# (Copyright) 2015 ABF OSIELL <http://osiell.com>
# (Copyright) 2018 Creu Blanca
#  License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).

import psutil
import os
import shlex
import subprocess
import logging

from odoo import api, fields, models, _
from odoo.tools import config
from odoo.exceptions import UserError


def is_exe(fpath):
    return os.path.isfile(fpath) and os.access(fpath, os.X_OK)


_logger = logging.getLogger(__name__)

SEND_NSCA_BIN = '/usr/sbin/send_nsca'


class NscaServer(models.Model):
    _name = "nsca.server"
    _description = u"NSCA Server"

    name = fields.Char(u"Hostname", required=True)
    port = fields.Integer(u"Port", default=5667, required=True)
    password = fields.Char(u"Password")
    encryption_method = fields.Selection(
        selection='_selection_encryption_method',
        string=u"Encryption method", default='1', required=True)
    config_dir_path = fields.Char(
        u"Configuration directory",
        compute='_compute_config_dir_path')
    config_file_path = fields.Char(
        u"Configuration file",
        compute='_compute_config_file_path')
    node_hostname = fields.Char(
        u"Hostname of this node", required=True,
        help=u"This is the hostname of the current Odoo node declared in the "
             u"monitoring server.")
    check_ids = fields.One2many(
        'nsca.check', 'server_id', string=u"Checks")
    check_count = fields.Integer(
        compute='_compute_check_count'
    )

    @api.depends('check_ids')
    def _compute_check_count(self):
        for r in self:
            r.check_count = len(r.check_ids)

    def _selection_encryption_method(self):
        return [
            ('0', u"0 - None (Do NOT use this option)"),
            ('1', u"1 - Simple XOR"),
            ('2', u"2 - DES"),
            ('3', u"3 - 3DES (Triple DES)"),
            ('4', u"4 - CAST-128"),
            ('5', u"5 - CAST-256"),
            ('6', u"6 - xTEA"),
            ('7', u"7 - 3WAY"),
            ('8', u"8 - BLOWFISH"),
            ('9', u"9 - TWOFISH"),
            ('10', u"10 - LOKI97"),
            ('11', u"11 - RC2"),
            ('12', u"12 - ARCFOUR"),
            ('14', u"14 - RIJNDAEL-128"),
            ('15', u"15 - RIJNDAEL-192"),
            ('16', u"16 - RIJNDAEL-256"),
            ('19', u"19 - WAKE"),
            ('20', u"20 - SERPENT"),
            ('22', u"22 - ENIGMA (Unix crypt)"),
            ('23', u"23 - GOST"),
            ('24', u"24 - SAFER64"),
            ('25', u"25 - SAFER128"),
            ('26', u"26 - SAFER+"),
        ]

    @api.multi
    def _compute_config_dir_path(self):
        for server in self:
            data_dir_path = config.get('data_dir')
            dir_path = os.path.join(
                data_dir_path, 'nsca_client', self.env.cr.dbname)
            server.config_dir_path = dir_path

    @api.multi
    def _compute_config_file_path(self):
        for server in self:
            file_name = 'send_nsca_%s.cfg' % server.id
            full_path = os.path.join(server.config_dir_path, file_name)
            server.config_file_path = full_path

    @api.multi
    def write_config_file(self):
        for server in self:
            try:
                os.makedirs(server.config_dir_path)
            except OSError as exception:
                if exception.errno != os.errno.EEXIST:
                    raise
            with open(server.config_file_path, 'w') as config_file:
                if server.password:
                    config_file.write('password=%s\n' % server.password)
                config_file.write(
                    'encryption_method=%s\n' % server.encryption_method)
        return True

    @api.multi
    def write(self, vals):
        res = super(NscaServer, self).write(vals)
        self.write_config_file()
        return res

    @api.model
    def create(self, vals):
        res = super(NscaServer, self).create(vals)
        res.write_config_file()
        return res

    @api.model
    def current_status(self):
        ram = 0
        cpu = 0
        if psutil:
            process = psutil.Process(os.getpid())
            # psutil changed its api through versions
            processes = [process]
            if config.get(
                    'workers') and process.parent:  # pragma: no cover
                if hasattr(process.parent, '__call__'):
                    process = process.parent()
                else:
                    process = process.parent
                if hasattr(process, 'children'):
                    processes += process.children(True)
                elif hasattr(process, 'get_children'):
                    processes += process.get_children(True)
            for process in processes:
                if hasattr(process, 'memory_percent'):
                    ram += process.memory_percent()
                if hasattr(process, 'cpu_percent'):
                    cpu += process.cpu_percent(interval=1)
        user_count = 0
        if 'bus.presence' in self.env.registry:
            user_count = self.env['bus.presence'].search_count([
                ('status', '=', 'online'),
            ])
        performance = {
            'cpu': {
                'value': cpu,
            },
            'ram': {
                'value': ram,
            },
            'user_count': {
                'value': user_count,
            },
        }
        return 0, u"OK", performance

    @api.multi
    def _prepare_command(self):
        """Prepare the shell command used to send the check result
        to the NSCA daemon.
        """
        cmd = u"/usr/sbin/send_nsca -H %s -p %s -c %s" % (
            self.name,
            self.port,
            self.config_file_path)
        return shlex.split(cmd)

    @api.model
    def _run_command(self, cmd, check_result):
        """Send the check result through the '/usr/sbin/send_nsca' command."""
        try:
            proc = subprocess.Popen(
                cmd,
                stdout=subprocess.PIPE,
                stdin=subprocess.PIPE,
                stderr=subprocess.STDOUT)
            stdout = proc.communicate(
                input=check_result)[0]
            _logger.debug("%s: %s", check_result, stdout.strip())
        except Exception as exc:
            _logger.error(exc)

    def _check_send_nsca_command(self):
        """Check if the NSCA client is installed."""
        if not is_exe(SEND_NSCA_BIN):
            raise UserError(
                _(u"Command '%s' not found. Please install the NSCA client.\n"
                  u"On Debian/Ubuntu: apt-get install nsca-client") % (
                    SEND_NSCA_BIN))

    def _format_check_result(self, service, rc, message):
        """Format the check result with tabulations as delimiter."""
        message = message.replace('\t', ' ')
        hostname = self.node_hostname
        check_result = u"%s\t%s\t%s\t%s" % (
            hostname, service, rc, message)
        return check_result.encode('utf-8')

    def _send_nsca(self, service, rc, message, performance):
        """Send the result of the check to the NSCA daemon."""
        msg = message
        if len(performance) > 0:
            msg += '| ' + ''.join(
                ["%s=%s%s;%s;%s;%s;%s" % (
                    key,
                    performance[key]['value'],
                    performance[key].get('uom', ''),
                    performance[key].get('warn', ''),
                    performance[key].get('crit', ''),
                    performance[key].get('min', ''),
                    performance[key].get('max', ''),
                ) for key in sorted(performance)])
        check_result = self._format_check_result(
            service, rc, msg)
        cmd = self._prepare_command()
        self._run_command(cmd, check_result)

    @api.multi
    def show_checks(self):
        self.ensure_one()
        action = self.env.ref('nsca_client.action_nsca_check_tree')
        result = action.read()[0]
        context = {'default_server_id': self.id}
        result['context'] = context
        result['domain'] = [('server_id', '=', self.id)]
        if len(self.check_ids) == 1:
            res = self.env.ref('nsca_client.view_nsca_check_form', False)
            result['views'] = [(res and res.id or False, 'form')]
            result['res_id'] = self.check_ids.id
        return result