"""An object-oriented interface to .netrc files."""

# Module and documentation by Eric S. Raymond, 21 Dec 1998

import os, shlex

__all__ = ["netrc", "NetrcParseError"]

class NetrcParseError(Exception):

    """Exception raised on syntax errors in the .netrc file."""

    def __init__(self, msg, filename=None, lineno=None):

        self.filename = filename

        self.lineno = lineno

        self.msg = msg

        Exception.__init__(self, msg)

    def __str__(self):

        return "%s (%s, line %s)" % (self.msg, self.filename, self.lineno)

class netrc:

    def __init__(self, file=None):

        if file is None:

            try:

                file = os.path.join(os.environ['HOME'], ".netrc")

            except KeyError:

                raise IOError("Could not find .netrc: $HOME is not set")

        fp = open(file)

        self.hosts = {}

        self.macros = {}

        lexer = shlex.shlex(fp)

        lexer.wordchars += r"""!"#$%&'()*+,-./:;<=>?@[\]^_`{|}~"""

        while 1:

            # Look for a machine, default, or macdef top-level keyword

            toplevel = tt = lexer.get_token()

            if not tt:

                break

            elif tt == 'machine':

                entryname = lexer.get_token()

            elif tt == 'default':

                entryname = 'default'

            elif tt == 'macdef':                # Just skip to end of macdefs

                entryname = lexer.get_token()

                self.macros[entryname] = []

                lexer.whitespace = ' \t'

                while 1:

                    line = lexer.instream.readline()

                    if not line or line == '\012':

                        lexer.whitespace = ' \t\r\n'

                        break

                    self.macros[entryname].append(line)

                continue

            else:

                raise NetrcParseError(

                    "bad toplevel token %r" % tt, file, lexer.lineno)

            # We're looking at start of an entry for a named machine or default.

            login = ''

            account = password = None

            self.hosts[entryname] = {}

            while 1:

                tt = lexer.get_token()

                if (tt=='' or tt == 'machine' or

                    tt == 'default' or tt =='macdef'):

                    if password:

                        self.hosts[entryname] = (login, account, password)

                        lexer.push_token(tt)

                        break

                    else:

                        raise NetrcParseError(

                            "malformed %s entry %s terminated by %s"

                            % (toplevel, entryname, repr(tt)),

                            file, lexer.lineno)

                elif tt == 'login' or tt == 'user':

                    login = lexer.get_token()

                elif tt == 'account':

                    account = lexer.get_token()

                elif tt == 'password':

                    password = lexer.get_token()

                else:

                    raise NetrcParseError("bad follower token %r" % tt,

                                          file, lexer.lineno)

    def authenticators(self, host):

        """Return a (user, account, password) tuple for given host."""

        if host in self.hosts:

            return self.hosts[host]

        elif 'default' in self.hosts:

            return self.hosts['default']

        else:

            return None

    def __repr__(self):

        """Dump the class data in the format of a .netrc file."""

        rep = ""

        for host in self.hosts.keys():

            attrs = self.hosts[host]

            rep = rep + "machine "+ host + "\n\tlogin " + repr(attrs[0]) + "\n"

            if attrs[1]:

                rep = rep + "account " + repr(attrs[1])

            rep = rep + "\tpassword " + repr(attrs[2]) + "\n"

        for macro in self.macros.keys():

            rep = rep + "macdef " + macro + "\n"

            for line in self.macros[macro]:

                rep = rep + line

            rep = rep + "\n"

        return rep

if __name__ == '__main__':

    print netrc()