#!/usr/bin/env python3
"""Import supported legacy settings without modifying either source or an existing destination."""
import argparse,json,os,tempfile,sys
from pathlib import Path
SCHEMA={
 'aiDoctrine':(0,0,1),
 'aiShadow':(0,0,1),
 'planeAltitudeMetres':(250,150,500),
 'planeReplacementSeconds':(60,30,1800),
 'planeSectorSeconds':(120,30,600),
 'planeReconEnabled':(1,0,1),
 'roadblockCount':(4,0,30),
 'civilianTrafficCount':(3,0,6),
 'startMode':(0,0,1),
 'keepWeaponOnUnconscious':(1,0,1),
 'restartOnEmpty':(1,0,1),
 'emptyRestartHours':(5,0,168),
 'reportIntervalSeconds':(10,5,60),
 'supportSquadLimit':(4,0,8),
 'responseRadiusMetres':(2000,500,5000),
 'aiIntelChancePercent':(60,0,100),
 'intelRevealChancePercent':(15,0,100),
 'radioDefenceSeconds':(180,30,1800),
 'startTimeMinutes':(840,0,1439),
 'timeMultiplier':(1,1,24),
 'startDateCode':(0,0,1501231),
 'weatherProfile':(0,0,3),
 'viewDistanceMetres':(0,0,10000),
 'automaticEquipmentChancePercent':(25,0,100),
 'antiAirChancePercent':(7,0,100),
 'antiPersonnelMineChancePercent':(60,0,100),
 'automaticConvoyEnabled':(1,0,1),
 'convoyCount':(3,0,20),
 'heliTimerMinutes':(15,1,1440),
}
AI_KEYS=('aiDoctrine','aiShadow','planeAltitudeMetres','planeReplacementSeconds','planeSectorSeconds','planeReconEnabled','reportIntervalSeconds','supportSquadLimit','responseRadiusMetres','automaticEquipmentChancePercent','antiAirChancePercent','antiPersonnelMineChancePercent','automaticConvoyEnabled','heliTimerMinutes')
INTEL_KEYS=('aiIntelChancePercent','intelRevealChancePercent')
def merge(ai=None,intel=None):
 result={key:spec[0] for key,spec in SCHEMA.items()};deferred=[]
 for label,data,keys in [('ai',ai,AI_KEYS),('intel',intel,INTEL_KEYS)]:
  if data is None:continue
  if not isinstance(data,dict):raise ValueError(label+' settings must be a JSON object')
  if 'configVersion' in data and (type(data['configVersion']) not in (int,float) or data['configVersion']!=1):
   raise ValueError(label+' configVersion must be 1')
  for key in keys:
   if key not in data:continue
   value=data[key];_,lo,hi=SCHEMA[key]
   if type(value) not in (int,float) or not lo<=value<=hi or int(value)!=value:
    raise ValueError(f'{key} must be an integer in [{lo},{hi}]')
   result[key]=int(value)
  recognized=set(keys)|{'configVersion'}
  if label=='ai' and 'stingerChanceOneIn' in data:
   old=data['stingerChanceOneIn']
   if type(old) not in (int,float) or not 0<=old<=10000 or int(old)!=old:
    raise ValueError('stingerChanceOneIn must be an integer in [0,10000]')
   if 'antiAirChancePercent' not in data:result['antiAirChancePercent']=int(100/old+0.5) if old else 0
   recognized.add('stingerChanceOneIn')
  if label=='ai' and 'convoyCount' in data:
   if 'automaticConvoyEnabled' in data:raise ValueError('Supply either convoyCount or automaticConvoyEnabled, not both')
   count=data['convoyCount']
   if type(count) not in (int,float) or not 0<=count<=20 or int(count)!=count:
    raise ValueError('convoyCount must be an integer in [0,20]')
   result['automaticConvoyEnabled']=int(count>0)
   result['convoyCount']=int(count)
   recognized.add('convoyCount')
  deferred.extend(label+':'+key for key in data if key not in recognized)
 return result,deferred

def write_new(path,text):
 path=Path(path)
 with tempfile.NamedTemporaryFile(mode='w',dir=path.parent,prefix='.rereintroduced-',delete=False) as f:
  tmp=Path(f.name)
  try:
   f.write(text);f.flush();os.fsync(f.fileno())
   # Atomic installation that cannot overwrite an existing file, even in a race.
   os.link(tmp,path)
  finally:tmp.unlink(missing_ok=True)

def main():
 p=argparse.ArgumentParser(description=__doc__)
 p.add_argument('--ai',type=Path,help='Read-only escapists-ai.json source')
 p.add_argument('--intel',type=Path,help='Read-only escapists-intel.json source')
 p.add_argument('--out',type=Path,help='New rereintroduced.json; omit to preview on stdout')
 a=p.parse_args()
 if not a.ai and not a.intel:p.error('Supply --ai and/or --intel')
 try:
  result,deferred=merge(json.loads(a.ai.read_text()) if a.ai else None,json.loads(a.intel.read_text()) if a.intel else None)
  text=json.dumps(result,indent=2,allow_nan=False)+'\n'
  if a.out:write_new(a.out,text)
  else:print(text,end='')
  if deferred:print('Migration notes; unrecognized settings remain deferred (source files retained): '+', '.join(deferred),file=sys.stderr)
 except (ValueError,OSError) as e:p.error(str(e))
if __name__=='__main__':main()