Database fix for rpi2caster 0.3 - store wedge definitions in a single column

rpi2caster_db_fix_03.py

#!/usr/bin/env python3
import os
from rpi2caster import database
from rpi2caster import matrix_data


DB = database.Database()


def correct_diecases():
    """Changes wedge_series, set_width -> wedge_name"""
    with DB.db_connection:
        cursor = DB.db_connection.cursor()
        cursor.execute('ALTER TABLE matrix_cases '
                       'RENAME TO old_matrix_cases')
        cursor.execute('CREATE TABLE matrix_cases ('
                       'diecase_id TEXT UNIQUE PRIMARY KEY, '
                       'typeface TEXT, '
                       'wedge TEXT, '
                       'layout TEXT NOT NULL)')
        cursor.execute('SELECT * FROM old_matrix_cases')
        diecases = cursor.fetchall()
        for diecase_definition in diecases:
            [diecase_id, type_series, type_size, wedge_series,
             set_width, typeface_name, layout] = diecase_definition
            if not set_width % 1:
                set_width = int(set_width)
            wedge_name = 'S%s-%sE' % (wedge_series, set_width)
            typeface = '%s-%s %s' % (type_series, type_size, typeface_name)
            data = [diecase_id, typeface, wedge_name, layout]
            cursor.execute('INSERT OR REPLACE INTO matrix_cases ('
                           'diecase_id, typeface, wedge, layout'
                           ') VALUES (?, ?, ?, ?)''', data)
        cursor.execute('DROP TABLE wedges')
        cursor.execute('DROP TABLE old_matrix_cases')
        DB.db_connection.commit()

with DB.db_connection:
    cursor = DB.db_connection.cursor()
    cursor.execute('PRAGMA table_info(matrix_cases)')
    column_items = [col_item[1] for col_item in cursor.fetchall()]
if column_items == ['diecase_id', 'type_series', 'type_size',
                    'wedge_series', 'set_width', 'typeface_name',
                    'layout']:
    print('You have an old style diecases table. This will be changed '
          'with rpi2caster 0.3')
    old_style = True
else:
    print('Your database is already corrected. '
          'No need to do anything.')
    old_style = False
        
try:
    os.system('cp %s %s' % (DB.path, DB.path + '.bak'))
    if old_style:
        print('This will correct the database, so that there is'
              ' a single column "wedges" and "typeface".')
        correct_diecases()
        print('Now check if there are the same diecases '
              'as you had before...')
        matrix_data.list_diecases()
except AttributeError:
    print('You are using older version of the program. '
          'No need to change the database.')