class ArrayEntryToken

class ArrayEntryToken implements TokenInterface {
    
    /** @var TokenInterface */
    private $key;
    
    /** @var TokenInterface */
    private $value;
    
    /**
     * @param mixed $key   exact value or token
     * @param mixed $value exact value or token
     */
    public function __construct($key, $value) {
        $this->key = $this->wrapIntoExactValueToken($key);
        $this->value = $this->wrapIntoExactValueToken($value);
    }
    
    /**
     * Scores half of combined scores from key and value tokens for same entry. Capped at 8.
     * If argument implements \ArrayAccess without \Traversable, then key token is restricted to ExactValueToken.
     *
     * @param mixed $argument
     *
     * @throws InvalidArgumentException
     * @return false|int
     */
    public function scoreArgument($argument) {
        if ($argument instanceof \Traversable) {
            $argument = iterator_to_array($argument);
        }
        if ($argument instanceof \ArrayAccess) {
            $argument = $this->convertArrayAccessToEntry($argument);
        }
        if (!is_array($argument) || empty($argument)) {
            return false;
        }
        $keyScores = array_map(array(
            $this->key,
            'scoreArgument',
        ), array_keys($argument));
        $valueScores = array_map(array(
            $this->value,
            'scoreArgument',
        ), $argument);
        
        /** @var callable(int|false, int|false): (int|false) $scoreEntry */
        $scoreEntry = function ($value, $key) {
            return $value && $key ? min(8, ($key + $value) / 2) : false;
        };
        return max(array_map($scoreEntry, $valueScores, $keyScores));
    }
    
    /**
     * Returns false.
     *
     * @return boolean
     */
    public function isLast() {
        return false;
    }
    
    /**
     * Returns string representation for token.
     *
     * @return string
     */
    public function __toString() {
        return sprintf('[..., %s => %s, ...]', $this->key, $this->value);
    }
    
    /**
     * Returns key
     *
     * @return TokenInterface
     */
    public function getKey() {
        return $this->key;
    }
    
    /**
     * Returns value
     *
     * @return TokenInterface
     */
    public function getValue() {
        return $this->value;
    }
    
    /**
     * Wraps non token $value into ExactValueToken
     *
     * @param mixed $value
     * @return TokenInterface
     */
    private function wrapIntoExactValueToken($value) {
        return $value instanceof TokenInterface ? $value : new ExactValueToken($value);
    }
    
    /**
     * Converts instance of \ArrayAccess to key => value array entry
     *
     * @param \ArrayAccess<array-key, mixed> $object
     *
     * @return array<mixed>
     * @throws InvalidArgumentException
     */
    private function convertArrayAccessToEntry(\ArrayAccess $object) {
        if (!$this->key instanceof ExactValueToken) {
            throw new InvalidArgumentException(sprintf('You can only use exact value tokens to match key of ArrayAccess object' . PHP_EOL . 'But you used `%s`.', $this->key));
        }
        $key = $this->key
            ->getValue();
        if (!\is_int($key) && !\is_string($key)) {
            throw new InvalidArgumentException(sprintf('You can only use integer or string keys to match key of ArrayAccess object' . PHP_EOL . 'But you used `%s`.', $this->key));
        }
        return $object->offsetExists($key) ? array(
            $key => $object[$key],
        ) : array();
    }

}