import select

from sh import tail

# Connection to Mediawiki database.
dbconnection = mysql.connector.connect(user='dbuser', password='dbpassword', database='mediawikidb')

# Non-interactive Mysql cmd line to pipe commands through.
dbcursor = dbconnection.cursor()

# Blocklist Mysql query.
ipblocks_query = ("select ipb_address from ipblocks where ipb_address=%s")
# User Mysql query.
user_query = ("select user_name from user where user_name=%s")

table = iptc.Table(iptc.Table.FILTER)
rule = iptc.Rule()
chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), "INPUT")

# Iterate through each line in log-file.
f = subprocess.Popen(['tail','-F',"/var/log/nginx.log"],\
        stdout=subprocess.PIPE,stderr=subprocess.PIPE)
p = select.poll()
p.register(f.stdout)

while True:
        if p.poll(1):
                line = f.stdout.readline()
        # Select lines which contain an IP address at line start AND user talk page reference.
                if re.findall("^\d+\.\d+\.\d+\.\d+", line) and re.findall("User:\w+", line):
                        found = 0
                        # Replace line with IP address and user reference only.
                        line = re.findall("^\d+\.\d+\.\d+.\d+|User:\w+", line)
                        # Check if ip address is already blocked by iptables.
                        for chain in table.chains:
                                for rule in chain.rules:
                                        if re.sub("/255.255.255.255", "", rule.src) == line[0]:
                                                found = 1
                                                break
                        if found == 0:
                                line[1] = re.sub("User:", "", line[1])
                                line[1] = re.sub("_"," ", line[1])
                                # Query user against ipblocks table.
                                dbcursor.execute(ipblocks_query, (line[1],))
                                print (line[1])
                                row = dbcursor.fetchone()
                                # If user exists in ipblocks table.
                                if row is not None:
                                        print ("Is banned!")
                                        # If not found add to iptables.
                                        rule.in_interface = "eth0"
                                        rule.src = line[0]
                                        t = rule.create_target("DROP")
                                        chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), "INPUT")
                                        chain.insert_rule(rule)
                                        print ("Blocking IP address with iptables")
                                        print ("-")
                                # Check if user exists in user table.
                                else:
                                        dbcursor.execute(user_query, (line[1],))
                                        row = dbcursor.fetchone()
                                        if row is not None:
                                                print ("Is not banned!")
                                                print ("-")
                                        # If user doesn't exist block IP with iptables..
                                        else:
                                                print ("Does not exist!")
                                                rule.in_interface = "eth0"
                                                rule.src = line[0]
                                                t = rule.create_target("DROP")
                                                chain = iptc.Chain(iptc.Table(iptc.Table.FILTER), "INPUT")
                                                chain.insert_rule(rule)
                                                print ("Blocking IP address with iptables")
                                                print ("-")
        time.sleep(1)