myCRED: DW Questions & Answers Custom hook

/**
 * Register Hook
 * @since 1.0
 * @version 1.0
 */
add_filter( 'mycred_setup_hooks', 'mycred_hook_dw_qanda' );
function mycred_hook_dw_qanda( $installed ) {
    $installed['dw_questions'] = array(
        'title'       => __( 'DW Question Answer', 'mycred' ),
        'description' => __( 'Awards %_plural% for best answers. To award %_plural% for new questions and answers, use the "%plural% for publishing content" hook above.', 'mycred' ),
        'callback'    => array( 'myCRED_DW_Question_Answer' )
    );
    return $installed;
}

if ( class_exists( 'myCRED_Hook' ) ) :

    /**
     * DW Question Answer Hook
     * @since 1.0
     * @version 1.0
     */
    if ( ! class_exists( 'myCRED_DW_Question_Answer' ) ) {
        class myCRED_DW_Question_Answer extends myCRED_Hook {

            /**
             * Construct
             */
            function __construct( $hook_prefs ) {
                parent::__construct( array(
                    'id'       => 'dw_questions',
                    'defaults' => array(
                        'vote_best_answer' => array(
                            'creds'       => 0,
                            'log'         => '%plural% for giving best answer'
                        ),
                        'unvoted_best_answer' => array(
                            'creds'       => 0,
                            'log'         => '%plural% deduction for unvoted best answer'
                        ),
                        'selected_best_answer' => array(
                            'creds'       => 0,
                            'log'         => '%plural% for selecting a best answer'
                        ),
                        'removed_best_answer' => array(
                            'creds'       => 0,
                            'log'         => '%plural% for removing your best answer selection'
                        )
                    )
                ), $hook_prefs );
            }

            /**
             * Run
             * @since 0.1
             * @version 1.0
             */
            public function run() {
                add_action( 'wp_ajax_dwqa-vote-best-answer',   array( $this, 'vote_best_answer' ), 1 );
                add_action( 'wp_ajax_dwqa-unvote-best-answer', array( $this, 'unvote_best_answer' ), 1 );
            }

            /**
             * Vote Best Answer
             * @since 0.1
             * @version 1.0
             */
            public function vote_best_answer() {
                // Security
                check_ajax_referer( '_dwqa_vote_best_answer', 'nonce' );

                // Must be logged in
                if ( ! is_user_logged_in() ) return;

                // Required
                if ( ! isset( $_POST['answer'] ) )
                    return;

                $this->best_answer( (int) $_POST['answer'] );
            }

            /**
             * Un-Vote Best Answer
             * @since 0.1
             * @version 1.0
             */
            public function unvote_best_answer() {
                // Security
                check_ajax_referer( '_dwqa_vote_best_answer', 'nonce' );

                // Must be logged in
                if ( ! is_user_logged_in() ) return;

                // Required
                if ( ! isset( $_POST['answer'] ) )
                    return;

                $this->best_answer( (int) $_POST['answer'], true );
            }

            /**
             * Award Best Answer
             * @since 0.1
             * @version 1.0
             */
            public function best_answer( $answer_id, $deduct = false ) {
                // Current user
                $user_id = get_current_user_id();

                // Get Question ID
                $question_id = get_post_meta( $answer_id, '_question', true );
                $question_id = absint( $question_id );

                // Get Question
                $question = get_post( $question_id );

                // Get Answer
                $answer = get_post( $answer_id );

                // If we are the question author or editor
                if ( $question->post_author == $user_id || current_user_can( 'edit_posts' ) ) {

                    // Make sure author is not excluded
                    if ( ! $this->core->exclude_user( $answer->post_author ) )  {

                        // Execute
                        if ( ! $deduct && $this->prefs['vote_best_answer']['creds'] != 0 )
                            $this->core->add_creds(
                                'voted_best_answer',
                                $answer->post_author,
                                $this->prefs['vote_best_answer']['creds'],
                                $this->prefs['vote_best_answer']['log'],
                                $answer_id,
                                array( 'ref_type' => 'post' )
                            );
                        elseif ( $deduct && $this->prefs['unvote_best_answer']['creds'] != 0 )
                            $this->core->add_creds(
                                'unvoted_best_answer',
                                $answer->post_author,
                                $this->prefs['unvote_best_answer']['creds'],
                                $this->prefs['unvote_best_answer']['log'],
                                $answer_id,
                                array( 'ref_type' => 'post' )
                            );

                    }

                    // Check Exclusion
                    if ( ! $this->core->exclude_user( $question->post_author ) ) {

                        // Execute
                        if ( ! $deduct && $this->prefs['selected_best_answer']['creds'] != 0 )
                            $this->core->add_creds(
                                'selected_best_answer',
                                $question->post_author,
                                $this->prefs['selected_best_answer']['creds'],
                                $this->prefs['selected_best_answer']['log'],
                                $question_id,
                                array( 'ref_type' => 'post' )
                            );
                        elseif ( $deduct && $this->prefs['removed_best_answer']['creds'] != 0 )
                            $this->core->add_creds(
                                'removed_best_answer',
                                $question->post_author,
                                $this->prefs['removed_best_answer']['creds'],
                                $this->prefs['removed_best_answer']['log'],
                                $question_id,
                                array( 'ref_type' => 'post' )
                            );

                    }

                }

            }

            /**
             * Preferences for Hook
             * @since 1.0
             * @version 1.0
             */
            public function preferences() {
                $prefs = $this->prefs; ?>

<h3>Answer Author</h3>
<label for="<?php echo $this->field_id( array( 'vote_best_answer', 'creds' ) ); ?>" class="subheader"><?php _e( 'Voted Best Answer', 'mycred' ); ?></label>
<ol>
    <li>
        <div class="h2"><input type="text" name="<?php echo $this->field_name( array( 'vote_best_answer', 'creds' ) ); ?>" id="<?php echo $this->field_id( array( 'vote_best_answer', 'creds' ) ); ?>" value="<?php echo $this->core->number( $prefs['vote_best_answer']['creds'] ); ?>" size="8" /></div>
    </li>
    <li class="empty">&nbsp;</li>
    <li>
        <label for="<?php echo $this->field_id( array( 'vote_best_answer', 'log' ) ); ?>"><?php _e( 'Log template', 'mycred' ); ?></label>
        <div class="h2"><input type="text" name="<?php echo $this->field_name( array( 'vote_best_answer', 'log' ) ); ?>" id="<?php echo $this->field_id( array( 'vote_best_answer', 'log' ) ); ?>" value="<?php echo esc_attr( $prefs['vote_best_answer']['log'] ); ?>" class="long" /></div>
        <span class="description"><?php _e( 'Available template tags: General and Post (Answer) related.', 'mycred' ); ?></span>
    </li>
</ol>
<!-- Answer Author Unvoted Best Answer -->
<label for="<?php echo $this->field_id( array( 'unvoted_best_answer', 'creds' ) ); ?>" class="subheader"><?php _e( 'Unvoted Best Answer', 'mycred' ); ?></label>
<ol>
    <li>
        <div class="h2"><input type="text" name="<?php echo $this->field_name( array( 'unvoted_best_answer', 'creds' ) ); ?>" id="<?php echo $this->field_id( array( 'unvoted_best_answer', 'creds' ) ); ?>" value="<?php echo $this->core->number( $prefs['unvoted_best_answer']['creds'] ); ?>" size="8" /></div>
    </li>
    <li class="empty">&nbsp;</li>
    <li>
        <label for="<?php echo $this->field_id( array( 'unvoted_best_answer', 'log' ) ); ?>"><?php _e( 'Log template', 'mycred' ); ?></label>
        <div class="h2"><input type="text" name="<?php echo $this->field_name( array( 'unvoted_best_answer', 'log' ) ); ?>" id="<?php echo $this->field_id( array( 'unvoted_best_answer', 'log' ) ); ?>" value="<?php echo esc_attr( $prefs['unvoted_best_answer']['log'] ); ?>" class="long" /></div>
        <span class="description"><?php _e( 'Available template tags: General and Post (Answer) related.', 'mycred' ); ?></span>
    </li>
</ol>
<h3>Question Author</h3>
<!-- Question Author Set Best Answer -->
<label for="<?php echo $this->field_id( array( 'selected_best_answer', 'creds' ) ); ?>" class="subheader"><?php _e( 'Choosing a Best Answer', 'mycred' ); ?></label>
<ol>
    <li><?php echo $this->core->template_tags_general( __( 'Option to award %_plural% to the Question author for selecting a best answer.', 'mycred' ) ); ?></li>
    <li>
        <div class="h2"><input type="text" name="<?php echo $this->field_name( array( 'selected_best_answer', 'creds' ) ); ?>" id="<?php echo $this->field_id( array( 'selected_best_answer', 'creds' ) ); ?>" value="<?php echo $this->core->number( $prefs['selected_best_answer']['creds'] ); ?>" size="8" /></div>
    </li>
    <li class="empty">&nbsp;</li>
    <li>
        <label for="<?php echo $this->field_id( array( 'selected_best_answer', 'log' ) ); ?>"><?php _e( 'Log template', 'mycred' ); ?></label>
        <div class="h2"><input type="text" name="<?php echo $this->field_name( array( 'selected_best_answer', 'log' ) ); ?>" id="<?php echo $this->field_id( array( 'selected_best_answer', 'log' ) ); ?>" value="<?php echo esc_attr( $prefs['selected_best_answer']['log'] ); ?>" class="long" /></div>
        <span class="description"><?php _e( 'Available template tags: General and Post (Question) related.', 'mycred' ); ?></span>
    </li>
</ol>
<!-- Question Author Remove Best Answer -->
<label for="<?php echo $this->field_id( array( 'removed_best_answer', 'creds' ) ); ?>" class="subheader"><?php _e( 'Removing Best Answer', 'mycred' ); ?></label>
<ol>
    <li>
        <div class="h2"><input type="text" name="<?php echo $this->field_name( array( 'removed_best_answer', 'creds' ) ); ?>" id="<?php echo $this->field_id( array( 'removed_best_answer', 'creds' ) ); ?>" value="<?php echo $this->core->number( $prefs['removed_best_answer']['creds'] ); ?>" size="8" /></div>
    </li>
    <li class="empty">&nbsp;</li>
    <li>
        <label for="<?php echo $this->field_id( array( 'removed_best_answer', 'log' ) ); ?>"><?php _e( 'Log template', 'mycred' ); ?></label>
        <div class="h2"><input type="text" name="<?php echo $this->field_name( array( 'removed_best_answer', 'log' ) ); ?>" id="<?php echo $this->field_id( array( 'removed_best_answer', 'log' ) ); ?>" value="<?php echo esc_attr( $prefs['removed_best_answer']['log'] ); ?>" class="long" /></div>
        <span class="description"><?php _e( 'Available template tags: General and Post (Question) related.', 'mycred' ); ?></span>
    </li>
</ol>
<?php
            }
        }
    }
endif;