import platform
import os
import socket
import sqlite3
import shutil
import sys
import urllib.request
import urllib
import http.client
import smtplib
from   urllib.error   import URLError, HTTPError
from   datetime       import datetime, timedelta

def email(user, pwd, recipient, subject, body):
    FROM = user
    TO = recipient if isinstance(recipient, list) else [recipient]
    SUBJECT = subject
    TEXT = body

    # Prepare actual message
    message = """From: %s\nTo: %s\nSubject: %s\n\n%s
    """ % (FROM, ", ".join(TO), SUBJECT, TEXT)
    try:
        server = smtplib.SMTP("smtp.gmail.com", 587)
        server.ehlo()
        server.starttls()
        server.login(user, pwd)
        server.sendmail(FROM, TO, message)
        server.close()
        print('成功寄出電子郵件')
    except:
        print("寄送電子郵件發生錯誤！")



deviceName = ""
if len(sys.argv) > 1:
    deviceName = sys.argv[1].lower()
else:
    print("Usage: diskFreeSpace deviceName")
    print("Ex1.:  diskFreeSpace F:")
    print("Ex2.:  diskFreeSpace /")
    print("Ex3.:  diskFreeSpace /Volumes/Macintash\\ HD")
    print("")
    sys.exit(-1)

dbFile = "diskFreeSpace2.db"
conn = sqlite3.connect(dbFile)
print("Opened database successfully")
c = conn.cursor()
c.execute('''
          CREATE TABLE IF NOT EXISTS freeSpaceLog 
          (
            id             INTEGER PRIMARY KEY AUTOINCREMENT,
            freeBits       INTTEGER  NOT NULL DEFAULT 0,
            CRDT           TIMESTAMP          DEFAULT CURRENT_TIMESTAMP,
            delta          INTEGER,
            ZODT           DATETIME
          );
          ''')
print("freeSpaceLog created successfully")
conn.commit()

now1 = datetime.now()
nws1 = now1.strftime("%Y-%m-%d %H:%M:%S")
lastFree = 0
oldDate = now1
results = c.execute("SELECT id, freeBits, CRDT FROM freeSpaceLog ORDER BY id desc LIMIT 1")
for row in results:
   print("id = ", row[0])
   print("freeBits = ", row[1])
   print("CRDT = ", row[2], "\n")
   lastFree = row[1]
   oldDate  = row[2]

total, used, free = shutil.disk_usage(deviceName)
print(free)
c.execute('''
          INSERT INTO freeSpaceLog(freeBits,CRDT) VALUES (
          ''' + str(free) + ",'" + nws1 + "'" + ''')''')
conn.commit()

if lastFree == 0:
   print("This is the first time running and can not estimate usage date!")
   sys.exit(1)

rl2 = c.execute('''
                SELECT MAX(id) from freeSpaceLog
                ''')
maxid = 0
for row in rl2:
    maxid = row[0]
    print("MAX(id) = ", maxid)

spaceUsed = lastFree - free
c.execute("UPDATE freeSpaceLog set delta = " + 
          str(spaceUsed) + 
          " WHERE id = " + str(maxid))
conn.commit()

c.execute("update freeSpaceLog " +
          "set ZODT = datetime(strftime('%s',CRDT) + freeBits / delta * 86400, 'unixepoch', 'localtime') " +
          "WHERE id = " + str(maxid))
conn.commit()

c.execute("""
          update freeSpaceLog 
          set delta = (select avg(delta) from freespacelog where id > 1)
          where id = 1
          """)
conn.commit()

c.execute("""
          update freeSpaceLog
          set ZODT = datetime(strftime('%s',CRDT) + freeBits / delta * 86400, 'unixepoch', 'localtime')
          where id = 1
          """)
conn.commit()

msg = ""
host = socket.gethostname()
if spaceUsed == 0:
    msg = deviceName + " no space used! for " + host
else:
    rl3 = c.execute("SELECT ZODT FROM freeSpaceLog WHERE id = 1")
    diskFullDate = ""
    for row in rl3:
        diskFullDate = row[0]
    msg = host + " disk " + deviceName + " will be full at " + diskFullDate

conn.close()
print(msg)

gmail_user = '請填入您的用來寄信的gmail信箱地址'
gmail_password = '請填入您的gmail密碼'
email_to = '請填入收信的電子郵件信箱' 
subject = 'diskFreeSpace2 硬碟空間資訊'
body = msg

email(gmail_user,gmail_password,email_to,subject,body)



'''
目的：監視硬碟空間與估計硬碟空間用完的日期。
作者：寶焰自在工作室  徐承岳  Mario Hsu。
沿革：
     2020-05-25  0.0.0.3  1.為了釋出，方便應用，訊息通知改由Email來完成。
                          2.變更檔案名稱為diskFreeSpace2.py。
                          3.產生的資料庫檔案也變更為diskFreeSpace2.db。
                          4.email函式來自 https://stackoverflow.com/questions/10147455/how-to-send-an-email-with-gmail-as-provider-using-python
     2019-11-09  0.0.0.2  1.增加資料庫欄位。
                          2.變更估計用完日期採平均數計算。
     2019-11-04  0.0.0.1  1.誕生日。
'''