<?php
// If this file is called directly, abort.
if ( ! defined( 'ABSPATH' ) ) {
    die();
}
/**
 * Custom Affiliate Links Metabox For Links Post Type.
 */
class Affiliate_Links_Metabox {

    /**
     * List of custom fields.
     */
    public $fields = array(
        array(
            'name'        => '_affiliate_links_target',
            'title'       => 'Link Target URL',
            'description' => '* Enter your target URL.',
            'type'        => 'url',
            'required'    => 'required'
        ),
        array(
            'name'        => '_affiliate_links_description',
            'title'       => 'Link Description',
            'description' => 'Describe your link.',
            'type'        => 'text'
        )
    );

    /**
     * Hook into the appropriate actions when the class is constructed.
     */
    public function __construct() {

        // Add metabox actions.
        add_action( 'load-post.php', array( $this, 'init_metabox' ) );
        add_action( 'load-post-new.php', array( $this, 'init_metabox' ) );

        // Add custom field values to admin grid columns.
        add_filter( 'manage_posts_columns', array( $this, 'columns_head' ) );
        add_action( 'manage_posts_custom_column', array( $this, 'columns_content' ), 10, 2 );

        // Add custom styling.
        add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_scripts' ) );

    }

    /**
     * Add admin css file.
     */
    public function enqueue_scripts( $hook ) {

        if ( $hook != 'post.php' AND $hook != 'post-new.php' ) {
            return;
        }

        wp_register_style( 'affiliate-links', AFFILIATE_LINKS_PLUGIN_URL . 'admin/css/affiliate-links-admin.css', false, '1.0' );
        wp_enqueue_style( 'affiliate-links' );

    }

    /**
     * Modify admin grid column headers.
     */
    public function columns_head( $defaults ) {

        $defaults['permalink'] = __( 'Link URL', Affiliate_Links::$text_domain );

        foreach( $this->fields as $field ) {

            $defaults[ $field['name'] ] = $field['title'];

        }

        $defaults['_affiliate_links_stat'] = __( 'Hits', Affiliate_Links::$text_domain );

        return $defaults;

    }

    /**
     * Modify admin grid columns.
     */
    public function columns_content( $column_name, $post_id ) {

        if( $column_name == 'permalink' ) {

            echo get_the_permalink( $post_id );

        } else {

            echo get_post_meta( $post_id, $column_name, true );

        }

    }

    /**
     * Add appropriate actions.
     */
    public function init_metabox() {

        add_action( 'add_meta_boxes', array( $this, 'add_meta_box' ) );
        add_action( 'save_post', array( $this, 'save' ) );

    }

    /**
     * Adds the meta box container.
     */
    public function add_meta_box( $post_type ) {

        $post_types = array( Affiliate_Links::$post_type );

        if ( in_array( $post_type, $post_types )) {
            add_meta_box(
                'affiliate_links_settings',
                __( 'Link Settings', Affiliate_Links::$text_domain ),
                array( $this, 'render_meta_box_content' ),
                $post_type,
                'advanced',
                'high'
            );
        }

    }

    /**
     * Save metabox.
     */
    public function save( $post_id ) {

        // Check if our nonce is set.
        if ( ! isset( $_POST['affiliate_links_custom_box_nonce'] ) )
            return $post_id;

        $nonce = $_POST['affiliate_links_custom_box_nonce'];

        // Verify that the nonce is valid.
        if ( ! wp_verify_nonce( $nonce, 'affiliate_links_custom_box' ) )
            return $post_id;

        // If this is an autosave, our form has not been submitted, so we don't want to do anything.
        if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
            return $post_id;

        // Check the user's permissions.
        if ( ! current_user_can( 'edit_post', $post_id ) )
            return $post_id;

        foreach( $this->fields as $field ) {

            // Sanitize the user input.
            $custom_field = isset( $_POST[ $field['name'] ] ) ? sanitize_text_field( $_POST[ $field['name'] ] ) : '';

            // Update the meta field.
            update_post_meta( $post_id, $field['name'], $custom_field );

        }

    }

    /**
     * Render metabox content.
     */
    public function render_meta_box_content( $post ) {

        echo '<table class="form-table">';

        // Add an nonce field so we can check for it later.
        wp_nonce_field( 'affiliate_links_custom_box', 'affiliate_links_custom_box_nonce' );

        $this->link_field( $post->ID );

        foreach( $this->fields as $field ){

            // Retrieve an existing value from the database.
            $value = get_post_meta( $post->ID, $field['name'], true );
            $this->generate_field( $field, $value );

        }

        $this->stats_field( $post->ID );

        echo '</table>';

    }

    /**
     * Generate settings field html.
     */
    public function generate_field( $field, $value ) {

        $name  = esc_attr( $field['name'] );
        $title = esc_attr( $field['title'] );
        $desc  = esc_html( $field['description'] );
        $type  = esc_html( $field['type'] );
        ?>
        <tr>
       		<th>
                <label for="<?php echo $name ?>" class="<?php echo $name ?>_label"><?php echo $title ?></label>
            </th>
            <td>
       			<input
                    type="<?php echo $type ?>"
                    id="<?php echo $name ?>"
                    name="<?php echo $name ?>"
                    class="<?php echo $name ?>_field"
                    <?php if( !empty($field['required']) ) echo $field['required'] ?>
                    value="<?php echo esc_attr__( $value ) ?>"
                >
                <p class="description"><?php echo $desc ?></p>
       		</td>
        </tr>
        <?php

    }

    /**
     * Generate fields for hit stats displaying.
     */
    public function stats_field( $post_id ) {

        $count = esc_html( get_post_meta( $post_id, '_affiliate_links_stat', true ) );
        ?>
        <tr>
            <th><?php _e( 'Total Hits', Affiliate_Links::$text_domain ) ?></th>
            <td>
                <span><?php echo $count ?></span>
                <p class="description"><?php _e( 'Total count of link redirects.', Affiliate_Links::$text_domain ) ?></p>
            </td>
        </tr>
        <?php

    }

    /**
     * Generate fields for permalink displaying.
     */
    public function link_field( $post_id ) {

        ?>
        <tr>
            <th><?php _e( 'Your link', Affiliate_Links::$text_domain ) ?></th>
            <td>
                <span><?php the_permalink( $post_id ) ?></span>
                <p class="description"><?php _e( 'To change this link you should edit Permalink at the top of screen.', Affiliate_Links::$text_domain ) ?></p>
            </td>
        </tr>
        <?php

    }

}

/**
 * Calls the class on the post edit screen.
 */
if ( is_admin() ) {

    new Affiliate_Links_Metabox();

}