import os
import sys
from datetime import datetime, timezone, timedelta
import time
try:
    import psycopg2
except ModuleNotFoundError as mod_not_found:
    print(f"{mod_not_found}'. Run 'pip install -r requirements.txt' and try again")
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
import smtplib
from smtplib import SMTPException, SMTPAuthenticationError, SMTPConnectError, SMTPRecipientsRefused
import socket
from socket import gaierror

def smtp_config():

    secrets_filepath = "secrets/secrets.txt"
    smtp_host = get_parameter("smtp_host", secrets_filepath)
    smtp_user_login = get_parameter("smtp_user_login", secrets_filepath)
    smtp_user_password = get_parameter("smtp_user_password", secrets_filepath)
    email_subject = get_parameter("email_subject", secrets_filepath)

    return (smtp_host, smtp_user_login, smtp_user_password, email_subject)

def db_config():

    config_filepath = "config/db_config.txt"
    mastodon_db = get_parameter("mastodon_db", config_filepath)
    mastodon_db_user = get_parameter("mastodon_db_user", config_filepath)
    mailing_db = get_parameter("mailing_db", config_filepath)
    mailing_db_user = get_parameter("mailing_db_user", config_filepath)
    mailing_db_table = get_parameter("mailing_db_table", config_filepath)
    inactive_days = get_parameter("inactive_days", config_filepath)

    return (mastodon_db, mastodon_db_user, mailing_db, mailing_db_user, mailing_db_table, inactive_days)

def get_parameter( parameter, file_path ):
    
    # Check if secrets file exists
    if not os.path.isfile(file_path):
        if file_path == "secrets/secrets.txt":
            print("File %s not found, exiting. Run setup.py."%file_path)
        elif file_path == "config/db_config.txt":
            print("File %s not found, exiting. Run db-setup.py."%file_path)
        sys.exit(0)

    # Find parameter in file
    with open( file_path ) as f:
        for line in f:
            if line.startswith( parameter ):
                return line.replace(parameter + ":", "").strip()

    # Cannot find parameter, exit
    print(file_path + "  Missing parameter %s "%parameter)
    print("Run setup.py")
    sys.exit(0)

class Inactives:

    name = "Inactives"

    def __init__(self):

        smtp_host, smtp_user_login, smtp_user_password, email_subject = smtp_config()
        
        mastodon_db, mastodon_db_user, mailing_db, mailing_db_user, mailing_db_table, inactive_days = db_config()

        self.smtp_host = smtp_host
        self.smtp_user_login = smtp_user_login
        self.smtp_user_password = smtp_user_password
        self.email_subject = email_subject
        self.mastodon_db = mastodon_db
        self.mastodon_db_user = mastodon_db_user
        self.mailing_db = mailing_db
        self.mailing_db_user = mailing_db_user
        self.mailing_db_table = mailing_db_table
        self.inactive_days = inactive_days
        self.now = datetime.now(timezone.utc)

    def id(self):

        ###############################################################################
        # get id of inactive users from inactive database

        conn = None

        try:

            conn = psycopg2.connect(database = self.mailing_db, user = self.mailing_db_user, password = "", host = "/var/run/postgresql", port = "5432")

            cur = conn.cursor()

            cur.execute("SELECT account_id FROM " + self.mailing_db_table)

            rows = cur.fetchall()

            if rows != []:

                inactive_users_id = []

                for row in rows:

                    inactive_users_id.append(row[0])

            else:

                inactive_users_id = []

            cur.close()

            return inactive_users_id

        except (Exception, psycopg2.DatabaseError) as error:

            print(error)

        finally:

            if conn is not None:

                conn.close()

    def delete(self,ids_lst):

        print(f'\nChecking {len(ids_lst)} ids to delete reactivated or deleted accounts...')
        
        i = 0

        while i < len(ids_lst):

            seen = self.check_alive(self, ids_lst[i])

            try:

                conn = psycopg2.connect(database = self.mailing_db, user = self.mailing_db_user, password = "", host = "/var/run/postgresql", port = "5432")

                cur = conn.cursor()

                cur.execute("SELECT emailed_at FROM " + self.mailing_db_table + " where account_id=(%s)", (ids_lst[i],))

                row = cur.fetchone()

                email_datetime = row[0]

                email_datetime = email_datetime.replace(tzinfo=None)

                if seen != None:

                    reactivated = email_datetime < seen

                    last_year = datetime.today() - timedelta(days=int(self.inactive_days))

                if reactivated == True or seen == None or seen > last_year: #if inactive user had reactivated its account or had deleted it we must delete related row from 'mailing_db_table'

                    cur.execute("DELETE FROM " + self.mailing_db_table + " where account_id=(%s)", (ids_lst[i],))

                    print(f"Deleting user {ids_lst[i]}")

                    conn.commit()

                cur.close()

                i += 1

            except (Exception, psycopg2.DatabaseError) as error:

                print(error)

            finally:

                if conn is not None:

                    conn.close()

    def get_inactives(self):

        ###############################################################################
        # Connect to Mastodon's Postgres DB to get last six months inactive users 
        ###############################################################################

        conn = None

        try:

            conn = psycopg2.connect(database = self.mastodon_db, user = self.mastodon_db_user, password = "", host = "/var/run/postgresql", port = "5432")

            cur = conn.cursor()

            cur.execute("select account_id, email, current_sign_in_at from users where current_sign_in_at < now() - interval '" + self.inactive_days + " days' and disabled=False and approved=True order by current_sign_in_at desc")
            
            rows = cur.fetchall()

            inactive_account_id = []
            
            inactive_email = []

            current_sign_in_at = []

            for row in rows:
                
                inactive_account_id.append(row[0])

                inactive_email.append(row[1])

                current_sign_in_at.append(row[2])

            cur.close()
            
            print(f'inactive accounts found: {len(inactive_account_id)}')

            return (inactive_account_id, inactive_email, current_sign_in_at)

        except (Exception, psycopg2.DatabaseError) as error:

            print(error)

        finally:

            if conn is not None:

                conn.close()

    def usernames(self, account_ids):

        ########################################################################################################
        # get accounts usernames                                                                                #
        ########################################################################################################

        inactive_usernames = []

        i = 0
        while i < len(account_ids):

            conn = None

            try:

                conn = psycopg2.connect(database = self.mastodon_db, user = self.mastodon_db_user, password = "", host = "/var/run/postgresql", port = "5432")

                cur = conn.cursor()

                inactive_id = account_ids[i]

                cur.execute("select username from accounts where id = '%s';", [inactive_id])

                row = cur.fetchone()

                new_username = row[0]

                inactive_usernames.append(new_username)

                i += 1

                cur.close()

            except (Exception, psycopg2.DatabaseError) as error:

                print(error)

            finally:

                if conn is not None:

                    conn.close()

        return inactive_usernames

    def mailing(self, account_ids, account_emails, account_usernames, account_current_sign_in_ats):

        ###########################################################################################################
        # email inactive users

        try:

            fp = open('message.txt')
            text = fp.read()
            message = MIMEText(text)
            fp.close()
      
        except:

            print("message.txt file not found! Create it and write in the message you want for your inactive users.")
            sys.exit(0)

        i = 0
        while i < len(account_emails):

            been_emailed = self.email_sent(self, account_ids[i])

            if been_emailed == False:

                # Create message object instance
                msg = MIMEMultipart()

                # Declare message elements
                msg['From'] = self.smtp_user_login
                msg['To'] = account_emails[i]
                msg['Subject'] = account_usernames[i] + " " + self.email_subject

                # Add the message body to the object instance
                msg.attach(message)

                try:

                    # Create the server connection
                    server = smtplib.SMTP(self.smtp_host)
                    # Switch the connection over to TLS encryption
                    server.starttls()
                    # Authenticate with the server
                    server.login(self.smtp_user_login, self.smtp_user_password)
                    # Send the message
                    server.sendmail(msg['From'], msg['To'], msg.as_string())
                    # Disconnect
                    server.quit()

                    print("Successfully sent email message to %s" % msg['To'])
                    emailed = True

                    self.write_db(self, self.now, account_ids[i], account_usernames[i], account_emails[i], self.now, emailed, account_current_sign_in_ats[i]) 

                    i += 1
                    time.sleep(5)

                except SMTPAuthenticationError as auth_error:

                    print(auth_error)
                    sys.exit(":-(")

                except socket.gaierror as socket_error:

                    print(socket_error)
                    print("Unknown SMTP server")
                    sys.exit(":-(")

                except SMTPRecipientsRefused as recip_error:

                    print(recip_error)
                    emailed = False
                    self.write_db(self, self.now, account_ids[i], account_usernames[i], account_emails[i], self.now, emailed, account_current_sign_in_ats[i])
                    i += 1

            else:

                emailed = True
                self.write_db(self, self.now, account_ids[i], account_usernames[i], account_emails[i], self.now, emailed, account_current_sign_in_ats[i])
                i += 1

    @staticmethod
    def write_db(self, now, id, username, email, emailed_at, emailed, current_sign_in_at):
        
        ###################################################################################
        # write to mailing database the status of inactive users


        insert_line = "INSERT INTO " + self.mailing_db_table + "(datetime, account_id, username, email, emailed_at, emailed, current_sign_in_at) VALUES(%s,%s,%s,%s,%s,%s,%s) ON CONFLICT DO NOTHING"

        conn = None

        try:

            conn = psycopg2.connect(database = self.mailing_db, user = self.mailing_db_user, password = "", host = "/var/run/postgresql", port = "5432")

            cur = conn.cursor()

            cur.execute("SELECT account_id FROM " + self.mailing_db_table + " where account_id=(%s)", (id,))

            row = cur.fetchone()

            if row == None:

                cur.execute(insert_line, (now, id, username, email, now, emailed, current_sign_in_at))

            else:

                if emailed == True:

                    cur.execute("SELECT datetime FROM " + self.mailing_db_table + " where account_id=(%s)", (id,))

                    row = cur.fetchone()

                    delta = now-row[0]

                    cur.execute("UPDATE " + self.mailing_db_table + " SET elapsed_days=(%s), email=(%s), emailed=(%s), current_sign_in_at=(%s) where account_id=(%s)", (delta.days, email, emailed, current_sign_in_at, id))

                    print(f"Updating user {str(id)}")

            conn.commit()

            cur.close()

        except (Exception, psycopg2.DatabaseError) as error:

            print(error)

        finally:

            if conn is not None:

                conn.close()

    @staticmethod
    def email_sent(self, account_id):

        ###############################################################################
        # check if inactive user had been already emailed

        been_emailed = False

        conn = None
        
        try:

            conn = psycopg2.connect(database = self.mailing_db, user = self.mailing_db_user, password = "", host = "/var/run/postgresql", port = "5432")

            cur = conn.cursor()

            cur.execute("SELECT emailed FROM " + self.mailing_db_table + " where account_id=(%s)", (account_id,))

            row = cur.fetchone()

            if row != None:

                been_emailed = row[0]

            cur.close()

            return been_emailed

        except (Exception, psycopg2.DatabaseError) as error:

            print(error)

        finally:

            if conn is not None:

                conn.close()

    @staticmethod
    def check_alive(self, id):

        conn = None

        try:

            conn = psycopg2.connect(database = self.mastodon_db, user = self.mastodon_db_user, password = "", host = "/var/run/postgresql", port = "5432")

            cur = conn.cursor()

            cur.execute("select current_sign_in_at from users where account_id=(%s)", (id,))

            row = cur.fetchone()

            if row != None:
                
                seen = row[0]
            else:
                
                seen = None
            
            cur.close()

            return seen

        except (Exception, psycopg2.DatabaseError) as error:

            print(error)