<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\helpers;

/**
 * BaseVarDumper provides concrete implementation for [[VarDumper]].
 *
 * Do not use BaseVarDumper. Use [[VarDumper]] instead.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class BaseVarDumper
{
    private static $_objects;
    private static $_output;
    private static $_depth;


    /**
     * Displays a variable.
     * This method achieves the similar functionality as var_dump and print_r
     * but is more robust when handling complex objects such as Yii controllers.
     * @param mixed $var variable to be dumped
     * @param integer $depth maximum depth that the dumper should go into the variable. Defaults to 10.
     * @param boolean $highlight whether the result should be syntax-highlighted
     */
    public static function dump($var, $depth = 10, $highlight = false)
    {
        echo static::dumpAsString($var, $depth, $highlight);
    }

    /**
     * Dumps a variable in terms of a string.
     * This method achieves the similar functionality as var_dump and print_r
     * but is more robust when handling complex objects such as Yii controllers.
     * @param mixed $var variable to be dumped
     * @param integer $depth maximum depth that the dumper should go into the variable. Defaults to 10.
     * @param boolean $highlight whether the result should be syntax-highlighted
     * @return string the string representation of the variable
     */
    public static function dumpAsString($var, $depth = 10, $highlight = false)
    {
        self::$_output = '';
        self::$_objects = [];
        self::$_depth = $depth;
        self::dumpInternal($var, 0);
        if ($highlight) {
            $result = highlight_string("<?php\n" . self::$_output, true);
            self::$_output = preg_replace('/&lt;\\?php<br \\/>/', '', $result, 1);
        }

        return self::$_output;
    }

    /**
     * @param mixed $var variable to be dumped
     * @param integer $level depth level
     */
    private static function dumpInternal($var, $level)
    {
        switch (gettype($var)) {
            case 'boolean':
                self::$_output .= $var ? 'true' : 'false';
                break;
            case 'integer':
                self::$_output .= "$var";
                break;
            case 'double':
                self::$_output .= "$var";
                break;
            case 'string':
                self::$_output .= "'" . addslashes($var) . "'";
                break;
            case 'resource':
                self::$_output .= '{resource}';
                break;
            case 'NULL':
                self::$_output .= "null";
                break;
            case 'unknown type':
                self::$_output .= '{unknown}';
                break;
            case 'array':
                if (self::$_depth <= $level) {
                    self::$_output .= '[...]';
                } elseif (empty($var)) {
                    self::$_output .= '[]';
                } else {
                    $keys = array_keys($var);
                    $spaces = str_repeat(' ', $level * 4);
                    self::$_output .= '[';
                    foreach ($keys as $key) {
                        self::$_output .= "\n" . $spaces . '    ';
                        self::dumpInternal($key, 0);
                        self::$_output .= ' => ';
                        self::dumpInternal($var[$key], $level + 1);
                    }
                    self::$_output .= "\n" . $spaces . ']';
                }
                break;
            case 'object':
                if (($id = array_search($var, self::$_objects, true)) !== false) {
                    self::$_output .= get_class($var) . '#' . ($id + 1) . '(...)';
                } elseif (self::$_depth <= $level) {
                    self::$_output .= get_class($var) . '(...)';
                } else {
                    $id = array_push(self::$_objects, $var);
                    $className = get_class($var);
                    $spaces = str_repeat(' ', $level * 4);
                    self::$_output .= "$className#$id\n" . $spaces . '(';
                    foreach ((array) $var as $key => $value) {
                        $keyDisplay = strtr(trim($key), "\0", ':');
                        self::$_output .= "\n" . $spaces . "    [$keyDisplay] => ";
                        self::dumpInternal($value, $level + 1);
                    }
                    self::$_output .= "\n" . $spaces . ')';
                }
                break;
        }
    }

    /**
     * Exports a variable as a string representation.
     *
     * The string is a valid PHP expression that can be evaluated by PHP parser
     * and the evaluation result will give back the variable value.
     *
     * This method is similar to `var_export()`. The main difference is that
     * it generates more compact string representation using short array syntax.
     *
     * It also handles objects by using the PHP functions serialize() and unserialize().
     *
     * PHP 5.4 or above is required to parse the exported value.
     *
     * @param mixed $var the variable to be exported.
     * @return string a string representation of the variable
     */
    public static function export($var)
    {
        self::$_output = '';
        self::exportInternal($var, 0);
        return self::$_output;
    }

    /**
     * @param mixed $var variable to be exported
     * @param integer $level depth level
     */
    private static function exportInternal($var, $level)
    {
        switch (gettype($var)) {
            case 'NULL':
                self::$_output .= 'null';
                break;
            case 'array':
                if (empty($var)) {
                    self::$_output .= '[]';
                } else {
                    $keys = array_keys($var);
                    $outputKeys = ($keys !== range(0, count($var) - 1));
                    $spaces = str_repeat(' ', $level * 4);
                    self::$_output .= '[';
                    foreach ($keys as $key) {
                        self::$_output .= "\n" . $spaces . '    ';
                        if ($outputKeys) {
                            self::exportInternal($key, 0);
                            self::$_output .= ' => ';
                        }
                        self::exportInternal($var[$key], $level + 1);
                        self::$_output .= ',';
                    }
                    self::$_output .= "\n" . $spaces . ']';
                }
                break;
            case 'object':
                try {
                    $output = 'unserialize(' . var_export(serialize($var), true) . ')';
                } catch (\Exception $e) {
                    // serialize may fail, for example: if object contains a `\Closure` instance
                    // so we use regular `var_export()` as fallback
                    $output = var_export($var, true);
                }
                self::$_output .= $output;
                break;
            default:
                self::$_output .= var_export($var, true);
        }
    }
}
