1.  **`/mnt/ssd_data/html/early_access/db_migration.php`**: Create a new file named `db_migration.php` to handle the data migration logic. This script will be responsible for connecting to the database, reading data from the `timetable` table, and inserting data into the `locations` table.
2.  **`/mnt/ssd_data/html/early_access/db_migration.php`**: Implement database connection logic in `db_migration.php`. Include error handling for database connection failures.
3.  **`/mnt/ssd_data/html/early_access/db_migration.php`**: Implement logic to read `_location` data from the `timetable` table within `db_migration.php`. Handle cases where the `_location` field is null or empty.
4.  **`/mnt/ssd_data/html/early_access/db_migration.php`**: Implement logic to insert location data into the `locations` table within `db_migration.php`. Ensure that the script handles potential database errors during insertion.
5.  **`/mnt/ssd_data/html/early_access/db_migration.php`**: Implement logic in `db_migration.php` to prevent duplicate entries in the `locations` table based on location name/details.
6.  **`/mnt/ssd_data/html/early_access/db_migration.php`**: Create a rollback mechanism within `db_migration.php` in case the data migration fails midway. This mechanism should revert any changes made to the database.
7.  **`/mnt/ssd_data/html/early_access/config.php`**: Add Google Calendar API credentials to the configuration file (`config.php`).
8.  **`/mnt/ssd_data/html/early_access/google_calendar_api.php`**: Create a new file named `google_calendar_api.php` and implement functions for authenticating with the Google Calendar API. Include error handling for authentication failures.
9.  **`/mnt/ssd_data/html/early_access/google_calendar_api.php`**: Implement a function in `google_calendar_api.php` to fetch calendar events. Include error handling for API request failures.
10. **`/mnt/ssd_data/html/early_access/google_calendar_api.php`**: Implement a function in `google_calendar_api.php` to create new calendar events. Include error handling and retry mechanisms for API request failures.
11. **`/mnt/ssd_data/html/early_access/google_calendar_api.php`**: Implement a function in `google_calendar_api.php` to update existing calendar events. Include error handling and retry mechanisms for API request failures.
12. **`/mnt/ssd_data/html/early_access/google_calendar_api.php`**: Implement a function in `google_calendar_api.php` to delete calendar events. Include error handling.
13. **`/mnt/ssd_data/html/early_access/config.php`**: Add Google Maps API key to the configuration file (`config.php`).
14. **`/mnt/ssd_data/html/early_access/google_maps_api.php`**: Create a new file named `google_maps_api.php` and implement a function to geocode addresses using the Google Maps API. Include error handling and retry mechanisms.
15. **`/mnt/ssd_data/html/early_access/google_maps_api.php`**: Implement a function in `google_maps_api.php` to calculate distances between locations using the Google Maps API. Include error handling.
16. **`/mnt/ssd_data/html/early_access/db_migration.php`**: Integrate Google Maps API calls within `db_migration.php` to fetch geographic coordinates (latitude, longitude) for each location and store it in the `locations` table. Handle API rate limits and errors gracefully.
17. **`/mnt/ssd_data/html/early_access/timetable.php`**: Modify the `timetable.php` file (or relevant files where location data is used) to use the new `locations` table for retrieving and displaying location information.
18. **`/mnt/ssd_data/html/early_access/admin.php`**: Modify `admin.php` to reflect changes in the locations table and any admin functions using locations.
19. **`/mnt/ssd_data/html/early_access/coachs-site.php`**: Modify `coachs-site.php` to reflect changes in the locations table.
20. **`/mnt/ssd_data/html/early_access/db_migration.php`**: Add logging to `db_migration.php` to record the progress and any errors encountered during the migration.
21. **`/mnt/ssd_data/html/early_access/db_migration.php`**: Implement a mechanism to trigger the `db_migration.php` script automatically upon deployment or application update.
22. **`/mnt/ssd_data/html/early_access/index.php`**: Schedule db_migration.php with a CRON-JOB.