<?php namespace Cms\Classes;

/**
 * Defines some file-system helpers for the CMS system.
 *
 * @package october\system
 * @author Alexey Bobkov, Samuel Georges
 */
class FileHelper
{
    /**
     * Validates a CMS object file or directory name.
     * CMS object file names can contain only alphanumeric symbols, dashes, underscores and dots.
     * Name can also begin with a component name, eg: MyComponent::filename.
     * @param string $fileName Specifies a path to validate
     * @return boolean Returns true if the file name is valid. Otherwise returns false.
     */
    public static function validateName($fileName)
    {
        return preg_match('/^([a-z0-9\-\.]+\:{2})?[a-z0-9\_\-\.\/]+$/i', $fileName) ? true : false;
    }

    /**
     * Validates whether a file has an allowed extension.
     * @param string $fileName Specifies a path to validate
     * @param array $allowedExtensions A list of allowed file extensions
     * @param boolean $allowEmpty Determines whether the file extension could be empty.
     * @return boolean Returns true if the file extension is valid. Otherwise returns false.
     */
    public static function validateExtension($fileName, $allowedExtensions, $allowEmpty = true)
    {
        $extension = strtolower(pathinfo($fileName, PATHINFO_EXTENSION));
        if (!strlen($extension))
            return $allowEmpty;

        return in_array($extension, $allowedExtensions);
    }

    /**
     * Validates a CMS object path.
     * CMS object directory and file names can contain only alphanumeric symbols, dashes and dots.
     * CMS objects support only a single level of subdirectories.
     * @param string $filePath Specifies a path to validate
     * @param integer $maxNesting Specifies the maximum allowed nesting level
     * @return boolean Returns true if the file name is valid. Otherwise returns false.
     */
    public static function validatePath($filePath, $maxNesting = 2)
    {
        if (strpos($filePath, '..') !== false)
            return false;

        if (strpos($filePath, './') !== false || strpos($filePath, '//') !== false)
            return false;

        $segments = explode('/', $filePath);
        if ($maxNesting !== null && count($segments) > $maxNesting)
            return false;

        foreach ($segments as $segment)
            if (!self::validateName($segment))
                return false;

        return true;
    }

    /**
     * Formats an INI file string from an array
     * @param array $data Data to format.
     * @param int $level Specifies the level of array value.
     * @return string Returns the INI file string.
     */
    public static function formatIniString($data, $level = 1)
    {
        $content = null;

        $sections = [];
        foreach ($data as $key=>$value) {
            if (is_array($value)) {
                if ($level == 1)
                    $sections[$key] = self::formatIniString($value, $level+1);
                else {
                    foreach ($value as $val)
                        $content .= $key.'[] = "'.$val.'"'.PHP_EOL;
                }
            } elseif (strlen($value))
                $content .= $key.' = "'.$value.'"'.PHP_EOL;
        }

        foreach ($sections as $key=>$section)
            $content .= PHP_EOL.'['.$key.']'.PHP_EOL.$section.PHP_EOL;

        return trim($content);
    }
}