class Condition

class Condition extends ConditionBase {
    
    /**
     * {@inheritdoc}
     */
    public function compile($configs) {
        $and = strtoupper($this->conjunction) == 'AND';
        $single_conditions = [];
        $condition_groups = [];
        foreach ($this->conditions as $condition) {
            if ($condition['field'] instanceof ConditionInterface) {
                $condition_groups[] = $condition;
            }
            else {
                if (!isset($condition['operator'])) {
                    $condition['operator'] = is_array($condition['value']) ? 'IN' : '=';
                }
                // Process the value for operator that use it.
                if (!in_array($condition['operator'], [
                    'IS NULL',
                    'IS NOT NULL',
                ], TRUE)) {
                    // Lowercase condition value(s) for case-insensitive matches.
                    if (is_array($condition['value'])) {
                        $condition['value'] = array_map('mb_strtolower', $condition['value']);
                    }
                    elseif (!is_bool($condition['value'])) {
                        $condition['value'] = mb_strtolower($condition['value']);
                    }
                }
                $single_conditions[] = $condition;
            }
        }
        $return = [];
        if ($single_conditions) {
            foreach ($configs as $config_name => $config) {
                foreach ($single_conditions as $condition) {
                    $match = $this->matchArray($condition, $config, explode('.', $condition['field']));
                    // If AND and it's not matching, then the rest of conditions do not
                    // matter and this config object does not match.
                    // If OR and it is matching, then the rest of conditions do not
                    // matter and this config object does match.
                    if ($and != $match) {
                        break;
                    }
                }
                if ($match) {
                    $return[$config_name] = $config;
                }
            }
        }
        elseif (!$condition_groups || $and) {
            // If there were no single conditions then either:
            // - Complex conditions, OR: need to start from no entities.
            // - Complex conditions, AND: need to start from all entities.
            // - No complex conditions (AND/OR doesn't matter): need to return all
            //   entities.
            $return = $configs;
        }
        foreach ($condition_groups as $condition) {
            $group_entities = $condition['field']->compile($configs);
            if ($and) {
                $return = array_intersect_key($return, $group_entities);
            }
            else {
                $return = $return + $group_entities;
            }
        }
        return $return;
    }
    
    /**
     * {@inheritdoc}
     */
    public function exists($field, $langcode = NULL) {
        return $this->condition($field, NULL, 'IS NOT NULL', $langcode);
    }
    
    /**
     * {@inheritdoc}
     */
    public function notExists($field, $langcode = NULL) {
        return $this->condition($field, NULL, 'IS NULL', $langcode);
    }
    
    /**
     * Matches for an array representing one or more config paths.
     *
     * @param array $condition
     *   The condition array as created by the condition() method.
     * @param array $data
     *   The config array or part of it.
     * @param array $needs_matching
     *   The list of config array keys needing a match. Can contain config keys
     *   and the * wildcard.
     * @param array $parents
     *   The current list of parents.
     *
     * @return bool
     *   TRUE when the condition matched to the data else FALSE.
     */
    protected function matchArray(array $condition, array $data, array $needs_matching, array $parents = []) {
        $parent = array_shift($needs_matching);
        if ($parent === '*') {
            $candidates = array_keys($data);
        }
        else {
            // Avoid a notice when calling match() later.
            if (!isset($data[$parent])) {
                $data[$parent] = NULL;
            }
            $candidates = [
                $parent,
            ];
        }
        foreach ($candidates as $key) {
            if ($needs_matching) {
                if (is_array($data[$key])) {
                    $new_parents = $parents;
                    $new_parents[] = $key;
                    if ($this->matchArray($condition, $data[$key], $needs_matching, $new_parents)) {
                        return TRUE;
                    }
                }
                elseif ($condition['operator'] === 'IS NULL') {
                    return TRUE;
                }
            }
            elseif ($this->match($condition, $data[$key])) {
                return TRUE;
            }
        }
        return FALSE;
    }
    
    /**
     * Perform the actual matching.
     *
     * @param array $condition
     *   The condition array as created by the condition() method.
     * @param string $value
     *   The value to match against.
     *
     * @return bool
     *   TRUE when matches else FALSE.
     */
    protected function match(array $condition, $value) {
        // "IS NULL" and "IS NOT NULL" conditions can also deal with array values,
        // so we return early for them to avoid problems.
        if (in_array($condition['operator'], [
            'IS NULL',
            'IS NOT NULL',
        ], TRUE)) {
            $should_be_set = $condition['operator'] === 'IS NOT NULL';
            return $should_be_set === isset($value);
        }
        if (isset($value)) {
            // We always want a case-insensitive match.
            if (!is_bool($value)) {
                $value = mb_strtolower($value);
            }
            switch ($condition['operator']) {
                case '=':
                    return $value == $condition['value'];
                case '>':
                    return $value > $condition['value'];
                case '<':
                    return $value < $condition['value'];
                case '>=':
                    return $value >= $condition['value'];
                case '<=':
                    return $value <= $condition['value'];
                case '<>':
                    return $value != $condition['value'];
                case 'IN':
                    return array_search($value, $condition['value']) !== FALSE;
                case 'NOT IN':
                    return array_search($value, $condition['value']) === FALSE;
                case 'STARTS_WITH':
                    return strpos($value, $condition['value']) === 0;
                case 'CONTAINS':
                    return strpos($value, $condition['value']) !== FALSE;
                case 'ENDS_WITH':
                    return substr($value, -strlen($condition['value'])) === (string) $condition['value'];
                default:
                    throw new QueryException('Invalid condition operator.');
            }
        }
        return FALSE;
    }

}