#!/usr/bin/env python
"""
.. module:: MySQL
    :synopsis: Module providing a mysql type service

.. moduleauthor:: Dave Pedu <dave@davepedu.com>

"""

from pyircbot.modulebase import ModuleBase
import sys
import pymysql as MySQLdb  # python 3.x


class MySQL(ModuleBase):
    def __init__(self, bot, moduleName):
        ModuleBase.__init__(self, bot, moduleName)
        self.services = ["mysql"]
        self.connection = self.getConnection()

    def getConnection(self):
        return Connection(self)


class Connection:
    def __init__(self, master):
        self.config = master.config
        self.log = master.log
        self._connect()

    # Check if the table requested exists
    def tableExists(self, tablename):
        c = self.getCursor()
        c.execute("SHOW TABLES;")
        tables = c.fetchall()
        if len(tables) == 0:
            return False
        key = list(tables[0].keys())[0]
        for table in tables:
            if table[key] == tablename:
                return True
        return False

    def query(self, queryText, args=()):
        """Execute a MySQL query and return the cursor

        :param queryText: the mysql query as a string, using '%s' for token replacement
        :type queryText: str
        :param args: arguments to be escaped into the query
        :type args: tuple
        :returns: cursor -- the sql cursor"""
        c = self.getCursor()
        if len(args) == 0:
            c.execute(queryText)
        else:
            c.execute(queryText, args)
        return c

    # Returns a cusor object, after checking for connectivity
    def getCursor(self):
        self.ensureConnected()
        if sys.version_info > (3, 0):
            c = self.connection.cursor(MySQLdb.cursors.DictCursor)
        else:
            c = self.connection.cursor(cursorclass=MySQLdb.cursors.DictCursor)
        c.execute("USE `%s`;" % self.config["database"])
        return c

    def escape(self, s):
        """Escape a string using the mysql server

        :param s: the string to escape
        :type s: str
        :returns: str -- the escaped string"""
        self.ensureConnected()
        return self.connection.escape_string(s)

    def ensureConnected(self):
        try:
            self.connection.ping()
        except:
            try:
                self.connection.close()
            except:
                pass
            del self.connection
            self._connect()

    def ondisable(self):
        self.connection.close()

    # Connects to the database server, and selects a database (Or attempts to create it if it doesn't exist yet)
    def _connect(self):
        self.log.info("MySQL: Connecting to db host at %s" % self.config["host"])
        self.connection = MySQLdb.connect(host=self.config["host"], user=self.config["username"],
                                          passwd=self.config["password"])
        self.log.info("MySQL: Connected.")
        self.connection.autocommit(True)
        c = None
        if sys.version_info > (3, 0):
            c = self.connection.cursor(MySQLdb.cursors.DictCursor)
        else:
            c = self.connection.cursor(cursorclass=MySQLdb.cursors.DictCursor)

        c.execute("SHOW DATABASES")
        dblist = c.fetchall()
        found = False
        for row in dblist:
            if row["Database"] == self.config["database"]:
                found = True
        if not found:
            c.execute("CREATE DATABASE `%s`;" % self.config["database"])
        c.execute("USE `%s`;" % self.config["database"])
        c.close()