<?php
/*
 * Copyright 2011 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Collection of static utility methods used for convenience across
 * the client library.
 *
 * @author Chirag Shah <chirags@google.com>
 */
class Google_Utils {
    public static function urlSafeB64Encode($data) {
        $b64 = base64_encode($data);
        $b64 = str_replace(
            array('+', '/', '\r', '\n', '='),
            array('-', '_'),
            $b64
        );
        return $b64;
    }

    public static function urlSafeB64Decode($b64) {
        $b64 = str_replace(
            array('-', '_'),
            array('+', '/'),
            $b64
        );
        return base64_decode($b64);
    }

    /**
     * Misc function used to count the number of bytes in a post body, in the
     * world of multi-byte chars and the unpredictability of
     * strlen/mb_strlen/sizeof, this is the only way to do that in a sane
     * manner at the moment.
     *
     * This algorithm was originally developed for the
     * Solar Framework by Paul M. Jones
     *
     * @link   http://solarphp.com/
     * @link   http://svn.solarphp.com/core/trunk/Solar/Json.php
     * @link   http://framework.zend.com/svn/framework/standard/trunk/library/Zend/Json/Decoder.php
     * @param string $str
     * @return int The number of bytes in a string.
     */
    public static function getStrLen($str) {
        $strlenVar = strlen($str);
        $d = $ret = 0;
        for ($count = 0; $count < $strlenVar; ++$count) {
            $ordinalValue = ord($str{$ret});
            switch (true) {
                case (($ordinalValue >= 0x20) && ($ordinalValue <= 0x7F)):
                    // characters U-00000000 - U-0000007F (same as ASCII)
                    $ret++;
                    break;
                case (($ordinalValue & 0xE0) == 0xC0):
                    // characters U-00000080 - U-000007FF, mask 110XXXXX
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $ret += 2;
                    break;
                case (($ordinalValue & 0xF0) == 0xE0):
                    // characters U-00000800 - U-0000FFFF, mask 1110XXXX
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $ret += 3;
                    break;
                case (($ordinalValue & 0xF8) == 0xF0):
                    // characters U-00010000 - U-001FFFFF, mask 11110XXX
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $ret += 4;
                    break;
                case (($ordinalValue & 0xFC) == 0xF8):
                    // characters U-00200000 - U-03FFFFFF, mask 111110XX
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $ret += 5;
                    break;
                case (($ordinalValue & 0xFE) == 0xFC):
                    // characters U-04000000 - U-7FFFFFFF, mask 1111110X
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $ret += 6;
                    break;
                default:
                    $ret++;
            }
        }
        return $ret;
    }

    /**
     * Normalize all keys in an array to lower-case.
     * @param array $arr
     * @return array Normalized array.
     */
    public static function normalize($arr) {
        if (!is_array($arr)) {
            return array();
        }

        $normalized = array();
        foreach ($arr as $key => $val) {
            $normalized[strtolower($key)] = $val;
        }
        return $normalized;
    }

    /**
     * Convert a string to camelCase
     * @param string $value
     * @return string
     */
    public static function camelCase($value) {
        $value = ucwords(str_replace(array('-', '_'), ' ', $value));
        $value = str_replace(' ', '', $value);
        $value[0] = strtolower($value[0]);
        return $value;
    }
}