"""Apply verified 1950-2026 combined PATSTAT IPC/CPC downloads to blank final-master fields."""
import csv,gzip,json,os
from collections import defaultdict,Counter
from pathlib import Path
csv.field_size_limit(100_000_000)
BASE=Path('/Users/deep1003/data3/webofscience_ai_global_export/bibtex/ai_policy_organized_20260619/patstat')
RAW=BASE/'online_sql_exports/patstat_2026_spring_ai_expanded_v2_full_fields'
OUT=BASE/'final_master_20260712';FINAL=OUT/'patstat_ai_complete_master_legacy_priority_20260712.csv.gz';TMP=OUT/'_ipc_cpc_backfill.tmp.csv.gz'
vals=defaultdict(lambda:{'ipc':[],'cpc':[]})
def add(a,k,v):
 v=(v or '').strip()
 if v and v not in vals[a][k]:vals[a][k].append(v)
for p in sorted(RAW.glob('patstat_ai_classification_*_rows_*.csv')):
  with p.open(encoding='utf-8-sig',newline='') as f:
   for r in csv.DictReader(f,delimiter=';'):
    for key,col in [('ipc','all_ipc_codes'),('cpc','all_cpc_codes')]:
     for code in (r.get(col,'') or '').split(';'):add(r.get('app_id',''),key,code)
filled=Counter();rows=0
with gzip.open(FINAL,'rt',encoding='utf-8',newline='') as src,gzip.open(TMP,'wt',encoding='utf-8',newline='') as dst:
 rd=csv.DictReader(src);w=csv.DictWriter(dst,fieldnames=rd.fieldnames);w.writeheader()
 for r in rd:
  rows+=1;x=vals.get(r['app_id'])
  if x:
   if not (r.get('all_ipc_codes')or'').strip() and x['ipc']:r['all_ipc_codes']='; '.join(x['ipc']);r['ipc_count']=str(len(x['ipc']));filled['ipc']+=1
   if not (r.get('all_cpc_codes')or'').strip() and x['cpc']:r['all_cpc_codes']='; '.join(x['cpc']);r['cpc_count']=str(len(x['cpc']));filled['cpc']+=1
  w.writerow(r)
os.replace(TMP,FINAL)
report={'state':'applied','years':[1950,2026],'rows':rows,'download_app_ids':len(vals),'filled_blank_rows':dict(filled),'rule':'existing nonblank values preserved; only blanks filled'}
(OUT/'ipc_cpc_backfill_1950_2026_report.json').write_text(json.dumps(report,indent=2),encoding='utf-8')
print(json.dumps(report,indent=2))