# Chaos Monkey implementation (simplified)
import random
import boto3
import logging
from datetime import datetime, time

logger = logging.getLogger(__name__)

class ChaosMonkey:
    def __init__(self, ec2_client, enabled: bool = False):
        self.ec2 = ec2_client
        self.enabled = enabled

    def is_business_hours(self) -> bool:
        """Only run during business hours (9 AM - 5 PM weekdays)"""
        now = datetime.now()
        if now.weekday() >= 5:  # Weekend
            return False
        current_time = now.time()
        return time(9, 0) <= current_time <= time(17, 0)

    def get_eligible_instances(self, tag_filter: str = "chaos-enabled=true") -> list:
        """Only instances tagged for chaos"""
        response = self.ec2.describe_instances(
            Filters=[
                {'Name': 'tag:chaos-enabled', 'Values': ['true']},
                {'Name': 'instance-state-name', 'Values': ['running']}
            ]
        )
        instances = []
        for reservation in response['Reservations']:
            for instance in reservation['Instances']:
                instances.append(instance['InstanceId'])
        return instances

    def terminate_random_instance(self) -> str | None:
        if not self.enabled:
            logger.info("Chaos Monkey disabled — skipping")
            return None

        if not self.is_business_hours():
            logger.info("Outside business hours — skipping chaos")
            return None

        eligible = self.get_eligible_instances()
        if not eligible:
            logger.warning("No eligible instances found")
            return None

        target = random.choice(eligible)
        logger.warning(f"Chaos Monkey terminating instance: {target}")

        self.ec2.terminate_instances(InstanceIds=[target])
        return target
Chaos Engineering — Chaos Monkey, Game Days

Chaos Engineering — Chaos Monkey, Game Days

Chaos Engineering — Chaos Monkey, Game Days
