"""Test the Mac USB reader against a temporary pseudo-terminal, not hardware."""
from pathlib import Path
import os
import pty
import select
import signal
import subprocess
import sys
import tempfile
import time

ROOT = Path(__file__).resolve().parents[1]


def exercise(diag_only):
    master, slave = pty.openpty()
    port = os.ttyname(slave)
    process = None
    try:
        with tempfile.TemporaryDirectory(prefix='banban-usb-reader-') as directory:
            output = Path(directory) / 'capture.log'
            command = [sys.executable, str(ROOT / 'tools/read_usb_log.py'), '--port', port, '--output', str(output)]
            if diag_only:
                command.append('--diag-only')
            process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
            notice = b''
            deadline = time.monotonic() + 5
            while '已连接'.encode() not in notice:
                assert time.monotonic() < deadline, notice.decode(errors='replace')
                if select.select([process.stderr], [], [], 0.1)[0]:
                    notice += os.read(process.stderr.fileno(), 4096)
                assert process.poll() is None, notice.decode(errors='replace')
            payload = '[现场诊断] 中文连续测试\r\nordinary application log\r\n[USB日志] 在线\n[现场诊断] 最后一行'.encode()
            os.write(master, payload[:3])  # Deliberately split a UTF-8 character.
            time.sleep(0.02)
            os.write(master, payload[3:])
            deadline = time.monotonic() + 5
            while not output.exists() or '[USB日志] 在线' not in output.read_text():
                assert time.monotonic() < deadline
                time.sleep(0.02)
            process.send_signal(signal.SIGINT)
            stdout, stderr = process.communicate(timeout=5)
            assert process.returncode == 0, stderr.decode()
            saved = output.read_text()
            assert '\ufffd' not in saved
            assert '[现场诊断] 中文连续测试' in saved
            assert '[USB日志] 在线' in saved
            assert '[现场诊断] 最后一行' in saved
            assert ('ordinary application log' in saved) != diag_only
            assert '[现场诊断] 中文连续测试' in stdout.decode()
    finally:
        if process and process.poll() is None:
            process.kill()
            process.communicate()
        os.close(master)
        os.close(slave)


if __name__ == '__main__':
    exercise(False)
    exercise(True)
    print('PASS: pseudo-terminal USB capture, split UTF-8, diagnostic filter, Ctrl+C and final-line flush')