"""
Functionality to allow establishing new slave contexts over an SSH connection.
"""

import commands

import econtext.master


class Stream(econtext.master.Stream):
    python_path = 'python'

    #: The path to the SSH binary.
    ssh_path = 'ssh'

    def construct(self, hostname, username=None, ssh_path=None, **kwargs):
        super(Stream, self).construct(**kwargs)
        self.hostname = hostname
        self.username = username
        if ssh_path:
            self.ssh_path = ssh_path
        self.name = 'ssh.' + hostname

    def default_name(self):
        return self.hostname

    def get_boot_command(self):
        bits = [self.ssh_path]
        if self.username:
            bits += ['-l', self.username]
        bits.append(self.hostname)
        base = super(Stream, self).get_boot_command()
        return bits + map(commands.mkarg, base)