AstroFields/Core

<?php

namespace WCM\AstroFields\Core\Helpers;

/**
 * Class ContextParser
 * @package WCM\AstroFields\Core\Helpers
 * Based upon the answer by @author deceze on StackOverflow
 * @link http://stackoverflow.com/a/6313849/376483
 * @license CC-BY-SA 3.0
 */
class ContextParser implements ParserInterface
{
    /** @type Array */
    private $input;

    /** @type string */
    private $context;

    /**
     * Temporary storage for nested `array_reduce()` in `zip()`
     * @type Array
     */
    private $tmp;

    /**
     * Attach input and context to the properties
     * Filters out/Removes empty values from the input
     * @codeCoverageIgnore
     * @param array  $input
     * @param string $context
     */
    public function setup( Array $input, $context )
    {
        # $input = array_map( 'strtolower', $input );
        # $input = array_change_key_case( $input, CASE_LOWER );
        $this->input   = array_filter( $input );
        $this->context = $context;
    }

    /**
     * Return the parsed context array
     * Array keys (numerical) get sorted
     * @return array
     */
    public function getResult()
    {
        return array_values( $this->map(
            $this->cartesian( $this->input ),
            $this->context
        ) );
    }

    /**
     * @codeCoverageIgnore
     * @param array  $product
     * @param string $context
     * @return array
     */
    protected function map( Array $product, $context )
    {
        $results = array();
        foreach ( $product as $part )
        {
            $temp = $context;
            foreach ( $part as $key => $value )
                $temp = str_replace( $key, $value, $temp );

            $results[] = $temp;
        }

        return array_unique( $results );
    }

    /**
     * @codeCoverageIgnore
     * @param array $input
     * @return array
     */
    protected function cartesian( Array $input )
    {
        $keys    = array_keys( $input );
        $product = array_shift( $input );
        $product = array_reduce(
            $input,
            array( $this, 'zip' ),
            $product
        );
        return array_map( function( $n ) use ( $keys )
        {
            return array_combine(
                $keys,
                (array) $n
            );
        }, $product );
    }

    /**
     * @codeCoverageIgnore
     * @param array $input
     * @param array $product
     * @return mixed
     */
    protected function zip( Array $input, Array $product )
    {
        // PHP 5.3 fix
        $parser = $this;

        return array_reduce( $input, function( $carry, $item ) use ( $product, $parser )
        {
            return array_merge(
                $carry,
                $parser->inject( $item, $product )
            );
        }, array() );
    }

    /**
     * @codeCoverageIgnore
     * @param $carry
     * @param $item
     * @return array
     */
    protected function reduce( $carry, $item )
    {
        return array_merge(
            $carry,
            $this->inject( $item, $this->tmp )
        );
    }

    /**
     * @codeCoverageIgnore
     * @param string $element
     * @param array  $array
     * @return array
     */
    public function inject( $element, Array $array )
    {
        return array_map( function( $n ) use ( $element )
        {
            return array_merge(
                (array) $element,
                (array) $n
            );
        }, $array );
    }
}