import paramiko
import schedule
import time
import os
import sys
from flask import Flask, jsonify, render_template_string
from threading import Thread
import logging

app = Flask(__name__)

vps_status = {}

# 设置日志
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(levelname)s - %(message)s',
    handlers=[
        logging.StreamHandler(sys.stdout),
        logging.StreamHandler(sys.stderr)
    ]
)
logger = logging.getLogger()

def get_vps_configs():
    configs = []
    index = 1
    while True:
        hostname = os.environ.get(f'HOSTNAME_{index}')
        if not hostname:
            break
        
        config = {
            'index': index,
            'hostname': hostname,
            'username': os.environ.get(f'USERNAME_{index}'),
            'password': os.environ.get(f'PASSWORD_{index}'),
            'script_path': os.environ.get(f'SCRIPT_PATH_{index}')
        }
        configs.append(config)
        
        logger.info(f"Config {index}: {config['hostname']}, {config['username']}, {config['script_path']}")
        
        index += 1
    return configs

def check_and_run_script(config):
    logger.info(f"Checking VPS {config['index']}: {config['hostname']}")
    client = None
    try:
        client = paramiko.SSHClient()
        client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

        client.connect(
            hostname=config['hostname'], 
            username=config['username'],
            password=config['password'],
            port=22
        )

        script_path = config['script_path']
        script_name = os.path.basename(script_path)

        # 获取上次保存的 PID（如果有）
        last_pid = vps_status.get(config['index'], {}).get('pid', None)

        # 使用pgrep检查进程是否正在运行并获取PID 
        check_command = f"pgrep -f {script_name}"
        stdin, stdout, stderr = client.exec_command(check_command)
        current_pid = stdout.read().decode('utf-8').strip()

        if current_pid:
            # 如果有PID,进程在运行
            if current_pid == last_pid:
                # PID与上次一致,进程一直在运行
                status = "Active"
                pid = current_pid
                logger.info(f"Script is running. PID: {pid}")
            else:
                # PID与上次不一致,进程曾经中断过,已被重启
                status = "Restarted" 
                pid = current_pid
                logger.info(f"Script has been restarted. New PID: {pid}")
        else:
            logger.info(f"Script not running on {config['hostname']}. Executing restart script.")
            restart_command = f"nohup /bin/sh {script_path} > /dev/null 2>&1 & echo $!"  
            stdin, stdout, stderr = client.exec_command(restart_command)
            new_pid = stdout.read().decode('utf-8').strip()

            if new_pid.isdigit():
                pid = new_pid
                status = "Restarted"
                logger.info(f"Script restarted. New PID: {pid}")
            else:
                pid = "N/A" 
                status = "Restart Failed"
                logger.error(f"Failed to restart script")

        # 获取脚本运行时间 
        if pid != "N/A":
            runtime_command = f"ps -p {pid} -o etime"
            stdin, stdout, stderr = client.exec_command(runtime_command)
            output = stdout.read().decode('utf-8').strip()
            runtime = output.split("\n")[-1].strip() if output else "Unknown"
        else:
            runtime = "N/A"
        
        vps_status[config['index']] = {
            'hostname': config['hostname'], 
            'status': status,
            'last_check': time.strftime('%Y-%m-%d %H:%M:%S'),
            'username': config['username'],
            'runtime': runtime,
            'pid': pid
        }

    except Exception as e:
        logger.error(f"Error occurred while checking VPS {config['index']} - {config['hostname']}: {str(e)}")
        vps_status[config['index']] = {
            'hostname': config['hostname'],
            'status': f"Error: {str(e)}",   
            'last_check': time.strftime('%Y-%m-%d %H:%M:%S'),
            'username': config['username'],
            'runtime': "N/A",
            'pid': "N/A"
        }
    finally:
        if client:
            client.close()

def check_all_vps():
    logger.info("Starting VPS check")
    vps_configs = get_vps_configs()
    for config in vps_configs:
        check_and_run_script(config)
    
    # 创建表格头
    table = "+---------+-----------------------+----------+-------------------------+----------+-------------------+-------+\n"
    table += "| Index   | Hostname              | Status   | Last Check              | Username | Runtime           | PID   |\n"  
    table += "+---------+-----------------------+----------+-------------------------+----------+-------------------+-------+\n"

    # 添加每个VPS的状态
    for index in sorted(vps_status.keys()):
        status = vps_status[index]
        table += "| {:<7} | {:<21} | {:<8} | {:<23} | {:<8} | {:<17} | {:<5} |\n".format(
            index,
            status['hostname'][:21], 
            status['status'][:8],
            status['last_check'],
            status['username'][:8],
            status['runtime'][:17],  # 展示运行时间
            status['pid'][:5]
        )
        table += "+---------+-----------------------+----------+-------------------------+----------+-------------------+-------+\n"
    
    logger.info("\n" + table)

@app.route('/')
def index():
    sorted_indexes = sorted(vps_status.keys())
    html = '''
    <h1>VPS Status Overview</h1>
    <table border="1">
        <tr>
            <th>Index</th>
            <th>Hostname</th>
            <th>Status</th>
            <th>Last Check</th>
            <th>Username</th>
            <th>Runtime</th>
            <th>PID</th>
        </tr>
        {% for index in sorted_indexes %}
        <tr>
            <td><a href="/status/{{ index }}">{{ index }}</a></td>
            <td>{{ vps_status[index].hostname }}</a></td>
            <td>{{ vps_status[index].status }}</td>
            <td>{{ vps_status[index].last_check }}</td>
            <td>{{ vps_status[index].username }}</td>
            <td>{{ vps_status[index].runtime }}</td>
            <td>{{ vps_status[index].pid }}</td>
        </tr>
        {% endfor %}
    </table>
    '''
    return render_template_string(html, vps_status=vps_status, sorted_indexes=sorted_indexes)

@app.route('/status/<int:index>')
def vps_status_detail(index):
    if index in vps_status:
        return jsonify(vps_status[index])
    else:
        return jsonify({"error": "VPS not found"}), 404

@app.route('/health')
def health_check():
    return jsonify({"status": "healthy", "uptime": time.time() - start_time}), 200

def run_flask():
    app.run(host='0.0.0.0', port=8080)

def main():
    global start_time
    start_time = time.time()
    
    logger.info("===== VPS monitoring script is starting =====")
    
    flask_thread = Thread(target=run_flask)
    flask_thread.start()
    logger.info("Flask server started in background")

    vps_configs = get_vps_configs()
    logger.info(f"Found {len(vps_configs)} VPS configurations")

    logger.info("Running initial VPS check")
    check_all_vps()

    schedule.every(15).minutes.do(check_all_vps)
    logger.info("Scheduled VPS check every 15 minutes")
    
    logger.info("===== VPS monitoring script is running =====")
    
    heartbeat_count = 0
    while True:
        schedule.run_pending()
        time.sleep(60)
        heartbeat_count += 1
        if heartbeat_count % 5 == 0:  # 每5分钟输出一次心跳信息
            logger.info(f"Heartbeat: Script is still running. Uptime: {heartbeat_count} minutes")

if __name__ == "__main__":
    main()