well thank you for posting a picture but now after seeing this pic id say maybe your bird has a leg infection and should be seen by a AVIAN vet...
those caked crusted piles of droppings are NOT healthy and also dont look to be healthy droppings (form /color) and this birds environment to be very honest, is filthy
...as so it also seems its feathers are in very poor condition.
looks to me like a grass keet/bourke...it is NOT a rosella...but salyummz your first concern should not be what type is it but improving on its cleanliness and living conditions
as a pet bird living like this is NOT healthy to it OR YOU .... and getting it to a AVAIN vet....and very possibly getting it on a better diet
that cage needs a THOROUGH scrapping /scrubbing and disenfecting
then should be cleaned everyday or every other day of all debris and poops ...put some paper towel on the bottom to help with keeping it clean once you get it THOROUGHLY cleaned and disenfected.
this bird is im CERTAIN sick very sick and thats why it was "thrown in for good measure"...those poops say internal illness and a avian vet needs to run test on it.