"""Read only the target game's Windows audio-session state and volume meter.

Does not record audio, access microphones, or change device/volume settings.
"""
import argparse
import ctypes as c
import json
import time
import uuid

p=argparse.ArgumentParser()
p.add_argument("pid",type=int)
a=p.parse_args()
ole=c.OleDLL("ole32")
P=c.c_void_p
I=c.c_int32
U=c.c_uint32
F=c.c_float
def guid(s): return (c.c_ubyte*16).from_buffer_copy(uuid.UUID(s).bytes_le)
def call(obj,index,types=(),args=()):
    vt=c.cast(obj,c.POINTER(c.POINTER(P))).contents
    return c.WINFUNCTYPE(I,P,*types)(vt[index])(obj,*args)
def check(hr):
    if hr<0: raise OSError(f"COM HRESULT 0x{hr&0xffffffff:08x}")
def qi(obj,iid):
    out=P()
    check(call(obj,0,(P,c.POINTER(P)),(guid(iid),c.byref(out))))
    return out
refs=[]
def keep(obj):
    refs.append(obj)
    return obj
ole.CoInitializeEx.argtypes=[P,U]
ole.CoCreateInstance.argtypes=[P,P,U,P,c.POINTER(P)]
ole.CoTaskMemFree.argtypes=[P]
check(ole.CoInitializeEx(None,0))
try:
    enum=P()
    check(ole.CoCreateInstance(guid("BCDE0395-E52F-467C-8E3D-C4579291692E"),None,23,guid("A95664D2-9614-4F35-A746-DE8DB63617E6"),c.byref(enum)))
    keep(enum)
    devices=P()
    check(call(enum,3,(I,U,c.POINTER(P)),(0,1,c.byref(devices))))
    keep(devices)
    count=U()
    check(call(devices,3,(c.POINTER(U),),(c.byref(count),)))
    found=0
    for i in range(count.value):
        dev=P()
        check(call(devices,4,(U,c.POINTER(P)),(i,c.byref(dev))))
        keep(dev)
        manager=P()
        check(call(dev,3,(P,U,P,c.POINTER(P)),(guid("77AA99A0-1BD6-484F-8BC7-2C654C9A9B6F"),23,None,c.byref(manager))))
        keep(manager)
        sessions=P()
        check(call(manager,5,(c.POINTER(P),),(c.byref(sessions),)))
        keep(sessions)
        sc=I()
        check(call(sessions,3,(c.POINTER(I),),(c.byref(sc),)))
        for j in range(sc.value):
            session=P()
            check(call(sessions,4,(I,c.POINTER(P)),(j,c.byref(session))))
            keep(session)
            sc2=keep(qi(session,"BFB7FF88-7239-4FC9-8FA2-07C950BE9C6D"))
            pid=U()
            check(call(sc2,14,(c.POINTER(U),),(c.byref(pid),)))
            if pid.value!=a.pid: continue
            found+=1
            meter=keep(qi(session,"C02216F6-8C67-4B5B-9D00-D008E73E0064"))
            volume=keep(qi(session,"87CE5498-68D6-44E5-9215-6DA47EF883D8"))
            state,muted=I(),I()
            vol,peak=F(),F()
            check(call(session,3,(c.POINTER(I),),(c.byref(state),)))
            check(call(volume,4,(c.POINTER(F),),(c.byref(vol),)))
            check(call(volume,6,(c.POINTER(I),),(c.byref(muted),)))
            maximum=0.0
            for _ in range(12):
                check(call(meter,3,(c.POINTER(F),),(c.byref(peak),)))
                maximum=max(maximum,peak.value)
                time.sleep(0.25)
            print(json.dumps({"pid":a.pid,"active":state.value==1,"muted":bool(muted.value),"volume":vol.value,"peak_over_3_seconds":maximum}))
    if not found: print(json.dumps({"pid":a.pid,"audio_sessions_found":0}))
finally:
    for ref in reversed(refs): call(ref,2)
    ole.CoUninitialize()