import socket, struct, subprocess, threading, time, sys
from pathlib import Path
ROOT=Path(__file__).resolve().parents[1]
DRIVER=ROOT/'tests'/(sys.argv[1] if len(sys.argv)>1 else 'driver')
def exact(s,n):
    b=b''
    while len(b)<n:
        part=s.recv(n-len(b))
        if not part: raise EOFError
        b+=part
    return b
def run(mode, function=3):
    listener=socket.socket(); listener.bind(('127.0.0.1',0)); listener.listen(); listener.settimeout(2)
    issues=[]
    def server():
        first=True
        try:
            while True:
                try: s,_=listener.accept()
                except (socket.timeout,OSError): break
                with s:
                    s.settimeout(2)
                    while True:
                        try:
                            h=exact(s,7); p=exact(s,struct.unpack('>H',h[4:6])[0]-1)
                        except (EOFError,ConnectionError,socket.timeout): break
                        if first and mode in ('close','timeout','bad_tid','bad_length','write_drop'):
                            first=False
                            if mode=='timeout': time.sleep(.12)
                            elif mode=='bad_tid': s.sendall(b'\xff\xff'+h[2:4]+b'\x00\x07'+h[6:7]+b'\x03\x04\x00\x2a\x00\x2b')
                            elif mode=='bad_length': s.sendall(h[:4]+b'\xff\xff'+h[6:7])
                            break
                        if first and mode=='exception': reply=bytes([p[0]|128,2]); first=False
                        elif function==16: reply=p[:5]
                        elif function==1: reply=b'\x01\x01\x03'
                        else: reply=b'\x03\x04\x00\x2a\x00\x2b'
                        packet=h[:4]+struct.pack('>H',len(reply)+1)+h[6:7]+reply
                        if mode=='fragment':
                            for b in packet: s.sendall(bytes([b])); time.sleep(.001)
                        else: s.sendall(packet)
        except Exception as e: issues.append(e)
    worker=threading.Thread(target=server); worker.start()
    try:
        p=subprocess.run([str(DRIVER),str(listener.getsockname()[1]),str(function),'2'],capture_output=True,text=True,timeout=4)
        assert p.returncode==0,(mode,p.stdout,p.stderr)
        ok,err,reconnect,uncertain,last,a,b=map(int,p.stdout.split())
        assert ok==2
        if function==3: assert (a,b)==(42,43)
        if function==1: assert (a,b)==(1,1)
        if mode in ('close','timeout','bad_tid','bad_length','write_drop'): assert err>=1 and reconnect>=1
        if mode=='exception': assert err==1 and reconnect==0 and last==9
        if mode=='write_drop': assert uncertain==1
        print('PASS',mode,p.stdout.strip())
    finally:
        listener.close(); worker.join(3)
    assert not issues,issues
for mode in ('normal','fragment','close','timeout','bad_tid','bad_length','exception'): run(mode)
run('write_drop',16)
run('coils',1)