__main__.py

# Copyright 2017-2020 Palantir Technologies, Inc.
# Copyright 2021- Python Language Server Contributors.

import argparse
import json
import logging
import logging.config
import sys
import time

from ._version import __version__
from .python_lsp import (
    PythonLSPServer,
    start_io_lang_server,
    start_tcp_lang_server,
    start_ws_lang_server,
)

LOG_FORMAT = "%(asctime)s {0} - %(levelname)s - %(name)s - %(message)s".format(
    time.localtime().tm_zone
)


def add_arguments(parser) -> None:
    parser.description = "Python Language Server"

    parser.add_argument(
        "--tcp", action="store_true", help="Use TCP server instead of stdio"
    )
    parser.add_argument(
        "--ws", action="store_true", help="Use Web Sockets server instead of stdio"
    )
    parser.add_argument("--host", default="127.0.0.1", help="Bind to this address")
    parser.add_argument("--port", type=int, default=2087, help="Bind to this port")
    parser.add_argument(
        "--check-parent-process",
        action="store_true",
        help="Check whether parent process is still alive using os.kill(ppid, 0) "
        "and auto shut down language server process when parent process is not alive."
        "Note that this may not work on a Windows machine.",
    )

    log_group = parser.add_mutually_exclusive_group()
    log_group.add_argument(
        "--log-config", help="Path to a JSON file containing Python logging config."
    )
    log_group.add_argument(
        "--log-file",
        help="Redirect logs to the given file instead of writing to stderr."
        "Has no effect if used with --log-config.",
    )

    parser.add_argument(
        "-v",
        "--verbose",
        action="count",
        default=0,
        help="Increase verbosity of log output, overrides log config file",
    )

    parser.add_argument(
        "-V", "--version", action="version", version="%(prog)s v" + __version__
    )


def main() -> None:
    parser = argparse.ArgumentParser()
    add_arguments(parser)
    args = parser.parse_args()
    _configure_logger(args.verbose, args.log_config, args.log_file)

    if args.tcp:
        start_tcp_lang_server(
            args.host, args.port, args.check_parent_process, PythonLSPServer
        )
    elif args.ws:
        start_ws_lang_server(args.port, args.check_parent_process, PythonLSPServer)
    else:
        stdin, stdout = _binary_stdio()
        start_io_lang_server(stdin, stdout, args.check_parent_process, PythonLSPServer)


def _binary_stdio():
    """Construct binary stdio streams (not text mode).

    This seems to be different for Window/Unix Python2/3, so going by:
        https://stackoverflow.com/questions/2850893/reading-binary-data-from-stdin
    """
    stdin, stdout = sys.stdin.buffer, sys.stdout.buffer
    return stdin, stdout


def _configure_logger(verbose=0, log_config=None, log_file=None) -> None:
    root_logger = logging.root

    if log_config:
        with open(log_config, "r", encoding="utf-8") as f:
            logging.config.dictConfig(json.load(f))
    else:
        formatter = logging.Formatter(LOG_FORMAT)
        if log_file:
            log_handler = logging.handlers.RotatingFileHandler(
                log_file,
                mode="a",
                maxBytes=50 * 1024 * 1024,
                backupCount=10,
                encoding=None,
                delay=0,
            )
        else:
            log_handler = logging.StreamHandler()
        log_handler.setFormatter(formatter)
        root_logger.addHandler(log_handler)

    if verbose == 0:
        level = logging.WARNING
    elif verbose == 1:
        level = logging.INFO
    elif verbose >= 2:
        level = logging.DEBUG

    root_logger.setLevel(level)


if __name__ == "__main__":
    main()