Family Law Essentials: Spousal Maintenance Conundrum

Mujhe to abhi bhi thodi si confusion hai ki spousal maintenance ka concept kaisa hai. Exam mein 3 din hi hai aur meh still samjh nahi paa rahoon ki yeh dono alag-alag cases mein kaunse rules lagte hain. Mithu vs. Mithal (1979 SC) mein yeh theek hai ki spousal maintenance ek right hai, lekin Dhanuka vs. Dhanuka (1987 SC) mein yeh kya hai, wohi rule nahi laga. Meri confusion yeh hai ki kyun kuch cases mein husband ko maintenance pay karna padta hai aur kuch mein wife ko. Aur agar wife income-less hai to maintenance kaise diya jata hai?