#!/usr/bin/env python3
#
# Copyright 2019 Ricardo Branco <rbranco@suse.de>
# MIT License
#
"""
Show all instances created on cloud providers
"""

import argparse
import datetime
import logging
import sys

from os.path import basename
from operator import attrgetter, itemgetter
from threading import Thread
from dateutil import parser

import jmespath

from cachetools import cached, TTLCache

from providers.amazon import AWS
from providers.az import Azure
from providers.gcp import GCP
from output import Output


USAGE = "Usage: " + basename(sys.argv[0]) + """ [OPTIONS]
Options:
    -a, --all                           show all instances
    -o, --output text|html|json|JSON    output type
    -p, --port PORT                     run a web server on port PORT
    -r, --reverse                       reverse sort
    -s, --sort name|time|status         sort type
    -t, --time TIME_FORMAT              time format as used by strftime(3)
    -h, --help                          show this help message and exit
    -d, --debug                         debug mode
    -V, --version                       show version and exit
"""

__version__ = "0.1.8"


def fix_date(date):
    """
    Converts datetime object or string to local time or the
    timezone specified by the TZ environment variable
    """
    # NOTE: From Python 3.3 we can omit tz in datetime.astimezone()
    if isinstance(date, datetime.datetime):
        return date.astimezone().strftime(args.time)
    if isinstance(date, str):
        return parser.parse(timestr=date).astimezone().strftime(args.time)
    if date is None:
        return ""
    return "%s" % date


def perror(msg, err):
    """
    Print an error message and exit
    """
    if isinstance(err, Exception):
        err = "%s: %s" % (err.__class__.__name__, err)
    logging.error("%s: %s", msg, err)
    sys.exit(1)


def _print_amazon_instances():
    """
    Print information about AWS EC2 instances
    """
    filters = [
        {
            'Name': 'instance-state-name',
            'Values': [
                'pending', 'running', 'stopping',
                'stopped', 'shutting-down', 'terminated'
            ]
        }
    ]
    if not args.all:
        filters = [{'Name': 'instance-state-name', 'Values': ['running']}]
    else:
        filters = None
    instances = aws.get_instances(filters=filters)
    if args.sort:
        instances = [_ for _ in instances]
        keys = {
            'name': itemgetter('InstanceId'),
            'time': itemgetter('LaunchTime', 'InstanceId'),
            'status': lambda k: (aws.get_status(k), k['InstanceId'])
        }
        instances.sort(key=keys[args.sort], reverse=args.reverse)
    for instance in instances:
        instance['LaunchTime'] = fix_date(instance['LaunchTime'])
        if args.output == "JSON":
            output.info(item=instance)
        else:
            output.info(
                cloud="AWS",
                name=instance['InstanceId'],
                type=instance['InstanceType'],
                status=aws.get_status(instance),
                created=instance['LaunchTime'],
                location=instance['Placement']['AvailabilityZone'])


def print_amazon_instances():
    "Handle exceptions"
    try:
        _print_amazon_instances()
    except KeyboardInterrupt:
        sys.exit(1)
    except Exception as error:  # pylint: disable=broad-except
        perror("AWS", error)


def _print_azure_instances():
    """
    Print information about Azure Compute instances
    """
    filter_instance_view = """
        statuses[1].display_status == 'VM starting' ||
        statuses[1].display_status == 'VM running' ||
        statuses[1].display_status == 'VM stopping' ||
        statuses[1].display_status == 'VM stopped' ||
        statuses[1].display_status == 'VM deallocating' ||
        statuses[1].display_status == 'VM deallocated'"""
    if not args.all:
        filter_instance_view = "statuses[1].display_status == 'VM running'"
    else:
        filter_instance_view = None
    if filter_instance_view:
        filter_instance_view = jmespath.compile(filter_instance_view)
    instances = azure.get_instances(
        filter_instance_view=filter_instance_view)
    if args.sort:
        instances = [_ for _ in instances]
        keys = {
            'name': attrgetter('name'),
            'time': attrgetter('date', 'name'),
            'status': attrgetter('status', 'name')
        }
        instances.sort(key=keys[args.sort], reverse=args.reverse)
    for instance in instances:
        instance.date = fix_date(instance.date)
        if args.output == "JSON":
            output.info(
                item=instance.as_dict())
        else:
            output.info(
                cloud="Azure",
                name=instance.name,
                type=instance.hardware_profile.vm_size,
                status=instance.status,
                created=instance.date,
                location=instance.location)


def print_azure_instances():
    "Handle exceptions"
    try:
        _print_azure_instances()
    except KeyboardInterrupt:
        sys.exit(1)
    except Exception as error:  # pylint: disable=broad-except
        perror("Azure", error)


def _print_google_instances():
    """
    Print information about Google Compute instances
    """
    filters = """
        status = provisioning OR
        status = staging OR
        status = running OR
        status = stopping OR
        status = stopped OR
        status = suspending OR
        status = suspended OR
        status = terminated
    """
    if not args.all:
        filters = "status = running"
    else:
        filters = None
    instances = gcp.get_instances(filters=filters)
    if args.sort:
        instances = [_ for _ in instances]
        keys = {
            'name': itemgetter('name'),
            'time': itemgetter('creationTimestamp', 'name'),
            'status': itemgetter('status', 'name'),
        }
        instances.sort(key=keys[args.sort], reverse=args.reverse)
    for instance in instances:
        instance['creationTimestamp'] = fix_date(instance['creationTimestamp'])
        if args.output == "JSON":
            output.info(item=instance)
        else:
            output.info(
                cloud="GCP",
                name=instance['name'],
                type=instance['machineType'].rsplit('/', 1)[-1],
                status=gcp.get_status(instance),
                created=instance['creationTimestamp'],
                location=instance['zone'].rsplit('/', 1)[-1])


def print_google_instances():
    "Handle exceptions"
    try:
        _print_google_instances()
    except Exception as error:  # pylint: disable=broad-except
        perror("GCP", error)


@cached(cache=TTLCache(maxsize=2, ttl=120))
def main():
    """
    Main function
    """
    if args.port:
        sys.stdout = StringIO()
    output.header()
    threads = [
        Thread(target=print_amazon_instances),
        Thread(target=print_azure_instances),
        Thread(target=print_google_instances)
    ]
    for thread in threads:
        thread.start()
    for thread in threads:
        thread.join()
    output.footer()
    if args.port:
        sys.stdout.flush()
        response = sys.stdout.getvalue()
        sys.stdout.close()
        return response
    return None


def handle_requests(request):
    """
    Handle HTTP requests
    """
    logging.info(request)
    response = main()
    return Response(response)


def web_server():
    """
    Setup the WSGI server
    """
    with Configurator() as config:
        config.add_route('handle_requests', '/')
        config.add_view(handle_requests, route_name='handle_requests')
        app = config.make_wsgi_app()
        server = make_server('0.0.0.0', args.port, app)
        server.serve_forever()


def setup_logging():
    """
    Setup logging
    """
    logging.basicConfig(
        format="%(asctime)s %(levelname)-8s %(message)s" if args.port else None,
        stream=sys.stderr,
        level=logging.DEBUG if args.debug else
        logging.INFO if args.port else logging.ERROR)


if __name__ == "__main__":
    argparser = argparse.ArgumentParser(usage=USAGE, add_help=False)
    argparser.add_argument('-a', '--all', action='store_true')
    argparser.add_argument('-d', '--debug', action='store_true')
    argparser.add_argument('-h', '--help', action='store_true')
    argparser.add_argument('-o', '--output', default='text',
                           choices=['text', 'html', 'json', 'JSON'])
    argparser.add_argument('-p', '--port', type=int)
    argparser.add_argument('-r', '--reverse', action='store_true')
    argparser.add_argument('-s', '--sort', choices=['name', 'status', 'time'])
    argparser.add_argument('-t', '--time', default="%a %b %d %H:%M:%S %Z %Y")
    argparser.add_argument('-V', '--version', action='store_true')
    args = argparser.parse_args()

    if args.help or args.version:
        print(USAGE if args.help else __version__)
        sys.exit(0)

    setup_logging()

    try:
        aws = AWS()
    except Exception as error:  # pylint: disable=broad-except
        perror("AWS", error)
    try:
        azure = Azure()
    except Exception as error:  # pylint: disable=broad-except
        perror("Azure", error)
    try:
        gcp = GCP()
    except Exception as error:  # pylint: disable=broad-except
        perror("GCP", error)

    _keys = "cloud name type status created location"
    _fmt = '{d[cloud]}\t{d[name]:32}\t{d[type]:>23}\t{d[status]:>16}\t{d[created]:30}\t{d[location]}'

    if args.port:
        args.output = "html"
    output = Output(type=args.output.lower(), keys=_keys, fmt=_fmt)

    if args.port:
        from io import StringIO
        from wsgiref.simple_server import make_server
        from pyramid.config import Configurator
        from pyramid.response import Response

        web_server()
        sys.exit(1)

    try:
        main()
    except KeyboardInterrupt:
        sys.exit(1)
