import random
import string
import sys
import uuid

import sqlalchemy as sa


TOTAL = 10000000
BATCH_SIZE = 10000


meta = sa.MetaData()

users = sa.Table(
    'users', meta,
    sa.Column('user_id', sa.Integer, primary_key=True, nullable=False),
    sa.Column('external_id', sa.String(32), unique=True, nullable=False),
    sa.Column('name', sa.String(32), unique=True, nullable=False),
    sa.Column('metadata', sa.Text),
    sa.Column('date_created', sa.DateTime, server_default=sa.text('now()'), nullable=False, index=True),
    mysql_engine='innodb',
)

eng = sa.create_engine('mysql+pymysql://root:devel@127.0.0.1:3306/devel')
meta.create_all(bind=eng, checkfirst=True)


n_rows = eng.execute(sa.select([sa.func.count(users.c.user_id)])).scalar()
if not n_rows:
    count = 0
    with eng.begin():
        for _ in range(TOTAL // BATCH_SIZE):
            data = [
                {'external_id': str(uuid.uuid4()).replace('-', ''),
                 'name': ''.join(random.choice(string.ascii_letters) for _ in range(12)),
                 'metadata': 'something'}
                for _ in range(BATCH_SIZE)
            ]
            eng.execute(users.insert().values(data))

            count += BATCH_SIZE
            print('Inserted %d rows...' % count)

print('Total rows: %d' % eng.execute(sa.select([sa.func.count(users.c.user_id)])).scalar())