Chris@0: <?php
Chris@0: namespace GuzzleHttp;
Chris@0: 
Chris@0: /**
Chris@0:  * Expands URI templates. Userland implementation of PECL uri_template.
Chris@0:  *
Chris@0:  * @link http://tools.ietf.org/html/rfc6570
Chris@0:  */
Chris@0: class UriTemplate
Chris@0: {
Chris@0:     /** @var string URI template */
Chris@0:     private $template;
Chris@0: 
Chris@0:     /** @var array Variables to use in the template expansion */
Chris@0:     private $variables;
Chris@0: 
Chris@0:     /** @var array Hash for quick operator lookups */
Chris@0:     private static $operatorHash = [
Chris@0:         ''  => ['prefix' => '',  'joiner' => ',', 'query' => false],
Chris@0:         '+' => ['prefix' => '',  'joiner' => ',', 'query' => false],
Chris@0:         '#' => ['prefix' => '#', 'joiner' => ',', 'query' => false],
Chris@0:         '.' => ['prefix' => '.', 'joiner' => '.', 'query' => false],
Chris@0:         '/' => ['prefix' => '/', 'joiner' => '/', 'query' => false],
Chris@0:         ';' => ['prefix' => ';', 'joiner' => ';', 'query' => true],
Chris@0:         '?' => ['prefix' => '?', 'joiner' => '&', 'query' => true],
Chris@0:         '&' => ['prefix' => '&', 'joiner' => '&', 'query' => true]
Chris@0:     ];
Chris@0: 
Chris@0:     /** @var array Delimiters */
Chris@0:     private static $delims = [':', '/', '?', '#', '[', ']', '@', '!', '$',
Chris@0:         '&', '\'', '(', ')', '*', '+', ',', ';', '='];
Chris@0: 
Chris@0:     /** @var array Percent encoded delimiters */
Chris@0:     private static $delimsPct = ['%3A', '%2F', '%3F', '%23', '%5B', '%5D',
Chris@0:         '%40', '%21', '%24', '%26', '%27', '%28', '%29', '%2A', '%2B', '%2C',
Chris@0:         '%3B', '%3D'];
Chris@0: 
Chris@0:     public function expand($template, array $variables)
Chris@0:     {
Chris@0:         if (false === strpos($template, '{')) {
Chris@0:             return $template;
Chris@0:         }
Chris@0: 
Chris@0:         $this->template = $template;
Chris@0:         $this->variables = $variables;
Chris@0: 
Chris@0:         return preg_replace_callback(
Chris@0:             '/\{([^\}]+)\}/',
Chris@0:             [$this, 'expandMatch'],
Chris@0:             $this->template
Chris@0:         );
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Parse an expression into parts
Chris@0:      *
Chris@0:      * @param string $expression Expression to parse
Chris@0:      *
Chris@0:      * @return array Returns an associative array of parts
Chris@0:      */
Chris@0:     private function parseExpression($expression)
Chris@0:     {
Chris@0:         $result = [];
Chris@0: 
Chris@0:         if (isset(self::$operatorHash[$expression[0]])) {
Chris@0:             $result['operator'] = $expression[0];
Chris@0:             $expression = substr($expression, 1);
Chris@0:         } else {
Chris@0:             $result['operator'] = '';
Chris@0:         }
Chris@0: 
Chris@0:         foreach (explode(',', $expression) as $value) {
Chris@0:             $value = trim($value);
Chris@0:             $varspec = [];
Chris@0:             if ($colonPos = strpos($value, ':')) {
Chris@0:                 $varspec['value'] = substr($value, 0, $colonPos);
Chris@0:                 $varspec['modifier'] = ':';
Chris@0:                 $varspec['position'] = (int) substr($value, $colonPos + 1);
Chris@0:             } elseif (substr($value, -1) === '*') {
Chris@0:                 $varspec['modifier'] = '*';
Chris@0:                 $varspec['value'] = substr($value, 0, -1);
Chris@0:             } else {
Chris@0:                 $varspec['value'] = (string) $value;
Chris@0:                 $varspec['modifier'] = '';
Chris@0:             }
Chris@0:             $result['values'][] = $varspec;
Chris@0:         }
Chris@0: 
Chris@0:         return $result;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Process an expansion
Chris@0:      *
Chris@0:      * @param array $matches Matches met in the preg_replace_callback
Chris@0:      *
Chris@0:      * @return string Returns the replacement string
Chris@0:      */
Chris@0:     private function expandMatch(array $matches)
Chris@0:     {
Chris@0:         static $rfc1738to3986 = ['+' => '%20', '%7e' => '~'];
Chris@0: 
Chris@0:         $replacements = [];
Chris@0:         $parsed = self::parseExpression($matches[1]);
Chris@0:         $prefix = self::$operatorHash[$parsed['operator']]['prefix'];
Chris@0:         $joiner = self::$operatorHash[$parsed['operator']]['joiner'];
Chris@0:         $useQuery = self::$operatorHash[$parsed['operator']]['query'];
Chris@0: 
Chris@0:         foreach ($parsed['values'] as $value) {
Chris@0:             if (!isset($this->variables[$value['value']])) {
Chris@0:                 continue;
Chris@0:             }
Chris@0: 
Chris@0:             $variable = $this->variables[$value['value']];
Chris@0:             $actuallyUseQuery = $useQuery;
Chris@0:             $expanded = '';
Chris@0: 
Chris@0:             if (is_array($variable)) {
Chris@0:                 $isAssoc = $this->isAssoc($variable);
Chris@0:                 $kvp = [];
Chris@0:                 foreach ($variable as $key => $var) {
Chris@0:                     if ($isAssoc) {
Chris@0:                         $key = rawurlencode($key);
Chris@0:                         $isNestedArray = is_array($var);
Chris@0:                     } else {
Chris@0:                         $isNestedArray = false;
Chris@0:                     }
Chris@0: 
Chris@0:                     if (!$isNestedArray) {
Chris@0:                         $var = rawurlencode($var);
Chris@0:                         if ($parsed['operator'] === '+' ||
Chris@0:                             $parsed['operator'] === '#'
Chris@0:                         ) {
Chris@0:                             $var = $this->decodeReserved($var);
Chris@0:                         }
Chris@0:                     }
Chris@0: 
Chris@0:                     if ($value['modifier'] === '*') {
Chris@0:                         if ($isAssoc) {
Chris@0:                             if ($isNestedArray) {
Chris@0:                                 // Nested arrays must allow for deeply nested
Chris@0:                                 // structures.
Chris@0:                                 $var = strtr(
Chris@0:                                     http_build_query([$key => $var]),
Chris@0:                                     $rfc1738to3986
Chris@0:                                 );
Chris@0:                             } else {
Chris@0:                                 $var = $key . '=' . $var;
Chris@0:                             }
Chris@0:                         } elseif ($key > 0 && $actuallyUseQuery) {
Chris@0:                             $var = $value['value'] . '=' . $var;
Chris@0:                         }
Chris@0:                     }
Chris@0: 
Chris@0:                     $kvp[$key] = $var;
Chris@0:                 }
Chris@0: 
Chris@0:                 if (empty($variable)) {
Chris@0:                     $actuallyUseQuery = false;
Chris@0:                 } elseif ($value['modifier'] === '*') {
Chris@0:                     $expanded = implode($joiner, $kvp);
Chris@0:                     if ($isAssoc) {
Chris@0:                         // Don't prepend the value name when using the explode
Chris@0:                         // modifier with an associative array.
Chris@0:                         $actuallyUseQuery = false;
Chris@0:                     }
Chris@0:                 } else {
Chris@0:                     if ($isAssoc) {
Chris@0:                         // When an associative array is encountered and the
Chris@0:                         // explode modifier is not set, then the result must be
Chris@0:                         // a comma separated list of keys followed by their
Chris@0:                         // respective values.
Chris@0:                         foreach ($kvp as $k => &$v) {
Chris@0:                             $v = $k . ',' . $v;
Chris@0:                         }
Chris@0:                     }
Chris@0:                     $expanded = implode(',', $kvp);
Chris@0:                 }
Chris@0:             } else {
Chris@0:                 if ($value['modifier'] === ':') {
Chris@0:                     $variable = substr($variable, 0, $value['position']);
Chris@0:                 }
Chris@0:                 $expanded = rawurlencode($variable);
Chris@0:                 if ($parsed['operator'] === '+' || $parsed['operator'] === '#') {
Chris@0:                     $expanded = $this->decodeReserved($expanded);
Chris@0:                 }
Chris@0:             }
Chris@0: 
Chris@0:             if ($actuallyUseQuery) {
Chris@0:                 if (!$expanded && $joiner !== '&') {
Chris@0:                     $expanded = $value['value'];
Chris@0:                 } else {
Chris@0:                     $expanded = $value['value'] . '=' . $expanded;
Chris@0:                 }
Chris@0:             }
Chris@0: 
Chris@0:             $replacements[] = $expanded;
Chris@0:         }
Chris@0: 
Chris@0:         $ret = implode($joiner, $replacements);
Chris@0:         if ($ret && $prefix) {
Chris@0:             return $prefix . $ret;
Chris@0:         }
Chris@0: 
Chris@0:         return $ret;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Determines if an array is associative.
Chris@0:      *
Chris@0:      * This makes the assumption that input arrays are sequences or hashes.
Chris@0:      * This assumption is a tradeoff for accuracy in favor of speed, but it
Chris@0:      * should work in almost every case where input is supplied for a URI
Chris@0:      * template.
Chris@0:      *
Chris@0:      * @param array $array Array to check
Chris@0:      *
Chris@0:      * @return bool
Chris@0:      */
Chris@0:     private function isAssoc(array $array)
Chris@0:     {
Chris@0:         return $array && array_keys($array)[0] !== 0;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Removes percent encoding on reserved characters (used with + and #
Chris@0:      * modifiers).
Chris@0:      *
Chris@0:      * @param string $string String to fix
Chris@0:      *
Chris@0:      * @return string
Chris@0:      */
Chris@0:     private function decodeReserved($string)
Chris@0:     {
Chris@0:         return str_replace(self::$delimsPct, self::$delims, $string);
Chris@0:     }
Chris@0: }