import hashlib,json,secrets
from datetime import date,timedelta
from pathlib import Path
TEAMS=['A&O Shearman','Abelex','BIP Law & Tax','Bipart','Bird & Bird','BonelliErede','CBB Law','Deloitte Legal','Dentons','DIZLegal','Giovannelli','Gianni & Origoni','GPBL','GPLaw','Greenberg Traurig','Latham & Watkins','LCA','Legance','Lexia','Linklaters','Marchetti','Orsingher Ortu','Pedersoli Gattai','Ropes & Gray','Sala Colombo','Simmons & Simmons']
TOP=['Simmons & Simmons','Legance','BonelliErede','CBB Law','DIZLegal','Gianni & Origoni','Bipart','GPLaw']
WEEKS=['2026-11-02','2026-11-09','2026-11-16','2026-11-23','2026-11-30','2026-12-14','2027-01-11','2027-01-18','2027-01-25','2027-02-01']
class RNG:
 def __init__(self,seed):self.seed=bytes.fromhex(seed);self.counter=0
 def below(self,n):
  limit=(1<<256)-((1<<256)%n)
  while True:
   x=int.from_bytes(hashlib.sha256(self.seed+self.counter.to_bytes(8,'big')).digest(),'big');self.counter+=1
   if x<limit:return x%n
 def shuffle(self,x):
  x=list(x)
  for i in range(len(x)-1,0,-1):j=self.below(i+1);x[i],x[j]=x[j],x[i]
  return x
def draw(seed):
 rng=RNG(seed);attempts=0
 while True:
  attempts+=1; rounds=[];edges=set();topcounts={t:0 for t in TOP};valid=True
  for turn in range(3):
   a=rng.shuffle(TEAMS);pairs=[a[i:i+2] for i in range(0,26,2)];rounds.append(pairs)
   for x,y in pairs:
    edge=tuple(sorted([x,y]))
    if edge in edges:valid=False
    edges.add(edge)
    if x in TOP and y in TOP:topcounts[x]+=1;topcounts[y]+=1
  if not valid or max(topcounts.values())>1:continue
  break
 # Dates are assigned only after the accepted opponent draw.
 slots=[]
 for w in WEEKS:
  d=date.fromisoformat(w);slots.extend([d.isoformat()]+[(d+timedelta(days=1)).isoformat()]*3)
 slots=slots[:39]
 while True:
  ordered=[rng.shuffle(r) for r in rounds]
  matches=[p for r in ordered for p in r]
  ai=next(i for i,p in enumerate(matches[:13]) if 'Abelex' in p)
  if slots[ai]!='2026-11-10':continue
  used=set();ok=True
  for d,p in zip(slots,matches):
   for t in p:
    if (d,t) in used:ok=False
    used.add((d,t))
  if ok:break
 return {'seed':seed,'attempts':attempts,'teams':TEAMS,'top8':TOP,'weeks':WEEKS,'matches':[{'id':i+1,'round':i//13+1,'date':slots[i],'A':p[0],'B':p[1]} for i,p in enumerate(matches)]}
if __name__=='__main__':
 import sys
 seed=sys.argv[1] if len(sys.argv)>1 else secrets.token_hex(32)
 r=draw(seed);Path('tmp/redraw').mkdir(parents=True,exist_ok=True);Path('tmp/redraw/verbale.json').write_text(json.dumps(r,ensure_ascii=False,indent=2));print(json.dumps(r,ensure_ascii=False))