class FilepathNamespaceExtractor

class FilepathNamespaceExtractor {
    
    /** @var array<string, string> */
    private $rootNamespaces;
    
    /** @var array<string, bool> dir(string) => true(bool) */
    private $skipDirs;
    
    /** @var list<string> */
    private $extensions;
    
    /**
     * @param array<string, string> $rootNamespaces directory(string) => namespace
     * @param list<string> $skipDirs
     * @param list<string> $extensions index(integer) => extension
     */
    public function __construct(array $rootNamespaces, array $skipDirs, array $extensions) {
        $this->rootNamespaces = $rootNamespaces;
        $this->skipDirs = array_fill_keys($skipDirs, true);
        $this->extensions = array_map(static function (string $extension) : string {
            return strtolower($extension);
        }, $extensions);
    }
    public function getTypeNameFromProjectPath(string $path) : ?string {
        $extension = strtolower(pathinfo($path, PATHINFO_EXTENSION));
        if (!in_array($extension, $this->extensions, true)) {
            return null;
        }
        
        /** @var list<string> $pathParts */
        $pathParts = preg_split('~[/\\\\]~', $path);
        $rootNamespace = null;
        while (count($pathParts) > 0) {
            array_shift($pathParts);
            foreach ($this->rootNamespaces as $directory => $namespace) {
                if (!StringHelper::startsWith(implode('/', $pathParts) . '/', $directory . '/')) {
                    continue;
                }
                $directoryPartsCount = count(explode('/', $directory));
                for ($i = 0; $i < $directoryPartsCount; $i++) {
                    array_shift($pathParts);
                }
                $rootNamespace = $namespace;
                break 2;
            }
        }
        if ($rootNamespace === null) {
            return null;
        }
        array_unshift($pathParts, $rootNamespace);
        $typeName = implode('\\', array_filter($pathParts, function (string $pathPart) : bool {
            return !isset($this->skipDirs[$pathPart]);
        }));
        return substr($typeName, 0, -strlen('.' . $extension));
    }

}