Playing around with features

Features.php

<?php

// could be abstract class?
interface FeatureInterface {
	function isSupported();
}

interface LetmeinInterface extends FeatureInterface {
	function letmein($username, $password);
}

class CWPLetmein implements LetmeinInterface {

	function _construct(\CWPEnvironment $environment) {
		$this->env = $environment;
	}

	function isSupported() {
		// CWPLetmeInConfig is a DataObject with a HasOne to CWPEnvironment that contains data
		// that DNEnvironment shouldnt care about. It's a feature specific data stored somewhere ...
		$config = CWPLetmeInConfig::get()->where('CWPEnvironmentID', $this->env->ID);
		return $config->isEnabled;
	}

	function letmein($username, $password) {
		$config = CWPLetmeInConfig::get()->where('CWPEnvironmentID', $this->env->ID);
		$config->username = $username;
		$config->password = $password;
		$config->write();
		$this->schedulePuppetRerun($config);
		return true;
	}
}

class RainforestLetmein implements LetmeinInterface  {

	function _construct(\RainforestEnvironment $environment) {
		$this->env = $environment;
	}

	function isSupported() {
		if (!$this->env->manifestAtLeat('4.1.3')) {
			throw new BackendUnsupportedException('at least 4.1.3');
		}
		return true;
	}

  // Use $this->env to get base data, maybe this backend queries some other data?
	function letmein($username, $password) {
		return true;
	}
}

// mysite specific environment
class RainforestEnvironment {

	function supports($feature) {
		if($this->features == null) {
			$this->features = $this->initSupports();
		}

		if(isset($this->features[$feature])) {
			// this might throw an exception, or highlight that it's supported, but not usable at the moment
			if($this->features[$feature]->isSupported()) {
				$this->features[$feature];
			}
		}
		return false;
	}

	// could be setup somewhere else
	function initSupports() {
		$features = [
			GenericFeatureInterface::class => new SomeGenericFeature($this),
			DomainsSupportInterface::class => new RainforestDomains($this),
		];
    if($this->manifestAtLeast('4.1.3')) {
      $features[LetmeinInterface::class] => new RainforestLetmein($this),
    }

    // db value, feature flag, bad example perhaps?
    if($this->NewDeployModal) {
      $features[DeployScreenInterface::class] = new DeployDispatcher($this);
    } else {
      $features[DeployScreenInterface::class] = new DNRoot($this); // eh, I hope you get the point
    }
    return $features;
	}
}

// On UI dispatcher action:
try {
	if ($feature = $env->supports(LetmeinInterface::class)) {
		$feature->letmein($username, $password);
	}
} catch (\BackendUnsupportedException $ex) {
	// show warning for user? can we use something else than exceptions?
}

// UI / Rendering? where is that? I dunno..