Chris@13: <?php declare(strict_types=1);
Chris@13: 
Chris@13: namespace PhpParser;
Chris@13: 
Chris@13: use PhpParser\Node\Name;
Chris@13: use PhpParser\Node\Name\FullyQualified;
Chris@13: use PhpParser\Node\Stmt;
Chris@13: 
Chris@13: class NameContext
Chris@13: {
Chris@13:     /** @var null|Name Current namespace */
Chris@13:     protected $namespace;
Chris@13: 
Chris@13:     /** @var Name[][] Map of format [aliasType => [aliasName => originalName]] */
Chris@13:     protected $aliases = [];
Chris@13: 
Chris@13:     /** @var Name[][] Same as $aliases but preserving original case */
Chris@13:     protected $origAliases = [];
Chris@13: 
Chris@13:     /** @var ErrorHandler Error handler */
Chris@13:     protected $errorHandler;
Chris@13: 
Chris@13:     /**
Chris@13:      * Create a name context.
Chris@13:      *
Chris@13:      * @param ErrorHandler $errorHandler Error handling used to report errors
Chris@13:      */
Chris@13:     public function __construct(ErrorHandler $errorHandler) {
Chris@13:         $this->errorHandler = $errorHandler;
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Start a new namespace.
Chris@13:      *
Chris@13:      * This also resets the alias table.
Chris@13:      *
Chris@13:      * @param Name|null $namespace Null is the global namespace
Chris@13:      */
Chris@13:     public function startNamespace(Name $namespace = null) {
Chris@13:         $this->namespace = $namespace;
Chris@13:         $this->origAliases = $this->aliases = [
Chris@13:             Stmt\Use_::TYPE_NORMAL   => [],
Chris@13:             Stmt\Use_::TYPE_FUNCTION => [],
Chris@13:             Stmt\Use_::TYPE_CONSTANT => [],
Chris@13:         ];
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Add an alias / import.
Chris@13:      *
Chris@13:      * @param Name   $name        Original name
Chris@13:      * @param string $aliasName   Aliased name
Chris@13:      * @param int    $type        One of Stmt\Use_::TYPE_*
Chris@13:      * @param array  $errorAttrs Attributes to use to report an error
Chris@13:      */
Chris@13:     public function addAlias(Name $name, string $aliasName, int $type, array $errorAttrs = []) {
Chris@13:         // Constant names are case sensitive, everything else case insensitive
Chris@13:         if ($type === Stmt\Use_::TYPE_CONSTANT) {
Chris@13:             $aliasLookupName = $aliasName;
Chris@13:         } else {
Chris@13:             $aliasLookupName = strtolower($aliasName);
Chris@13:         }
Chris@13: 
Chris@13:         if (isset($this->aliases[$type][$aliasLookupName])) {
Chris@13:             $typeStringMap = [
Chris@13:                 Stmt\Use_::TYPE_NORMAL   => '',
Chris@13:                 Stmt\Use_::TYPE_FUNCTION => 'function ',
Chris@13:                 Stmt\Use_::TYPE_CONSTANT => 'const ',
Chris@13:             ];
Chris@13: 
Chris@13:             $this->errorHandler->handleError(new Error(
Chris@13:                 sprintf(
Chris@13:                     'Cannot use %s%s as %s because the name is already in use',
Chris@13:                     $typeStringMap[$type], $name, $aliasName
Chris@13:                 ),
Chris@13:                 $errorAttrs
Chris@13:             ));
Chris@13:             return;
Chris@13:         }
Chris@13: 
Chris@13:         $this->aliases[$type][$aliasLookupName] = $name;
Chris@13:         $this->origAliases[$type][$aliasName] = $name;
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Get current namespace.
Chris@13:      *
Chris@13:      * @return null|Name Namespace (or null if global namespace)
Chris@13:      */
Chris@13:     public function getNamespace() {
Chris@13:         return $this->namespace;
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Get resolved name.
Chris@13:      *
Chris@13:      * @param Name $name Name to resolve
Chris@13:      * @param int  $type One of Stmt\Use_::TYPE_{FUNCTION|CONSTANT}
Chris@13:      *
Chris@13:      * @return null|Name Resolved name, or null if static resolution is not possible
Chris@13:      */
Chris@13:     public function getResolvedName(Name $name, int $type) {
Chris@13:         // don't resolve special class names
Chris@13:         if ($type === Stmt\Use_::TYPE_NORMAL && $name->isSpecialClassName()) {
Chris@13:             if (!$name->isUnqualified()) {
Chris@13:                 $this->errorHandler->handleError(new Error(
Chris@13:                     sprintf("'\\%s' is an invalid class name", $name->toString()),
Chris@13:                     $name->getAttributes()
Chris@13:                 ));
Chris@13:             }
Chris@13:             return $name;
Chris@13:         }
Chris@13: 
Chris@13:         // fully qualified names are already resolved
Chris@13:         if ($name->isFullyQualified()) {
Chris@13:             return $name;
Chris@13:         }
Chris@13: 
Chris@13:         // Try to resolve aliases
Chris@13:         if (null !== $resolvedName = $this->resolveAlias($name, $type)) {
Chris@13:             return $resolvedName;
Chris@13:         }
Chris@13: 
Chris@13:         if ($type !== Stmt\Use_::TYPE_NORMAL && $name->isUnqualified()) {
Chris@13:             if (null === $this->namespace) {
Chris@13:                 // outside of a namespace unaliased unqualified is same as fully qualified
Chris@13:                 return new FullyQualified($name, $name->getAttributes());
Chris@13:             }
Chris@13: 
Chris@13:             // Cannot resolve statically
Chris@13:             return null;
Chris@13:         }
Chris@13: 
Chris@13:         // if no alias exists prepend current namespace
Chris@13:         return FullyQualified::concat($this->namespace, $name, $name->getAttributes());
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Get resolved class name.
Chris@13:      *
Chris@13:      * @param Name $name Class ame to resolve
Chris@13:      *
Chris@13:      * @return Name Resolved name
Chris@13:      */
Chris@13:     public function getResolvedClassName(Name $name) : Name {
Chris@13:         return $this->getResolvedName($name, Stmt\Use_::TYPE_NORMAL);
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Get possible ways of writing a fully qualified name (e.g., by making use of aliases).
Chris@13:      *
Chris@13:      * @param string $name Fully-qualified name (without leading namespace separator)
Chris@13:      * @param int    $type One of Stmt\Use_::TYPE_*
Chris@13:      *
Chris@13:      * @return Name[] Possible representations of the name
Chris@13:      */
Chris@13:     public function getPossibleNames(string $name, int $type) : array {
Chris@13:         $lcName = strtolower($name);
Chris@13: 
Chris@13:         if ($type === Stmt\Use_::TYPE_NORMAL) {
Chris@13:             // self, parent and static must always be unqualified
Chris@13:             if ($lcName === "self" || $lcName === "parent" || $lcName === "static") {
Chris@13:                 return [new Name($name)];
Chris@13:             }
Chris@13:         }
Chris@13: 
Chris@13:         // Collect possible ways to write this name, starting with the fully-qualified name
Chris@13:         $possibleNames = [new FullyQualified($name)];
Chris@13: 
Chris@13:         if (null !== $nsRelativeName = $this->getNamespaceRelativeName($name, $lcName, $type)) {
Chris@13:             // Make sure there is no alias that makes the normally namespace-relative name
Chris@13:             // into something else
Chris@13:             if (null === $this->resolveAlias($nsRelativeName, $type)) {
Chris@13:                 $possibleNames[] = $nsRelativeName;
Chris@13:             }
Chris@13:         }
Chris@13: 
Chris@13:         // Check for relevant namespace use statements
Chris@13:         foreach ($this->origAliases[Stmt\Use_::TYPE_NORMAL] as $alias => $orig) {
Chris@13:             $lcOrig = $orig->toLowerString();
Chris@13:             if (0 === strpos($lcName, $lcOrig . '\\')) {
Chris@13:                 $possibleNames[] = new Name($alias . substr($name, strlen($lcOrig)));
Chris@13:             }
Chris@13:         }
Chris@13: 
Chris@13:         // Check for relevant type-specific use statements
Chris@13:         foreach ($this->origAliases[$type] as $alias => $orig) {
Chris@13:             if ($type === Stmt\Use_::TYPE_CONSTANT) {
Chris@13:                 // Constants are are complicated-sensitive
Chris@13:                 $normalizedOrig = $this->normalizeConstName($orig->toString());
Chris@13:                 if ($normalizedOrig === $this->normalizeConstName($name)) {
Chris@13:                     $possibleNames[] = new Name($alias);
Chris@13:                 }
Chris@13:             } else {
Chris@13:                 // Everything else is case-insensitive
Chris@13:                 if ($orig->toLowerString() === $lcName) {
Chris@13:                     $possibleNames[] = new Name($alias);
Chris@13:                 }
Chris@13:             }
Chris@13:         }
Chris@13: 
Chris@13:         return $possibleNames;
Chris@13:     }
Chris@13: 
Chris@13:     /**
Chris@13:      * Get shortest representation of this fully-qualified name.
Chris@13:      *
Chris@13:      * @param string $name Fully-qualified name (without leading namespace separator)
Chris@13:      * @param int    $type One of Stmt\Use_::TYPE_*
Chris@13:      *
Chris@13:      * @return Name Shortest representation
Chris@13:      */
Chris@13:     public function getShortName(string $name, int $type) : Name {
Chris@13:         $possibleNames = $this->getPossibleNames($name, $type);
Chris@13: 
Chris@13:         // Find shortest name
Chris@13:         $shortestName = null;
Chris@13:         $shortestLength = \INF;
Chris@13:         foreach ($possibleNames as $possibleName) {
Chris@13:             $length = strlen($possibleName->toCodeString());
Chris@13:             if ($length < $shortestLength) {
Chris@13:                 $shortestName = $possibleName;
Chris@13:                 $shortestLength = $length;
Chris@13:             }
Chris@13:         }
Chris@13: 
Chris@13:        return $shortestName;
Chris@13:     }
Chris@13: 
Chris@13:     private function resolveAlias(Name $name, $type) {
Chris@13:         $firstPart = $name->getFirst();
Chris@13: 
Chris@13:         if ($name->isQualified()) {
Chris@13:             // resolve aliases for qualified names, always against class alias table
Chris@13:             $checkName = strtolower($firstPart);
Chris@13:             if (isset($this->aliases[Stmt\Use_::TYPE_NORMAL][$checkName])) {
Chris@13:                 $alias = $this->aliases[Stmt\Use_::TYPE_NORMAL][$checkName];
Chris@13:                 return FullyQualified::concat($alias, $name->slice(1), $name->getAttributes());
Chris@13:             }
Chris@13:         } elseif ($name->isUnqualified()) {
Chris@13:             // constant aliases are case-sensitive, function aliases case-insensitive
Chris@13:             $checkName = $type === Stmt\Use_::TYPE_CONSTANT ? $firstPart : strtolower($firstPart);
Chris@13:             if (isset($this->aliases[$type][$checkName])) {
Chris@13:                 // resolve unqualified aliases
Chris@13:                 return new FullyQualified($this->aliases[$type][$checkName], $name->getAttributes());
Chris@13:             }
Chris@13:         }
Chris@13: 
Chris@13:         // No applicable aliases
Chris@13:         return null;
Chris@13:     }
Chris@13: 
Chris@13:     private function getNamespaceRelativeName(string $name, string $lcName, int $type) {
Chris@13:         if (null === $this->namespace) {
Chris@13:             return new Name($name);
Chris@13:         }
Chris@13: 
Chris@13:         if ($type === Stmt\Use_::TYPE_CONSTANT) {
Chris@13:             // The constants true/false/null always resolve to the global symbols, even inside a
Chris@13:             // namespace, so they may be used without qualification
Chris@13:             if ($lcName === "true" || $lcName === "false" || $lcName === "null") {
Chris@13:                 return new Name($name);
Chris@13:             }
Chris@13:         }
Chris@13: 
Chris@13:         $namespacePrefix = strtolower($this->namespace . '\\');
Chris@13:         if (0 === strpos($lcName, $namespacePrefix)) {
Chris@13:             return new Name(substr($name, strlen($namespacePrefix)));
Chris@13:         }
Chris@13: 
Chris@13:         return null;
Chris@13:     }
Chris@13: 
Chris@13:     private function normalizeConstName(string $name) {
Chris@13:         $nsSep = strrpos($name, '\\');
Chris@13:         if (false === $nsSep) {
Chris@13:             return $name;
Chris@13:         }
Chris@13: 
Chris@13:         // Constants have case-insensitive namespace and case-sensitive short-name
Chris@13:         $ns = substr($name, 0, $nsSep);
Chris@13:         $shortName = substr($name, $nsSep + 1);
Chris@13:         return strtolower($ns) . '\\' . $shortName;
Chris@13:     }
Chris@13: }