#! /usr/bin/python

"""
Status check for lava-coordinator
"""

#  Copyright 2015 Linaro Limited
#  Author Neil Williams <neil.williams@linaro.org>
#
#  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 os
import sys
import socket
import json
import time
import errno
from socket import gethostname

HOST = 'localhost'       # The coordinator hostname default


def read_settings(filename):
    """
    NodeDispatchers need to use the same port and blocksize as the Coordinator,
    so read the same conffile.
    """
    settings = {"port": 3079,
                "coordinator_hostname": "localhost",
                "blocksize": 4 * 1024}
    if not os.path.exists(filename):
        # unknown as there is no usable configuration
        print "No lava-coordinator configuration file found!"
        sys.exit(3)
    with open(filename) as stream:
        jobdata = stream.read()
        json_default = json.loads(jobdata)
    if "port" in json_default:
        settings['port'] = json_default['port']
    if "blocksize" in json_default:
        settings['blocksize'] = json_default["blocksize"]
    if "coordinator_hostname" in json_default:
        settings['coordinator_hostname'] = json_default['coordinator_hostname']
    return settings

# pylint: disable=too-many-branches,too-many-statements,too-many-locals


def lava_poll(port, host, name, request):
    """
    Modified poll equivalent
    """
    errors = []
    warnings = []
    while True:
        sock = None
        count = 0
        while count < 5:
            try:
                sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
                sock.connect((host, port))
                break
            except socket.error as exc:
                if exc.errno == errno.ECONNRESET:
                    warnings.append("connection reset by peer: bug 1020")
                errors.append("not connected, sleeping for 1 second")
                time.sleep(1)
                sock = None
                count += 1
                warnings.append("retrying port %s on %s" % (port, host))
        if count >= 5:
            break
        msg = {
            "group_name": "group1",
            "group_size": 2,
            "hostname": gethostname(),
            "role": "client",
            "client_name": name,
            "request": request,
            "message": None
        }
        msg_str = json.dumps(msg)
        msg_len = len(msg_str)
        try:
            # send the length as 32bit hexadecimal
            ret_bytes = sock.send("%08X" % msg_len)
            if ret_bytes == 0:
                warnings.append(
                    "zero bytes sent for length - connection closed?")
                continue
            ret_bytes = sock.send(msg_str)
            if ret_bytes == 0:
                warnings.append(
                    "zero bytes sent for message - connection closed?")
                continue
        except socket.error as exc:
            errors.append("socket error '%d' on send" % exc.message)
            sock.close()
            continue
        try:
            data = str(sock.recv(8))  # 32bit limit
            data = sock.recv(1024)
        except socket.error as exc:
            errors.append("Exception on receive: %s" % exc)
            continue
        try:
            json_data = json.loads(data)
        except ValueError:
            warnings.append("data not JSON %s" % data)
            break
        if 'response' not in json_data:
            errors.append("no response field in data")
            break
        if json_data['response'] != 'wait':
            break
        else:
            break
        sock.shutdown(socket.SHUT_RDWR)
        sock.close()
    ret = 0
    if errors:
        ret = 2
    elif warnings:
        ret = 1
    if errors or warnings:
        print "E:%s W:%s" % (errors, warnings)
        return ret
    else:
        return ret


def main():
    """ Run a simple check on the API
    """
    port = 3079  # The same port as used by the server
    host = 'localhost'
    conffile = "/etc/lava-coordinator/lava-coordinator.conf"
    settings = read_settings(conffile)
    port = settings['port']
    host = settings['coordinator_hostname']
    ret1 = lava_poll(port, host, 'status', 'group_data')
    ret2 = lava_poll(port, host, 'status', 'clear_group')
    if not ret1 and not ret2:
        print "status check complete. No errors"
    if ret1 and ret1 >= ret2:
        sys.exit(ret1)
    if ret2:
        sys.exit(ret2)


if __name__ == '__main__':
    main()