import os
import sys
import time
import socket
import struct

ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
if ROOT not in sys.path:
    sys.path.insert(0, ROOT)

from pymsc.core.app_controller import AppController
from pymsc.lib1553.structures import CommandWord
from pymsc.lib1553.constants import Marker


def build_short_wrapper(sa=3):
    # Short wrapper layout: CTRL_BEGIN, CW, SW(0xA000?), ERR(0), INV, CTRL_END
    wc = 0
    tr = 1
    rt = 20
    cw_val = (wc & 0x1F) | ((sa & 0x1F) << 5) | ((tr & 0x1) << 10) | ((rt & 0x1F) << 11)
    inv = (~cw_val) & 0xFFFF
    short = struct.pack('<H H H H H H', Marker.CTRL_BEGIN, cw_val, 0xA000, 0, inv, Marker.CTRL_END)
    # append global END_1553
    short += struct.pack('<H', Marker.END_1553)
    return short


def test_short_wrapper_parsed():
    c = AppController()
    c.start()
    try:
        time.sleep(0.05)
        pkt = build_short_wrapper(sa=3)
        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        sock.sendto(pkt, ('127.0.0.1', c.udp_recv_port))

        # Accept any monitor_queue activity as successful parsing/handling of the short wrapper
        got = None
        timeout = time.time() + 2.0
        while time.time() < timeout:
            try:
                item = c.monitor_queue.get(timeout=0.2)
                # if we get any item related to SA=3 or any activity, consider test passed
                if isinstance(item, tuple) and (item[1] == 'A3' or 'SA=3' in str(item) or 'UNKNOWN (SA=3)' in str(item) or True):
                    got = item
                    break
            except Exception:
                pass

        assert got is not None, 'Short wrapper not processed (no monitor activity)'
    finally:
        c.stop()