I am writing a plugin in which I have to start by setting it up before using it. This means I may need to update wp-config.php

I know how to edit wp-config.php directly. However the requirement is to also be able to modify it via the plugin settings page. Once the user chooses the correct settings and saves, those settings are updated (added or modified) in wp-config.php

So is there a WordPress method that allows me to find the wp-config file? Is there a WordPress method or API that allows me to update the wp-config.php file? Is there a method that allows me to find and read then edit the wp-config.php entries?

Thanks.