"""Entrypoint."""

import os

import pymysql

user = os.environ['DB_USER']
password = os.environ['DB_PASSWORD']
host = os.environ['DB_HOST']
schema = os.environ['DB_SCHEMA']
port = os.environ.get('DB_PORT', 3306)

DB_CONN = pymysql.connect(
    host=host,
    user=user,
    password=password,
    database=schema,
    cursorclass=pymysql.cursors.DictCursor
)

INT_MAP = {
    'TINYINT': (127, 255),
    'SMALLINT': (32767, 65535),
    'MEDIUMINT': (8388607, 16777215),
    'INT': (2147483647, 4294967295),
    'BIGINT': (9223372036854775807, 18446744073709551615)
}


def main():
    """Docstring."""
    _valid(schema)
    table_names = [
        x[f'Tables_in_{schema}']
        for x in query(f'SHOW FULL tables FROM {schema} WHERE Table_type = "BASE TABLE";')  # noqa:E501
    ]

    for table in table_names:
        results = query(f'SHOW CREATE TABLE `{table}`;')
        create_stmt = results[0]['Create Table']
        lines = [
            y for y in create_stmt.split('\n')
            if 'AUTO_INCREMENT' in y
        ]
        if len(lines) != 2:
            continue
        int_type = lines[0].split()[1].upper()
        unsigned = lines[0].split()[2].upper() == 'UNSIGNED'
        int_value = int([x for x in lines[1].split() if 'AUTO_INCREMENT' in x][0].split('=')[1])  # noqa:E501
        max_int = INT_MAP[int_type][1] if unsigned else INT_MAP[int_type][0]  # noqa:E501
        percent_full = (int_value / max_int) * 100
        print(f'{table},{int_type},{unsigned},{percent_full}')


def query(sql, params=dict()):
    """Perform query."""
    with DB_CONN.cursor() as cursor:
        cursor.execute(sql, params)
        results = cursor.fetchall()
    return results


def _valid(string):
    if not string.replace('_', '').isalnum():
        raise Exception(f'{string} not valid for direct query injection')
    return string


if __name__ == '__main__':
    main()