<?php
/*
* This file is part of Psy Shell.
*
* (c) 2012-2020 Justin Hileman
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Psy\CodeCleaner;
use PhpParser\Node;
use PhpParser\Node\Name;
use PhpParser\Node\Name\FullyQualified as FullyQualifiedName;
use PhpParser\Node\Stmt\GroupUse;
use PhpParser\Node\Stmt\Namespace_;
use PhpParser\Node\Stmt\Use_;
use PhpParser\Node\Stmt\UseUse;
use PhpParser\NodeTraverser;
/**
* Provide implicit use statements for subsequent execution.
*
* The use statement pass remembers the last use statement line encountered:
*
* use Foo\Bar as Baz;
*
* ... which it then applies implicitly to all future evaluated code, until the
* current namespace is replaced by another namespace.
*/
class UseStatementPass extends CodeCleanerPass
{
private $aliases = [];
private $lastAliases = [];
private $lastNamespace = null;
/**
* Re-load the last set of use statements on re-entering a namespace.
*
* This isn't how namespaces normally work, but because PsySH has to spin
* up a new namespace for every line of code, we do this to make things
* work like you'd expect.
*
* @param Node $node
*/
public function enterNode(Node $node)
{
if ($node instanceof Namespace_) {
// If this is the same namespace as last namespace, let's do ourselves
// a favor and reload all the aliases...
if (\strtolower($node->name) === \strtolower($this->lastNamespace)) {
$this->aliases = $this->lastAliases;
}
}
}
/**
* If this statement is a namespace, forget all the aliases we had.
*
* If it's a use statement, remember the alias for later. Otherwise, apply
* remembered aliases to the code.
*
* @param Node $node
*/
public function leaveNode(Node $node)
{
// Store a reference to every "use" statement, because we'll need them in a bit.
if ($node instanceof Use_) {
foreach ($node->uses as $use) {
$alias = $use->alias ?: \end($use->name->parts);
$this->aliases[\strtolower($alias)] = $use->name;
}
return NodeTraverser::REMOVE_NODE;
}
// Expand every "use" statement in the group into a full, standalone "use" and store 'em with the others.
if ($node instanceof GroupUse) {
foreach ($node->uses as $use) {
$alias = $use->alias ?: \end($use->name->parts);
$this->aliases[\strtolower($alias)] = Name::concat($node->prefix, $use->name, [
'startLine' => $node->prefix->getAttribute('startLine'),
'endLine' => $use->name->getAttribute('endLine'),
]);
}
return NodeTraverser::REMOVE_NODE;
}
// Start fresh, since we're done with this namespace.
if ($node instanceof Namespace_) {
$this->lastNamespace = $node->name;
$this->lastAliases = $this->aliases;
$this->aliases = [];
return;
}
// Do nothing with UseUse; this an entry in the list of uses in the use statement.
if ($node instanceof UseUse) {
return;
}
// For everything else, we'll implicitly thunk all aliases into fully-qualified names.
foreach ($node as $name => $subNode) {
if ($subNode instanceof Name) {
if ($replacement = $this->findAlias($subNode)) {
$node->$name = $replacement;
}
}
}
return $node;
}
/**
* Find class/namespace aliases.
*
* @param Name $name
*
* @return FullyQualifiedName|null
*/
private function findAlias(Name $name)
{
$that = \strtolower($name);
foreach ($this->aliases as $alias => $prefix) {
if ($that === $alias) {
return new FullyQualifiedName($prefix->toString());
} elseif (\substr($that, 0, \strlen($alias) + 1) === $alias.'\\') {
return new FullyQualifiedName($prefix->toString().\substr($name, \strlen($alias)));
}
}
}
}