#!/usr/bin/env python3
"""Exercise production worker with real sockets/PTYS and deliberately sparse PLC calls."""
import ctypes as C
import os,pty,select,socket,struct,subprocess,tempfile,time,threading
from pathlib import Path
root=Path(__file__).resolve().parents[1]
with tempfile.TemporaryDirectory() as td:
 so=Path(td)/'worker.so'
 subprocess.run(['cc','-shared','-fPIC','-std=c11','-Wall','-Wextra','-Werror','-O2','-pthread',
  *[str(root/'src'/f) for f in ['atom_mb.c','atom_rtu.c','atom_server.c','atom_bridge.c','atom_worker.c']],'-o',str(so)],check=True)
 lib=C.CDLL(str(so));U=C.c_uint32;W=C.c_uint16;B=C.c_uint8
 lib.ab_call.argtypes=[U,U,U,W,B,B,W,W,C.POINTER(W),U,C.POINTER(U),U,C.c_uint64,U,U,U];lib.ab_call.restype=U
 def call(cmd,h=0,ip=0,port=0,f=3,addr=0,q=1,values=(),ct=100,rt=100,retry=10,unit=1):
  data=(W*2000)(*values);status=(U*24)()
  result=lib.ab_call(cmd,h,ip,port,unit,f,addr,q,data,2000,status,24,0,ct,rt,retry)
  return result,list(status),list(data)
 def until(fn,seconds=1):
  end=time.monotonic()+seconds
  while time.monotonic()<end:
   v=fn()
   if v:return v
   time.sleep(.002)
  raise AssertionError('condition timed out')
 def configure(watchdog=2000,cpu=-1):
  r,s,_=call(40,addr=cpu+1,ct=1,rt=watchdog);assert r==0,(r,s)
 def client(port):
  r,s,_=call(1,ip=0x7f000001,port=port);assert not r;h=s[0]
  assert not call(9,h,rt=100)[0];assert not call(3,h)[0]
  until(lambda:call(5,h)[1][1]==3)
  return h
 def recv_exact(peer,count):
  result=b''
  while len(result)<count:
   v=peer.recv(count-len(result));assert v;result+=v
  return result
 def server():
  r,s,_=call(30,ip=0x7f000001,port=port);assert not r;h=s[0]
  for t in range(4):assert not call(35,h,f=t,q=8,values=[0]*8)[0]
  assert not call(32,h)[0]
  until(lambda:call(34,h)[1][1])
  return h
 probe=socket.socket();probe.bind(('127.0.0.1',0));port=probe.getsockname()[1];probe.close()
 try:
  configure();sh=server();ch=client(port)
  assert not call(6,ch,q=2)[0]
  # The reply deadline is 100 ms; the PLC deliberately does nothing for 250 ms.
  time.sleep(.25)
  r,s,d=call(7,ch);assert not r and s[3] and not s[4] and d[:2]==[0,0],s
  assert call(6,ch)[0]==2 # Completion cannot be overwritten before acknowledgment.
  r,m,_=call(12,ch);assert not r and m[21]<100 and m[22]>=100,m
  assert call(10,ch)[0]==0
  print('PASS worker completes TCP before timeout with PLC absent for 250 ms; result retained and timed')
  # Remote write must survive a stale PLC push before the PLC pulls its result.
  peer=socket.create_connection(('127.0.0.1',port));peer.settimeout(1)
  pdu=struct.pack('>BHH',6,0,4321);peer.sendall(struct.pack('>HHHB',1,0,len(pdu)+1,1)+pdu)
  assert recv_exact(peer,12)[7:]==pdu
  assert call(35,sh,f=2,q=8,values=[0]*8)[0]==0
  assert call(36,sh,f=2,q=8)[2][0]==4321
  # After acknowledgment a deliberate application override is permitted.
  call(35,sh,f=2,q=8,values=[42]*8);assert call(36,sh,f=2,q=8)[2][0]==42
  assert call(35,sh,f=2,addr=1,q=8,values=[0]*8)[0]==1 # explicit recreate for remap
  peer.close();call(2,ch);call(31,sh)
  print('PASS autonomous TCP slave and lossless remote-write handoff')
  # Real serial PTY, again no PLC ticks after submission.
  master,slave=pty.openpty();path=os.ttyname(slave);os.close(slave)
  r,s,_=call(20,ip=9600,unit=0,f=8,addr=1,q=len(path),ct=0,values=list(path.encode()));assert not r;h=s[0]
  call(9,h,rt=100);call(3,h);until(lambda:call(5,h)[1][1]==3)
  call(6,h,unit=1,f=3,q=1)
  assert select.select([master],[],[],1)[0];request=os.read(master,256);assert len(request)==8
  def crc(p):
   c=65535
   for b in p:
    c^=b
    for _ in range(8):c=(c>>1)^(0xa001 if c&1 else 0)
   return c
  p=bytes([1,3,2,0,77]);os.write(master,p+struct.pack('<H',crc(p)))
  time.sleep(.25);r,s,d=call(7,h);assert not r and s[3] and d[0]==77,s
  call(2,h);os.close(master)
  print('PASS RTU completion while PLC does not scan for 250 ms')
  # Watchdog cancels an in-flight write without replaying it on resume.
  configure(100)
  listener=socket.socket();listener.bind(('127.0.0.1',0));listener.listen();listener.settimeout(1)
  h=client(listener.getsockname()[1]);peer,_=listener.accept();peer.settimeout(1)
  call(11,h,rt=1000);assert not call(6,h,f=16,q=1,values=[9])[0]
  packet=recv_exact(peer,15);assert packet[7]==16
  time.sleep(.16)
  # command 12 is read-only and does not renew the scan lease.
  r,s,_=call(12,h);assert not r and s[1]==0 and s[5]==10 and s[9]==1,s
  assert peer.recv(1)==b''
  call(5,h);peer2,_=listener.accept();peer2.settimeout(.03)
  try:assert not peer2.recv(1), 'write replayed'
  except socket.timeout:pass
  call(2,h);peer.close();peer2.close();listener.close()
  print('PASS scan watchdog closes transport, preserves uncertain write, resumes without replay')
  # Server closes its listener when scanning ceases and recovers on refresh.
  configure(100);sh=server();time.sleep(.16)
  probe=socket.socket();probe.settimeout(.1);assert probe.connect_ex(('127.0.0.1',port))!=0;probe.close()
  call(34,sh);until(lambda:call(34,sh)[1][1]);call(31,sh)
  print('PASS server watchdog and restart')
  # CPU selection, failure reporting, and restoring inherited mask.
  configure(cpu=min(os.sched_getaffinity(0)))
  r,s,_=call(41);assert not r and s[3]==min(os.sched_getaffinity(0))+1
  assert call(40,addr=65535,ct=1,rt=2000)[0]==1
  configure()
  failures=[]
  def reader():
   for _ in range(200):
    if call(41)[0]:failures.append('snapshot failure')
  threads=[threading.Thread(target=reader) for _ in range(4)]
  for t in threads:t.start()
  for t in threads:t.join()
  assert not failures
  print('PASS configurable affinity, invalid arguments, concurrent snapshot access')
  for _ in range(20):
   lib.ab_shutdown();assert call(41)[1][1]==0;configure();assert call(41)[1][1]==1
  print('PASS repeated joined shutdown/restart')
 finally:lib.ab_shutdown()