import requests
import json
import smtplib
import time
from bs4 import BeautifulSoup
from email.mime.text import MIMEText
import os

DEBUG_MODE = True

URL = 'https://www.cmlab.csie.ntu.edu.tw/status-gpu/'
GPU_LIMIT = 2
GOOGLE_CODE = os.environ['GOOGLE_CODE']
MAIL_CD_HOUR = 6
MAIL_MESSAGE = '''
Hi, {}<br>
<br>
提醒您，您目前在 {} 伺服器上已經使用了 {} 張 {}，<br>
依照 CMLab 規定，每人在每台 CML workstation 上至多使用 2 顆 GPU，詳細規定請參閱 https://www.cmlab.csie.ntu.edu.tw/wiki/doku.php?id=workstation:rule <br>
<br>
為了公平起見，建議您降低 GPU 使用量！<br>
雖然我們不會直接處理，但若有人檢舉，我們會停止您運行的程式！<br>
若有其他問題歡迎來信討論！謝謝您的配合！<br>
<br>
* 信件由網管自動化工具寄出，若為錯誤寄送請忽略此信件。<br>
<br>
Best,<br>
CMLab Unix Manager, Ting-Jun Wang<br>
CMLab, National Taiwan University<br>
Email: unix_manager@cmlab.csie.ntu.edu.tw<br>
<pre>
            __  __     _             
           / / / /__  (_)_ __        
   __  ___/ /_/ / _ \/ /\ \ /        
  /  |/  /\____/_//_/_//_\_\____ ____
 / /|_/ / _ `/ _ \/ _ `/ _ `/ -_) __/
/_/  /_/\_,_/_//_/\_,_/\_, /\__/_/   
                      /___/          
</pre>
'''

def get_server_gpu_status() -> list:
    '''
        It will get html from CMLab webpage.
        and retrive the server name & users who are using GPU resources.

        Input:
            None
        Output:
            servers(list):
                [
                    {
                        'name': 'cml5'
                        'users': [
                            ['snsd0805', 'timmy'], ['timmy']
                        ], 
                        'gpus': ['V100', 'V100']
                    },
                    ...
                ]

            means that 'cml5' server has 2 'V100', and the user 'snsd0805' is using 1 GPU and the user 'timmy' is usig 2 GPU now.

    '''
    servers = []

    # get HTML file
    response = requests.get(URL)
    soup = BeautifulSoup(response.text, 'html.parser')

    # find the table which shows the GPU status
    table = soup.find('pre')
    boxes = table.prettify().split('\n\n')

    # retrive all server, one box means one server
    for box in boxes[:-1]:
        soup = BeautifulSoup(box, 'html.parser')
        # get server name
        server_name = soup.find('span', class_='f7').text.replace(' ', '')
        gpu_names = []

        users = []
        gpus = box.split('\n')
        for i in gpus[:]:
            if 'f6' in i:           # if this line is for a single GPU informations
                soup = BeautifulSoup(i, 'html.parser')

                # get all users who is using this server's GPU resources.
                user_objs = soup.findAll('span', class_='f0')
                user_in_this_gpu = set()
                
                # get users on this GPU
                for user_obj in user_objs:
                    if user_obj != None:
                        username = user_obj.text
                        if username != 'gdm':
                            user_in_this_gpu.add(username)

                # get gpu names
                gpu_name = soup.find('span', class_='f4').text.replace(' ', '')

                # log gpu name & users on this GPU
                gpu_names.append(gpu_name)
                users.append(list(user_in_this_gpu))

        servers.append({
            'name': server_name,
            'users': users,
            'gpu': gpu_names
        })
    return servers

def filter(server_status: list, limit: int = 2) -> list:
    '''
        You can set some rule here.
        it will return the a list which contains the username that exceed the limit.
        Rules now (2024/03/11):
            - 每人每台僅限使用 2 張卡

        I add this function beacause that we may need more filter rules. we can add some rules in this function easily

        Input:
            server_status (list): from get_server_gpu_status()
            limit (int): GPU limit (default: 2)
        Output:
            violators (list): a violator list(set) e.g. [ {'user': 'snsd0805', 'usage': [{'server': 'cml5', 'gpu': 'NVDIA3090', 'number': 3}...] }] means that the violator 'snsd0805' is using 3 GPU.
    '''
    violators = []

    counter = {}

    for server in server_status:
        print(server)
    '''
    for user in server_status['users']:
        if user not in counter:
            counter[user] = 1
        else:
            counter[user] += 1
        
    for k, v in counter.items():
        if v > limit:
            violators.append({
                'user': k,
                'gpu': v,
            })
    '''
    return violators

def mail_notify(server_name: str, gpu_name: str, violators: list) -> None:
    def check_send(log: dict, username: str) -> bool:
        if DEBUG_MODE:
            return True
        if username not in log:
            return True
        else:
            if time.time() - log[username] >= (MAIL_CD_HOUR*60*60):        # 6 hr 提醒一次
                
                return True
            else:
                return False

    # get last send time
    with open('send_log.json') as fp:
        send_log = json.load(fp)

    for violator in violators:
        username = violator['user']
        print(f'    {username}')

        if check_send(send_log, username):
            # update log
            send_log[username] = time.time()
            with open('send_log.json', 'w') as fp:
                json.dump(send_log, fp)
            usage = violator['gpu']
            msg = MAIL_MESSAGE.format(username, server_name, usage, gpu_name)
            msg = MIMEText(msg, 'html') # 郵件內文
            msg['Subject'] = f'[網管通知] 提醒您已經超過 CMLab GPU 使用限制！({username})' + "(DEBUG MODE)" if DEBUG_MODE else ""
            msg['From'] = 'unix_manager@cmlab.csie.ntu.edu.tw'
            msg['To'] = f'{username}@cmlab.csie.ntu.edu.tw' if not DEBUG_MODE else 'snsd0805@cmlab.csie.ntu.edu.tw'
            msg['Cc'] = 'unix_manager@cmlab.csie.ntu.edu.tw' if not DEBUG_MODE else 'snsd0805@cmlab.csie.ntu.edu.tw'

            smtp = smtplib.SMTP('smtp.gmail.com', 587)
            smtp.ehlo()
            smtp.starttls()
            smtp.login('snsd0805@cmlab.csie.ntu.edu.tw', GOOGLE_CODE)

            status = smtp.send_message(msg)
            if status == {}:
                print(f'    {username}, 郵件傳送成功！')
            else:
                print(f'    {username}, 郵件傳送失敗...')
            smtp.quit()


if __name__ == '__main__':
    server_status = get_server_gpu_status()
    for i in server_status:
        print(i)

    violators = filter(server_status, 2)
    '''
    for server in server_status:
        print(server['name'], server['gpu'])
        violators = filter(server, 2)
        print(violators)
        mail_notify(server['name'], server['gpu'], violators)
        print("=" * 20)
    '''