#!/usr/bin/env python

import re
import sys
import os
from pprint import pformat


def token_is_variable(line_number, token):

    if token.isdigit():
        return True

    if token.startswith('('):
        assert token.endswith(')'), "%d: token %s should end with )" % (line_number, token)
        return True

    if token.startswith('['):
        assert token.endswith(']'), "%d: token %s should end with ]" % (line_number, token)
        return True

    if token.startswith('{'):
        # I don't really care about checking for this I just put
        # these asserts in here to bug sharpd
        assert token.endswith('}'), "%d: token %s should end with }" % (line_number, token)
        return True

    assert '|' not in token, "%d: Weird token %s has a | but does not start with [ or (" % (line_number, token)

    if token in ('WORD',
                 '.LINE', # where is this defined?
                 'PATH',
                 'A.B.C.D',
                 'A.B.C.D/M',
                 'X:X::X:X',
                 'X:X::X:X/M',
                 'ASN:nn_or_IP-address:nn'): # where is this defined?
        return True

    re_number_range = re.search('^<\d+-\d+>$', token)
    if re_number_range:
        return True

    return False


def get_argv_translator(line_number, line):
    table = {}
    line = line.strip()
    assert line.startswith('"'), "%d: line does not start with \"\n%s" % (line_number, line)
    assert line.endswith('",'), "%d: line does not end with \",\n%s" % (line_number, line)

    line = line[1:-2]

    funky_chars = ('+', '"')
    for char in funky_chars:
        if char in line:
            raise Exception("%d: Add support for tokens in\n%s\n\nsee BGP_INSTANCE_CMD down below" % (line_number, line))

    old_style_index = 0
    for (token_index, token) in enumerate(line.split()):
        if token_is_variable(line_number, token):
            # print "%s is a token" % token
            table[old_style_index] = token_index
            old_style_index += 1
        else:
            # print "%s is NOT a token" % token
            pass

    return table


def update_argvs(filename):
    lines = []

    with open(filename,  'r') as fh:
        state = None
        defun_line_number = None
        cmd_string = None
        argv_translator = {}
        print_translator = False

        for (line_number, line) in enumerate(fh.readlines()):
            new_line = line

            if state is None:
                if line.startswith('DEFUN ('):
                    assert line.count(',') == 1, "Too many commas in\n%s" % line
                    state = 'DEFUN_HEADER'
                    defun_line_number = line_number

            elif state == 'DEFUN_HEADER':
                if line.startswith('DEFUN'):
                    raise Exception("ERROR on line %d, found DEFUN inside DEFUN" % line_number)

                elif line.startswith('ALIAS'):
                    raise Exception("ERROR on line %d, found ALIAS inside DEFUN" % line_number)

                elif line.strip() == '{':
                    state = 'DEFUN_BODY'

                elif line_number == defun_line_number + 2:

                    # in the middle
                    line = line.replace('" CMD_AS_RANGE "', '<1-4294967295>')
                    line = line.replace('" DYNAMIC_NEIGHBOR_LIMIT_RANGE "', '<1-5000>')
                    line = line.replace('" BGP_INSTANCE_CMD "', '(view|vrf) WORD')
                    line = line.replace('" BGP_INSTANCE_ALL_CMD "', '(view|vrf) all')
                    line = line.replace('" CMD_RANGE_STR(1, MULTIPATH_NUM) "', '<1-255>')
                    line = line.replace('" QUAGGA_IP_REDIST_STR_BGPD "', '(kernel|connected|static|rip|ospf|isis|pim|table)')
                    line = line.replace('" QUAGGA_IP6_REDIST_STR_BGPD "', '(kernel|connected|static|ripng|ospf6|isis|table)')

                    # endswith
                    line = line.replace('" CMD_AS_RANGE,', ' <1-4294967295>",')
                    line = line.replace('" DYNAMIC_NEIGHBOR_LIMIT_RANGE,', ' <1-5000>",')
                    line = line.replace('" BGP_INSTANCE_CMD,', ' (view|vrf) WORD",')
                    line = line.replace('" BGP_INSTANCE_ALL_CMD,', ' (view|vrf) all",')
                    line = line.replace('" CMD_RANGE_STR(1, MULTIPATH_NUM),', '<1-255>",')
                    line = line.replace('" CMD_RANGE_STR(1, MAXTTL),', '<1-255>",')

                    line = line.replace('" BGP_UPDATE_SOURCE_REQ_STR,', ' (A.B.C.D|X:X::X:X|WORD)",')
                    line = line.replace('" BGP_UPDATE_SOURCE_OPT_STR,', ' {A.B.C.D|X:X::X:X|WORD}",')
                    line = line.replace('" QUAGGA_IP_REDIST_STR_BGPD,', ' (kernel|connected|static|rip|ospf|isis|pim|table)",')
                    line = line.replace('" QUAGGA_IP6_REDIST_STR_BGPD,', ' (kernel|connected|static|ripng|ospf6|isis|table)",')

                    # startswith 
                    line = line.replace('LISTEN_RANGE_CMD "', '"bgp listen range (A.B.C.D/M|X:X::X:X/M) ')
                    line = line.replace('NO_NEIGHBOR_CMD2 "', '"no neighbor (A.B.C.D|X:X::X:X|WORD) ')
                    line = line.replace('NEIGHBOR_CMD2 "', '"neighbor (A.B.C.D|X:X::X:X|WORD) ')
                    line = line.replace('NO_NEIGHBOR_CMD "', '"no neighbor (A.B.C.D|X:X::X:X) ')
                    line = line.replace('NEIGHBOR_CMD "', '"neighbor (A.B.C.D|X:X::X:X) ')

                    # solo
                    line = line.replace('NO_NEIGHBOR_CMD2,', '"no neighbor (A.B.C.D|X:X::X:X|WORD)",')
                    line = line.replace('NEIGHBOR_CMD2,', '"neighbor (A.B.C.D|X:X::X:X|WORD)",')
                    line = line.replace('NO_NEIGHBOR_CMD,', '"no neighbor (A.B.C.D|X:X::X:X)",')
                    line = line.replace('NEIGHBOR_CMD,', '"neighbor (A.B.C.D|X:X::X:X)",')

                    if line.rstrip().endswith('" ,'):
                        line = line.replace('" ,', '",')

                    argv_translator = get_argv_translator(line_number, line)
                    print_translator = True

            elif state == 'DEFUN_BODY':
                if line.rstrip() == '}':
                    state = None
                    defun_line_number = None
                    cmd_string = None
                    argv_translator = {}

                elif 'argv[' in new_line:
                    for index in reversed(argv_translator.keys()):
                        old_argv = "argv[%d]" % index
                        new_argv = "argv[%d]->arg" % argv_translator[index]
                        new_line = new_line.replace(old_argv, new_argv)

            # uncomment to debug state machine
            print "%5d %12s: %s" % (line_number, state, new_line.rstrip())
            if print_translator:
                print "%s\n" % pformat(argv_translator)
                print_translator = False

            lines.append(new_line)

    with open(filename, 'w') as fh:
        for line in lines:
            fh.write(line)


if __name__ == '__main__':

    filename = sys.argv[1]
    if os.path.exists(filename):
        update_argvs(filename)
    else:
        print "ERROR: could not find file %s" % filename