import os
import sys
import psycopg2
import pdb

class Database():

    name = 'database library'

    def __init__(self, config_file=None, db=None, db_user=None, db_user_password=None):

        self.config_file = "config/db_config.txt"
        self.db = self.__get_parameter("db", self.config_file)
        self.db_user = self.__get_parameter("db_user", self.config_file)
        self.db_user_password = self.__get_parameter("db_user_password", self.config_file)

        db_setup = self.__check_dbsetup(self)

        if not db_setup:

            self.db = input("\nversions database name: ")
            self.db_user = input("\nversions database user: ")
            self.db_user_password = input("\nversions database user password: ")

            self.__create_config(self)
            self.__write_config(self)

    def get_versions(self):

        topten_servers = []

        topten_versions = []

        topten_users = []

        try:

            conn = None

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

            cur = conn.cursor()

            cur.execute("select count(version), version, sum(users) from mau where software='mastodon' and alive group by version order by count(version) desc limit 10")

            rows = cur.fetchall()

            for row in rows:

                topten_servers.append(row[0])

                topten_versions.append(row[1])

                topten_users.append(row[2])

            cur.execute("select count(version) from mau where software='mastodon' and alive")

            row = cur.fetchone()

            mast_servers = row[0]

            cur.execute ("select sum(users) from mau where software='mastodon' and alive")

            row = cur.fetchone()

            mast_users = row[0]

            cur.close()

        except (Exception, psycopg2.DatabaseError) as error:

          print(error)

        finally:

          if conn is not None:

            conn.close()

        return (topten_servers, topten_versions, topten_users, mast_servers, mast_users)

    @staticmethod
    def __check_dbsetup(self):

        db_setup = False

        try:

            conn = None

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

            db_setup = True

        except (Exception, psycopg2.DatabaseError) as error:

            print(error)

        return db_setup

    def __get_parameter(self, parameter, config_file):

        if not os.path.isfile(config_file):
            print(f"File {config_file} not found..")
            return

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

        print(f"{config_file} Missing parameter {parameter}")

        sys.exit(0)

    @staticmethod
    def __create_config(self):

        if not os.path.exists('config'):

            os.makedirs('config')

        if not os.path.exists(self.config_file):

            print(self.config_file + " created!")
            with open(self.config_file, 'w'): pass

    @staticmethod
    def __write_config(self):

        with open(self.config_file, 'a') as the_file:

            the_file.write(f'db: {self.db}\ndb_user: {self.db_user}\ndb_user_password: {self.db_user_password}')

            print(f"adding parameters to {self.config_file}\n")