import datetime
import logging
import time

import requests

import pykube

from pykube import Pod, Node
from pykube.objects import APIObject, NamespacedAPIObject

from .utils import get_short_error_message

logger = logging.getLogger(__name__)

session = requests.Session()


# https://github.com/kubernetes/community/blob/master/contributors/design-proposals/instrumentation/resource-metrics-api.md
class NodeMetrics(APIObject):

    version = 'metrics.k8s.io/v1beta1'
    endpoint = 'nodes'
    kind = 'NodeMetrics'


# https://github.com/kubernetes/community/blob/master/contributors/design-proposals/instrumentation/resource-metrics-api.md
class PodMetrics(NamespacedAPIObject):

    version = 'metrics.k8s.io/v1beta1'
    endpoint = 'pods'
    kind = 'PodMetrics'


def map_node_status(status: dict):
    return {
        'addresses': status.get('addresses'),
        'capacity': status.get('capacity'),
        'allocatable': status.get('allocatable')
    }


def map_node(node: dict):
    return {
        'name': node['metadata']['name'],
        'labels': node['metadata']['labels'],
        'status': map_node_status(node['status']),
        'pods': {}
    }


def map_pod(pod: dict):
    return {
        'name': pod['metadata']['name'],
        'namespace': pod['metadata']['namespace'],
        'labels': pod['metadata'].get('labels', {}),
        'phase': pod['status'].get('phase'),
        'startTime': pod['status']['startTime'] if 'startTime' in pod['status'] else '',
        'containers': []
    }


def map_container(cont: dict, pod: dict):
    obj = {'name': cont['name'], 'image': cont['image'], 'resources': cont['resources']}
    status = list([s for s in pod.get('status', {}).get('containerStatuses', []) if s['name'] == cont['name']])
    if status:
        obj.update(**status[0])
    return obj


def parse_time(s: str):
    return datetime.datetime.strptime(s, '%Y-%m-%dT%H:%M:%SZ').replace(tzinfo=datetime.timezone.utc).timestamp()


def query_kubernetes_cluster(cluster):
    cluster_id = cluster.id
    api_server_url = cluster.api_server_url
    nodes = {}
    pods_by_namespace_name = {}
    unassigned_pods = {}
    for node in Node.objects(cluster.client):
        obj = map_node(node.obj)
        nodes[obj['name']] = obj
    now = time.time()
    for pod in Pod.objects(cluster.client, namespace=pykube.all):
        obj = map_pod(pod.obj)
        if 'deletionTimestamp' in pod.metadata:
            obj['deleted'] = parse_time(pod.metadata['deletionTimestamp'])
        for cont in pod.obj['spec']['containers']:
            obj['containers'].append(map_container(cont, pod.obj))
        if obj['phase'] in ('Succeeded', 'Failed'):
            last_termination_time = 0
            for container in obj['containers']:
                termination_time = container.get('state', {}).get('terminated', {}).get('finishedAt')
                if termination_time:
                    termination_time = parse_time(termination_time)
                    if termination_time > last_termination_time:
                        last_termination_time = termination_time
            if (last_termination_time and last_termination_time < now - 3600) or (obj.get('reason') == 'Evicted'):
                # the job/pod finished more than an hour ago or if it is evicted by cgroup limits
                # => filter out
                continue
        pods_by_namespace_name[(obj['namespace'], obj['name'])] = obj
        pod_key = '{}/{}'.format(obj['namespace'], obj['name'])
        node_name = pod.obj['spec'].get('nodeName')
        if node_name in nodes:
            nodes[node_name]['pods'][pod_key] = obj
        else:
            unassigned_pods[pod_key] = obj

    try:
        for node_metrics in NodeMetrics.objects(cluster.client):
            key = node_metrics.name
            nodes[key]['usage'] = node_metrics.obj.get('usage', {})
    except Exception as e:
        logger.warning('Failed to query node metrics {}: {}'.format(cluster.id, get_short_error_message(e)))
    try:
        for pod_metrics in PodMetrics.objects(cluster.client, namespace=pykube.all):
            key = (pod_metrics.namespace, pod_metrics.name)
            pod = pods_by_namespace_name.get(key)
            if pod:
                for container in pod['containers']:
                    for container_metrics in pod_metrics.obj.get('containers', []):
                        if container['name'] == container_metrics['name']:
                            container['resources']['usage'] = container_metrics['usage']
    except Exception as e:
        logger.warning('Failed to query pod metrics for cluster {}: {}'.format(cluster.id, get_short_error_message(e)))
    return {
        'id': cluster_id,
        'api_server_url': api_server_url,
        'nodes': nodes,
        'unassigned_pods': unassigned_pods
    }