static Expression <Func <Author, bool> > GetFilterCondition(AuthorMaintenanceFilterCondition condition)
{
return(condition switch
{
AuthorMaintenanceFilterCondition.NoFilter => a => true,
AuthorMaintenanceFilterCondition.NoBio => a => string.IsNullOrEmpty(a.Biography),
AuthorMaintenanceFilterCondition.NoBooks => a => a.Books.Count == 0,
AuthorMaintenanceFilterCondition.NoDateOfBirth => a => a.DateOfBirth.Equals((DateTime?)null),
AuthorMaintenanceFilterCondition.NoNationality => a => a.Nationality.Equals(null),
AuthorMaintenanceFilterCondition.NoMugshot => a => a.MugshotPath.Contains("placeholder"),
_ => throw new ArgumentOutOfRangeException(nameof(condition), "Invalid filter condition!")
});
public async Task <IEnumerable <LookupItem> > GetAuthorLookupAsync(string viewModelName,
AuthorMaintenanceFilterCondition authorMaintenanceFilterCondition = AuthorMaintenanceFilterCondition.NoFilter)
{
var filter = GetFilterCondition(authorMaintenanceFilterCondition);
await using var ctx = _contextCreator();
return(await ctx.Authors
.AsNoTracking()
.Where(filter)
.OrderBy(a => a.LastName)
.Select(a =>
new LookupItem
{
Id = a.Id,
DisplayMember = $"{a.LastName}, {a.FirstName}",
Picture = GetPictureThumbnail(a.MugshotPath) ?? _placeholderPic,
ViewModelName = viewModelName,
InfoText = $"Books: {a.Books.Count}",
})
.ToListAsync());