import psycopg2
import yaml

# get the parameters to connect

def __run__(params):
    conn = None
    try:
        conn = psycopg2.connect(host=params.get('host'),
                port=int(params.get('port')),
                database=params.get('dbname'),
                user=params.get('user'),
                password=params.get('passwd'))
        cursor = conn.cursor()

# get slave lag
        cursor.execute("""
                SELECT
                CASE WHEN pg_last_xlog_receive_location() = pg_last_xlog_replay_location()
                THEN 0
                ELSE EXTRACT (EPOCH FROM now() - pg_last_xact_replay_timestamp())::INTEGER
                END AS log_delay;
                """)
        slave_lag = cursor.fetchone()[0]

        if slave_lag > 2:
            return[2, 'CRITICAL: Replication is not synchronized! Lag: %s' % slave_lag]
        elif slave_lag == 0:

            # verify this database is powerdns
            database = ''
            cursor.execute("select current_database()")
            database = cursor.fetchone()

            if database[0] == 'powerdns':

                thresolds = yaml.load(params.get('thresholds'))

                cursor.execute("""SELECT 'monit' AS object_name, replication_monit.d, 
                                (date_part('epoch'::text, now() - replication_monit.d::timestamp with time zone) / 60::double precision)::integer AS age
                                FROM replication_monit
                                LIMIT 1;
                                """)
                (name, d, d_int) = cursor.fetchone()

                if d_int > int(thresolds['critical']):
                    return [2, 'CRITICAL: Behind {0} minutes'.format(d_int)]
                elif d_int > int(thresolds['warning']):
                    return [1, 'WARNING: Behind {0} minutes'.format(d_int)]
                else:
                    return[0, 'OK: Replication synchronized! Behind {0} minutes.'.format(d_int)]
            else:
                return[0, 'OK: Replication synchronized!']
        else:
            return[2, 'CRITICAL: Impossible to determine the lag']
    except Exception, e:
         return [2, 'CRITICAL: {0}'.format(str(e))]
         print "erro"
    finally:
        try:
            if conn:
                conn.close()
        except:
            # finally clause, don't bother about errors here
            pass