using System;

using System.Data;

using System.Reflection;

using SqlRepo.Abstractions;

namespace SqlRepo

{

public class EntityArrayMemberMapper<TItem> : IEntityMemberMapper

where TItem: class, new()

{

private readonly IEntityMappingProfile<TItem> itemMappingProfile;

public EntityArrayMemberMapper(MemberInfo memberInfo, IEntityMappingProfile<TItem> itemMappingProfile)

{

this.itemMappingProfile = itemMappingProfile;

this.MemberInfo = memberInfo;

}

public MemberInfo MemberInfo { get; }

public void Map(object entity, IDataRecord dataRecord)

{

var itemInstance = (TItem)Activator.CreateInstance(typeof(TItem));

this.itemMappingProfile.Map(itemInstance, dataRecord);

if(!(this.MemberInfo.GetValue(entity) is TItem[] currentValue))

{

currentValue = new[] {itemInstance};

this.MemberInfo.SetValue(entity, currentValue);

}

else

{

if(!this.ArrayContainsItem(currentValue, itemInstance))

{

var newItemIndex = currentValue.Length;

var newLength = newItemIndex + 1;

Array.Resize(ref currentValue, newLength);

currentValue[newItemIndex] = itemInstance;

this.MemberInfo.SetValue(entity, currentValue);

}

}

}

private bool ArrayContainsItem(TItem[] array, TItem item)

{

foreach(var entity in array)

{

if(this.itemMappingProfile.EntitiesMatch(item, entity))

{

return true;

}

}

return false;

}

}

}