"""Utilities for s3fuse plugin."""
# Copyright 2015 TrilioData Inc.
# All Rights Reserved.

import errno
import fcntl
import os
import socket
import struct
import subprocess

from multiprocessing import Process
from time import sleep

try:
    import ConfigParser
except ImportError:
    import configparser as ConfigParser

from oslo_log import log as logging

LOG = logging.getLogger(__name__)


def run_process(method, progress_tracking_file_path, *args):
    """Run processs."""
    try:
        process = Process(target=method, args=args)
        process.start()
        if process.is_alive():
            sleep(10)
            # update the timestamp so the workloadmgr knows contego
            # is alive and kicking
            os.utime(progress_tracking_file_path, None)
    except Exception as ex:
        raise ex


def get_ip_address(ifname):
    """Get IP address of the interface."""
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    return socket.inet_ntoa(fcntl.ioctl(
        s.fileno(),
        0x8915,  # SIOCGIFADDR
        struct.pack('256s', ifname[:15])
    )[20:24])


def get_lan_ip(config_file):
    """IP address."""
    def get_config_value(cfg, Section, Option, Key=None):
        if cfg.has_option(Section, Option):
            return cfg.get(Section, Option, Key)
        else:
            return None

    cfg = ConfigParser.ConfigParser()
    cfg.read(config_file)
    ip = get_config_value(cfg, 'DEFAULT', 'my_ip')

    if ip is not None:
        return ip
    return socket.gethostname()


def ensure_tree(path):
    """Create a directory (and any ancestor directories required).

    :param path: Directory to create
    """
    try:
        os.makedirs(path)
    except OSError as exc:
        if exc.errno == errno.EEXIST:
            if not os.path.isdir(path):
                raise
        else:
            raise


def touch_file(file_path):
    """Utility to simulate the filesystem "touch" command.

    Args:
        file_path (str): Path to file to be touched.
    """
    # In order to support both local filesystem and Fuse mounts we
    # need to open the file and call os.utime. Opening the file updates
    # the time stamp for Fuse mounts, but os.utime() updates for local/nfs
    # file systems.
    with open(file_path, 'a'):
        os.utime(file_path, None)


def update_progress(progress_tracking_file_path, progress_msg):
    """Update progrsss."""
    LOG.info("update_progress %s: %s" %
             (progress_tracking_file_path, progress_msg))
    try:
        with open(progress_tracking_file_path, 'a') as progress_tracking_file:
            progress_tracking_file.write(progress_msg)
    except Exception:
        sleep(10)
        with open(progress_tracking_file_path, 'a') as progress_tracking_file:
            progress_tracking_file.write(progress_msg)


def get_progress(progress_tracking_file_path):
    """Return the content of progress file."""
    try:
        with open(progress_tracking_file_path, 'r') as progress_tracking_file:
            return progress_tracking_file.readlines()
    except Exception:
        sleep(10)
        with open(progress_tracking_file_path, 'r') as progress_tracking_file:
            return progress_tracking_file.readlines()


def run_cmd(
        cmd,
        stdin=subprocess.PIPE,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        shell=False):
    """Run shell command and return the pointer to the process."""
    process = subprocess.Popen(cmd,
                               stdin=stdin,
                               stdout=stdout,
                               stderr=stderr,
                               shell=False)
    return process


def poll_process(
        process,
        cmd,
        sleep_time=5,
        no_of_count=0,
        progress_file=None):
    """Poll process."""
    try:
        count = 0
        while process.poll() is None:
            if no_of_count != 0 and count > no_of_count:
                break
            sleep(sleep_time)
            count += 1
            if progress_file is not None:
                # update the timestamp so the workloadmgr knows contego
                # is alive and kicking
                touch_file(progress_file)

        process.stdin.close()
        _returncode = process.returncode
        if _returncode:
            LOG.error(('Result was %s' % _returncode))
            LOG.exception("Execution error %(exit_code)d (%(stderr)s). "
                          "cmd %(cmd)s" %
                          {'exit_code': _returncode,
                           'stderr': str(process.stderr.read(), 'utf-8'),
                           'cmd': cmd})
        return _returncode
    except Exception as ex:
        raise ex


def get_cmd_specs(cmd, **kwargs):
    """Get commandspecs."""
    def _key_check(locals, keys):
        for key in keys:
            if locals[key] is None:
                raise Exception(
                    "Required parameter: %s for %s " +
                    "connection can not be None" %
                    (key, locals['cmd']))
    try:
        authorized_key = kwargs.get('authorized_key', None)
        user = kwargs.get('user', None)
        host = kwargs.get('host', None)
        if cmd == 'ssh':
            _key_check(locals(), ['authorized_key', 'user', 'host'])
            cmdspec = [
                'ssh',
                '-o',
                'StrictHostKeyChecking=no',
                '-i',
                authorized_key,
                user + '@' + host]
        elif cmd == 'scp':
            source_path = kwargs.get('source_path', None)
            dest_path = kwargs.get('dest_path', None)
            _key_check(locals(), ['authorized_key', 'user',
                                  'host', 'source_path', 'dest_path'])
            cmdspec = [
                'scp',
                '-o',
                'StrictHostKeyChecking=no',
                '-i',
                authorized_key,
                '-r',
                user +
                '@' +
                host +
                ':' +
                source_path +
                "/*",
                dest_path]
        return cmdspec
    except Exception as ex:
        raise ex


class get_dummy_object(object):
    """Return python object from a dict."""

    def __init__(self, **kwargs):
        """Constructor."""
        self.__dict__.update(kwargs)