#! /usr/bin/python

#  Copyright 2014 Linaro Limited
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA 02110-1301, USA.

import logging
import pexpect
import sys
import time
import re
from common import SwitchDriver

class CiscoSX300(SwitchDriver):

    connection = None

    # No extra capabilities for this switch/driver yet
    _capabilities = [
    ]

    # Regexp of expected hardware information - fail if we don't see
    # this
    _expected_descr_re = re.compile('S.300-\d+')

    logfile = sys.stderr
    logfile = None

    def __init__(self, switch_hostname, switch_telnetport=23):
        self.exec_string = "/usr/bin/telnet %s %d" % (switch_hostname, switch_telnetport)

    ################################
    ### Switch-level API functions
    ################################

    # Connect to the switch and log in
    def switch_connect(self, username, password, enablepassword):
        logging.debug("Connecting to Switch with: %s" % self.exec_string)
        self.connection = pexpect.spawn(self.exec_string, logfile = self.logfile)
        self._login(username, password)

        # Try to avoid paged output
        self.connection.setwinsize(132, 1000)

        # And grab details about the switch. in case we need it
        self._get_systemdata()

        # And also validate them - make sure we're driving a switch of
        # the correct model! Also store the serial number
        descr_regex = re.compile('System Description:.\s+(\S.*)')
        sn_regex = re.compile('SN:\s+(\S_)')
        descr = ""

        for line in self._systemdata:
            match = descr_regex.match(line)
            if match:
                descr = match.group(1)
            match = sn_regex.match(line)
            if match:
                self.serial_number = match.group(1)

        if not self._expected_descr_re.match(descr):
            raise IOError("Switch %s not recognised by this driver: abort" % descr)

        # Now build a list of our ports, for later sanity checking
        self._ports = self._get_port_names()
        if len(self._ports) < 4:
            raise IOError("Not enough ports detected - problem!")

    # Log out of the switch and drop the connection and all state
    def switch_disconnect(self):
        self._logout()
        logging.debug("Closing connection: %s" % self.connection)
        self.connection.close(True)
        self._ports = []
        self._prompt_name = ''
        self._systemdata = []
        del(self)

    # Save the current running config into flash - we want config to
    # remain across reboots
    def switch_save_running_config(self):
        self._cli("copy running-config startup-config")
        self.connection.expect("Y/N")
        self._cli("y")
        self.connection.expect("succeeded")

    # Restart the switch - we need to reload config to do a
    # roll-back. Do NOT save running-config first if the switch asks -
    # we're trying to dump recent changes, not save them.
    #
    # This will also implicitly cause a connection to be closed 
    def switch_restart(self):
        self._cli("reload")
        index = self.connection.expect(['Are you sure', 'will reset'])
        if index == 0:
            self._cli("y") # Yes, continue without saving
            self.connection.expect("reset the whole")

        # Fall through
        self._cli("y") # Yes, continue to reset
        self.connection.close(True)

    ################################
    ### VLAN API functions
    ################################

    # Create a VLAN with the specified tag
    def vlan_create(self, tag):
        logging.debug("Creating VLAN %d" % tag)
        self._configure()
        self._cli("vlan database")
        self._cli("vlan %d" % tag)
        self._end_configure()

        # Validate it happened
        vlans = self.vlan_get_list()
        for vlan in vlans:
            if vlan == tag:
                return
        raise IOError("Failed to create VLAN %d" % tag)

    # Destroy a VLAN with the specified tag
    def vlan_destroy(self, tag):
        logging.debug("Destroying VLAN %d" % tag)
        self._configure()
        self._cli("no vlan %d" % tag)
        self._end_configure()

        # Validate it happened
        vlans = self.vlan_get_list()
        for vlan in vlans:
            if vlan == tag:
                raise IOError("Failed to destroy VLAN %d" % tag)

    # Set the name of a VLAN
    def vlan_set_name(self, tag, name):
        logging.debug("Setting name of VLAN %d to %s" % (tag, name))
        self._configure()
        self._cli("vlan %d" % tag)
        self._cli("interface vlan %d" % tag)
        self._cli("name %s" % name)
        self._end_configure()

        # Validate it happened
        read_name = self.vlan_get_name(tag)
        if read_name != name:
            raise IOError("Failed to set name for VLAN %d (name found is \"%s\", not \"%s\")"
                          % (tag, read_name, name))

    # Get a list of the VLAN tags currently registered on the switch
    def vlan_get_list(self):
        logging.debug("Grabbing list of VLANs")
        vlans = []

        regex = re.compile('^ *(\d+).*(D|S|G|R)')

        self._cli("show vlan")
        for line in self._read_paged_output():
            match = regex.match(line)
            if match:
                vlans.append(int(match.group(1)))
        return vlans

    # For a given VLAN tag, ask the switch what the associated name is
    def vlan_get_name(self, tag):
        logging.debug("Grabbing the name of VLAN %d" % tag)
        name = None
        regex = re.compile('^ *\d+\s+(\S+).*(D|S|G|R)')
        self._cli("show vlan tag %d" % tag)
        for line in self._read_paged_output():
            match = regex.match(line)
            if match:
                name = match.group(1)
        name.strip()
        return name
        

    ################################
    ### Port API functions
    ################################    

    # Set the mode of a port: access or trunk
    def port_set_mode(self, port, mode):
        logging.debug("Setting port %s to %s" % (port, mode))
        if not self._is_port_mode_valid(mode):
            raise IndexError("Port mode %s is not allowed" % mode)
        if not self._is_port_name_valid(port):
            raise IndexError("Port name %s not recognised" % port)
        self._configure()
        self._cli("interface %s" % port)
        self._cli("switchport mode %s" % mode)
        self._end_configure()

        # Validate it happened
        read_mode = self.port_get_mode(port)
        if read_mode != mode:
            raise IOError("Failed to set mode for port %s" % port)


    # Get the mode of a port: access or trunk
    def port_get_mode(self, port):
        logging.debug("Getting mode of port %s" % port)
        mode = ''
        if not self._is_port_name_valid(port):
            raise IndexError("Port name %s not recognised" % port)
        regex = re.compile('Port Mode: (\S+)')
        self._cli("show interfaces switchport %s" % port)
        for line in self._read_paged_output():
            match = regex.match(line)
            if match:
                mode = match.group(1)
        return mode.lower()

    # Set an access port to be in a specified VLAN (tag)
    def port_set_access_vlan(self, port, tag):
        logging.debug("Setting access port %s to VLAN %d" % (port, tag))
        if not self._is_port_name_valid(port):
            raise IndexError("Port name %s not recognised" % port)
        if not (self.port_get_mode(port) == "access"):
            raise IndexError("Port %s not in access mode" % port)

        self._configure()
        self._cli("interface %s" % port)
        self._cli("switchport access vlan %d" % tag)
        self._end_configure()        

        # Validate things worked
        read_vlan = int(self.port_get_access_vlan(port))
        if read_vlan != tag:
            raise IOError("Failed to move access port %s to VLAN %d - got VLAN %d instead"
                          % (port, tag, read_vlan))

    # Add a trunk port to a specified VLAN (tag)
    def port_add_trunk_to_vlan(self, port, tag):
        logging.debug("Adding trunk port %s to VLAN %d" % (port, tag))
        if not self._is_port_name_valid(port):
            raise IndexError("Port name %s not recognised" % port)
        if not (self.port_get_mode(port) == "trunk"):
            raise IndexError("Port %s not in trunk mode" % port)
        self._configure()
        self._cli("interface %s" % port)
        self._cli("switchport trunk allowed vlan add %d" % tag)
        self._end_configure()        

        # Validate it happened
        read_vlans = self.port_get_trunk_vlan_list(port)
        for vlan in read_vlans:
            if vlan == tag:
                return
        raise IOError("Failed to add trunk port %s to VLAN %d" % (port, tag))
        
    # Remove a trunk port from a specified VLAN (tag)
    def port_remove_trunk_from_vlan(self, port, tag):
        logging.debug("Removing trunk port %s from VLAN %d" % (port, tag))
        if not self._is_port_name_valid(port):
            raise IndexError("Port name %s not recognised" % port)
        if not (self.port_get_mode(port) == "trunk"):
            raise IndexError("Port %s not in trunk mode" % port)
        self._configure()
        self._cli("interface %s" % port)
        self._cli("switchport trunk allowed vlan remove %d" % tag)
        self._end_configure()        

        # Validate it happened
        read_vlans = self.port_get_trunk_vlan_list(port)
        for vlan in read_vlans:
            if vlan == tag:
                raise IOError("Failed to remove trunk port %s from VLAN %d" % (port, tag))

    # Get the configured VLAN tag for an access port (tag)
    def port_get_access_vlan(self, port):
        logging.debug("Getting VLAN for access port %s" % port)
        vlan = 1
        if not self._is_port_name_valid(port):
            raise IndexError("Port name %s not recognised" % port)
        if not (self.port_get_mode(port) == "access"):
            raise IndexError("Port %s not in access mode" % port)
        regex = re.compile('(\d+)\s+\S+\s+Untagged\s+Static')
        self._cli("show interfaces switchport %s" % port)
        for line in self._read_paged_output():
            match = regex.match(line)
            if match:
                vlan = match.group(1)
        return int(vlan)

    # Get the list of configured VLAN tags for a trunk port
    def port_get_trunk_vlan_list(self, port):
        logging.debug("Getting VLANs for trunk port %s" % port)
        vlans = [ ]
        if not self._is_port_name_valid(port):
            raise IndexError("Port name %s not recognised" % port)
        if not (self.port_get_mode(port) == "trunk"):
            raise IndexError("Port %s not in trunk mode" % port)
        regex = re.compile('(\d+)\s+\S+\s+(Tagged|Untagged)\s+Static')
        self._cli("show interfaces switchport %s" % port)
        for line in self._read_paged_output():
            match = regex.match(line)
            if match:
                vlans.append (int(match.group(1)))
        return vlans

    ################################
    ### Internal functions
    ################################

    def _login(self, username, password):
        logging.debug("attempting login with username %s, password %s" % (username, password))
        self._cli("")
        self.connection.expect("User Name:")
        self._cli("%s" % username)
        self.connection.expect("Password:")
        self._cli("%s" % password, False)
        while True:
            index = self.connection.expect(['User Name:', 'authentication failed', r'(.*)#', '.*'])
            if index == 0 or index == 1: # Failed to log in!
                logging.error("Login failure: %s\n" % self.connection.match)
                raise IOError
            elif index == 2:
                self._prompt_name = self.connection.match.group(1).strip()
                return 0

    def _logout(self):
        logging.debug("Logging out")
        self._cli("exit", False)

    def _configure(self):
        self._cli("configure terminal")

    def _end_configure(self):
        self._cli("end")

    def _read_paged_output(self):
        buf = []
        prompt = self._prompt_name + '#'
        while True:
            index = self.connection.expect(['\x1b\[0mMore:.*<return>.*$', prompt])
            if index == 0: # More: <space>
                for line in self.connection.before.split('\r\n'):
                    buf.append(line.strip())
                self._cli(' ', False)
            elif index == 1: # Back to a prompt, says output is finished
                break

        for line in self.connection.before.split('\r\n'):
            buf.append(line.strip())

        return buf

    def _get_port_names(self):
        logging.debug("Grabbing list of ports")
        interfaces = []

        # Use "Up" or "Down" to only identify lines in the output that
        # match interfaces that exist
        regex = re.compile('^(\w+).*(Up|Down)')

        self._cli("show interfaces status detailed")
        for line in self._read_paged_output():
            match = regex.match(line)
            if match:
                interfaces.append(match.group(1))
        return interfaces

    def _show_config(self):
        logging.debug("Grabbing config")
        self._cli("show running-config")
        return self._read_paged_output()

    def _show_clock(self):
        logging.debug("Grabbing time")
        self._cli("show clock")
        return self._read_paged_output()

    def _get_systemdata(self):

        self._systemdata = []

        logging.debug("Grabbing system data")
        self._cli("show system")
        for line in self._read_paged_output():
            self._systemdata.append(line)

        logging.debug("Grabbing system sw and hw versions")
        self._cli("show version")
        for line in self._read_paged_output():
            self._systemdata.append(line)

    ######################################
    # Internal port access helper methods
    ######################################
    # N.B. No parameter checking here, for speed reasons - if you're
    # calling this internal API then you should already have validated
    # things yourself! Equally, no post-set checks in here - do that
    # at the higher level.
    ######################################
    
    # Wrapper around connection.send - by default, expect() the same
    # text we've sent, to remove it from the output from the
    # switch. For the few cases where we don't need that, override
    # this using echo=False.
    # Horrible, but seems to work.
    def _cli(self, text, echo=True):
        self.connection.send(text + '\r')
        if echo:
            self.connection.expect(text)

if __name__ == "__main__":
#    p = CiscoSX300('10.172.2.52', 23)
    p = CiscoSX300('10.0.3.15', 23)
    p.switch_connect('cisco', 'cisco', None)
    #buf = p._show_clock()
    #print "%s" % buf
    #buf = p._show_config()
    #p._dump_list(buf)

    print "System data:"
    p._dump_list(p._systemdata)

    print "Creating VLANs for testing:"
    for i in [ 2, 3, 4, 5, 20 ]:
        p.vlan_create(i)
        p.vlan_set_name(i, "test%d" % i)
        print "  %d (test%d)" % (i, i)

    #print "And dump config\n"
    #buf = p._show_config()
    #print "%s" % buf

    #print "Destroying VLAN 2\n"
    #p.vlan_destroy(2)

    #print "And dump config\n"
    #buf = p._show_config()
    #print "%s" % buf

    #print "Port names are:"
    #buf = p.switch_get_port_names()
    #p._dump_list(buf)

    #buf = p.vlan_get_name(25)
    #print "VLAN with tag 25 is called \"%s\"" % buf

    #p.vlan_set_name(35, "foo")
    #print "VLAN with tag 35 is called \"foo\""

    #buf = p.port_get_mode("fa12")
    #print "Port fa12 is in %s mode" % buf

    # Test access stuff
    print "Set fa6 to access mode"
    p.port_set_mode("fa6", "access")
    print "Move fa6 to VLAN 2"
    p.port_set_access_vlan("fa6", 2)
    buf = p.port_get_access_vlan("fa6")
    print "Read from switch: fa6 is on VLAN %s" % buf
    print "Move fa6 back to default VLAN 1"
    p.port_set_access_vlan("fa6", 1)
    #print "And move fa6 back to a trunk port"
    #p.port_set_mode("fa6", "trunk")
    #buf = p.port_get_mode("fa6")
    #print "Port fa6 is in %s mode" % buf

    # Test trunk stuff
    print "Set gi2 to trunk mode"
    p.port_set_mode("gi2", "trunk")
    print "Add gi2 to VLAN 2"
    p.port_add_trunk_to_vlan("gi2", 2)
    print "Add gi2 to VLAN 3"
    p.port_add_trunk_to_vlan("gi2", 3)
    print "Add gi2 to VLAN 4"
    p.port_add_trunk_to_vlan("gi2", 4)
    print "Read from switch: which VLANs is gi2 on?"
    buf = p.port_get_trunk_vlan_list("gi2")
    p._dump_list(buf)

    print "Remove gi2 from VLANs 3,3,4"
    p.port_remove_trunk_from_vlan("gi2", 3)
    p.port_remove_trunk_from_vlan("gi2", 3)
    p.port_remove_trunk_from_vlan("gi2", 4)
    print "Read from switch: which VLANs is gi2 on?"
    buf = p.port_get_trunk_vlan_list("gi2")
    p._dump_list(buf)

 #   print "Adding lots of ports to VLANs"
 #   p.port_add_trunk_to_vlan("fa1", 2)
 #   p.port_add_trunk_to_vlan("fa3", 2)
 #   p.port_add_trunk_to_vlan("fa5", 2)
 #   p.port_add_trunk_to_vlan("fa7", 2)
 #   p.port_add_trunk_to_vlan("fa9", 2)
 #   p.port_add_trunk_to_vlan("fa11", 2)
 #   p.port_add_trunk_to_vlan("fa13", 2)
 #   p.port_add_trunk_to_vlan("fa15", 2)
 #   p.port_add_trunk_to_vlan("fa17", 2)
 #   p.port_add_trunk_to_vlan("fa19", 2)
 #   p.port_add_trunk_to_vlan("fa21", 2)
 #   p.port_add_trunk_to_vlan("fa23", 2)
 #   p.port_add_trunk_to_vlan("gi4", 2)

    print "VLANs are:"
    buf = p.vlan_get_list()
    p._dump_list(buf)

#    print 'Restarting switch, to explicitly reset config'
#    p.switch_restart()

#    p.switch_save_running_config()
#    p._show_config()