#!/usr/bin/env python2

###############################################################################
# Copyright 2019 UChicago Argonne, LLC.
# (c.f. AUTHORS, LICENSE)
#
# This file is part of the NRM project.
# For more info, see https://xgitlab.cels.anl.gov/argo/nrm
#
# SPDX-License-Identifier: BSD-3-Clause
###############################################################################

from __future__ import print_function
import argparse
import logging
import signal
import os
import nrm.messaging
import uuid
import sys
import time

logger = logging.getLogger('nrm')


class CommandLineInterface(object):

    """Implements a command line interface to the NRM."""

    def __init__(self):
        pass

    def do_signal(self, uuid, signum, stackframe):
        if uuid:
            logger.info("received signal %d, killing the application..",
                        signum)
            self.client.send(
                    "Kill",
                    container_uuid=uuid)
            logger.info("killed the application, exiting.")
        else:
            logger.info("received signal %d, exiting", signum)
        exit(130)

    def setup(self):
        # upstream RPC port
        upstream_client_port = 3456
        upstream_client_param = "tcp://localhost:%d" % (upstream_client_port)
        self.client = nrm.messaging.UpstreamRPCClient(upstream_client_param)

        # take care of signals
        def handler(signum, frame):
            self.do_signal(None, signum, frame)
        signal.signal(signal.SIGINT, handler)
        signal.signal(signal.SIGTERM, handler)

        self.client.connect()

    def do_listen(self, argv):
        """ Connect to the NRM and listen for pub/sub messages."""
        upstream_pub_port = 2345
        upstream_pub_param = "tcp://localhost:%d" % (upstream_pub_port)
        self.pub_client = nrm.messaging.UpstreamPubClient(upstream_pub_param)
        self.pub_client.connect()

        while(True):
            msg = self.pub_client.recv()
            logger.debug("pub message: %s", msg)

            def print_if_filter():
                if argv.filter:
                    if argv.filter == msg.tag:
                        if (msg.tag == "performance" or
                           msg.tag == "progress"):
                            print("%s, %s, %s" % (msg.tag, time.time(),
                                                  msg.payload))
                        if msg.tag == "power":
                            print("%s, %s, %s" % (msg.tag, time.time(),
                                                  msg.total))
                        if msg.tag == "exit":
                            print("%s, %s, %s" % (msg.tag, time.time(),
                                                  msg.profile_data))
                else:
                    print("%s, %s" % (msg.tag, time.time()))
                sys.stdout.flush()
            print_if_filter()

    def do_run(self, argv):
        """ Connect to the NRM and ask to spawn a container and run a command
        in it.

        The NRM should reply for container info."""

        # build the command as a JSON dict containing enough info. We add to
        # the command a container uuid as a way to make sure that we can make
        # the command idempotent.
        environ = os.environ
        # environ = []
        container_uuid = argv.ucontainername or str(uuid.uuid4())

        # simple check + error msg + non-zero return code
        def sanitize_manifest(path):
            if os.path.isfile(path):
                return(os.path.abspath(path))
            else:
                logger.error("Manifest file not found: %s", path)
                sys.exit(1)

        # command fsm
        state = 'init'
        outeof = False
        erreof = False
        exitmsg = None
        self.client.send(
                tag="run",
                manifest=sanitize_manifest(argv.manifest),
                path=argv.command,
                args=argv.args,
                environ=dict(environ),
                container_uuid=container_uuid)

        # the first message tells us if we started a container or not
        msg = self.client.recv()
        assert msg.tag == 'start'

        def handler(signum, frame):
            self.do_signal(msg.container_uuid, signum, frame)
        signal.signal(signal.SIGINT, handler)

        state = 'started'
        while(True):
            msg = self.client.recv()
            assert msg.tag in ['stdout', 'stderr', 'exit']

            if msg.tag == 'stdout':
                logger.debug("container msg: %r", msg)
                if msg.payload == 'eof':
                    outeof = True
                else:
                    print(msg.payload, file=sys.stdout)
                    sys.stdout.flush()
            elif msg.tag == 'stderr':
                logger.debug("container msg: %r", msg)
                if msg.payload == 'eof':
                    erreof = True
                else:
                    print(msg.payload, file=sys.stderr)
                    sys.stderr.flush()
            elif msg.tag == 'exit':
                state = 'exiting'
                exitmsg = msg
            else:
                logger.error("unexpected message: %r", msg)
            if outeof and erreof and state == 'exiting':
                state = 'exit'
                istatus = int(exitmsg.status)
                logger.debug("command ended with istatus %r.", exitmsg)
                if os.WIFSIGNALED(istatus):
                    logger.error("command ended due to signal %s" %
                                 str(os.WTERMSIG(istatus)))
                    sys.exit(1)
                elif os.WIFEXITED(istatus):
                    s = int(os.WTERMSIG(istatus))
                    if s > 0:
                        logger.error("command ended with exit code %s" %
                                     str(s))
                    sys.exit(s)
                else:
                    logger.error(
                            "non-compliant exit code received from"
                            "daemon: %s" % str(exitmsg.status))
                    sys.exit(1)
                break

    def do_list(self, argv):
        """Connect to the NRM and ask to list the containers present on the
        system.

        The NRM should respond to us with one message listing all
        containers."""

        self.client.send(tag="list")
        msg = self.client.recv()
        assert msg.tag == 'list'
        logger.info("list response: %r", msg)

    def do_kill(self, argv):
        """Connect to the NRM and ask to kill a container by uuid.

        The NRM should respond to us with a message containing the exit status
        of the top process of the container."""

        self.client.send(tag="kill", container_uuid=argv.uuid)
        msg = self.client.recv()
        assert msg.tag == 'exit'
        logger.info("container exit: %r", msg)

    def do_setpower(self, argv):
        """ Connect to the NRM and ask to change the power limit.

        The NRM should answer with an acknowledgment."""

        # build the command as a JSON dict giving enough info. This is an
        # idempotent command, so we will repeat the command if we don't get a
        # timely answer.
        # TODO: check that the level makes a little bit of sense in the first
        # place
        self.client.send(tag="setPower", limit=str(argv.limit))
        msg = self.client.recv()
        assert msg.tag == 'getPower'
        logger.info("command received by the daemon: %r", msg)

    def main(self):
        parser = argparse.ArgumentParser()
        parser.add_argument("-v", "--verbose",
                            help="verbose logging information",
                            action='store_true')
        subparsers = parser.add_subparsers()

        # run container
        parser_run = subparsers.add_parser("run")
        parser_run.add_argument("manifest", help="manifest file to apply")
        parser_run.add_argument("command", help="command to execute")
        parser_run.add_argument("args", help="command arguments",
                                nargs=argparse.REMAINDER)
        parser_run.add_argument("-u", "--ucontainername", help="""user-specified
                                name for container used to attach proceses""",
                                nargs='?', const=None, default=None)
        parser_run.set_defaults(func=self.do_run)

        # kill container
        parser_kill = subparsers.add_parser("kill")
        parser_kill.add_argument("uuid", help="uuid of the container")
        parser_kill.set_defaults(func=self.do_kill)

        # list containers
        parser_list = subparsers.add_parser("list")
        parser_list.set_defaults(func=self.do_list)

        # listen
        parser_listen = subparsers.add_parser("listen")
        parser_listen.add_argument("-u", "--uuid",
                                   help="container uuid to listen for",
                                   default=None)
        parser_listen.add_argument("-f", "--filter",
                                   help="type of message to filter and"
                                        " prettyprint, in {power,performance}",
                                   default=None)
        parser_listen.set_defaults(func=self.do_listen)

        # setpowerlimit
        parser_setpower = subparsers.add_parser("setpower")
        parser_setpower.add_argument("-f", "--follow",
                                     help="listen for power changes",
                                     action='store_true')
        parser_setpower.add_argument("limit",
                                     help="set new power limit",
                                     type=float)
        parser_setpower.set_defaults(func=self.do_setpower)

        args = parser.parse_args()
        if args.verbose:
            logger.setLevel(logging.DEBUG)

        self.setup()
        args.func(args)


if __name__ == "__main__":
    logging.basicConfig(level=logging.INFO)
    cli = CommandLineInterface()
    cli.main()