import MySQLdb
import time
import StringIO
import re
from wol import *
import os
from Util import *
import abc
import sqlite3
from mysql2sqlite import mysql_to_sqlite


def isMachineResponding(machineName):
    (returnCode, stdout, stderr) = executeProgram(['ping', '-o', '-t', '1', machineName])
    # log( 'isMachineResponding : result of command %s : %d' % (command, returnCode) )
    
    if returnCode == 0:
        return True
    else:
        bMachineNameIsNotKnown = (returnCode == 68)
        bMachineIsNotResponding = (returnCode == 2)
        if bMachineIsNotResponding is False:
            bBUG_00000004_IS_STILL_ALIVE = True
            if bBUG_00000004_IS_STILL_ALIVE is True and returnCode == 142:
                log('isMachineResponding : bug00000004 Unexpected return code : returnCode=%d, stdout="%s", stderr="%s" , machineName = %s' % (returnCode, stdout, stderr, machineName))
                # don't stop the program until we understand bug00000004
            elif bBUG_00000004_IS_STILL_ALIVE is True and returnCode == -14:  # I had this error code on 07/09/2009 20:38 but I don't know yet what that means
                log('isMachineResponding : bug00000004 Unexpected return code : returnCode=%d, stdout="%s", stderr="%s" , machineName = %s' % (returnCode, stdout, stderr, machineName))
                # don't stop the program until we understand bug00000004
            else:
                log('isMachineResponding : Unexpected return code : returnCode=%d, stdout="%s", stderr="%s" , machineName = %s' % (returnCode, stdout, stderr, machineName))
                assert(False)
        return False


class ISqlDatabaseBackend(object):
    def __init__(self):
        pass

    @abc.abstractmethod
    def query(self, sql_query):
        """
        :param str sql_query: the sql query to perform
        """
        pass


class RemoteMysqlDb(ISqlDatabaseBackend):
    def __init__(self, db_server_fqdn, db_user, db_name):
        """
        :param str db_server_fqdn: the fully qualified domain name of the server hosting the database, eg simpatix10.univ-rennes1.fr
        :param str db_user: the user for accessing the inventory database, eg simpadb_reader
        :param str db_name: the name of the inventory database, eg simpadb
        """
        self._db_server_fqdn = db_server_fqdn
        self._db_user = db_user
        self._db_name = db_name
        self._connect()
        
    def _connect(self):
        self._conn = MySQLdb.connect(self._db_server_fqdn, self._db_user, '', self._db_name)
        assert(self._conn)

    def query(self, sql_query):
        """
        :param str sql_query: the sql query to perform
        """
        self._conn.query(sql_query)
        rows = conn.store_result()
        return rows

        
class SqlFile(ISqlDatabaseBackend):
    def __init__(self, sql_file_path, truncate_hex_strings=False):
        """
        :param str sql_file_path: the path of the sql file containing the inventory database
        """
        self._sql_file_path = sql_file_path
        self._cur = None  # sqlite cursor

        sqlite_db_path = ':memory:'  # sqlite-specific special name for a file stored in memory. We could use something like '/tmp/simpadb.sqlite' here but this would make parsing really slow (1 minute instead of 1s), unless either :
        # - proper fix : group of INSERT statements are surrounded by BEGIN and COMMIT (see http://stackoverflow.com/questions/4719836/python-and-sqlite3-adding-thousands-of-rows)
        # - the file is stored on a solid state disk
        try:
            os.remove(sqlite_db_path)
        except:
            pass
        check_same_thread = False
        # this is to prevent the following error when run from apache/django : SQLite objects created in a thread can only be used in that same thread.The object was created in thread id 139672342353664 and this is thread id 139672333960960
        # accordig to https://stackoverflow.com/questions/48218065/programmingerror-sqlite-objects-created-in-a-thread-can-only-be-used-in-that-sa this is ok, as long as there are no concurrent writes
        # If set False, the returned connection may be shared across multiple threads. When using multiple threads with the same connection writing operations should be serialized by the user to avoid data corruption
        # I hope it's safe here but I'm not 100% sure though. Anyway, if the database gets corrupt, it not a big deal since this memory resident database gets reconstructed from the sql file...
        self._con = sqlite3.connect(sqlite_db_path, check_same_thread=check_same_thread)
        f = open(self._sql_file_path, 'r')
        sql = f.read()  # watch out for built-in `str`
        # print(sql)
        self._cur = self._con.cursor()
        # print(mysql_to_sqlite(sql))
        sqlite_sql = mysql_to_sqlite(sql, truncate_hex_strings)
        # with open('/tmp/toto.sqlite.sql', 'w') as f:
        #    f.write(sqlite_sql)
        # with open('/tmp/toto.sqlite.sql', 'r') as f:
        #    sqlite_sql = f.read()
        self._cur.executescript(sqlite_sql)

    def query(self, sql_query):
        """
        :param str sql_query: the sql query to perform
        """
        pass
        self._cur.execute(sql_query)
        rows = self._cur.fetchall()
        return rows


class TableAttrNotFound(Exception):
    def __init__(self, table, key_name, key_value, attr_name):
        message = "failed to find in table %s a value for %s where %s is %s" % (table, attr_name, key_name, key_value)
        super(TableAttrNotFound, self).__init__(message)
        self.table = table
        self.key_name = key_name
        self.key_value = key_value
        self.attr_name = attr_name


class SqlDatabaseReader(object):
    
    def __init__(self, inv_provider):
        """
        :param ISqlDatabaseBackend inv_provider: the input that provides the inventory data
        """
        self._inv_provider = inv_provider

    def query(self, sql_query):
        """
        performs a query on the sql database
        
        :param str sql_query: the sql query to perform
        """
        return self._inv_provider.query(sql_query)

    def get_table_attr(self, table, key_name, key_value, attr_name):
        """
        reads the value of the fiven attribute of the given item in the given table
        
        :param str table: the name of the table to read
        :param str key_name: the name of the column that stores the id of the item to read
        :param str key_value: the id of the item to read
        :param str attr_name: the name of the attribute to read from the item
        """
        attr_value = None
        rows = self.query("SELECT " + attr_name + " FROM " + table + " WHERE " + key_name + "='" + key_value + "'")
        if len(rows) > 0:
            attr_value = rows[0][0]
        else:
            raise TableAttrNotFound(table, key_name, key_value, attr_name)
        return attr_value


def machineNameToMacAddress(machineName):
    conn = MySQLdb.connect('simpatix10', 'simpadb_reader', '', 'simpadb')
    assert(conn)
    sqlQuery = """SELECT mac_address FROM ethernet_cards WHERE machine_name='""" + machineName + """' AND type='normal'"""
    # print sqlQuery
    conn.query(sqlQuery)
    r = conn.store_result()
    row = r.fetch_row(0)
    assert( len(row) == 1)
    # print 'row =', row
    macAddress = row[0][0]
    # print macAddress
    conn.close()
    return macAddress


def getLightOutManagementIpAddress(machineName):
    """
        the light out management ip of servers allows to talk to the server even when it's asleep
    """
    conn = MySQLdb.connect('simpatix10', 'simpadb_reader', '', 'simpadb')
    assert(conn)
    sqlQuery = """SELECT ip_address_1,ip_address_2,ip_address_3,ip_address_4 FROM ethernet_cards WHERE machine_name='""" + machineName + """' AND type='light_out_management'"""
    # print sqlQuery
    conn.query(sqlQuery)
    r = conn.store_result()
    row = r.fetch_row(0)
    assert(len(row) == 1)
    # print 'row =', row
    ipAddress = ('%s.%s.%s.%s') % (row[0][0], row[0][1], row[0][2], row[0][3])
    # print macAddress
    conn.close()
    return ipAddress


def getClusterMachinesNames():
    clusterMachinesNames = []
    conn = MySQLdb.connect('simpatix10', 'simpadb_reader', '', 'simpadb')
    assert(conn)
    sqlQuery = """SELECT name FROM machines WHERE affectation='cluster'"""
    # print sqlQuery
    conn.query(sqlQuery)
    r = conn.store_result()
    rows = r.fetch_row(0)
    for row in rows:
        # print row
        clusterMachinesNames.append(row[0])
    conn.close()
    return clusterMachinesNames


def machineSupportsIpmi(machineName):
    if (machineName == 'simpatix') or (machineName == 'simpatix01' or (machineName == 'simpa-mac2')):
        # the command ipmitool sensor on simpatix doesn't work :
        # Unabled to establish a session with the BMC.
        # Command failed due to Unknown (0xFFFEF921) (0xFFFEF921)
        return False
    return True


def putToSleep(machineName):
    # note : pmset must be executed as root
    (returnCode, stdout, stderr) = executeCommand(['ssh', machineName, 'pmset sleepnow'])
    """
    print returnCode
    print 'stdout :'
    print stdout
    print 'stderr :'
    print stderr
    """
    assert(returnCode == 0)
    # check if the command succeeded by looking at the output (that's the only way I found)
    f = StringIO.StringIO(stdout)
    line = f.readline()
    f.close()
    matchObj = re.match('^Sleeping now...', line)
    if matchObj:
        return True
    else:
        return False


def wakeUp(machineName):
    macAddress = machineNameToMacAddress(machineName)
    wake_on_lan(macAddress)
    return True

    
def isNonRespondingMachineSleeping(machineName):
    """
        note : crappy method to detect if the machine is sleeping (if other methods are available, I would be very interested)
    """
    wakeUp(machineName)
    time.sleep(120)
    if isMachineResponding(machineName):
        putToSleep(machineName)
        time.sleep(30)  # allow a little time to make sure the machine is ready to receive other wake on lan messages
        return True
    else:
        return False


if __name__ == '__main__':
    """
    for i in range(30):
        machineName = 'simpatix%d' % (i+10)
        print 'lom ip of %s is %s' % (machineName, getLightOutManagementIpAddress(machineName))
    """
    wakeUp('simpatix21')
    # print putToSleep('simpatix13')
    # print isNonRespondingMachineSleeping('simpatix13')