trait FetchModeTrait

trait FetchModeTrait {
    
    /**
     * Map FETCH_* modes to their literal for inclusion in messages.
     *
     * @see https://github.com/php/php-src/blob/master/ext/pdo/php_pdo_driver.h#L65-L80
     */
    protected array $fetchModeLiterals = [
        \PDO::FETCH_DEFAULT => 'FETCH_DEFAULT',
        \PDO::FETCH_LAZY => 'FETCH_LAZY',
        \PDO::FETCH_ASSOC => 'FETCH_ASSOC',
        \PDO::FETCH_NUM => 'FETCH_NUM',
        \PDO::FETCH_BOTH => 'FETCH_BOTH',
        \PDO::FETCH_OBJ => 'FETCH_OBJ',
        \PDO::FETCH_BOUND => 'FETCH_BOUND',
        \PDO::FETCH_COLUMN => 'FETCH_COLUMN',
        \PDO::FETCH_CLASS => 'FETCH_CLASS',
        \PDO::FETCH_INTO => 'FETCH_INTO',
        \PDO::FETCH_FUNC => 'FETCH_FUNC',
        \PDO::FETCH_NAMED => 'FETCH_NAMED',
        \PDO::FETCH_KEY_PAIR => 'FETCH_KEY_PAIR',
        \PDO::FETCH_CLASS | \PDO::FETCH_CLASSTYPE => 'FETCH_CLASS | FETCH_CLASSTYPE',
        \PDO::FETCH_CLASS | \PDO::FETCH_PROPS_LATE => 'FETCH_CLASS | FETCH_PROPS_LATE',
    ];
    
    /**
     * The fetch modes supported.
     */
    protected array $supportedFetchModes = [
        \PDO::FETCH_ASSOC,
        \PDO::FETCH_CLASS,
        \PDO::FETCH_CLASS | \PDO::FETCH_PROPS_LATE,
        \PDO::FETCH_COLUMN,
        \PDO::FETCH_NUM,
        \PDO::FETCH_OBJ,
    ];
    
    /**
     * Converts a row of data in FETCH_ASSOC format to FETCH_NUM.
     *
     * @param array $rowAssoc
     *   A row of data in FETCH_ASSOC format.
     *
     * @return array
     *   The row in FETCH_NUM format.
     */
    protected function assocToNum(array $rowAssoc) : array {
        return array_values($rowAssoc);
    }
    
    /**
     * Converts a row of data in FETCH_ASSOC format to FETCH_OBJ.
     *
     * @param array $rowAssoc
     *   A row of data in FETCH_ASSOC format.
     *
     * @return object
     *   The row in FETCH_OBJ format.
     */
    protected function assocToObj(array $rowAssoc) : \stdClass {
        return (object) $rowAssoc;
    }
    
    /**
     * Converts a row of data in FETCH_ASSOC format to FETCH_CLASS.
     *
     * @param array $rowAssoc
     *   A row of data in FETCH_ASSOC format.
     * @param string $className
     *   Name of the created class.
     * @param array $constructorArguments
     *   Elements of this array are passed to the constructor.
     *
     * @return object
     *   The row in FETCH_CLASS format.
     */
    protected function assocToClass(array $rowAssoc, string $className, array $constructorArguments) : object {
        $classObj = new $className(...$constructorArguments);
        foreach ($rowAssoc as $column => $value) {
            $classObj->{$column} = $value;
        }
        return $classObj;
    }
    
    /**
     * Converts a row of data in FETCH_ASSOC format to FETCH_COLUMN.
     *
     * @param array $rowAssoc
     *   A row of data in FETCH_ASSOC format.
     * @param string[] $columnNames
     *   The list of the row columns.
     * @param int $columnIndex
     *   The index of the column to fetch the value of.
     *
     * @return string|false
     *   The value of the column, or FALSE if the column is not defined.
     */
    protected function assocToColumn(array $rowAssoc, array $columnNames, int $columnIndex) : mixed {
        return $rowAssoc[$columnNames[$columnIndex]] ?? FALSE;
    }

}