#!/usr/bin/env python

# Copyright 2020-present Open Networking Foundation
#
# 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 sys
import os
import json
import enum
import time
import datetime
import requests
from pytz import timezone
from datetime import date
from collections import namedtuple
from rancher import Client as RancherClient
from slack import WebClient as SlackClient
from slack.errors import SlackApiError


class Status(enum.Enum):
    healthy = 1
    unhealthy = 2
    error = 3  # check failed
    unavailable = 4  # check not automated


CONF = json.loads(
    open(os.getenv('CONFIG_FILE', "./config.json")).read(),
    object_hook=lambda d: namedtuple('X', d.keys())(*d.values())
)

EMOJI = {
    Status.healthy: CONF.slack.emoji.healthy,
    Status.unhealthy: CONF.slack.emoji.unhealthy,
    Status.error: CONF.slack.emoji.error,
    Status.unavailable: CONF.slack.emoji.unavailable
}

HEALTHY_STATES = ["active", "connected"]

REPORT_HEADER = '''\
*******************************************************************************
'''
REPORT_HEADER += CONF.slack.report_header
REPORT_HEADER += date.today().strftime(" %d/%m/%Y\n")
REPORT_HEADER += EMOJI[Status.healthy] + " Healthy   "
REPORT_HEADER += EMOJI[Status.unhealthy] + " Unhealthy   "
REPORT_HEADER += EMOJI[Status.error] + " Checks failed   "
REPORT_HEADER += EMOJI[Status.unavailable] + " Checks not automated\n"
REPORT_HEADER += '''\
*******************************************************************************
'''

MSG_PREFIX_BLANK = "      :warning-sign: "
MSG_PREFIX_ERROR = "       [ERROR]: "


def _get_status(state_string):
    if state_string in HEALTHY_STATES:
        return Status.healthy
    else:
        return Status.unhealthy


def _get_report(name, status, msg=[]):
    report = []
    if not status:
        return []
    report += [EMOJI[status] + " " + name]
    msg_prefix = MSG_PREFIX_ERROR if status == Status.error else MSG_PREFIX_BLANK
    for m in msg:
        report += [msg_prefix + m]
    return report


def _run_adb_command(adb_path, ssh_client, command):
    final_command = adb_path + " shell " + command
    stdin, stdout, stderr = ssh_client.exec_command(final_command)
    error = stderr.read().decode("ascii").strip("\n")
    if "Error" in error:
        msg = "failed to run command: " + final_command
        return False, msg
    output = stdout.read().decode("ascii").strip("\n")
    time.sleep(2)
    return True, output


def get_project_status(cluster, project):
    status = ""
    msg = []

    projects = cluster.projects(name=project.name)
    check_type = project.check_type
    unhealthy = []
    for p in projects:
        targets = p.apps() if check_type == "app" else p.workloads()
        for target in targets.data:
            status = _get_status(target.state)
            if status == Status.unhealthy:
                warning = check_type + " " + target.name + " is unhealthy"
                unhealthy += [warning]
    if status == Status.unhealthy:
        msg += unhealthy

    return status, msg


def get_aether_network_status(edge_name):
    status = ""
    msg = []

    try:
        req_url = CONF.edge_monitoring.api_url + "/" + edge_name
        response = requests.get(req_url)

        if response.status_code == 404:
            return Status.unavailable, []
        response.raise_for_status()
    except Exception as e:
        return Status.error, str(e)

    json_resp = json.loads(response.text)['edge']

    last_update = datetime.datetime.fromtimestamp(json_resp['last_update'])
    time_diff = datetime.datetime.now() - last_update
    time_diff_mins = int(round(time_diff.total_seconds() / 60))
    if time_diff_mins > 10:
        msg += ['status report not received for ' + str(time_diff_mins) + 'min']
        return Status.error, msg

    status = Status.healthy

    cp_status = _get_status(json_resp['status']['control_plane'])
    if cp_status is not Status.healthy:
        status = Status.unhealthy
        msg += ["control plane is not healthy"]

    up_status = _get_status(json_resp['status']['user_plane'])
    if up_status is not Status.healthy:
        status = Status.unhealthy
        msg += ["user plane is not healthy"]

    return status, msg


def get_k8s_status(cluster):
    status = ""
    msg = []

    status = _get_status(cluster.state)
    if cluster.state == "unavailable" or status is Status.unhealthy:
        msg += [cluster.transitioningMessage]
        return Status.error, msg

    for component in cluster.componentStatuses:
        for condition in component.conditions:
            if condition.status != "True":
                msg += [component.name + " is unhealthy"]
    for node in cluster.nodes():
        if _get_status(node.state) != Status.healthy:
            msg += [node.hostname + " is unhealthy"]

    return status, msg


def get_cluster_health_report(cluster, edge=False):
    status = ""
    msg = []
    report = ["*[" + cluster.name + "]*"]

    # Check K8S API health
    k8s_status, msg = get_k8s_status(cluster)
    report += _get_report("Kubernetes", k8s_status, msg)

    # Check managed project health
    for project in CONF.managed_projects:
        status = ""
        msg = []
        if k8s_status == Status.healthy:
            status, msg = get_project_status(cluster, project)
        else:
            status = Status.error
        report += _get_report(project.display, status, msg)

    # Check Aether network health for Edges
    # TODO: separate report for control plane and user plane
    if edge:
        status, msg = get_aether_network_status(cluster.name)
        report += _get_report("Aether Network", status, msg)

    report_string = "\n".join(report)
    return report_string


def main():
    report = REPORT_HEADER

    # Get cluster status from Rancher
    try:
        rancher_client = RancherClient(
            url=CONF.rancher.api_url, access_key=CONF.rancher.access_key,
            secret_key=CONF.rancher.secret_key)
        response = rancher_client.list_cluster()
    except Exception as e:
        report += _get_report("Rancher", Status.error, [str(e)])
        response = namedtuple('X', "data")([])

    # Check cluster health and make a report
    for cluster in response.data:
        if "production" in cluster.name:
            edge = True if "edge" in cluster.name else False
            report += get_cluster_health_report(cluster, edge)
            report += "\n\n"

    # Publish the report to Slack channel
    try:
        slack_client = SlackClient(token=CONF.slack.api_token)
        response = slack_client.chat_postMessage(
            channel=CONF.slack.channel,
            text=report)
    except SlackApiError as e:
        assert e.response["ok"] is False
        assert e.response["error"]
        print(f"Got an error: {e.response['error']}")


if __name__ == "__main__":
    main()