#!/usr/bin/env python3

import json, os.path, requests, sys, time
from datetime import datetime

OPENSTACK_USER = 'prometheus'
OPENSTACK_PASSWORD = 'REDACTED'
OPENSTACK_PROJECT = 'Prometheus'

SERVER_NAME = 'ServerHealthCheck'
SERVER_FLAVOR = 'e4b7e835-927a-4400-9b89-6e93968f0033'
SERVER_IMAGE = '30fb86b3-31d8-4191-be7d-aacf6c317c3e'

SCRIPT_FILE = os.path.basename(__file__)
STATE_FILE = os.path.splitext(SCRIPT_FILE)[0] + '.json'


def _url(path):
    return 'https://example.org' + path


def token_refresh():
    r = requests.post(_url(':5000/v3/auth/tokens'), json={
        'auth': {
            'identity': {
                'methods': ['password'],
                'password': {
                    'user': {
                        'name': OPENSTACK_USER,
                        'domain': { 'id': 'default' },
                        'password': OPENSTACK_PASSWORD,
                    }
                }
            },
            'scope': {
                'project': {
                    'domain': { 'id': 'default' },
                    'name': OPENSTACK_PROJECT
                }
            }
        }})

    if not r.status_code == 201:
        sys.exit("New token request returned status code {}".format(r.status_code))

    token = {'token_content': r.headers['X-Subject-Token'],
             'token_expiration': r.json()["token"]["expires_at"]}

    with open(STATE_FILE, 'w') as f:
        json.dump(token, f)


def server_create():
    r = requests.post(_url(':8774/v2.1/servers'), headers=headers, json={
        'server': {
            'name': SERVER_NAME,
            'flavorRef': SERVER_FLAVOR,
            'imageRef': SERVER_IMAGE
        }})

    if not r.status_code == 202:
        sys.exit("Server create request returned status code {}".format(r.status_code))

    server_id = r.json()["server"]["id"]
    return(server_id)


def server_status(server):
    r = requests.get(_url(':8774/v2.1/servers/' + server), headers=headers)

    server_status = r.json()["server"]["status"]
    return(server_status)


def server_delete(server):
    r = requests.delete(_url(':8774/v2.1/servers/' + server), headers=headers)

    if not r.status_code == 204:
        sys.exit("Server create request returned status code {}".format(r.status_code))


if __name__ == '__main__':
    # Get new auth token if state file does not exist
    if not os.path.isfile(STATE_FILE):
        token_refresh()

    # Load JSON state file as dictionary
    with open(STATE_FILE, 'r') as f:
        data = json.load(f)

    # Get new auth token if current token expired
    if (datetime.now().isoformat() >= data["token_expiration"]):
        print("Token expired")
        token_refresh()

    # Set HTTP headers with auth token
    headers = {'X-Auth-Token': data["token_content"],
               'Content-type': 'application/json'}

    # Create new server
    server = server_create()

    # Check server status
    status = server_status(server)
    request_seconds = 0
    while not status == 'ACTIVE':
        time.sleep(5)
        request_seconds += 5

        if request_seconds >= 120:
            sys.exit("Server creation took more than 120 seconds.")

        status = server_status(server)

    # Delete server
    server_delete(server)