#!/usr/bin/env python3

import psutil
import requests
import time
import json
import logging
from datetime import datetime, timezone
import os
import sys

# ===============================
# Paths
# ===============================
CONFIG_FILE = "/opt/server-monitor/config.json"
LOG_FILE = "/opt/server-monitor/agent.log"

# Ensure log directory exists
os.makedirs(os.path.dirname(LOG_FILE), exist_ok=True)

# ===============================
# Setup Logging
# ===============================
logging.basicConfig(
    filename=LOG_FILE,
    level=logging.INFO,
    format="%(asctime)s - %(levelname)s - %(message)s"
)

# ===============================
# Load Configuration
# ===============================
def load_config():
    try:
        with open(CONFIG_FILE, "r") as f:
            return json.load(f)
    except FileNotFoundError:
        logging.error(f"Configuration file {CONFIG_FILE} not found.")
        sys.exit(1)
    except json.JSONDecodeError:
        logging.error(f"Configuration file {CONFIG_FILE} is not valid JSON.")
        sys.exit(1)

config = load_config()
API_URL = config.get("api_url")
API_KEY = config.get("api_key")
SERVER_NAME = config.get("server_name", "Unknown-Server")
INTERVAL = config.get("interval", 30)

if not API_URL or not API_KEY:
    logging.error("API URL or API KEY not set in configuration.")
    sys.exit(1)

# ===============================
# Collect Metrics
# ===============================
def get_metrics():
    cpu_usage = psutil.cpu_percent(interval=1)

    memory = psutil.virtual_memory()
    ram_total = round(memory.total / (1024 ** 2))
    ram_used = round(memory.used / (1024 ** 2))
    ram_free = round(memory.available / (1024 ** 2))
    ram_percent = memory.percent

    disk_data = {}
    for partition in psutil.disk_partitions():
        try:
            usage = psutil.disk_usage(partition.mountpoint)
            disk_data[partition.mountpoint] = {
                "total_gb": round(usage.total / (1024 ** 3), 2),
                "used_gb": round(usage.used / (1024 ** 3), 2),
                "free_gb": round(usage.free / (1024 ** 3), 2),
                "percent": usage.percent
            }
        except PermissionError:
            continue

    uptime_seconds = int(time.time() - psutil.boot_time())

    return {
        "server_name": SERVER_NAME,
        "cpu_usage": cpu_usage,
        "ram": {
            "total_mb": ram_total,
            "used_mb": ram_used,
            "free_mb": ram_free,
            "percent": ram_percent
        },
        "disk": disk_data,
        "uptime_seconds": uptime_seconds,
        "timestamp": datetime.now(timezone.utc).isoformat()
    }

# ===============================
# Send Metrics
# ===============================
def send_metrics(data):
    headers = {
        "Authorization": f"Bearer {API_KEY}",
        "Content-Type": "application/json"
    }

    try:
        response = requests.post(API_URL, headers=headers, json=data, timeout=10)
        if response.status_code == 200:
            logging.info("Metrics sent successfully.")
        else:
            logging.error(f"Server responded with {response.status_code}: {response.text}")
    except requests.RequestException as e:
        logging.error(f"Error sending metrics: {e}")

# ===============================
# Main Loop
# ===============================
def main():
    logging.info("Server Monitor Agent Started")
    try:
        while True:
            metrics = get_metrics()
            send_metrics(metrics)
            time.sleep(INTERVAL)
    except KeyboardInterrupt:
        logging.info("Server Monitor Agent stopped manually.")
    except Exception as e:
        logging.exception(f"Unexpected error: {e}")

if __name__ == "__main__":
    main()