#!/usr/bin/env python3
"""
heartbeat-poc.py — Proof of Concept heartbeat sender

Run on Pi 4 to test end-to-end pipeline:
  Pi → API → WebSocket → Dashboard

Usage:
  python3 heartbeat-poc.py

Requirements:
  pip install requests
"""

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

# ── Config ──────────────────────────────────────────────────────
API_BASE = os.environ.get('API_BASE', 'http://localhost:3001')
DEVICE_ID = os.environ.get('DEVICE_ID', 'DEMO-001')   # khớp với seed
API_KEY = os.environ.get('API_KEY', 'dev-api-key-demo-001')  # khớp với seed
INTERVAL_SECONDS = int(os.environ.get('INTERVAL_SECONDS', 30))


def get_device_info() -> dict:
    """Gather device telemetry — stub cho POC."""
    try:
        # Nhiệt độ CPU (Linux)
        with open('/sys/class/thermal/thermal_zone0/temp') as f:
            temp_milli = int(f.read().strip())
            temp_c = round(temp_milli / 1000, 1)
    except Exception:
        temp_c = None

    try:
        # Battery (nếu có)
        result = subprocess.run(
            ['cat', '/sys/class/power_supply/BAT0/capacity'],
            capture_output=True, text=True
        )
        battery = int(result.stdout.strip()) if result.returncode == 0 else None
    except Exception:
        battery = None

    try:
        # Disk free (GB)
        result = subprocess.run(
            ['df', '-BG', '--output=avail', '/'],
            capture_output=True, text=True
        )
        lines = result.stdout.strip().split('\n')
        if len(lines) >= 2:
            free_str = lines[1].strip().rstrip('G')
            storage_free = int(free_str)
        else:
            storage_free = 50
    except Exception:
        storage_free = 50

    try:
        # Network status
        result = subprocess.run(
            ['ping', '-c1', '-W1', '8.8.8.8'],
            capture_output=True
        )
        network_status = 'online' if result.returncode == 0 else 'degraded'
    except Exception:
        network_status = 'online'

    return {
        'tempC': temp_c,
        'batteryPct': battery,
        'storageFreeGb': storage_free,
        'networkStatus': network_status,
        'lastCaptureAt': datetime.utcnow().isoformat(),
        'capturesToday': 0,
    }


def send_heartbeat(device_id: str, api_key: str) -> bool:
    """Gửi heartbeat lên API."""
    import requests

    payload = {
        'deviceId': device_id,
        'apiKey': api_key,
        'status': 'online',
        'firmwareVersion': 'poc-1.0.0',
        **get_device_info(),
    }

    url = f'{API_BASE}/v1/devices/{device_id}/heartbeat'

    try:
        resp = requests.post(url, json=payload, timeout=10)
        if resp.ok:
            data = resp.json()
            print(f"[{datetime.now().strftime('%H:%M:%S')}] "
                  f"✓ heartbeat sent | pending commands: {data.get('pendingCommands', 0)}")
            return True
        else:
            print(f"[{datetime.now().strftime('%H:%M:%S')}] "
                  f"✗ API error {resp.status_code}: {resp.text[:100]}")
            return False
    except Exception as e:
        print(f"[{datetime.now().strftime('%H:%M:%S')}] ✗ connection error: {e}")
        return False


def main():
    parser = argparse.ArgumentParser(description='POC Heartbeat Sender')
    parser.add_argument('--device-id', default=DEVICE_ID, help='Device ID')
    parser.add_argument('--api-key', default=API_KEY, help='API Key')
    parser.add_argument('--interval', type=int, default=INTERVAL_SECONDS, help='Seconds between heartbeats')
    parser.add_argument('--once', action='store_true', help='Send once and exit')
    args = parser.parse_args()

    print(f'=== Heartbeat POC ===')
    print(f'  Device:    {args.device_id}')
    print(f'  API:       {API_BASE}')
    print(f'  Interval:  {args.interval}s')
    print(f'  Dashboard: http://localhost:3000')
    print()

    if args.once:
        send_heartbeat(args.device_id, args.api_key)
        return

    print('Press Ctrl+C to stop.\n')
    while True:
        send_heartbeat(args.device_id, args.api_key)
        time.sleep(args.interval)


if __name__ == '__main__':
    main()