#!/usr/bin/env python
# -*- coding: utf-8 -*-

#   COPYRIGHT NOTICE STARTS HERE

#   Copyright 2019 © Samsung Electronics Co., Ltd.
#
#   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.

#   COPYRIGHT NOTICE ENDS HERE


from __future__ import print_function
import sys
import argparse
import yaml
import requests
import subprocess
import datetime
from time import sleep
from os.path import expanduser
from itertools import chain
import csv
from requests.packages.urllib3.exceptions import InsecureRequestWarning


def add_resource_kind(resources, kind):
    for item in resources:
        item['kind'] = kind
    return resources

def get_resources(server, namespace, api, kind, ssl_verify=False):
    url = '/'.join([server, api, 'namespaces', namespace, kind])
    try:
        req = requests.get(url, verify=ssl_verify)
    except requests.exceptions.ConnectionError as err:
        sys.exit('Could not connect to {}'.format(server))
    json = req.json()
    # kind is <resource>List in response so [:-4] removes 'List' from value
    return add_resource_kind(json['items'], json['kind'][:-4])

def pods_by_parent(pods, parent):
    for pod in pods:
        if pod['metadata']['labels']['app'] == parent:
            yield pod

def k8s_controller_ready(k8s_controller):
    if k8s_controller['kind'] == 'Job':
        return k8s_controller['status'].get('succeeded', 0) == k8s_controller['spec']['completions']
    return k8s_controller['status'].get('readyReplicas', 0) == k8s_controller['spec']['replicas']

def get_not_ready(data):
    return [x for x in data if not k8s_controller_ready(x)]

def get_apps(data):
    return [x['metadata']['labels']['app'] for x in data]

def get_names(data):
    return [x['metadata']['name'] for x in data]

def pod_ready(pod):
    try:
        return [x['status'] for x in pod['status']['conditions']
                    if x['type'] == 'Ready'][0] == 'True'
    except (KeyError, IndexError):
        return False

def not_ready_pods(pods):
    for pod in pods:
        if not pod_ready(pod):
            yield pod

def analyze_k8s_controllers(resources_data):
    resources = {'total_count': len(resources_data)}
    resources['not_ready_list'] = get_apps(get_not_ready(resources_data))
    resources['ready_count'] = resources['total_count'] - len(resources['not_ready_list'])

    return resources

def get_k8s_controllers(namespace, k8s_url):
    k8s_controllers = {}

    k8s_controllers['deployments'] = {'data': get_resources(k8s_url, namespace,
        'apis/apps/v1', 'deployments')}
    k8s_controllers['deployments'].update(analyze_k8s_controllers(k8s_controllers['deployments']['data']))

    k8s_controllers['statefulsets'] = {'data': get_resources(k8s_url, namespace,
        'apis/apps/v1', 'statefulsets')}
    k8s_controllers['statefulsets'].update(analyze_k8s_controllers(k8s_controllers['statefulsets']['data']))

    k8s_controllers['jobs'] = {'data': get_resources(k8s_url, namespace,
        'apis/batch/v1', 'jobs')}
    k8s_controllers['jobs'].update(analyze_k8s_controllers(k8s_controllers['jobs']['data']))

    not_ready_controllers = chain.from_iterable(
            k8s_controllers[x]['not_ready_list'] for x in k8s_controllers)

    return k8s_controllers, list(not_ready_controllers)

def get_k8s_url(kube_config):
    # TODO: Get login info
    with open(kube_config) as f:
        config = yaml.load(f)
    # TODO: Support cluster by name
    return config['clusters'][0]['cluster']['server']

def exec_healthcheck(hp_script, namespace):
    try:
        hc = subprocess.check_output(
                ['sh', hp_script, namespace, 'health'],
                stderr=subprocess.STDOUT)
        return 0, hc.output
    except subprocess.CalledProcessError as err:
        return err.returncode, err.output

def check_readiness(k8s_url, namespace, verbosity):
        k8s_controllers, not_ready_controllers = get_k8s_controllers(namespace, k8s_url)

        # check pods only when it is explicitly wanted (judging readiness by deployment status)
        if verbosity > 1:
            pods = get_resources(k8s_url, namespace, 'api/v1', 'pods')
            unready_pods = chain.from_iterable(
                   get_names(not_ready_pods(
                       pods_by_parent(pods, x)))
                   for x in not_ready_controllers)
        else:
            unready_pods = []

        print_status(verbosity, k8s_controllers, unready_pods)
        return not not_ready_controllers

def check_in_loop(k8s_url, namespace, max_time, sleep_time, verbosity):
    max_end_time = datetime.datetime.now() + datetime.timedelta(minutes=max_time)
    ready = False
    while datetime.datetime.now() < max_end_time:
        ready = check_readiness(k8s_url, namespace, verbosity)
        if ready:
            return ready
        sleep(sleep_time)
    return ready

def check_helm_releases():
    helm = subprocess.check_output(['helm', 'ls'])
    if helm == '':
        sys.exit('No Helm releases detected.')
    helm_releases = csv.DictReader(
            map(lambda x: x.replace(' ', ''), helm.split('\n')),
            delimiter='\t')
    failed_releases = [release['NAME'] for release in helm_releases
            if release['STATUS'] == 'FAILED']
    return helm, failed_releases


def create_ready_string(ready, total, prefix):
    return '{:12} {}/{}'.format(prefix, ready, total)

def print_status(verbosity, resources, not_ready_pods):
    ready_strings = []
    ready = {k: v['ready_count'] for k,v in resources.items()}
    count = {k: v['total_count'] for k,v in resources.items()}
    if verbosity > 0:
        ready_strings += [
                create_ready_string(ready[k], count[k], k.capitalize()) for k in ready
                ]
    total_ready = sum(ready.values())
    total_count = sum(count.values())
    ready_strings.append(create_ready_string(total_ready, total_count, 'Ready'))
    status_strings = ['\n'.join(ready_strings)]
    if verbosity > 1:
        if not_ready_pods:
            status_strings.append('\nWaiting for pods:\n{}'.format('\n'.join(not_ready_pods)))
        else:
            status_strings.append('\nAll pods are ready!')
    print('\n'.join(status_strings), '\n')

def parse_args():
    parser = argparse.ArgumentParser(description='Monitor ONAP deployment progress')
    parser.add_argument('--namespace', '-n', default='onap',
            help='Kubernetes namespace of ONAP')
    parser.add_argument('--server', '-s', help='address of Kubernetes cluster')
    parser.add_argument('--kubeconfig', '-c',
            default=expanduser('~') + '/.kube/config',
            help='path to .kube/config file')
    parser.add_argument('--health-path', '-hp', help='path to ONAP robot ete-k8s.sh')
    parser.add_argument('--no-helm', action='store_true', help='Do not check Helm')
    parser.add_argument('--check-frequency', '-w', default=300, type=int,
            help='time between readiness checks in seconds')
    parser.add_argument('--max-time', '-t', default=120, type=int,
            help='max time to run readiness checks in minutes')
    parser.add_argument('--single-run', '-1', action='store_true',
            help='run check loop only once')
    parser.add_argument('-v', dest='verbosity', action='count', default=0,
            help='increase output verbosity, e.g. -vv is more verbose than -v')

    return parser.parse_args()

def main():
    args = parse_args()

    if not args.no_helm:
        try:
            helm_output, failed_releases = check_helm_releases()
            if failed_releases:
                print('Deployment of {} failed.'.format(','.join(failed_releases)))
                sys.exit(1)
            elif args.verbosity > 1:
                print(helm_output)
        except IOError as err:
            sys.exit(err.strerror)

    requests.packages.urllib3.disable_warnings(InsecureRequestWarning)
    k8s_url = args.server if args.server is not None else get_k8s_url(args.kubeconfig)

    ready = False
    if args.single_run:
        ready = check_readiness(k8s_url, args.namespace, args.verbosity)
    else:
        if not check_in_loop(k8s_url, args.namespace, args.max_time, args.check_frequency, args.verbosity):
            # Double-check last 5 minutes and write verbosely in case it is not ready
            ready = check_readiness(k8s_url, args.namespace, 2)

    if args.health_path is not None:
        try:
            hc_rc, hc_output = exec_healthcheck(args.health_path, args.namespace)
        except IOError as err:
            sys.exit(err.strerror)
        if args.verbosity > 1 or hc_rc > 0:
            print(hc_output.decode('utf-8'))
        sys.exit(hc_rc)

    if not ready:
        sys.exit('Deployment is not ready')

if __name__ == '__main__':
    main()