingModel;

using FluentNHibernate.Utils;



namespace FluentNHibernate.Mapping

{

    public class NaturalIdPart<T> : INaturalIdMappingProvider

    {

        private readonly AttributeStore<NaturalIdMapping> attributes = new AttributeStore<NaturalIdMapping>();

        private readonly IList<PropertyMapping> properties = new List<PropertyMapping>();

        private readonly IList<ManyToOneMapping> manyToOnes = new List<ManyToOneMapping>();

        private bool nextBool = true;



        public NaturalIdPart() { }



        /// <summary>

        /// Defines a property to be used for this natural-id.

        /// </summary>

        /// <param name="expression">A member access lambda expression for the property</param>

        /// <returns>The natural id part fluent interface</returns>

        public NaturalIdPart<T> Property(Expression<Func<T, object>> expression)

        {

            var member = expression.ToMember();

            return Property(expression, member.Name);

        }



        /// <summary>

        /// Defines a property to be used for this natural-id with an explicit column name.

        /// </summary>

        /// <param name="expression">A member access lambda expression for the property</param>

        /// <param name="columnName">The column name in the database to use for this natural id, or null to use the property name</param>

        /// <returns>The natural id part fluent interface</returns>

        public NaturalIdPart<T> Property(Expression<Func<T, object>> expression, string columnName)

        {

            var member = expression.ToMember();

            return Property(member, columnName);

        }



        protected virtual NaturalIdPart<T> Property(Member member, string columnName)

        {

            var key = new PropertyMapping

            {

                Name = member.Name,

                Type = new TypeReference(member.PropertyType)

            };

            key.AddColumn(new ColumnMapping { Name = columnName });



            properties.Add(key);



            return this;

        }



        /// <summary>

        /// Defines a reference to be used as a many-to-one key for this natural-id with an explicit column name.

        /// </summary>

        /// <param name="expression">A member access lambda expression for the property</param>

        /// <returns>The natural ID part fluent interface</returns>

        public NaturalIdPart<T> Reference(Expression<Func<T, object>> expression)

        {

            var member = expression.ToMember();

            return Reference(expression, member.Name);

        }



        /// <summary>

        /// Defines a reference to be used as a many-to-one key for this natural-id with an explicit column name.

        /// </summary>

        /// <param name="expression">A member access lambda expression for the property</param>

        /// <param name="columnName">The column name in the database to use for this key, or null to use the property name</param>

        /// <returns>The natural id part fluent interface</returns>

        public NaturalIdPart<T> Reference(Expression<Func<T, object>> expression, string columnName)

        {

            var member = expression.ToMember();

            return Reference(expression, columnName);

        }



        protected virtual NaturalIdPart<T> Reference(Member member, string columnName)

        {

            var key = new ManyToOneMapping

            {

                Name = member.Name,

                Class = new TypeReference(member.PropertyType),

                ContainingEntityType = typeof(T)

            };

            key.AddColumn(new ColumnMapping { Name = columnName });



            manyToOnes.Add(key);



            return this;

        }



        public NaturalIdPart<T> ReadOnly()

        {

            attributes.Set(x => x.Mutable, nextBool);

            nextBool = true;

            return this;

        }



        [DebuggerBrowsable(DebuggerBrowsableState.Never)]

        public NaturalIdPart<T> Not

        {

            get

            {

                nextBool = false;

                return this;

            }

        }



        NaturalIdMapping INaturalIdMappingProvider.GetNaturalIdMapping()

        {

            var mapping = new NaturalIdMapping(attributes.CloneInner());



            properties.Each(mapping.AddProperty);

            manyToOnes.Each(mapping.AddReference);



            return mapping;

        }

    }

}