private static IQueryable <EFTypes.IndexedFile> Filter(TaggerDbContext dbContext, ProcessedInput userQuery)
{
var idsMatchingIncludeCriteria = FileIdsMatchingCriteria(dbContext, userQuery.IncludeTerms, Enumerable.All);
var idsMatchingExcludeCriteria = FileIdsMatchingCriteria(dbContext, userQuery.ExcludeTerms, Enumerable.Any);
return(dbContext.FileRecords
.Include(fileRec => fileRec.FileTagPairs)
.Where(fileRec => userQuery.IncludeTerms.Count == 0 ? true : idsMatchingIncludeCriteria.Contains(fileRec.Id))
.Where(fileRec => !idsMatchingExcludeCriteria.Contains(fileRec.Id)));
}
public static IEnumerable <EFTypes.IndexedFile> GetPage(TaggerDbContext dbContext, ProcessedInput userQuery, int itemsPerPage)
{
var page = Math.Max(1, userQuery.Page);
return
(Filter(dbContext, userQuery)
.Skip(itemsPerPage * (page - 1))
.Take(itemsPerPage)
.AsEnumerable());
}
private static ImmutableList <int> FileIdsMatchingCriteria(TaggerDbContext dbContext, ImmutableList <string> terms, Func <IEnumerable <ImmutableList <int> >, Func <ImmutableList <int>, bool>, bool> anyOrAll)
{
ImmutableList <ImmutableList <int> > fileIdsPerTerm =
terms.Select
(s =>
(
from pair in dbContext.FileTagPairs
where EF.Functions.Like(pair.Tag, $"%{s}%")
select pair.FileRecordId
)
.ToImmutableList()
).ToImmutableList();
return(fileIdsPerTerm
.SelectMany(x => x)
.Distinct()
.Where(x => anyOrAll(fileIdsPerTerm, y => y.Contains(x)))
.ToImmutableList());
}
public FileListController(ILogger <FileListController> logger, TaggerDbContext dbContext)
{
_logger = logger;
_dbContext = dbContext;
}
