package testsupport;

import com.jnape.palatable.lambda.functions.Fn1;

import com.jnape.palatable.lambda.functor.Applicative;

import com.jnape.palatable.lambda.monad.Monad;

import java.util.function.Function;

import static java.util.Objects.hash;

public final class EqualityAwareFn1<A, B> implements Fn1<A, B> {

private final A a;

private final Fn1<A, B> fn;

public EqualityAwareFn1(A a, Fn1<A, B> fn) {

this.a = a;

this.fn = fn;

}

@Override

public B apply(A a) {

return fn.apply(a);

}

@Override

public <C> EqualityAwareFn1<A, C> flatMap(Function<? super B, ? extends Monad<C, Fn1<A, ?>>> f) {

return new EqualityAwareFn1<>(a, fn.flatMap(f));

}

@Override

public <C> EqualityAwareFn1<A, C> fmap(Function<? super B, ? extends C> f) {

return new EqualityAwareFn1<>(a, fn.fmap(f));

}

@Override

public <C> EqualityAwareFn1<A, C> zip(Applicative<Function<? super B, ? extends C>, Fn1<A, ?>> appFn) {

return new EqualityAwareFn1<>(a, fn.zip(appFn));

}

@Override

public <C> EqualityAwareFn1<A, C> pure(C c) {

return new EqualityAwareFn1<>(a, fn.pure(c));

}

@Override

@SuppressWarnings("unchecked")

public boolean equals(Object other) {

return other instanceof Fn1 && ((Fn1<A, B>) other).apply(a).equals(apply(a));

}

@Override

public int hashCode() {

return hash(a, fn);

}

}