How to reuse php templates as shortcodes?

You can write a wrap function for short code like that.

function simplest_shortcode_ever() {
    ob_start();
    ?>
        Your PHP Logic here
    <?php
    return ob_get_clean();
}
add_shortcode( 'simple_shortcode', 'simplest_shortcode_ever' );

And then use it[simple_shortcode]