import subprocess
import multiprocessing
import sys
import random
import libtmux


class TmuxSession:
    """ A tmux session """

    tmux_server = libtmux.Server()

    def __init__(self, session):
        self.session = session
        self.session_id = session.id

    @classmethod
    def create_detached(cls, name=None):
        """ Create a new detached tmux session, returning the TmuxSession """
        if not name:
            name = "patch2vimsession-{:04x}".format(random.randint(0, 1 << 16 - 1))
        session = cls.tmux_server.new_session(session_name=name, attach=False)
        return cls(session)

    def attach(self):
        """ Attach the tmux session to the current terminal. Does NOT return until the
        tmux session ends or is detached. """
        self.session.attach_session()

    def attach_ro(self):
        """ Same as `attach`, but attaches a tmux session in a read-only fashion (see
        `tmux attach -r`). """
        # libtmux is not expressive enough to avoid `subprocess` here...
        subprocess.run(["tmux", "attach", "-r", "-t", self.session.id], check=True)

    def session_exists(self):
        """ Checks that the session exists """
        return self.tmux_server.has_session(self.session_id)

    def process_attach(self, read_only=True):
        """ Runs `self.attach` in a `multiprocessing.Process` and returns the process.
        """
        target = self.attach_ro if read_only else self.attach
        process = multiprocessing.Process(target=target)
        process.start()
        return process

    def send_keys(self, *args):
        """ Send keys to the tmux process. See `man tmux` and `tmux send-keys` for
        documentation """
        for arg in args:
            self.session.attached_pane.send_keys(
                arg, suppress_history=False, enter=False
            )


#        subprocess.run(
#            ["tmux", "send-keys", "-t", self.session.id] + list(args), check=True
#        )