import os
import socket
import re
import json
import threading
import urllib2

import time
from contextlib import closing

from mininet.log import info, warn, error
from mininet.node import Switch, Host

SIMPLE_SWITCH_GRPC = 'simple_switch_grpc'
PKT_BYTES_TO_DUMP = 80
VALGRIND_PREFIX = 'valgrind --leak-check=yes'
SWITCH_START_TIMEOUT = 5  # seconds
BMV2_LOG_LINES = 5
BMV2_DEFAULT_DEVICE_ID = 0


def parseBoolean(value):
    if value in ['1', 1, 'true', 'True']:
        return True
    else:
        return False


def pickUnusedPort():
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.bind(('localhost', 0))
    addr, port = s.getsockname()
    s.close()
    return port


def writeToFile(path, value):
    with open(path, "w") as f:
        f.write(str(value))


def watchDog(sw):
    while True:
        if sw.stopped:
            return
        with closing(socket.socket(socket.AF_INET, socket.SOCK_STREAM)) as s:
            if s.connect_ex(('127.0.0.1', sw.grpcPort)) == 0:
                time.sleep(1)
            else:
                warn("\n*** WARN: BMv2 instance %s died!\n" % sw.name)
                sw.printBmv2Log()
                print ("-" * 80) + "\n"
                return


class ONOSHost(Host):
    def __init__(self, name, inNamespace=True, **params):
        Host.__init__(self, name, inNamespace=inNamespace, **params)

    def config(self, **params):
        r = super(Host, self).config(**params)
        for off in ["rx", "tx", "sg"]:
            cmd = "/sbin/ethtool --offload %s %s off" \
                  % (self.defaultIntf(), off)
            self.cmd(cmd)
        # disable IPv6
        self.cmd("sysctl -w net.ipv6.conf.all.disable_ipv6=1")
        self.cmd("sysctl -w net.ipv6.conf.default.disable_ipv6=1")
        self.cmd("sysctl -w net.ipv6.conf.lo.disable_ipv6=1")
        return r


class ONOSBmv2Switch(Switch):
    """BMv2 software switch with gRPC server"""

    def __init__(self, name, json=None, debugger=False, loglevel="warn",
                 elogger=False, grpcport=None, cpuport=255,
                 thriftport=None, netcfg=True, dryrun=False, pipeconf="",
                 pktdump=False, valgrind=False, gnmi=False,
                 portcfg=True, onosdevid=None, **kwargs):
        Switch.__init__(self, name, **kwargs)
        self.grpcPort = pickUnusedPort() if not grpcport else grpcport
        self.thriftPort = pickUnusedPort() if not thriftport else thriftport
        self.cpuPort = cpuport
        self.json = json
        self.debugger = parseBoolean(debugger)
        self.loglevel = loglevel
        # Important: Mininet removes all /tmp/*.log files in case of exceptions.
        # We want to be able to see the bmv2 log if anything goes wrong, hence
        # avoid the .log extension.
        self.logfile = '/tmp/bmv2-%s-log' % self.name
        self.elogger = parseBoolean(elogger)
        self.pktdump = parseBoolean(pktdump)
        self.netcfg = parseBoolean(netcfg)
        self.dryrun = parseBoolean(dryrun)
        self.valgrind = parseBoolean(valgrind)
        self.netcfgfile = '/tmp/bmv2-%s-netcfg.json' % self.name
        self.pipeconfId = pipeconf
        self.injectPorts = parseBoolean(portcfg)
        self.withGnmi = parseBoolean(gnmi)
        self.longitude = kwargs['longitude'] if 'longitude' in kwargs else None
        self.latitude = kwargs['latitude'] if 'latitude' in kwargs else None
        if onosdevid is not None and len(onosdevid) > 0:
            self.onosDeviceId = onosdevid
        else:
            self.onosDeviceId = "device:bmv2:%s" % self.name
        self.logfd = None
        self.bmv2popen = None
        self.stopped = False

        # Remove files from previous executions
        self.cleanupTmpFiles()

        writeToFile("/tmp/bmv2-%s-grpc-port" % self.name, self.grpcPort)
        writeToFile("/tmp/bmv2-%s-thrift-port" % self.name, self.thriftPort)

    def getSourceIp(self, dstIP):
        """
        Queries the Linux routing table to get the source IP that can talk with
        dstIP, and vice versa.
        """
        ipRouteOut = self.cmd('ip route get %s' % dstIP)
        r = re.search(r"src (\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})", ipRouteOut)
        return r.group(1) if r else None

    def getDeviceConfig(self, srcIP):

        basicCfg = {
            "driver": "bmv2"
        }

        if self.longitude and self.latitude:
            basicCfg["longitude"] = self.longitude
            basicCfg["latitude"] = self.latitude

        cfgData = {
            "generalprovider": {
                "p4runtime": {
                    "ip": srcIP,
                    "port": self.grpcPort,
                    "deviceId": BMV2_DEFAULT_DEVICE_ID,
                    "deviceKeyId": "p4runtime:%s" % self.onosDeviceId
                }
            },
            "piPipeconf": {
                "piPipeconfId": self.pipeconfId
            },
            "basic": basicCfg
        }

        if self.withGnmi:
            cfgData["generalprovider"]["gnmi"] = {
                "ip": srcIP,
                "port": self.grpcPort
            }

        if self.injectPorts:
            portData = {}
            portId = 1
            for intfName in self.intfNames():
                if intfName == 'lo':
                    continue
                portData[str(portId)] = {
                    "number": portId,
                    "name": intfName,
                    "enabled": True,
                    "removed": False,
                    "type": "copper",
                    "speed": 10000
                }
                portId += 1

            cfgData['ports'] = portData

        return cfgData

    def doOnosNetcfg(self, controllerIP):
        """
        Notifies ONOS about the new device via Netcfg.
        """
        srcIP = self.getSourceIp(controllerIP)
        if not srcIP:
            warn("*** WARN: unable to get switch IP address, won't do netcfg\n")
            return

        cfgData = {
            "devices": {
                self.onosDeviceId: self.getDeviceConfig(srcIP)
            }
        }
        with open(self.netcfgfile, 'w') as fp:
            json.dump(cfgData, fp, indent=4)

        if not self.netcfg:
            # Do not push config to ONOS.
            return

        # Build netcfg URL
        url = 'http://%s:8181/onos/v1/network/configuration/' % controllerIP
        # Instantiate password manager for HTTP auth
        pm = urllib2.HTTPPasswordMgrWithDefaultRealm()
        pm.add_password(None, url,
                        os.environ['ONOS_WEB_USER'],
                        os.environ['ONOS_WEB_PASS'])
        urllib2.install_opener(urllib2.build_opener(
            urllib2.HTTPBasicAuthHandler(pm)))
        # Push config data to controller
        req = urllib2.Request(url, json.dumps(cfgData),
                              {'Content-Type': 'application/json'})
        try:
            f = urllib2.urlopen(req)
            print f.read()
            f.close()
        except urllib2.URLError as e:
            warn("*** WARN: unable to push config to ONOS (%s)\n" % e.reason)

    def start(self, controllers):
        bmv2Args = [SIMPLE_SWITCH_GRPC] + self.grpcTargetArgs()
        if self.valgrind:
            bmv2Args = VALGRIND_PREFIX.split() + bmv2Args

        cmdString = " ".join(bmv2Args)

        if self.dryrun:
            info("\n*** DRY RUN (not executing bmv2)")

        info("\nStarting BMv2 target: %s\n" % cmdString)

        try:
            if not self.dryrun:
                # Start the switch
                self.logfd = open(self.logfile, "w")
                self.bmv2popen = self.popen(cmdString,
                                            stdout=self.logfd,
                                            stderr=self.logfd)
                self.waitBmv2Start()
                # We want to be notified if BMv2 dies...
                threading.Thread(target=watchDog, args=[self]).start()

            self.doOnosNetcfg(self.controllerIp(controllers))
        except Exception as ex:
            self.killBmv2()
            self.printBmv2Log()
            raise ex

    def grpcTargetArgs(self):
        args = ['--device-id %s' % str(BMV2_DEFAULT_DEVICE_ID)]
        for port, intf in self.intfs.items():
            if not intf.IP():
                args.append('-i %d@%s' % (port, intf.name))
        args.append('--thrift-port %s' % self.thriftPort)
        ntfaddr = 'ipc:///tmp/bmv2-%s-notifications.ipc' % self.name
        args.append('--notifications-addr %s' % ntfaddr)
        if self.elogger:
            nanologaddr = 'ipc:///tmp/bmv2-%s-nanolog.ipc' % self.name
            args.append('--nanolog %s' % nanologaddr)
        if self.debugger:
            dbgaddr = 'ipc:///tmp/bmv2-%s-debug.ipc' % self.name
            args.append('--debugger-addr %s' % dbgaddr)
        args.append('--log-console')
        if self.pktdump:
            args.append('--pcap --dump-packet-data %s' % PKT_BYTES_TO_DUMP)
        args.append('-L%s' % self.loglevel)
        if not self.json:
            args.append('--no-p4')
        else:
            args.append(self.json)
        # gRPC target-specific options
        args.append('--')
        args.append('--cpu-port %s' % self.cpuPort)
        args.append('--grpc-server-addr 0.0.0.0:%s' % self.grpcPort)
        return args

    def waitBmv2Start(self):
        # Wait for switch to open gRPC port, before sending ONOS the netcfg.
        # Include time-out just in case something hangs.
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        endtime = time.time() + SWITCH_START_TIMEOUT
        while True:
            result = sock.connect_ex(('127.0.0.1', self.grpcPort))
            if result == 0:
                # The port is open. Let's go! (Close socket first)
                sock.close()
                break
            # Port is not open yet. If there is time, we wait a bit.
            if endtime > time.time():
                time.sleep(0.2)
            else:
                # Time's up.
                raise Exception("Switch did not start before timeout")

    def printBmv2Log(self):
        if os.path.isfile(self.logfile):
            print "-" * 80
            print "%s log (from %s):" % (self.name, self.logfile)
            with open(self.logfile, 'r') as f:
                lines = f.readlines()
                if len(lines) > BMV2_LOG_LINES:
                    print "..."
                for line in lines[-BMV2_LOG_LINES:]:
                    print line.rstrip()

    @staticmethod
    def controllerIp(controllers):
        try:
            # onos.py
            clist = controllers[0].nodes()
        except AttributeError:
            clist = controllers
        assert len(clist) > 0
        return clist[0].IP()

    def killBmv2(self, log=False):
        if self.bmv2popen is not None:
            self.bmv2popen.kill()
        if self.logfd is not None:
            if log:
                self.logfd.write("*** PROCESS TERMINATED BY MININET ***\n")
            self.logfd.close()

    def cleanupTmpFiles(self):
        self.cmd("rm -f /tmp/bmv2-%s-*" % self.name)

    def stop(self, deleteIntfs=True):
        """Terminate switch."""
        self.stopped = True
        self.killBmv2(log=True)
        Switch.stop(self, deleteIntfs)


# Exports for bin/mn
switches = {'onosbmv2': ONOSBmv2Switch}
hosts = {'onoshost': ONOSHost}