# By: Riasat Ullah
# This file contains Nagios integration related views.

from data_syncers import syncer_services, syncer_task_instances
from dbqueries import db_integrations
from exceptions.user_exceptions import InvalidRequest
from integrations import nagios
from modules.router import Router
from objects.events import AcknowledgeEvent, ResolveEvent
from objects.task_payload import TaskPayload
from rest_framework.decorators import api_view
from rest_framework.response import Response
from translators import label_translator as _lt
from utils import constants, errors, info, key_manager, logging, times, var_names
from utils.db_connection import CACHE_CLIENT, CONN_POOL
from validations import request_validator
import configuration


@api_view(['POST'])
def process_incoming_webhook(request, integration_key, conn=None, cache=None):
    '''
    Processes the incoming webhook from Nagios.
    :param request: Http request
    :param integration_key: integration key passed in the url
    :param conn: db connection
    :param cache: cache client
    :return: Http response
    '''
    if request.method == 'POST':
        lang = request_validator.get_user_language(request)
        try:
            conn = CONN_POOL.get_db_conn() if conn is None else conn
            cache = CACHE_CLIENT if cache is None else cache

            unmasked_integ_key = key_manager.unmask_reference_key(integration_key)

            ng_notification_type = request.data[nagios.var_notification_type]
            ng_entity_type = request.data[nagios.var_entity_type]

            ng_host_name = request.data[nagios.var_host_name]
            ng_host_output = request.data[nagios.var_host_output]
            ng_host_perf_data = request.data[nagios.var_host_perf_data]
            ng_host_state = request.data[nagios.var_host_state]
            ng_host_state_id = request.data[nagios.var_host_state_id]

            ng_service_name = request.data[nagios.var_service_display_name]
            ng_service_output = request.data[nagios.var_service_output]
            ng_service_perf_data = request.data[nagios.var_service_perf_data]
            ng_service_state = request.data[nagios.var_service_state]
            ng_service_state_id = request.data[nagios.var_service_state_id]

            urgency = constants.critical_urgency

            if ng_entity_type == nagios.host_entity:
                alert_title = ' - '.join([ng_host_name, ng_host_state])
                alert_body = ng_host_output + '\n\n' + ng_host_perf_data

            elif ng_entity_type == nagios.service_entity:
                alert_title = ' - '.join([ng_host_name, ng_service_name, ng_service_state])
                alert_body = ng_service_output + '\n\n' + ng_service_perf_data

                if ng_service_state_id == nagios.service_warning_state_id:
                    urgency = constants.medium_urgency
            else:
                msg = 'Alert received from Nagios with entity type - ' + ng_entity_type + '. No action taken.'
                logging.info(msg)
                return Response(msg)

            current_time = times.get_current_timestamp()
            integ_id, serv_id, org_id = syncer_services.get_integration_key_details(
                conn, cache, current_time, unmasked_integ_key)

            integ_insts = db_integrations.get_integration_open_instances_trigger_info(
                conn, current_time, org_id, serv_id, integ_id)

            match_count = 0
            for inst_id, task_id, trig_info in integ_insts:
                if trig_info is not None:
                    source_payload = trig_info[var_names.source_payload]

                    # Update the status of the instance created if this is a recovery alert.
                    if source_payload[nagios.var_host_name] == ng_host_name and\
                            source_payload[nagios.var_service_display_name] == ng_service_name:

                        match_count += 1

                        # Group the alert if one already exists
                        if ng_notification_type == nagios.problem_notification:
                            payload = TaskPayload(
                                current_time, org_id, current_time.date(), alert_title, configuration.standard_timezone,
                                current_time.time(), text_msg=alert_body, urgency_level=urgency,
                                trigger_method=constants.integrations_api, trigger_info=request.data,
                                integration_id=integ_id, integration_key=integration_key, service_id=serv_id,
                                instantiate=False, alert=False, related_task_id=task_id,
                                task_status=constants.grouped_state
                            )
                            Router(conn, cache, payload).start()
                        elif ng_notification_type == nagios.recovery_notification:
                            event = ResolveEvent(inst_id, current_time, constants.integrations_api)
                            syncer_task_instances.resolve(conn, cache, event, org_id, is_sys_action=True)
                        elif ng_notification_type == nagios.acknowledgement_notification:
                            event = AcknowledgeEvent(inst_id, current_time, constants.integrations_api, None)
                            syncer_task_instances.acknowledge(conn, cache, event, org_id, is_sys_action=True)

            # Create a new task if this is a new alert.
            if match_count == 0:
                payload = TaskPayload(
                    current_time, org_id, current_time.date(), alert_title, configuration.standard_timezone,
                    current_time.time(), text_msg=alert_body, urgency_level=urgency,
                    trigger_method=constants.integrations_api, trigger_info=request.data, integration_id=integ_id,
                    integration_key=integration_key, service_id=serv_id
                )
                Router(conn, cache, payload).start()

            return Response(info.msg_internal_success)
        except InvalidRequest as e:
            logging.exception(str(e))
            return Response(_lt.get_label(errors.err_invalid_request, lang), status=400)
        except Exception as e:
            logging.exception(str(e))
            return Response(_lt.get_label(errors.err_system_error, lang), status=500)
        finally:
            CONN_POOL.put_db_conn(conn)