#!/usr/bin/python
# Abuse the docstring so running this with /bin/sh will do the right thing
"""exec" "/usr/bin/python" "$0"""
__doc__ = "Create a local user based on a launchpad account"
__all__ = ["create_user"]

import os, pwd, subprocess, urllib2, xml.dom.minidom

lp = "https://launchpad.net/~"

def verify_exists(lpuser):
    try:
        urllib2.urlopen(lp + lpuser)
        return True
    except:
        return False

def get_realname(lpuser):
    rdf = urllib2.urlopen(lp + lpuser + "/+rdf").read()
    tree = xml.dom.minidom.parseString(rdf)
    return tree.getElementsByTagName("foaf:name")[0].firstChild.nodeValue

def create_user(local_name, launchpad_name=None):
    if not launchpad_name:
        launchpad_name = local_name

    # Sanity checking
    try:
        pwd.getpwnam(local_name)
    except:
        pass
    else:
        raise LookupError("%s already exists on your local system" % local_name)
    if not verify_exists(launchpad_name):
        raise LookupError("%s does not have a launchpad account" % launchpad_name)
    try:
        sshkey = urllib2.urlopen(lp + launchpad_name + "/+sshkeys").read()
    except:
        raise LookupError("%s has not yet uploaded his/her SSH key to launchpad" % launchpad_name)

    # Add the user
    realname = get_realname(launchpad_name)
    if subprocess.call(["/usr/sbin/adduser",
                       "--gecos", realname,
                       "--disabled-password",
                       local_name]):
        raise RuntimeError("Could not create user %s" % local_name)
    user = pwd.getpwnam(local_name)
    os.mkdir(os.path.join(user.pw_dir, ".ssh"), 0700)
    os.chown(os.path.join(user.pw_dir, ".ssh"), user.pw_uid, user.pw_gid)
    fd = os.open(os.path.join(user.pw_dir, ".ssh", "authorized_keys2"), os.O_WRONLY | os.O_CREAT, 0600)
    os.write(fd, sshkey)
    os.close(fd)
    os.chown(os.path.join(user.pw_dir, ".ssh", "authorized_keys2"), user.pw_uid, user.pw_gid)

if __name__ == '__main__':
    import optparse, sys

    parser = optparse.OptionParser(usage="%prog [options] name\nCreate a local account based on a launchpad.net account")
    parser.add_option('-l', '--launchpad-name', 
                      dest="launchpad_name",
                      default=None,
                      help="Use this launchpad account",
                      metavar="NAME")
    opts, args = parser.parse_args()

    if len(args) != 1:
        parser.print_help()
        sys.exit(1)

    if os.geteuid() != 0:
        print >>sys.stderr, "Only root can add users to the system"
        sys.exit(1)

    local_name = args[0]
    launchpad_name = opts.launchpad_name or local_name
    try:
        create_user(local_name, launchpad_name)
    except LookupError, e:
        print >>sys.stderr, e.message
        sys.exit(1)