from radon.complexity import cc_visit
from src.universal_refactor.patch_generator import PatchGenerator
def compute_complexity(c):
    try: return sum(b.complexity for b in cc_visit(c))
    except: return 0
def evaluate_pair(a,b):
    diff=PatchGenerator.unified_diff(a,b)
    oc,nc=compute_complexity(a),compute_complexity(b)
    red=(oc-nc)/oc if oc else 0
    ch=sum(1 for l in diff.splitlines() if l.startswith('+') or l.startswith('-'))
    clean=max(0,1-min(ch/400,1))
    return {'complexity_reduction':red,'patch_cleanliness':clean,'diff':diff}