<?php
/**
* Copyright © Magento, Inc. All rights reserved.
* See COPYING.txt for license details.
*/
namespace Magento\Framework\Module;

use Magento\Framework\Data\Graph;

/**
* Checks for dependencies between modules
*/
class DependencyChecker
{
/**
* @var PackageInfo
*/
private $packageInfo;

/**
* @var ModuleList
*/
private $list;

/**
* @var ModuleList\Loader
*/
private $loader;

/**
* Constructor
*
* @param ModuleList $list
* @param ModuleList\Loader $loader
* @param PackageInfo $packageInfo
*/
public function __construct(ModuleList $list, ModuleList\Loader $loader, PackageInfo $packageInfo)
{
$this->list = $list;
$this->loader = $loader;
$this->packageInfo = $packageInfo;
}

/**
* Checks dependencies when disabling modules
*
* @param string[] $toBeDisabledModules
* @param string[] $currentlyEnabledModules
* @return array
* @throws \Magento\Framework\Exception\LocalizedException
*/
public function checkDependenciesWhenDisableModules($toBeDisabledModules, $currentlyEnabledModules = null)
{
$masterList = $currentlyEnabledModules ?? $this->list->getNames();
// assume disable succeeds: currently enabled modules - to-be-disabled modules
$enabledModules = array_diff($masterList, $toBeDisabledModules);
return $this->checkDependencyGraph(false, $toBeDisabledModules, $enabledModules);
}

/**
* Checks dependencies when enabling modules
*
* @param string[] $toBeEnabledModules
* @param string[] $currentlyEnabledModules
* @return array
* @throws \Magento\Framework\Exception\LocalizedException
*/
public function checkDependenciesWhenEnableModules(array $toBeEnabledModules, array $currentlyEnabledModules = null)
{
$masterList = $currentlyEnabledModules ?? $this->list->getNames();
// assume enable succeeds: union of currently enabled modules and to-be-enabled modules
$enabledModules = array_unique(array_merge($masterList, $toBeEnabledModules));
return $this->checkDependencyGraph(true, $toBeEnabledModules, $enabledModules);
}

/**
* Check the dependency graph
*
* @param bool $isEnable
* @param string[] $moduleNames list of modules to be enabled/disabled
* @param string[] $enabledModules list of enabled modules assuming enable/disable succeeds
* @return array
* @throws \Magento\Framework\Exception\LocalizedException
*/
private function checkDependencyGraph(bool $isEnable, array $moduleNames, array $enabledModules)
{
$fullModuleList = $this->loader->load();
$graph = $this->createGraph($fullModuleList);
$dependenciesMissingAll = [];
$graphMode = $isEnable ? Graph::DIRECTIONAL : Graph::INVERSE;
$modules = array_merge(
array_keys($fullModuleList),
$this->packageInfo->getNonExistingDependencies()
);
foreach ($moduleNames as $moduleName) {
$dependenciesMissing = [];
$paths = $graph->findPathsToReachableNodes($moduleName, $graphMode);
foreach ($modules as $module) {
if (isset($paths[$module])) {
if ($isEnable && !in_array($module, $enabledModules)) {
$dependenciesMissing[$module] = $paths[$module];
} elseif (!$isEnable && in_array($module, $enabledModules)) {
$dependenciesMissing[$module] = array_reverse($paths[$module]);
}
}
}
$dependenciesMissingAll[$moduleName] = $dependenciesMissing;
}
return $dependenciesMissingAll;
}

/**
* Create the dependency graph
*
* @param array $fullModuleList
* @return Graph
*/
private function createGraph(array $fullModuleList): Graph
{
$nodes = [];
$dependencies = [];

// build the graph data
foreach (array_keys($fullModuleList) as $moduleName) {
$nodes[] = $moduleName;
foreach ($this->packageInfo->getRequire($moduleName) as $dependModuleName) {
if ($dependModuleName) {
$dependencies[] = [$moduleName, $dependModuleName];
}
}
}
$nodes = array_unique(
array_merge($nodes, $this->packageInfo->getNonExistingDependencies())
);

return new Graph($nodes, $dependencies);
}
}