Dagger with wavy blade

[blue lander]

I just impulse bought this dagger because it was cheap and I liked the elegant curves of the blade. The seller only said that it was "probably" from Vietnam, but I don't see any resemblance to other knives from that region. The blade looks pretty well made but the hilt looks like it was made from brass bolts and knobs from a hardware store.

Any idea where it might actually be from? Will take better pictures when it arrives.