#!/usr/bin/env python3
"""
Autonomous Self-Healing Service — Background daemon
Runs healer.py as a persistent service with logging and alerting.

Usage:
    python healer_service.py start    # Start daemon
    python healer_service.py stop     # Stop daemon
    python healer_service.py status   # Check status
    python healer_service.py logs     # View logs
"""

import os
import sys
import time
import json
import signal
import subprocess
import argparse
from datetime import datetime

PID_FILE = "/tmp/healer_daemon.pid"
LOG_FILE = "/tmp/healer_daemon.log"
REPORT_FILE = "/tmp/healer_last_report.json"


def start_daemon():
    """Start the healer as a background process."""
    if os.path.exists(PID_FILE):
        with open(PID_FILE) as f:
            old_pid = f.read().strip()
        if os.path.exists(f"/proc/{old_pid}"):
            print(f"[Service] Healer already running (PID {old_pid})")
            return
        else:
            os.remove(PID_FILE)

    # Fork to background
    pid = os.fork()
    if pid > 0:
        print(f"[Service] Healer daemon started (PID {pid})")
        with open(PID_FILE, 'w') as f:
            f.write(str(pid))
        return

    # Child process
    os.setsid()
    sys.stdout = open(LOG_FILE, 'a')
    sys.stderr = open(LOG_FILE, 'a')

    print(f"\n{'='*60}")
    print(f"[Service] Daemon started at {datetime.utcnow().isoformat()}")
    print(f"{'='*60}\n")

    # Import and run healer
    from healer import SpaceHealer, HEALER_CONFIG

    healer = SpaceHealer()
    spaces = healer.discover_spaces()

    print(f"[Service] Monitoring {len(spaces)} spaces")
    print(f"[Service] Poll interval: {HEALER_CONFIG['poll_interval_seconds']}s")

    def handle_signal(signum, frame):
        print(f"[Service] Received signal {signum}, shutting down...")
        sys.exit(0)

    signal.signal(signal.SIGTERM, handle_signal)
    signal.signal(signal.SIGINT, handle_signal)

    while True:
        try:
            healer.run_cycle(spaces)
            healer.print_report()

            # Save report for external access
            report = healer.generate_report()
            with open(REPORT_FILE, 'w') as f:
                json.dump(report, f, indent=2)

        except Exception as e:
            print(f"[Service] ❌ Cycle error: {e}")

        time.sleep(HEALER_CONFIG["poll_interval_seconds"])


def stop_daemon():
    """Stop the healer daemon."""
    if not os.path.exists(PID_FILE):
        print("[Service] Healer not running")
        return

    with open(PID_FILE) as f:
        pid = f.read().strip()

    try:
        os.kill(int(pid), signal.SIGTERM)
        os.remove(PID_FILE)
        print(f"[Service] Healer stopped (PID {pid})")
    except ProcessLookupError:
        os.remove(PID_FILE)
        print("[Service] Healer was not running (stale PID file)")
    except Exception as e:
        print(f"[Service] Error stopping: {e}")


def check_status():
    """Check if daemon is running."""
    if not os.path.exists(PID_FILE):
        print("[Service] Healer: STOPPED")
        return

    with open(PID_FILE) as f:
        pid = f.read().strip()

    if os.path.exists(f"/proc/{pid}"):
        print(f"[Service] Healer: RUNNING (PID {pid})")
        if os.path.exists(REPORT_FILE):
            with open(REPORT_FILE) as f:
                report = json.load(f)
            print(f"  Last check: {report.get('generated_at', 'unknown')}")
            print(f"  Spaces monitored: {len(report.get('spaces', []))}")
            print(f"  Actions today: {report.get('actions_today', 0)}")
            print(f"  Est. daily cost: ${report.get('total_estimated_daily_cost', 0):.2f}")
    else:
        print(f"[Service] Healer: STOPPED (stale PID {pid})")
        os.remove(PID_FILE)


def view_logs(lines: int = 50):
    """View recent daemon logs."""
    if not os.path.exists(LOG_FILE):
        print("[Service] No logs found")
        return

    with open(LOG_FILE) as f:
        all_lines = f.readlines()

    for line in all_lines[-lines:]:
        print(line.rstrip())


def main():
    parser = argparse.ArgumentParser(description="Healer Service Manager")
    parser.add_argument("command", choices=["start", "stop", "status", "logs", "restart"])
    parser.add_argument("--lines", type=int, default=50, help="Lines of log to show")
    args = parser.parse_args()

    if args.command == "start":
        start_daemon()
    elif args.command == "stop":
        stop_daemon()
    elif args.command == "restart":
        stop_daemon()
        time.sleep(1)
        start_daemon()
    elif args.command == "status":
        check_status()
    elif args.command == "logs":
        view_logs(args.lines)


if __name__ == "__main__":
    main()