<?php

/**
 * The admin-specific functionality of the plugin.
 *
 * @link       http://wpreloaded.com/farhan-noor
 * @since      1.0.0
 *
 * @package    Applyonline
 * @subpackage Applyonline/admin
 */

/**
 * The admin-specific functionality of the plugin.
 *
 * Defines the plugin name, version, and two examples hooks for how to
 * enqueue the admin-specific stylesheet and JavaScript.
 *
 * @package    Applyonline
 * @subpackage Applyonline/admin
 * @author     Farhan Noor <farhan.noor@yahoo.com>
 */
class Applyonline_Admin {

	/**
	 * The ID of this plugin.
	 *
	 * @since    1.0.0
	 * @access   private
	 * @var      string    $plugin_name    The ID of this plugin.
	 */
	private $plugin_name;

	/**
	 * The version of this plugin.
	 *
	 * @since    1.0.0
	 * @access   private
	 * @var      string    $version    The current version of this plugin.
	 */
	private $version;

	/**
	 * Initialize the class and set its properties.
	 *
	 * @since    1.0.0
	 * @param      string    $plugin_name       The name of this plugin.
	 * @param      string    $version    The version of this plugin.
	 */
	public function __construct( $plugin_name, $version ) {

		$this->plugin_name = $plugin_name;
		$this->version = $version;
                
                add_action( 'init', array( $this, 'register_aol_post_types' ) );
                                
                add_shortcode( 'aol', array($this, 'shortcode_generator') );
                
                //Depricated.
                add_shortcode( 'aol_ads', array($this, 'shortcode_generator') );
                
                // Hook - Applicant Listing - Column Name
                add_filter( 'manage_edit-aol_application_columns', array ( $this, 'applicants_list_columns' ) );

                // Hook - Applicant Listing - Column Value
                add_action( 'manage_aol_application_posts_custom_column', array ( $this, 'applicants_list_columns_value' ), 10, 2 ); 
                
                add_filter('post_row_actions',array($this, 'aol_post_row_actions'), 10, 2);
                
                //Filter Aplications based on parent.
                add_action( 'pre_get_posts', array($this, 'applications_filter') );
                
                // Add Application data to the Application editor. 
                add_action ( 'edit_form_after_title', array ( $this, 'aol_application_post_editor' ) );                
                                
                new Applyonline_MetaBoxes();
                
                new Applyonline_Settings($version);
                
                new Applyonline_AjaxHandler();
	}

	/**
	 * Register the stylesheets for the admin area.
	 *
	 * @since    1.0.0
	 */
	public function enqueue_styles() {

		/**
		 * This function is provided for demonstration purposes only.
		 *
		 * An instance of this class should be passed to the run() function
		 * defined in Applyonline_Loader as all of the hooks are defined
		 * in that particular class.
		 *
		 * The Applyonline_Loader will then create the relationship
		 * between the defined hooks and the functions defined in this
		 * class.
		 */

		wp_enqueue_style( $this->plugin_name, plugin_dir_url( __FILE__ ) . 'css/applyonline-admin.css', array(), $this->version, 'all' );

	}

	/**
	 * Register the JavaScript for the admin area.
	 *
	 * @since    1.0.0
	 */
	public function enqueue_scripts() {

		/**
		 * This function is provided for demonstration purposes only.
		 *
		 * An instance of this class should be passed to the run() function
		 * defined in Applyonline_Loader as all of the hooks are defined
		 * in that particular class.
		 *
		 * The Applyonline_Loader will then create the relationship
		 * between the defined hooks and the functions defined in this
		 * class.
		 */

		wp_enqueue_script( $this->plugin_name, plugin_dir_url( __FILE__ ) . 'js/applyonline-admin.js', array( 'jquery' ), $this->version, false );

	}

        public static function register_aol_post_types(){
            /*Register Main Post Type*/
            $labels=array(
                'add_new'  => 'Create Ad',
                'add_new_item'  => 'New Ad',
                'edit_item'  => 'Edit Ad',
                'all_items' => 'All Ads',
                'menu_name' => 'Apply Online'
            );
            $args=array(
                'label' => __( 'All Ads', 'applyonline' ),
                'labels'=> $labels,
                'public'=>  true,
                'show_in_nav_menus' => false,
                'menu_icon'  => 'dashicons-admin-site',
                'description' => __( 'Ad Posting' ),
                'supports' => array('title', 'editor', 'excerpt'),
                'rewrite' => array('slug'=>'ads'),
            );
            register_post_type('aol_ad',$args);

            // Add new taxonomy, make it hierarchical (like categories)
            $labels = array(
                    'name'              => _x( 'Categories', 'taxonomy plural name',  'applyonline' ),
                    'singular_name'     => _x( 'Category','taxonomy singular name', 'applyonline' ),
                    'search_items'      => __( 'Search Categories' ),
                    'all_items'         => __( 'All Categories' ),
                    'parent_item'       => __( 'Parent Category' ),
                    'parent_item_colon' => __( 'Parent Category:' ),
                    'edit_item'         => __( 'Edit Category' ),
                    'update_item'       => __( 'Update Category' ),
                    'add_new_item'      => __( 'Add New Category' ),
                    'new_item_name'     => __( 'New Category Name' ),
            );

            $args = array(
                    'hierarchical'      => true,
                    'labels'            => $labels,
                    'show_ui'           => true,
                    'show_admin_column' => true,
                    'query_var'         => true,
                    'rewrite'           => array( 'slug' => 'adcat' ),
            );

            register_taxonomy( 'aol_ad_category', array( 'aol_ad' ), $args ); 
            
            /*Register Applications Post Type*/
            $lables= array(
                'edit_item'=>'Application'
                );
            $args=array(
                'label' => __( 'Applications', 'applyonline' ),
                'labels' => $lables,
                'public'            =>  true,
                'show_in_nav_menus' => false,
                'exclude_from_search'=> true,
                'publicly_queryable' => false,
                'map_meta_cap'      => true,
                'show_in_menu' => 'edit.php?post_type=aol_ad',
                'description' => __( 'List of Applications with their resume', 'applyonline' ),
                'supports' => array('editor'),
                'capabilities' => array(
                    'create_posts' => false,
                )
        );
            register_post_type('aol_application',$args);
        }
        
        /**
         * Shortcode Generator
         * @param type $atts
         * @return type
         */
        function shortcode_generator( $atts ) {
            $a = shortcode_atts( array(
                'categories' => NULL,
                'ads' => NULL,
                'excerpt' => 'yes',
                'per_page' => '-1'
            ), $atts );

            $args=array(
                'posts_per_page'=> $a['per_page'],
                'post_type'     =>'aol_ad',
            );
            if(isset($a['categories'])) {
                $args['tax_query'] = array(
                        array('taxonomy' => 'aol_ad_category', 'terms'    => explode(',',$atts['categories']))
                    );
            }

            if(isset($a['ads'])) {
                $args['post__in'] = explode(',',$atts['ads']);
            }            

            query_posts( $args );
            function custom_excerpt_more( $more ) {
                return '....';
            }
            add_filter( 'excerpt_more', 'custom_excerpt_more' );
            ob_start();
            echo '<ol class="aol_ad_list">';
            if(have_posts()): while(have_posts()): the_post();
            ?>
                <li>
                    <strong><?php the_title(); ?></strong>
                    <?php if($a['excerpt'] == 'yes') the_excerpt(); ?>
                    <a href="<?php the_permalink() ?>" class="read-more">Read More</a>
                </li>
            <?php
            endwhile; endif;
            echo '</ol>';
            $html=ob_get_clean();
            wp_reset_query();
            return $html;
        }    
        
        
        /**
         * Applicant Listing - Column Name
         *
         * @param   array   $columns
         * @access  public
         * @return  array
         */
        public function applicants_list_columns( $columns ){
            $columns = array (
                'cb'       => '<input type="checkbox" />',
                'title'    => __( 'Ad Title', 'applyonline' ),
                'applicant'=> __( 'Applicant', 'applyonline' ),
                'taxonomy' => __( 'Categories', 'applyonline' ),
                'date'     => __( 'Date', 'applyonline' ),
            );
            return $columns;
        }

        /**
         * Applicant Listing - Column Value
         *
         * @param   array   $columns
         * @param   int     $post_id
         * @access  public
         * @return  void
         */
        // 
        public function applicants_list_columns_value( $column, $post_id ){
            $keys = get_post_custom_keys( $post_id );
            switch ( $column ) {
                case 'applicant' :
                    $applicant_name = sprintf( '<a href="%s">%s</a>', esc_url( add_query_arg( array ( 'post' => $post_id, 'action' => 'edit' ), 'post.php' ) ), esc_html( get_post_meta( $post_id, $keys[ 0 ], TRUE ) )
                    );
                    echo $applicant_name;
                    break;
                case 'taxonomy' :
                    $parent_id = wp_get_post_parent_id( $post_id ); // get_post_field ( 'post_parent', $post_id );
                    $terms = get_the_terms( $parent_id, 'aol_ad_category' );
                    if ( ! empty( $terms ) ) {
                        $out = array ();
                        foreach ( $terms as $term ) {
                            $out[] = sprintf( '<a href="%s">%s</a>', esc_url( add_query_arg( array ( 'post_type' => get_post_type( $parent_id ), 'aol_ad_category' => $term->slug ), 'edit.php' ) ), esc_html( sanitize_term_field( 'name', $term->name, $term->term_id, 'jobpost_category', 'display' ) )
                            );
                        }
                        echo join( ', ', $out );
                    }/* If no terms were found, output a default message. */ else {
                        _e( 'No Categories' , 'applyonline');
                    }
                    break;
            }
        }                
    
        public function aol_post_row_actions($actions, $post){
            if($post->post_type == 'aol_application'){
                return null;
            }
            elseif($post->post_type == 'aol_ad'){
                $actions['test'] = '<a rel="permalink" title="View All Applications" href="'.  admin_url('edit.php?post_type=aol_application').'&ad='.$post->ID.'">Applications</a>';
                return $actions;
            }
        }
        
        public function applications_filter( $query ) {
            if ( $query->is_main_query() AND is_admin() AND isset($_GET['ad'])) {
                $query->set( 'post_parent', $_GET['ad'] );
            }
        }
        
        /**
         * Creates Detail Page for Applicants
         * 
         * 
         * @access  public
         * @since   1.0.0
         * @return  void
         */
        public function aol_application_post_editor (){
            global $post;
            if ( !empty ( $post ) and $post->post_type =='aol_application' ):
                $keys = get_post_custom_keys ( $post->ID );
                ?>
                <div class="wrap"><div id="icon-tools" class="icon32"></div>
                    <h3>
                        <?php
                        if ( in_array ( '_aol_app_Name', $keys ) ):
                            echo get_post_meta ( $post->ID, '_aol_app_Name', true );
                        endif;
                        if ( in_array ( 'resume', $keys ) ):
                            ?>
                            &nbsp; &nbsp; <small><a href="<?php echo get_post_meta ( $post->ID, 'resume', true ); ?>" target="_blank" ><?php echo __( 'Attachment' , 'applyonline' );?></a></small>
                        <?php endif; ?>

                    </h3>
                    <table class="widefat striped">
                        <?php
                        foreach ( $keys as $key ):
                            if ( substr ( $key, 0, 9 ) == '_aol_app_' ) {
                                echo '<tr><td>' . str_replace ( '_', ' ', substr ( $key, 9 ) ) . '</td><td>' . get_post_meta ( $post->ID, $key, true ) . '</td></tr>';
                            }
                        endforeach;
                        ?>
                    </table>
                </div>
                <h2><?php echo __( 'Notes' , 'applyonline' );?></h2>
                <?php
            endif;
        }        
    }

  /**
  * This class adds Meta Boxes to the Edit Screen of the Ads.
  * 
  * 
  * @since      1.0
  * @package    MetaBoxes
  * @subpackage MetaBoxes/includes
  * @author     Farhan Noor
  **/
 class Applyonline_MetaBoxes{
     
        /**
	 * Application Form Field Types.
	 *
	 * @since    1.3
	 * @access   public
	 * @var      string    $plugin_name    The ID of this plugin.
	 */
        var $app_field_types;
             
        public function __construct() {
            $this->app_field_types = array('text'=>'Text Field', 'text_area'=>'Text Area', 'date'=>'Date', 'checkbox'=>'Check Box', 'dropdown'=>'Drop Down', 'radio'=> 'Radio');
            add_action( 'add_meta_boxes_aol_ad', array($this, 'aol_meta_boxes') );
            add_action( 'save_post', array( $this, 'save_metas' ) );
        }
 
        /**
	 * Metaboxes for Ads Editor
	 *
	 * @since     1.0
	 */
        function aol_meta_boxes($post) {

            add_meta_box(
                    'aol_ad_metas',
                    __( 'Ad Features', 'applyonline' ),
                    array($this, 'ad_features'),
                    'aol_ad'
            );

            add_meta_box(
                    'aol_ad_app_fields',
                    __( 'Application Form Fields', 'applyonline' ),
                    array($this, 'application_form_fields'),
                    'aol_ad'
            );
        }
        
        function ad_features( $post ) {

            // Add a nonce field so we can check for it later.
                wp_nonce_field( 'myplugin_adpost_meta_awesome_box', 'adpost_meta_box_nonce' );

                /*
                 * Use get_post_meta() to retrieve an existing value
                 * from the database and use the value for the form.
                 */
            ?>
            <div class="ad_features adpost_fields">
                <ol id="ad_features">
                    <?php
                        $keys = get_post_custom_keys( $post->ID);
                        if($keys != NULL):
                            foreach($keys as $key):
                                if(substr($key, 0, 13)=='_aol_feature_'){
                                    $val=get_post_meta($post->ID, $key, TRUE);
                                    echo '<li><label for="'.$key.'">';
                                    _e( str_replace('_',' ',substr($key,13)), 'applyonline' );
                                    echo '</label> ';
                                    echo '<input type="text" id="'.$key.'" name="'.$key.'" value="' . esc_attr( $val ) . '" /> &nbsp; <div class="button removeField">Delete</div></li>';
                                }
                            endforeach;
                        endif;
                    ?>
                </ol>
            </div>
            <div class="clearfix clear"></div>
            <table id="adfeatures_form" class="alignleft">
            <thead>
                <tr>
                    <th class="left"><label for="adfeature_name">Feature</label></th>
                    <th><label for="adfeature_value">Value</label></th>
                </tr>
            </thead>
            <tbody>
                <tr>
                    <td class="left" id="adFeature">
                        <input type="text" id="adfeature_name" />
                    </td><td>
                        <input type="text" id="adfeature_value" />
                    </td>
                </tr>
                <tr>
                    <td colspan="2">
                        <div class=""><div class="button" id="addFeature">Add Feature</div></div>
                    </td>
                </tr>
            </tbody>
            </table>
            <div class="clearfix clear"></div>
            <?php 
        }
        
        public function application_fields_generator(){
            $app_fields = array('text'=>'Text Field', 'text_area'=>'Text Area', 'date'=>'Date', 'checkbox'=>'Check Box', 'dropdown'=>'Drop Down', 'radio'=> 'Radio');
            ?>
            <div class="clearfix clear"></div>
            <table id="adapp_form_fields" class="alignleft">
            <thead>
                <tr>
                    <th class="left"><label for="metakeyselect">Field</label></th>
                    <th><label for="metavalue">Type</label></th>
                </tr>
            </thead>
            <tbody>
                <tr>
                    <td class="left" id="newmetaleft">
                        <input type="text" id="adapp_name" />
                    </td><td>
                        <select id="adapp_field_type">
                            <?php
                                foreach($app_fields as $key => $val):
                                    echo '<option value="'.$key.'" class="'.$key.'">'.$val.'</option>';
                                endforeach;
                            ?>
                        </select>
                    </td>
                </tr>

                <tr>
                    <td colspan="2" ><input id="adapp_field_options" class="adapp_field_type" type="text" style="display: none;" placeholder="Option1, Option2, Option3" ></td>
                </tr>
                <tr>
                    <td colspan="2">
                        <div class=""><div class="button" id="addField">Add Field</div></div>
                    </td>
                </tr>
            </tbody>
            </table>
            <div class="clearfix clear"></div>
            <script>
                jQuery('document').ready(function($){
                    /*Application Field Type change*/
                    $('#adapp_field_type').change(function(){
                       var fieldType=$(this).val();

                       if(!(fieldType == 'text' || fieldType == 'date' || fieldType == 'text_area')){
                           $('#adapp_field_options').show();
                       }
                       else{
                           $('#adapp_field_options').hide();
                           $('#adapp_field_options').val('');
                       }
                    });

                    /*Add Application Field (Group Fields)*/
                    $('#addField').click(function(){
                        var fieldNameRaw=$('#adapp_name').val(); // Get Raw value.
                        var fieldNameRaw = fieldNameRaw.trim();    // Remove White Spaces from both ends.
                        var fieldName = fieldNameRaw.replace(" ", "_"); //Replace white space with _.
                        var fieldType = $('#adapp_field_type').val();
                        var fieldOptions = $('#adapp_field_options').val();
                        var style;


                        var fieldTypeHtml = $('#adapp_field_type').html();
                        if(fieldName != ''){
                            $('#adapp_name').css('border','none');
                            if(fieldType=='text' || fieldType=='date' || fieldType == 'text_area'){
                                style = "display:none";
                            }
                            else {
                                style = "";
                                $('#adapp_field_options').val('');
                                $('#adapp_field_options').hide();
                            }
                            $('#app_form_fields').append('<li class="'+fieldName+'"> &nbsp; <label for="'+fieldName+'">'+fieldNameRaw+'</label><select class="adapp_field_type" name="_aol_app_'+fieldName+'[type]">'+fieldTypeHtml+'</select><input type="text" class="'+fieldName+' adapp_field_options" name="_aol_app_'+fieldName+'[options]" value="'+fieldOptions+'" placeholder="Option1, Option2, Option3" style="'+style+'" /> &nbsp; <div class="button removeField">Delete</div></li>');
                            $('.'+fieldName+' .'+fieldType).attr('selected','selected');
                            $('#adapp_name').val('');
                            $('#adapp_field_type').val('text');
                        }
                        else{
                            $('#adapp_name').css('border','1px solid #F00');

                        }

                    });

                    /* Application Field Type change (already added) */
                    $('#app_form_fields').on('change', 'li .adapp_field_type',function(){

                        var fieldType=$(this).val();

                        if(!(fieldType == 'text' || fieldType == 'date' || fieldType == 'text_area')){
                           $(this).next().show();
                        }
                        else{
                           $(this).next().hide();
                        }
                    }); 


                    /*Add Job Feature*/
                    $('#addFeature').click(function(){
                        var fieldNameRaw=$('#adfeature_name').val(); // Get Raw value.
                        var fieldNameRaw = fieldNameRaw.trim();    // Remove White Spaces from both ends.
                        var fieldName = fieldNameRaw.replace(" ", "_"); //Replace white space with _.

                        var fieldVal = $('#adfeature_value').val();
                        var fieldVal = fieldVal.trim();

                        if(fieldName != '' && fieldVal!=''){
                            $('#ad_features').append('<li class="'+fieldName+'"><label for="'+fieldName+'">'+fieldNameRaw+'</label> <input type="text" name="_aol_feature_'+fieldName+'" value="'+fieldVal+'" > &nbsp; <div class="button removeField">Delete</div></li>');
                            $('#adfeature_name').val(""); //Reset Field value.
                            $('#adfeature_value').val(""); //Reset Field value.
                        }
                    });
                    /*Remove Job app or ad Feature Fields*/
                    $('.adpost_fields').on('click', 'li .removeField',function(){
                        $(this).parent('li').remove();
                    });         

                });
            </script>         
        <?php
        }
        
        public function application_form_fields( $post ) {
            //global $adfields;
            // Add a nonce field so we can check for it later.
            wp_nonce_field( 'myplugin_adpost_meta_awesome_box', 'adpost_meta_box_nonce' );

            /*
             * Use get_post_meta() to retrieve an existing value
             * from the database and use the value for the form.
             */
            ?>
            <div class="app_form_fields adpost_fields">
                <ol id="app_form_fields">
                    <?php
                    if(isset($post)):
                        $keys=get_post_custom_keys( $post->ID);
                        if($keys == NULL){ 
                            $default_fields = get_option('aol_default_fields') or $default_fields = array();
                            $keys = array_keys($default_fields);
                        }
                            foreach($keys as $key):
                                if(substr($key, 0, 9)=='_aol_app_'):

                                    $val=get_post_meta($post->ID, $key, TRUE) or $val=$default_fields[$key] ;
                                    !is_array($val)? $val=  unserialize($val): $val;
                                    $fields = NULL;
                                    foreach($this->app_field_types as $field_key => $field_val){
                                        if($val['type']==$field_key) $fields .= '<option value="'.$field_key.'" selected>'.$field_val.'</option>';
                                        else $fields .= '<option value="'.$field_key.'" >'.$field_val.'</option>';
                                    }                   
                                    //if($key.'[type]'=='text'){
                                        echo '<li class="'.$key.'"><label for="'.$key.'">'.str_replace('_',' ',substr($key,9)).'</label><select class="adapp_field_type" name="'.$key.'[type]">'.$fields.'</select>';
                                        if(!($val['type']=='text' or $val['type']=='date' or $val['type']=='text_area' )):
                                            echo '<input type="text" name="'.$key.'[options]" value="'.$val['options'].'" placeholder="Option1, option2, option3" />';
                                        else:
                                            echo '<input type="text" name="'.$key.'[options]" placeholder="Option1, option2, option3" style="display:none;"  />';
                                        endif;
                                        echo ' &nbsp; <div class="button removeField">Delete</div></li>';
                                    //}
                                endif;
                            endforeach;
                        endif;
                    ?>
                </ol>
            </div>  
            

            <?php
            $this->application_fields_generator();
        }     
        
        /**
	 * Save the meta when the post is saved.
	 *
	 * @param int $post_id The ID of the post being saved.
	 */
        function save_metas( $post_id ) {

            /*
             * We need to verify this came from our screen and with proper authorization,
             * because the save_post action can be triggered at other times.
             */

            // Check if our nonce is set.
            if ( ! isset( $_POST['adpost_meta_box_nonce'] ) ) {
                    return;
            }

            // Verify that the nonce is valid.
            if ( ! wp_verify_nonce( $_POST['adpost_meta_box_nonce'], 'myplugin_adpost_meta_awesome_box' ) ) {
                    return;
            }

            // 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;
            }

            // Check the user's permissions.
            if ( isset( $_POST['post_type'] ) && 'page' == $_POST['post_type'] ) {

                    if ( ! current_user_can( 'edit_page', $post_id ) ) {
                            return;
                    }

            } else {

                    if ( ! current_user_can( 'edit_post', $post_id ) ) {
                            return;
                    }
            }

            /* OK, it's safe for us to save the data now. */

            //Delete fields.
            $old_keys = get_post_custom_keys($post_id);
            $new_keys = array_keys($_POST);
            $removed_keys = array_diff($old_keys, $new_keys); //List of removed meta keys.
            foreach($removed_keys as $key => $val):
                if(substr($val, 0, 4) == '_aol') delete_post_meta($post_id, $val); //Remove meta from the db.
            endforeach;

            // Add new value.
            foreach ($_POST as $key => $val):
                // Make sure that it is set.
                if ( substr($key, 0, 13)=='_aol_feature_' and isset( $val ) ) {
                    //Sanitize user input.
                    $my_data = sanitize_text_field( $val );
                    update_post_meta( $post_id, $key,  $my_data); // Add new value.
                }

                // Make sure that it is set.
                elseif ( substr($key, 0, 9)=='_aol_app_' and isset( $val ) ) {
                    $my_data = serialize($_POST[$key]);
                    update_post_meta( $post_id, $key,  $my_data); // Add new value.
                }
                    //Update the meta field in the database.
            endforeach;
        }  

}

  /**
  * This class is responsible for plugin Settings.
  * 
  * 
  * @since      1.3
  * @package    Applyonline_settings
  * @author     Farhan Noor
  **/
class Applyonline_Settings extends Applyonline_MetaBoxes{
    
    private $version;

    public function __construct($version) {
        $this->version = $version;
        
        //Registering Submenus.
        add_action('admin_menu', array($this, 'sub_menus'));
        
        //Registering Settings.
        add_action( 'admin_init', array($this, 'registers_settings') );
    }


    public function sub_menus(){
        add_submenu_page( 'edit.php?post_type=aol_ad', 'AOL Settings', 'Settings', 'manage_options', 'settings', array($this, 'settings_page_callback') );
    }

    public function registers_settings(){
        register_setting( 'aol_settings_group', 'aol_recipients_emails' );
        register_setting( 'aol_settings_group', 'aol_application_message' );
        register_setting( 'aol_application_template', '_aol_app_Name' );
    }

    public function settings_page_callback(){
        ob_start();
        if ( !empty( $_POST['aol_default_app_fields'] ) && check_admin_referer( 'aol_awesome_pretty_nonce','aol_default_app_fields' ) ) {
            //Remove unnecessary fields
            foreach($_POST as $key => $val){
                if(substr($key, 0, 4) != '_aol') unset($_POST[$key]);
            }
            
            //Save aol default fields in DB.
            update_option('aol_default_fields', $_POST);
        }
        ?>
            <div class="wrap">
                <h2>Apply Online <small class="wp-caption alignright"><i>version <?php echo $this->version; print_r($this->app_field_types); ?></i></small></h2>
                <h2 class="nav-tab-wrapper">
                        <a class="nav-tab nav-tab-active" data-id="alerts">Alerts</a>
                        <a class="nav-tab" data-id="templates">Template</a>
                        <a class="nav-tab" data-id="how-to">How to</a>
                </h2>              
                <form action="options.php" method="post" name="">
                    <div class="tab-data first" id="alerts">
                        <?php 
                            settings_fields( 'aol_settings_group' ); 
                            do_settings_sections( 'aol_settings_group' );
                        ?>
                        <table class="form-table">
                            <tr>
                                <th><label for="">List of e-mails to get application alerts</label></th>
                                <td><textarea class="small-text code" name="aol_recipients_emails" cols="50" rows="5"><?php echo esc_attr( get_option('aol_recipients_emails') ); ?></textarea><p class="description">Just one email id in one line.</p></td>
                            </tr>
                            <tr>
                                <th><label for="">Application submission message</label></th>
                                <td>
                                    <textarea class="small-text code" name="aol_application_message" cols="50" rows="5" id="aol_submission_default_message"><?php echo esc_attr( get_option('aol_application_message','Your application has been submitted successfully. We will get back to you very soon.') ); ?></textarea>
                                    <br />
                                    <button id="aol_submission_default" class="button">Default Message</button>
                                </td>
                            </tr>
                        </table>
                        <?php submit_button(); ?>
                    </div>
                </form>
                <form id="template_form" method="post">
                    <div id="templates" class="tab-data">
                        <h3>Application form default fields</h3><hr />
                        <div class="app_form_fields adpost_fields">
                            <ol id="app_form_fields">
                                <?php 
                                    $app_fields = array('text'=>'Text Field', 'text_area'=>'Text Area', 'date'=>'Date', 'checkbox'=>'Check Box', 'dropdown'=>'Drop Down', 'radio'=> 'Radio');
                                    settings_fields( 'aol_application_template' );
                                    do_settings_sections( 'aol_application_template' );
                            
                                    $keys= get_option('aol_default_fields');
                                    if($keys != NULL):
                                        foreach($keys as $key => $val):
                                            if(substr($key, 0, 9)=='_aol_app_'):

                                                $fields = NULL;
                                                foreach($app_fields as $field_key => $field_val){
                                                    if($val['type']==$field_key) $fields .= '<option value="'.$field_key.'" selected>'.$field_val.'</option>';
                                                    else $fields .= '<option value="'.$field_key.'" >'.$field_val.'</option>';
                                                }
                                                //if($key.'[type]'=='text'){
                                                    echo '<li class="'.$key.'"><label for="'.$key.'">'.str_replace('_',' ',substr($key,9)).'</label><select class="adapp_field_type" name="'.$key.'[type]">'.$fields.'</select>';
                                                    if(!($val['type']=='text' or $val['type']=='date' or $val['type']=='text_area' )):
                                                        echo '<input type="text" name="'.$key.'[options]" value="'.$val['options'].'" placeholder="Option1, option2, option3" />';
                                                    else:
                                                        echo '<input type="text" name="'.$key.'[options]" placeholder="Option1, option2, option3" style="display:none;"  />';
                                                    endif;
                                                    echo ' &nbsp; <div class="button removeField">Delete</div></li>';
                                                //}
                                            endif;
                                        endforeach;
                                    endif;
                                ?>
                            </ol>
                        </div>  
                        <?php $this->application_fields_generator(); ?>
                        <hr />
                        <?php submit_button(); ?>
                    </div>
                    <?php wp_nonce_field( 'aol_awesome_pretty_nonce','aol_default_app_fields' ); ?>
                </form>
                <div class="tab-data" id="how-to">
                    <h3>How to create an ad?</h3>
                    In your WordPress admin panel, go to "Apply Online" menu and add a new ad listing.

                    <h3>How to show ad listings on the front-end?</h3>
                    Add [aol] shortcode in an existing page or add a new page and write shortcode anywhere in the page editor. Now click on VIEW to see all of your ads on front-end.

                    <h3>Can I show few adds on front-end?</h3>
                    Yes, you can show any number of ads on your website by using shortcode with "ads" attribute. Ad ids must be separated with commas i.e. [aol ads="1,2,3"].

                    <h3>Can I show ads from particular category only?</h3>
                    Yes, you can show ads from any category / categories using "categories" attribute. Categories' ids must be separated with commas i.e. [aol categories="1,2,3"].

                    <h3>Can I show ads without excerpt/summary?</h3>
                    Yes, use shortcode with "excerpt" attribute i.e. [aol excerpt="no"]

                    <h3>What attributes can i use in the shortcode?</h3>
                    Default shortcode with all attributes is [aol categories="1,2,3" ads="1,2,3" excerpt="no"]. Use only required attributes.

                    <h3>How can i get the id of a category or ad?</h3>
                    In admin panel, move your mouse pointer on an item in categories or ads table. Now you can view item ID in the info bar of the browser.
                </div>
            </div>
            <script>
                jQuery(document).ready(function($){
                    $('.tab-data:first').show();
                    $('.nav-tab').click(function(){
                        $('.nav-tab').removeClass('nav-tab-active');
                        $(this).addClass('nav-tab-active');

                        var target = $(this).data("id");

                        $('.tab-data').hide();
                        $("#"+target).show();
                    });
                });
            </script>
            <style>
                h3{margin-bottom: 5px;}
                .nav-tab{cursor: pointer}
                .tab-data{display: none;}
            </style>
        <?php
        return ob_get_flush();
    }           
 }

  /**
  * This class is responsible to hanld Ajax data.
  * 
  * 
  * @since      1.0
  * @package    AjaxHandler
  * @author     Farhan Noor
  **/
 class Applyonline_AjaxHandler{
        public function __construct() {
            add_action( 'wp_ajax_aol_app_form', array($this, 'aol_process_app_form') );
            add_action( 'wp_ajax_nopriv_aol_app_form', array($this, 'aol_process_app_form') );
        }
        
        public function aol_process_app_form(){
            $nonce=$_POST['wp_nonce'];
            if(!wp_verify_nonce($nonce, 'the_best_aol_ad_security_nonce')) die('Not Working');

            /*Initialixing Variables*/
            $error = null;
            $error_assignment = null;

            if (strlen($_FILES['applicant_resume']['name']) > 1) {
                $uploadfiles = $_FILES['applicant_resume'];
                if (is_array($uploadfiles)) {
                        $upload_dir = wp_upload_dir();
                        $assignment_upload_size = 200;
                        $time = (!empty($_SERVER['REQUEST_TIME'])) ? $_SERVER['REQUEST_TIME'] : (time() + (get_option('gmt_offset') * 3600)); // Fallback of now

                        $post_type = 'aol_ad';
                        $date = explode(" ", date('Y m d H i s', $time));
                        $timestamp = strtotime(date('Y m d H i s'));
                        if($post_type){
                            $upload_dir = array(
                                  'path' => WP_CONTENT_DIR . '/uploads/' . $post_type . '/' . $date[0],
                                  'url' => WP_CONTENT_URL . '/uploads/' . $post_type . '/' . $date[0],
                                  'subdir' => '',
                                  'basedir' => WP_CONTENT_DIR . '/uploads',
                                  'baseurl' => WP_CONTENT_URL . '/uploads',
                                  'error' => false,
                            );
                         }
                        if(!is_dir($upload_dir['path'])) wp_mkdir_p($upload_dir['path']);
                        
                        $var_cp_assigment_type= 'jpg,jpeg,png,doc,docx,pdf,rtf,odt,txt';

                        // look only for uploded files
                        if ($_FILES['applicant_resume']['error'] == 0) {
                            $filetmp = $_FILES['applicant_resume']['tmp_name'];
                            $filename = $_FILES['applicant_resume']['name'];
                            $filesize = $_FILES['applicant_resume']['size'];
                            $filetype = wp_check_filetype ( $filename );
                            $file_ext = strtolower($filetype['ext']);
                            
                            $max_upload_size = $assignment_upload_size*1048576; //Multiply by KBs
                            if($max_upload_size < $filesize){
                                    $assignment_error[] = 'Maximum upload File size allowed '.$assignment_upload_size.'MB';
                                    $error_assignment = 1;
                            }

                            $file_type_match = 0;
                            $var_cp_assigment_type_array = array();
                             if($var_cp_assigment_type){
                                     $var_cp_assigment_type_array = explode(',',$var_cp_assigment_type);
                            }
                            if(in_array($file_ext, $var_cp_assigment_type_array)){
                                $file_type_match = 1;
                            }
                             /**
                             * Check File Size
                             */
                            if($file_type_match == 0){
                                $assignment_error[] = 'Please upload file with one of the extenstions: '.$var_cp_assigment_type;
                                $error_assignment = 1;
                            }
                            // get file info
                            // @fixme: wp checks the file extension....
                            $filetype = wp_check_filetype( basename( $filename ), null );
                            $filetitle = preg_replace('/\.[^.]+$/', '', basename( $filename ) );
                            $filename = $filetitle . $timestamp . '.' . $filetype['ext'];
                            /**
                             * Check if the filename already exist in the directory and rename the
                             * file if necessary
                             */
                            $i = 0;
                            while ( file_exists( $upload_dir['path'] .'/' . $filename ) ) {
                              $filename = $filetitle . $timestamp . '_' . $i . '.' . $filetype['ext'];
                              $i++;
                            }
                            $filedest = $upload_dir['path'] . '/' . $filename;
                            /**
                             * Check write permissions
                             */
                            if ( !is_writeable( $upload_dir['path'] ) ) {
                              $assignment_error[] = 'Unable to write to directory %s. Is this directory writable by the server?';
                              $error_assignment = 1;
                            }
                            /**
                             * Save temporary file to uploads dir
                             */
                            if($error_assignment <> 1){
                                if ( !@move_uploaded_file($filetmp, $filedest) ){
                                  $assignment_error[] = 'Error, the file $filetmp could not moved to : $filedest';
                                  $error_assignment = 1;
                                }
                                $newupload = $upload_dir['url'].'/'.$filename;
                                $uploadpath = $upload_dir['path'].'/'.$filename;
                            }
                        }
                  }
            }
            if($error_assignment == 1){
                $errors = NULL;
                foreach($assignment_error as $error_value){
                        $errors .= esc_html__($error_value, 'applyonline').'<br />';
                }
                $response = json_encode( array( 'success' => false, 'error' => $errors ));    // generate the response.
                
                // response output
                header( "Content-Type: application/json" );
                echo $response;
                exit;
            }
                
            else{
                $args=  array(
                    'post_type'     =>'aol_application',
                    'post_content'  =>'',
                    'post_parent'    =>$_POST['ad_id'],
                    'post_title'    =>get_the_title($_POST['ad_id']),
                    'post_status'   =>'publish',
                );
                $pid=wp_insert_post($args);

                foreach($_POST as $key => $val):
                    if(substr($key,0,9) == '_aol_app_') add_post_meta($pid, $key, $val);
                    if(!empty($newupload)) add_post_meta($pid, 'resume', $newupload);
                endforeach;

                if($pid>0){
                    //send email alert.
                    $post_url = admin_url("post.php?post=$pid&action=edit");
                    
                    $admin_email = get_option('admin_email');
                    $emails_raw = get_option('aol_recipients_emails', $admin_email);
                    $emails = explode("\n", $emails_raw);
                    
                    $subject = 'Application Alert';
                    $headers = array('From: '.  get_bloginfo('name').' <'.get_bloginfo('admin_email').'>');
                    
                    $message = "<p>Hi,</p>"
                            . "<p>You just received an application against an add at ".get_bloginfo('url'). ".</p>"
                            . "<p> <b><a href='".$post_url."'>Click Here</a></b> to view this application.</p>"
                            . "<p>".  site_url()."</p>";
                    
                    add_filter( 'wp_mail_content_type', array($this, 'set_html_content_type') );
                    wp_mail( $emails, $subject, $message, $headers);
                    remove_filter( 'wp_mail_content_type', array($this, 'set_html_content_type') );
                    
                                        
                    $response = json_encode( array( 'success' => true ));    // generate the response.s
                }
                else $response = json_encode( array( 'success' => false ));    // generate the response.

                if($error) $response = json_encode( array( 'success' => false, 'error' => $error ));    // generate the response with error message.

                // response output
                header( "Content-Type: application/json" );
                echo $response;

                exit;
            }
        }
        
        function set_html_content_type() {
            return 'text/html';
        }
        
        public function save_setting_template(){
            // Check the user's permissions.

            if ( ! current_user_can( 'edit_page', $post_id ) ) {
                return;

            } else {

                    if ( ! current_user_can( 'edit_post', $post_id ) ) {
                            return;
                    }
            }

            /* OK, it's safe for us to save the data now. */

            //Delete fields.
            $old_keys = "SELECT $wpdb->options WHERE option_name like '_aol_app_%'";
            $new_keys = array_keys($_POST);
            $removed_keys = array_diff($old_keys, $new_keys); //List of removed meta keys.
            foreach($removed_keys as $key => $val):
                if(substr($val, 0, 3) == '_ad') delete_post_meta($post_id, $val); //Remove meta from the db.
            endforeach;

            // Add new value.
            foreach ($_POST as $key => $val):
                // Make sure that it is set.
                if ( substr($key, 0, 13)=='_aol_feature_' and isset( $val ) ) {
                    //Sanitize user input.
                    $my_data = sanitize_text_field( $val );
                    update_post_meta( $post_id, $key,  $my_data); // Add new value.
                }

                // Make sure that it is set.
                elseif ( substr($key, 0, 9)=='_aol_app_' and isset( $val ) ) {
                    $my_data = serialize($_POST[$key]);
                    update_post_meta( $post_id, $key,  $my_data); // Add new value.
                }
                    //Update the meta field in the database.
            endforeach;
        }  
}