So many compositions...

Let $f:\mathbb{R}-\{0,1\}\rightarrow\mathbb{R}$ be a function that satisfies the equation $\displaystyle f(x)+f\left(\frac{1-x}{x}\right)=1-x$ . If $f$ can be expressed as $\displaystyle f(x)=\frac{ax^3+bx^2+cx+dx}{ex^2+fx+gx}$ , where this fraction is irreducible, then what is the value of $a+b+c+d+e+f+g$ ? If you think $f$ can't be expressed in this form, enter $-1$ as your answer.