Need help with a Fourier series question

I don’t know if it’s been asked before (if it has please give me the link), and I don’t understand latex or anything so I’ll write it in plain words:
$$
f(x) =
begin{cases}
x & text{for } -frac{pi}{2} leq x leq frac{pi}{2} \
π-x & text{for } frac{pi}{2}< x leq frac{3π}{2}
end{cases}
$$
Find the Fourier series.
I feel like the function is odd so it should be simple but I keep messing it up.