Chris@0: <?php
Chris@0: 
Chris@0: namespace Grasmash\YamlExpander;
Chris@0: 
Chris@0: use Dflydev\DotAccessData\Data;
Chris@0: use Symfony\Component\Yaml\Yaml;
Chris@0: 
Chris@0: /**
Chris@0:  * Class Expander
Chris@0:  * @package Grasmash\YamlExpander
Chris@0:  */
Chris@0: class Expander
Chris@0: {
Chris@0: 
Chris@0:     /**
Chris@0:      * Parses a YAML string and expands property placeholders.
Chris@0:      *
Chris@0:      * Placeholders should formatted as ${parent.child}.
Chris@0:      *
Chris@0:      * @param string $yaml_string
Chris@0:      *   A string of YAML.
Chris@0:      * @param array $reference_array
Chris@0:      *   Optional. An array of reference values. This is not operated upon but is used as a
Chris@0:      *   reference to provide supplemental values for property expansion.
Chris@0:      *
Chris@0:      * @return array
Chris@0:      *   The modified array in which placeholders have been replaced with
Chris@0:      *   values.
Chris@0:      */
Chris@0:     public static function parse($yaml_string, $reference_array = [])
Chris@0:     {
Chris@0:         $array = Yaml::parse($yaml_string);
Chris@0:         return self::expandArrayProperties($array, $reference_array);
Chris@0:     }
Chris@0: 
Chris@0: 
Chris@0:     /**
Chris@0:      * Expands property placeholders in an array.
Chris@0:      *
Chris@0:      * Placeholders should formatted as ${parent.child}.
Chris@0:      *
Chris@0:      * @param array $array
Chris@0:      *   An array containing properties to expand.
Chris@0:      *
Chris@0:      * @return array
Chris@0:      *   The modified array in which placeholders have been replaced with
Chris@0:      *   values.
Chris@0:      */
Chris@0:     public static function expandArrayProperties($array, $reference_array = [])
Chris@0:     {
Chris@0:         $data = new Data($array);
Chris@0:         if ($reference_array) {
Chris@0:             $reference_data = new Data($reference_array);
Chris@0:             self::doExpandArrayProperties($data, $array, '', $reference_data);
Chris@0:         } else {
Chris@0:             self::doExpandArrayProperties($data, $array);
Chris@0:         }
Chris@0: 
Chris@0:         return $data->export();
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Performs the actual property expansion.
Chris@0:      *
Chris@0:      * @param Data $data
Chris@0:      *   A data object, containing the $array.
Chris@0:      * @param array $array
Chris@0:      *   The original, unmodified array.
Chris@0:      * @param string $parent_keys
Chris@0:      *   The parent keys of the current key in dot notation. This is used to
Chris@0:      *   track the absolute path to the current key in recursive cases.
Chris@0:      * @param Data|null $reference_data
Chris@0:      *   A reference data object. This is not operated upon but is used as a
Chris@0:      *   reference to provide supplemental values for property expansion.
Chris@0:      */
Chris@0:     protected static function doExpandArrayProperties(
Chris@0:         $data,
Chris@0:         $array,
Chris@0:         $parent_keys = '',
Chris@0:         $reference_data = null
Chris@0:     ) {
Chris@0:         foreach ($array as $key => $value) {
Chris@0:             // Boundary condition(s).
Chris@0:             if (is_null($value) || is_bool($value)) {
Chris@0:                 continue;
Chris@0:             }
Chris@0:             // Recursive case.
Chris@0:             if (is_array($value)) {
Chris@0:                 self::doExpandArrayProperties($data, $value, $parent_keys . "$key.", $reference_data);
Chris@0:             } // Base case.
Chris@0:             else {
Chris@0:                 self::expandStringProperties($data, $parent_keys, $reference_data, $value, $key);
Chris@0:             }
Chris@0:         }
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Expand a single property.
Chris@0:      *
Chris@0:      * @param Data $data
Chris@0:      *   A data object, containing the $array.
Chris@0:      * @param string $parent_keys
Chris@0:      *   The parent keys of the current key in dot notation. This is used to
Chris@0:      *   track the absolute path to the current key in recursive cases.
Chris@0:      * @param Data|null $reference_data
Chris@0:      *   A reference data object. This is not operated upon but is used as a
Chris@0:      *   reference to provide supplemental values for property expansion.
Chris@0:      * @param string $value
Chris@0:      *   The unexpanded property value.
Chris@0:      * @param string $key
Chris@0:      *   The immediate key of the property.
Chris@0:      *
Chris@0:      * @return mixed
Chris@0:      */
Chris@0:     protected static function expandStringProperties(
Chris@0:         $data,
Chris@0:         $parent_keys,
Chris@0:         $reference_data,
Chris@0:         $value,
Chris@0:         $key
Chris@0:     ) {
Chris@0:         // We loop through all placeholders in a given string.
Chris@0:         // E.g., '${placeholder1} ${placeholder2}' requires two replacements.
Chris@0:         while (strpos($value, '${') !== false) {
Chris@0:             $original_value = $value;
Chris@0:             $value = preg_replace_callback(
Chris@0:                 '/\$\{([^\$}]+)\}/',
Chris@0:                 function ($matches) use ($data, $reference_data) {
Chris@0:                     return self::expandStringPropertiesCallback(
Chris@0:                         $matches,
Chris@0:                         $data,
Chris@0:                         $reference_data
Chris@0:                     );
Chris@0:                 },
Chris@0:                 $value
Chris@0:             );
Chris@0: 
Chris@0:             // If no replacement occurred at all, break to prevent
Chris@0:             // infinite loop.
Chris@0:             if ($original_value == $value) {
Chris@0:                 break;
Chris@0:             }
Chris@0: 
Chris@0:             // Set value on $data object.
Chris@0:             if ($parent_keys) {
Chris@0:                 $full_key = $parent_keys . "$key";
Chris@0:             } else {
Chris@0:                 $full_key = $key;
Chris@0:             }
Chris@0:             $data->set($full_key, $value);
Chris@0:         }
Chris@0:         return $value;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Expansion callback used by preg_replace_callback() in expandProperty().
Chris@0:      *
Chris@0:      * @param array $matches
Chris@0:      *   An array of matches created by preg_replace_callback().
Chris@0:      * @param Data $data
Chris@0:      *   A data object containing the complete array being operated upon.
Chris@0:      * @param Data|null $reference_data
Chris@0:      *   A reference data object. This is not operated upon but is used as a
Chris@0:      *   reference to provide supplemental values for property expansion.
Chris@0:      *
Chris@0:      * @return mixed
Chris@0:      */
Chris@0:     public static function expandStringPropertiesCallback(
Chris@0:         $matches,
Chris@0:         $data,
Chris@0:         $reference_data = null
Chris@0:     ) {
Chris@0:         $property_name = $matches[1];
Chris@0:         $unexpanded_value = $matches[0];
Chris@0: 
Chris@0:         // Use only values within the subject array's data.
Chris@0:         if (!$reference_data) {
Chris@0:             return self::expandProperty($property_name, $unexpanded_value, $data);
Chris@0:         } // Search both the subject array's data and the reference data for a value.
Chris@0:         else {
Chris@0:             return self::expandPropertyWithReferenceData(
Chris@0:                 $property_name,
Chris@0:                 $unexpanded_value,
Chris@0:                 $data,
Chris@0:                 $reference_data
Chris@0:             );
Chris@0:         }
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Searches both the subject data and the reference data for value.
Chris@0:      *
Chris@0:      * @param string $property_name
Chris@0:      *   The name of the value for which to search.
Chris@0:      * @param string $unexpanded_value
Chris@0:      *   The original, unexpanded value, containing the placeholder.
Chris@0:      * @param Data $data
Chris@0:      *   A data object containing the complete array being operated upon.
Chris@0:      * @param Data|null $reference_data
Chris@0:      *   A reference data object. This is not operated upon but is used as a
Chris@0:      *   reference to provide supplemental values for property expansion.
Chris@0:      *
Chris@0:      * @return string
Chris@0:      *   The expanded string.
Chris@0:      */
Chris@0:     public static function expandPropertyWithReferenceData(
Chris@0:         $property_name,
Chris@0:         $unexpanded_value,
Chris@0:         $data,
Chris@0:         $reference_data
Chris@0:     ) {
Chris@0:         $expanded_value = self::expandProperty(
Chris@0:             $property_name,
Chris@0:             $unexpanded_value,
Chris@0:             $data
Chris@0:         );
Chris@0:         // If the string was not changed using the subject data, try using
Chris@0:         // the reference data.
Chris@0:         if ($expanded_value == $unexpanded_value) {
Chris@0:             $expanded_value = self::expandProperty(
Chris@0:                 $property_name,
Chris@0:                 $unexpanded_value,
Chris@0:                 $reference_data
Chris@0:             );
Chris@0:         }
Chris@0: 
Chris@0:         return $expanded_value;
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * Searches a data object for a value.
Chris@0:      *
Chris@0:      * @param string $property_name
Chris@0:      *   The name of the value for which to search.
Chris@0:      * @param string $unexpanded_value
Chris@0:      *   The original, unexpanded value, containing the placeholder.
Chris@0:      * @param Data $data
Chris@0:      *   A data object containing possible replacement values.
Chris@0:      *
Chris@0:      * @return mixed
Chris@0:      */
Chris@0:     public static function expandProperty($property_name, $unexpanded_value, $data)
Chris@0:     {
Chris@0:         if (strpos($property_name, "env.") === 0 &&
Chris@0:           !$data->has($property_name)) {
Chris@0:             $env_key = substr($property_name, 4);
Chris@0:             if (getenv($env_key)) {
Chris@0:                 $data->set($property_name, getenv($env_key));
Chris@0:             }
Chris@0:         }
Chris@0: 
Chris@0:         if (!$data->has($property_name)) {
Chris@0:             self::log("Property \${'$property_name'} could not be expanded.");
Chris@0:             return $unexpanded_value;
Chris@0:         } else {
Chris@0:             $expanded_value = $data->get($property_name);
Chris@0:             if (is_array($expanded_value)) {
Chris@0:                 $expanded_value = Yaml::dump($expanded_value, 0);
Chris@0:                 return $expanded_value;
Chris@0:             }
Chris@0:             self::log("Expanding property \${'$property_name'} => $expanded_value.");
Chris@0:             return $expanded_value;
Chris@0:         }
Chris@0:     }
Chris@0: 
Chris@0:     /**
Chris@0:      * @param $message
Chris@0:      */
Chris@0:     public static function log($message)
Chris@0:     {
Chris@0:         // print "$message\n";
Chris@0:     }
Chris@0: }