# -*- coding: utf-8 -*-
import argparse
import logging
import sys
import threading

import pymysql.cursors

from datetime import datetime


reload(sys)
sys.setdefaultencoding('utf8')

DATE_FORMAT = '%Y-%m-%d %H:%M:%S'


def db_conn(host, port, username, password, database, charset='utf8'):
    return pymysql.connect(
        host=host,
        port=port,
        user=username,
        password=password,
        db=database,
        charset=charset,
        cursorclass=pymysql.cursors.DictCursor)


class CleanTask(threading.Thread):

    def __init__(self, from_dt, to_dt):
        threading.Thread.__init__(self)
        self.start_dt = from_dt
        self.end_dt = to_dt

    def run(self):
        # tidb database
        host = '10.30.1.4'
        port = 4000
        username = 'root'
        password = ''
        database = 'lock_event_log'
        conn = db_conn(host, port, username, password, database)

        batch_size = 1000
        _dml = '''
        DELETE FROM `mbk_lock_event`
        WHERE CREATE_TIME >= '%s'
              AND CREATE_TIME < '%s'
            LIMIT %d
        '''

        _start_dt= self.start_dt.strftime(DATE_FORMAT)
        _end_dt= self.end_dt.strftime(DATE_FORMAT)

        count = 0
        with conn.cursor() as cursor:
            result = cursor.execute(_dml % (_start_dt, _end_dt, batch_size))
            conn.commit()
            count += result
            while result > 0:
                result = cursor.execute(_dml % (_start_dt, _end_dt, batch_size))
                conn.commit()
                count += result

        logging.info('delete %d records, time range [%s, %s)', count, self.start_dt.strftime(DATE_FORMAT), self.end_dt.strftime(DATE_FORMAT))


def dispatch_task(start_dt, end_dt, chunks):
    logging.info('Start data processing...')

    # dispatch task
    tasks = []

    slot = (end_dt - start_dt) / chunks
    n = 0
    for b, e in [(i*slot + start_dt, (i+1)*slot + start_dt) for i in xrange(chunks)]:
        logging.info("Task %d, time range [%s, %s)", n, b.strftime(DATE_FORMAT), e.strftime(DATE_FORMAT))
        task = CleanTask(b, e)
        tasks.append(task)
        n += 1

    for t in tasks:
        t.start()

    for t in tasks:
        t.join()

    logging.info('Finish data processing')


def main():
    arg_parser = argparse.ArgumentParser()
    arg_parser.add_argument('start_time', type=str, help='start time')
    arg_parser.add_argument('end_time', type=str, help='end time')
    arg_parser.add_argument('--chunks', type=int, default=1, help='# of chunks')
    args = arg_parser.parse_args()

    start_dt = datetime.strptime(args.start_time, DATE_FORMAT)
    end_dt = datetime.strptime(args.end_time, DATE_FORMAT)

    dispatch_task(start_dt, end_dt, args.chunks)


if __name__ == '__main__':
    # define logging
    root = logging.getLogger()
    root.setLevel(logging.DEBUG)

    ch = logging.StreamHandler(sys.stdout)
    ch.setLevel(logging.DEBUG)
    formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
    ch.setFormatter(formatter)
    root.addHandler(ch)

    main()