import argparse
import pathlib
import os
import sys
import time
import tempfile

import patch
from tmux import TmuxSession
from vim_session import VimSession
import logging


logger = logging.getLogger(__name__)


def parse_args():
    """ Parse command-line arguments """
    parser = argparse.ArgumentParser(prog="patch2vimedit")
    parser.add_argument(
        "-g",
        "--debug",
        action="store_true",
        help="Enable debug logging to /tmp/patch2log",
    )
    parser.add_argument(
        "-C",
        "--directory",
        metavar="DIR",
        help="Change to DIR before performing any operations.",
    )
    parser.add_argument(
        "patch",
        help=(
            "The patch file to be applied. If '-' is supplied, reads from STDIN "
            "instead."
        ),
    )
    return parser.parse_args()


def get_patch(patch_path):
    if patch_path == "-":
        return patch.PatchSet(sys.stdin)
    with open(patch_path, "rb") as stream:
        return patch.PatchSet(stream)


def configure_home(home):
    """ Configures the temporary home """
    tmux_conf_path = home / ".tmux.conf"
    vim_conf_path = home / ".vimrc"

    print("Configuring tmux in {}".format(tmux_conf_path))
    with tmux_conf_path.open("w") as tmux_conf:
        tmux_conf.write("set -g status off\n")
    with vim_conf_path.open("w") as vim_conf:
        vim_conf.write(
            """
syntax on
set bg=dark
set number
set ts=4
set sw=4
set et
set so=5
set noautoindent
set nosmartindent
set nocindent
set indentexpr&
"""
        )

    return tmux_conf_path, vim_conf_path


def apply_patchset(patchset):
    tmux_session = TmuxSession.create_detached()
    tmux_fg_process = tmux_session.process_attach(read_only=True)
    time.sleep(0.2)

    vim_session = VimSession(tmux_session)
    time.sleep(0.2)
    vim_session.apply_patchset(patchset)
    time.sleep(1)
    vim_session.quit()

    time.sleep(0.5)
    tmux_session.type_keys("exit", "enter")

    tmux_fg_process.join(1)
    if tmux_fg_process.exitcode is None:  # Did not terminate -- kill it
        tmux_fg_process.kill()
    if tmux_session.session_exists():
        tmux_session.session.kill_session()


def configure_log(args):
    if args.debug:
        logging.basicConfig(filename="/tmp/patch2log", level=logging.DEBUG)
    else:
        logging.basicConfig(level=logging.CRITICAL)

    logging.getLogger("libtmux").setLevel(logging.INFO)
    logging.getLogger("tmux").setLevel(logging.INFO)


def main():
    """ Entry-point function """
    args = parse_args()

    configure_log(args)

    patchset = get_patch(args.patch)

    if args.directory:
        chdir_to = pathlib.Path(args.directory)
        if not chdir_to.is_dir():
            print(
                (
                    "The required working directory '{}' does not exist, or is not a "
                    "directory."
                ).format(str(chdir_to)),
                file=sys.stderr,
            )
            sys.exit(1)
        os.chdir(chdir_to)

    with tempfile.TemporaryDirectory() as tmp_home_path:
        os.environ["HOME"] = tmp_home_path
        tmp_home = pathlib.Path(tmp_home_path)
        tmux_conf, _ = configure_home(tmp_home)
        TmuxSession.initialize_server(
            socket_name="patch2vimedit", config_file=tmux_conf.as_posix()
        )
        apply_patchset(patchset)


if __name__ == "__main__":
    main()