import json

import uncloud.secrets as secrets

from django.core.management.base import BaseCommand
from django.contrib.auth import get_user_model

from uncloud_vm.models import VMProduct, VMHost

class Command(BaseCommand):
    help = 'Select VM Host for VMs'

    def add_arguments(self, parser):
        parser.add_argument('--schedule-vms', action='store_true')
        parser.add_argument('--start-vms-here', action='store_true')
        parser.add_argument('--check-health', action='store_true')
        parser.add_argument('--vmhostname')
        print(parser)


    def handle(self, *args, **options):
        print(args)
        print(options)

        if options['schedule_vms']:
            self.schedule_vms(args, option)
        if options['start_vms_here']:
            if not options['vmhostname']:
                raise Exception("Argument vmhostname is required to know which vmhost we are on")
            self.start_vms(args, options)
        if options['check_health']:
            self.check_health(args, option)

    def start_vms(self, *args, **options):
        vmhost = VMHost.objects.get(status='active',
                                    hostname=options['vmhostname'])

        if not vmhost:
            print("No active vmhost {} exists".format(options['vmhostname']))
            return

        vms_to_start = VMProduct.objects.filter(vmhost=vmhost,
                                                status='creating')
        for vm in vms_to_start:

            """ run qemu:
            check if VM is not already active / qemu running
            prepare / create the Qemu arguments


            """

    def schedule_vms(self, *args, **options)):
        pending_vms = VMProduct.objects.filter(vmhost__isnull=True)
        vmhosts = VMHost.objects.filter(status='active')

        for vm in pending_vms:
            print(vm)

            found_vmhost = False
            for vmhost in vmhosts:
                if vmhost.available_cores >= vm.cores and vmhost.available_ram_in_gb >= vm.ram_in_gb:
                    vm.vmhost = vmhost
                    vm.status = "creating"
                    vm.save()
                    found_vmhost = True
                    print("Scheduled VM {} on VMHOST {}".format(vm, vmhost))
                    break

            if not found_vmhost:
                print("Error: cannot schedule VM {}, no suitable host found".format(vm))

    def check_health(self, *args, **options):
        pending_vms = VMProduct.objects.filter(vmhost__isnull=True)
        vmhosts = VMHost.objects.filter(status='active')

        # 1. Check that all active hosts reported back N seconds ago
        # 2. Check that no VM is running on a dead host
        # 3. Migrate VMs if necessary
        # 4. Check that no VMs have been pending for longer than Y seconds

        # If VM snapshots exist without a VM -> notify user (?)


        print("Nothing is good, you should implement me")