# -*- Mode:python; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
#
# Copyright (C) 2015-2019, The University of Memphis,
#                          Arizona Board of Regents,
#                          Regents of the University of California.
#
# This file is part of Mini-NDN.
# See AUTHORS.md for a complete list of Mini-NDN authors and contributors.
#
# Mini-NDN 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 3 of the License, or
# (at your option) any later version.
#
# Mini-NDN 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 Mini-NDN, e.g., in COPYING.md file.
# If not, see <http://www.gnu.org/licenses/>.
import json
import os

from minindn.apps.application import Application
from minindn.util import copyExistentFile
from minindn.minindn import Minindn

class Nfd(Application):
    def __init__(self, node, logLevel='NONE', csSize=65536,
                 csPolicy='lru', csUnsolicitedPolicy='drop-all'):
        Application.__init__(self, node)
        self.logLevel = node.params['params'].get('nfd-log-level', logLevel)

        self.confFile = '{}/nfd.conf'.format(self.homeDir)
        self.logFile = 'nfd.log'
        self.ndnFolder = '{}/.ndn'.format(self.homeDir)
        self.clientConf = '{}/client.conf'.format(self.ndnFolder)
        # Copy nfd.conf file from /usr/local/etc/ndn or /etc/ndn to the node's home directory
        # Use nfd.conf as default configuration for NFD, else use the sample
        possibleConfPaths = ['/usr/local/etc/ndn/nfd.conf', '/usr/local/etc/ndn/nfd.conf.sample',
                             '/etc/ndn/nfd.conf', '/etc/ndn/nfd.conf.sample']
        copyExistentFile(node, possibleConfPaths, self.confFile)

        # Using infoconv, we convert the local nfd.conf file to JSON and parse it into an object
        conf_file = json.loads(node.cmd("infoconv info2json < {}".format(self.confFile)))

        # Set log level
        conf_file["log"]["default_level"] = self.logLevel

        # Set socket file name and path
        # Retrieve the default socket path from the conf file; this avoids issues from #5316
        default_socket_path = os.path.dirname(conf_file["face_system"]["unix"]["path"])
        self.sockFile = '{}/{}.sock'.format(default_socket_path, node.name)
        # Set socket path in conf file to new socket
        conf_file["face_system"]["unix"]["path"] = self.sockFile
        # Create client configuration for host to ensure socket path is consistent
        # Suppress error if working directory exists from prior run
        os.makedirs(self.ndnFolder, exist_ok=True)
        # This will overwrite any existing client.conf files, which should not be an issue
        with open(self.clientConf, "w") as client_conf_file:
            client_conf_file.write("transport=unix://{}\n".format(self.sockFile))

        # Set CS parameters
        conf_file["tables"]["cs_max_packets"] = csSize
        conf_file["tables"]["cs_policy"] = csPolicy
        conf_file["tables"]["cs_unsolicited_policy"] = csUnsolicitedPolicy

        # To avoid complicated Bash piping, we write the JSON to a temporary file
        with open("{}/temp_nfd_conf.json".format(self.homeDir), "w") as temp_file:
            json.dump(conf_file, temp_file)

        # Convert our modified intermediate file and write to the new conf file
        node.cmd("infoconv json2info < {}/temp_nfd_conf.json > {}".format(self.homeDir, self.confFile))

        # Remove the intermediate JSON file
        os.remove("{}/temp_nfd_conf.json".format(self.homeDir))

        if not Minindn.ndnSecurityDisabled:
            # Generate key and install cert for /localhost/operator to be used by NFD
            node.cmd('ndnsec-key-gen /localhost/operator | ndnsec-cert-install -')

    def start(self):
        Application.start(self, 'nfd --config {}'.format(self.confFile), logfile=self.logFile)
        Minindn.sleep(0.5)