What is this scale called?

I'm working on a rather modern sonata that contains this rather strange scale; what kind of scale is it?

It goes like this:

D flat, E flat, F flat, G flat, A double flat, B double flat, C flat, C natural, D flat, E flat, E natural, F natural,
G natural, A flat, A natural.

Any idea whatever it's called in proper musical language?

It looks like its supposed to be the C# minor scale which is: C# - D# - E - F# - G# - A - B - C#

but I do not know for sure because I've never actually seen it before. sorry

the G# is missing in that case

Maybe it's a mode of some kind set in Db minor( or any other key)

It's difficult for me to tell but I'd say that's an Octatonic scale because of the notes you typed, or simply known as the diminished scale. The Octatonic scale is an 8 note scale usually used by jazz pianists to improvise on diminished chords and other alterations. Judging from the notes you've mentioned, this is actually and might be the Db diminished scale which is Db, Eb, E, F#, G, A, Bb, C, Db. You made a few mistakes on a few notes because a diminished scale is octatonic (8 pitches), and your scale is 12 notes after it repeats its self and stops at 16. Unless you've chromatically added those few notes to the scale to make it your own, you might have simply played your own altered version of a harmonic chromatic scale or simply just a chromatic scale. Judging by the 16 notes you mentioned, a chromatic scale has 12 pitches (notes). There's no such thing is music theory as a scale with more than 12 notes because you'd be repeating yourself since there are only 12 notes in Western music, and a chromatic scale has the most pitches (notes) at 12.

It's hard for me to actually tell what scale that is because of the few unfamiliar notes, but I'm assuming that it's a Db diminished scale judging from the tonic, and in that case you started on Db, or most likely an altered whole tone scale. Perhaps even an auxiliary diminished.

Cheers and good luck!