I recently used oppo a57 as it launch. According my opinion this was a very poor condition mobile. If you see its build quality it was very bad and other features are not so good.
But this is perfectly a camera phone. It has good camera especially selfie camera was nice. It take nice pics.
But other then camera no other feature was good in this mobile.
As my research this mobile has very bad online market but at offline it was best selling Mobile .I don’t know the reason but it is truth.
If you are going to buy it don’t buy. If you are searching for good mobile then Redmi or Samsung is good option.
I hope that it was helpful to you because it was loss to me by buying this phone.
But this was my opinion of you want to buy as per your wish.
Thanks.