<?php
/*
  Plugin Name: WP Questions
  Plugin URI: -
  Description: Question and Answer interface for developers
  Version: 1.0
  Author: Rakhitha Nimesh
  Author URI: http://www.innovativephp.com/
  License: GPLv2 or later
*/

add_action('init', 'register_wp_questions');

/*
* Register new custom post type for questions
*
* @return void
*/
function register_wp_questions() {

    $labels = array(
            'name'                  => __( 'Questions', 'wp_question' ),
            'singular_name'         => __( 'Question', 'wp_question' ),
            'add_new'               => __( 'Add New', 'wp_question' ),
            'add_new_item'          => __( 'Add New Question', 'wp_question' ),
            'edit_item'             => __( 'Edit Questions', 'wp_question' ),
            'new_item'              => __( 'New Question', 'wp_question' ),
            'view_item'             => __( 'View Question', 'wp_question' ),
            'search_items'          => __( 'Search Questions', 'wp_question' ),
            'not_found'             => __( 'No Questions found', 'wp_question' ),
            'not_found_in_trash'    => __( 'No Questions found in Trash', 'wp_question' ),
            'parent_item_colon'     => __( 'Parent Question:', 'wp_question' ),
            'menu_name'             => __( 'Questions', 'wp_question' ),
    );

    $args = array(
            'labels'                => $labels,
            'hierarchical'          => true,
            'description'           => __( 'Questions and Answers', 'wp_question' ),
            'supports'              => array( 'title', 'editor', 'comments' ),
            'public'                => true,
            'show_ui'               => true,
            'show_in_menu'          => true,
            'show_in_nav_menus'     => true,
            'publicly_queryable'    => true,
            'exclude_from_search'   => false,
            'has_archive'           => true,
            'query_var'             => true,
            'can_export'            => true,
            'rewrite'               => true,
            'capability_type'       => 'post'
    );

    register_post_type( 'wp_question', $args );
}

add_action( 'wp_enqueue_scripts', 'wpwa_frontend_scripts' );

/*
* Include neccessary scripts and styles for the plugin
*
* @return void
*/
function wpwa_frontend_scripts() {

    wp_enqueue_script( 'jquery' );
    wp_register_script( 'wp-questions', plugins_url( 'js/questions.js', __FILE__ ), array('jquery'), '1.0', TRUE );
    wp_enqueue_script( 'wp-questions' );

    wp_register_style( 'questions', plugins_url( 'css/questions.css', __FILE__ ) );
    wp_enqueue_style( 'questions' );

    $config_array = array(
            'ajaxURL' => admin_url( 'admin-ajax.php' ),
            'ajaxNonce' => wp_create_nonce( 'ques-nonce' )
    );

    wp_localize_script( 'wp-questions', 'wpwaconf', $config_array );
}


add_action( 'wp_ajax_mark_answer_status', 'wpwa_mark_answer_status' );

/*
* Mark the correct/incorrect status for each answer
*
* @return string
*/
function wpwa_mark_answer_status() {

    $data = isset( $_POST['data'] ) ? $_POST['data'] : array();

    $comment_id     = isset( $data["comment_id"] ) ? absint($data["comment_id"]) : 0;
    $answer_status  = isset( $data["status"] ) ? $data["status"] : 0;
    ;

    // Mark answers in correct status to incorrect
    // or incorrect status to correct
    if ("valid" == $answer_status) {
        update_comment_meta( $comment_id, "_wpwa_answer_status", 1 );
    } else {
        update_comment_meta( $comment_id, "_wpwa_answer_status", 0 );
    }

    echo json_encode( array("status" => "success") );
    exit;
}


/*
* Mark the correct/incorrect status for each answer
*
* @param  int    Post Id of the current question
* @return void
*/
function wpwa_get_correct_answers( $post_id ) {

    $args = array(
            'post_id'   => $post_id,
            'status'    => 'approve',
            'meta_key'  => '_wpwa_answer_status',
            'meta_value'=> 1,
    );

    // Get number of correct answers for given question
    $comments = get_comments( $args );
    printf(__('<cite class="fn">%s</cite> correct answers'), count( $comments ) );
}


/*
* Generate custom comments list with customized fields and values
*
* @param  array Automatically passed comments object
* @param  array Required arguments
* @param  int   Depth of comment
* @return void
*/
function wpwa_comment_list( $comment, $args, $depth ) {
    global $post;

    $GLOBALS['comment'] = $comment;

    // Get current logged in user and author of question
    $current_user           = wp_get_current_user();
    $author_id              = $post->post_author;
    $show_answer_status     = false;

    // Set the button status for authors of the question
    if ( is_user_logged_in() && $current_user->ID == $author_id ) {
        $show_answer_status = true;
    }

    // Get the correct/incorrect status of the answer
    $comment_id = get_comment_ID();
    $answer_status = get_comment_meta( $comment_id, "_wpwa_answer_status", true );



    ?>
<li <?php comment_class(); ?> id="li-comment-<?php comment_ID() ?>">
<article id="comment-<?php comment_ID(); ?>">
    <header class="comment-meta comment-author vcard">
            <?php
            // Display image of a tick for correct answers
            if ( $answer_status ) {
                echo "<div class='tick'><img src='".plugins_url( 'img/tick.png', __FILE__ )."' alt='Answer Status' /></div>";
            }
            ?>
            <?php echo get_avatar( $comment, $size = '48', $default = '<path_to_url>' ); ?>
    <?php printf(__('<cite class="fn">Answered by %s</cite>'), get_comment_author_link() ) ?>

    </header>
    <?php if ( '0' == $comment->comment_approved ) : ?>
    <em><?php _e('Your answer is awaiting moderation.') ?></em>
    <br />
    <?php endif; ?>


    <?php comment_text() ?>

    <div class="reply">
    <?php comment_reply_link( array_merge( $args, array('depth' => $depth, 'max_depth' => $args['max_depth']) ) ) ?>
    </div>


    <div>
            <?php
            // Display the button for authors to make the answer as correct or incorrect
            if ( $show_answer_status ) {

                $question_status = '';
                $question_status_text = '';
                if ( $answer_status ) {
                    $question_status = 'invalid';
                    $question_status_text = 'Mark as Incorrect';
                } else {
                    $question_status = 'valid';
                    $question_status_text = 'Mark as Correct';
                }

        ?>
        <input type="button" value="<?php echo $question_status_text; ?>"  class="answer-status answer_status-<?php echo $comment_id; ?>"
               data-ques-status="<?php echo $question_status; ?>" />
        <input type="hidden" value="<?php echo $comment_id; ?>" class="hcomment" />

                <?php
            }
    ?>
    </div>
</article>
</li>
    <?php
}