WWI era French tunic

[jtl977]

I bought this tunic from an ebay auction. It is supposedly French from the WWI era, but has no labels, markings, buttons, or anything by which to identify its origin. I am new to collecting French items, but from my research it appears to be part of an officers uniform. The absence of any labels or markings may possibly indicate the tunic was privately purchased and locally made? Any information about this uniform would be greatly appreciated.