# -*- coding: utf-8 -*-

# Copyright 2010 - 2017 RhodeCode GmbH and the AppEnlight project authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import sqlalchemy as sa
import logging

from datetime import datetime
from appenlight.models import Base, get_db_session
from appenlight.models.services.report_stat import ReportStatService
from appenlight.models.integrations import IntegrationException
from pyramid.threadlocal import get_current_request
from sqlalchemy.dialects.postgresql import JSON
from ziggurat_foundations.models.base import BaseModel
from ziggurat_foundations.models.services.resource import ResourceService

log = logging.getLogger(__name__)


class Event(Base, BaseModel):
    __tablename__ = "events"

    types = {
        "error_report_alert": 1,
        "slow_report_alert": 3,
        "comment": 5,
        "assignment": 6,
        "uptime_alert": 7,
        "chart_alert": 9,
    }

    statuses = {"active": 1, "closed": 0}

    id = sa.Column(sa.Integer, primary_key=True)
    start_date = sa.Column(sa.DateTime, default=datetime.utcnow)
    end_date = sa.Column(sa.DateTime)
    status = sa.Column(sa.Integer, default=1)
    event_type = sa.Column(sa.Integer, default=1)
    origin_user_id = sa.Column(sa.Integer(), sa.ForeignKey("users.id"), nullable=True)
    target_user_id = sa.Column(sa.Integer(), sa.ForeignKey("users.id"), nullable=True)
    resource_id = sa.Column(
        sa.Integer(), sa.ForeignKey("resources.resource_id"), nullable=True
    )
    target_id = sa.Column(sa.Integer)
    target_uuid = sa.Column(sa.Unicode(40))
    text = sa.Column(sa.UnicodeText())
    values = sa.Column(JSON(), nullable=False, default=None)

    def __repr__(self):
        return "<Event %s, app:%s, %s>" % (
            self.unified_alert_name(),
            self.resource_id,
            self.unified_alert_action(),
        )

    @property
    def reverse_types(self):
        return dict([(v, k) for k, v in self.types.items()])

    def unified_alert_name(self):
        return self.reverse_types[self.event_type]

    def unified_alert_action(self):
        event_name = self.reverse_types[self.event_type]
        if self.status == Event.statuses["closed"]:
            return "CLOSE"
        if self.status != Event.statuses["closed"]:
            return "OPEN"
        return event_name

    def send_alerts(self, request=None, resource=None, db_session=None):
        """" Sends alerts to applicable channels """
        db_session = get_db_session(db_session)
        db_session.flush()
        if not resource:
            resource = ResourceService.by_resource_id(self.resource_id)
        if not request:
            request = get_current_request()
        if not resource:
            return
        users = set([p.user for p in ResourceService.users_for_perm(resource, "view")])
        for user in users:
            for channel in user.alert_channels:
                matches_resource = not channel.resources or resource in [
                    r.resource_id for r in channel.resources
                ]
                if (
                    not channel.channel_validated
                    or not channel.send_alerts
                    or not matches_resource
                ):
                    continue
                else:
                    try:
                        channel.notify_alert(
                            resource=resource, event=self, user=user, request=request
                        )
                    except IntegrationException as e:
                        log.warning("%s" % e)

    def validate_or_close(self, since_when, db_session=None):
        """ Checks if alerts should stay open or it's time to close them.
            Generates close alert event if alerts get closed """
        event_types = [
            Event.types["error_report_alert"],
            Event.types["slow_report_alert"],
        ]
        app = ResourceService.by_resource_id(self.resource_id)
        # if app was deleted close instantly
        if not app:
            self.close()
            return

        if self.event_type in event_types:
            total = ReportStatService.count_by_type(
                self.event_type, self.resource_id, since_when
            )
            if Event.types["error_report_alert"] == self.event_type:
                threshold = app.error_report_threshold
            if Event.types["slow_report_alert"] == self.event_type:
                threshold = app.slow_report_threshold

            if total < threshold:
                self.close()

    def close(self, db_session=None):
        """
        Closes an event and sends notification to affected users
        """
        self.end_date = datetime.utcnow()
        self.status = Event.statuses["closed"]
        log.warning("ALERT: CLOSE: %s" % self)
        self.send_alerts()

    def text_representation(self):
        alert_type = self.unified_alert_name()
        text = ""
        if "slow_report" in alert_type:
            text += "Slow report alert"
        if "error_report" in alert_type:
            text += "Exception report alert"
        if "uptime_alert" in alert_type:
            text += "Uptime alert"
        if "chart_alert" in alert_type:
            text += "Metrics value alert"

        alert_action = self.unified_alert_action()
        if alert_action == "OPEN":
            text += " got opened."
        if alert_action == "CLOSE":
            text += " got closed."
        return text

    def get_dict(self, request=None):
        dict_data = super(Event, self).get_dict()
        dict_data["text"] = self.text_representation()
        dict_data["resource_name"] = self.resource.resource_name
        return dict_data