"""Verify the fixed 5.3 zone-selection exercise. Standard library; offline; no trading."""
from pathlib import Path
from decimal import Decimal
import csv,json,hashlib
def sha(b):return hashlib.sha256(b).hexdigest()
def load(path):
    with Path(path).open(encoding='utf-8-sig',newline='') as f:raw=list(csv.DictReader(f))
    rows=[]
    for r in raw:
        q={'time':r['time_mt5']}
        for k in ('open','high','low','close'):
            d=Decimal(r[k])*100000;q[k]=int(d.to_integral_value());assert abs(d-q[k])<Decimal('0.00001')
        rows.append(q)
    return rows
def select(rows):
    lows=[]
    for i in range(2,len(rows)-2):
        p=rows[i]['low']
        if p<min(x['low'] for x in rows[i-2:i]) and p<=min(x['low'] for x in rows[i+1:i+3]):
            lows.append({'i':i,'known':i+2,'price':p,'lower':p-20,'upper':p+20})
    kept=[];rejected=[]
    for q in lows:
        overlap=next((a for a in kept if q['lower']<=a['upper'] and q['upper']>=a['lower']),None)
        if overlap:
            rejected.append(dict(q,reason='overlap',retained_anchor=overlap['i']));continue
        episodes=[];previous_contact=False
        for i in range(q['known']+1,len(rows)):
            contact=rows[i]['low']<=q['upper'] and rows[i]['high']>=q['lower']
            if contact and not previous_contact:
                last=i+3
                if last<len(rows):
                    reaction=next((j for j in range(i+1,last+1) if rows[j]['close']>=q['upper']+50),None)
                    episodes.append({'start':i,'complete_at':last,'reaction':reaction})
            previous_contact=contact
        successes=[e for e in episodes if e['reaction'] is not None]
        kept.append(dict(q,episodes=episodes,reactions=len(successes),latest_reaction=max((e['reaction'] for e in successes),default=-1)))
    eligible=[q for q in kept if q['reactions']>=2]
    ranked=sorted(eligible,key=lambda q:(-q['reactions'],-q['latest_reaction'],q['price'],q['i']))
    return {'kept':kept,'rejected_overlap':rejected,'ranked':ranked,'selected':ranked[:3]}
def main():
    here=Path(__file__).parent;m=json.loads((here/'zone-selection.json').read_text('utf8'));p=here/'zone-selection.csv'
    assert sha(p.read_bytes())==m['excerpt_sha256']
    result=select(load(p));assert result==m['result']
    print(json.dumps({'status':'PASS','bars':120,'selected_centres':[q['price']/100000 for q in result['selected']],'zones_before_overlap_filter':len(result['kept'])+len(result['rejected_overlap']),'future_records_used':0}))
if __name__=='__main__':main()