public async Task <List <GroupedByOwnerGenderViewModel> > GetCatsGroupedByOwnerGender()
{
var ownersAndPetsResult = await _petsRepository.GetAllOwnersAndPets().ConfigureAwait(false);
if (null == ownersAndPetsResult)
{
return(null);
}
//first expand the items, and then group by owner gender
var groupedResults = ownersAndPetsResult
.Where(a => a.Pets != null) //exclude owners with no pets
.SelectMany(a => a.Pets.Select(b => new
{
//ASSUMPTION: if owner gender, owner name or cat name are null or empty, they would be returned as empty string.
//This behaviour can be confirmed with business, but as of now taking this assumption.
OwnerName = string.IsNullOrEmpty(a.Name) ? string.Empty : a.Name,
OwnerGender = string.IsNullOrEmpty(a.Gender) ? string.Empty : a.Gender,
PetName = string.IsNullOrEmpty(b.Name) ? string.Empty : b.Name,
PetType = string.IsNullOrEmpty(b.Type) ? string.Empty : b.Type,
}))
.GroupBy(x => x.OwnerGender)
.Select(g => new GroupedByOwnerGenderViewModel
{
OwnerGender = g.Key,
Cats = g
.Where(o => o.PetType.Equals("cat", StringComparison.OrdinalIgnoreCase))
.Select(o => new PetDetailsViewModel
{
Name = o.PetName,
OwnerName = o.OwnerName,
})
.OrderBy(c => c.Name).ThenBy(c => c.OwnerName) // cats are first sorted by their name, and then by their owner name
.ToList()
}).ToList();
var results = groupedResults.Where(g => g.Cats.Count > 0) //if owner has pets other than cats, this should be 0
.OrderBy(g => g.OwnerGender); //order by owner gender
//ASSUMPTION: if there are no pets for a gender, that gender wont be returned from our API.
//This can be confirmed with business if requirement is to show an empty section for that gender.
return(results.ToList());
}