"""
CPU Usage Detector
Polls CPU usage every 30 seconds. Sends a heartbeat event while usage is above
threshold; if usage drops below 85%, no event is sent and the previous event
expires naturally via its 30-second TTL.

Environment variables:
    AGGREGATOR_URL      - URL of the aggregator (default: http://localhost:5100)
    CHECK_INTERVAL      - Seconds between checks (default: 30)
    TTL                 - Event lifetime in seconds (default: 30)
    THRESHOLD_CRITICAL  - Percent usage for critical alert (default: 95)
    THRESHOLD_WARNING   - Percent usage for warning alert (default: 85)
"""

import os
import time
import psutil

from detectors.base import DEFAULT_AGGREGATOR_URL, send_event

AGGREGATOR_URL = os.environ.get("AGGREGATOR_URL", DEFAULT_AGGREGATOR_URL)
CHECK_INTERVAL = int(os.environ.get("CHECK_INTERVAL", 30))
TTL = int(os.environ.get("TTL", 30))
THRESHOLD_CRITICAL = int(os.environ.get("THRESHOLD_CRITICAL", 95))
THRESHOLD_WARNING = int(os.environ.get("THRESHOLD_WARNING", 85))

EVENT_ID = "cpu_usage"


def main():
    print("CPU Usage Detector started")
    print(f"  Aggregator: {AGGREGATOR_URL}")
    print(f"  Interval: {CHECK_INTERVAL}s, TTL: {TTL}s")
    print(f"  Thresholds: Warning={THRESHOLD_WARNING}%, Critical={THRESHOLD_CRITICAL}%")
    print()

    while True:
        cpu = psutil.cpu_percent(interval=1)  # 1-second blocking sample

        if cpu >= THRESHOLD_CRITICAL:
            send_event(AGGREGATOR_URL, EVENT_ID, 1, f"CPU {cpu:.0f}%", ttl=TTL)
        elif cpu >= THRESHOLD_WARNING:
            send_event(AGGREGATOR_URL, EVENT_ID, 2, f"CPU {cpu:.0f}%", ttl=TTL)
        else:
            print(f"[OK] CPU: {cpu:.0f}%")

        time.sleep(CHECK_INTERVAL - 1)  # 29s sleep + 1s sample = 30s total


if __name__ == "__main__":
    main()