"""
CPU Usage Detector
Monitors CPU usage and reports to the aggregator when thresholds are exceeded.

Environment variables:
    AGGREGATOR_URL      - URL of the aggregator (default: http://localhost:5100)
    CHECK_INTERVAL      - Seconds between checks (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, clear_event

# Configuration from environment
AGGREGATOR_URL = os.environ.get("AGGREGATOR_URL", DEFAULT_AGGREGATOR_URL)
CHECK_INTERVAL = int(os.environ.get("CHECK_INTERVAL", 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(f"CPU Usage Detector started")
    print(f"  Aggregator: {AGGREGATOR_URL}")
    print(f"  Interval: {CHECK_INTERVAL}s")
    print(f"  Thresholds: Warning={THRESHOLD_WARNING}%, Critical={THRESHOLD_CRITICAL}%")
    print()

    active_alerts = set()

    while True:
        # Get CPU usage over a 1-second sample
        cpu_percent = psutil.cpu_percent(interval=1)
        current_alerts = set()

        if cpu_percent >= THRESHOLD_CRITICAL:
            send_event(AGGREGATOR_URL, EVENT_ID, 1, f"CPU at {cpu_percent:.0f}%", CHECK_INTERVAL)
            current_alerts.add(EVENT_ID)
        elif cpu_percent >= THRESHOLD_WARNING:
            send_event(AGGREGATOR_URL, EVENT_ID, 2, f"CPU at {cpu_percent:.0f}%", CHECK_INTERVAL)
            current_alerts.add(EVENT_ID)
        else:
            print(f"[OK] CPU: {cpu_percent:.0f}%")

        # Clear alerts that are no longer active
        for eid in active_alerts - current_alerts:
            clear_event(AGGREGATOR_URL, eid)

        active_alerts = current_alerts

        time.sleep(CHECK_INTERVAL - 1)  # Account for 1s sample time


if __name__ == "__main__":
    main()