<?php
defined('ABSPATH') or die();

/* Posts */

/*
 * Since 1.0.0
 */
function ad_column_custom_post_column( $column, $post_id ) 
{
	$p = get_post( $post_id );

	if( is_object($p) && isset($p->ID) ) {

		$data = ad_column_custom_get_column( $p->post_type, $column );

		if( isset($data['name']) ) {
			$value = get_post_meta( $post_id, $column, true );

			echo esc_attr( $value != '' ? $value : '-' );
		}
	}
}

/*
 * Since 1.0.0
 */
function ad_column_custom_add_post_column( $columns = array(), $post_type = 'page' )
{
	$data = get_option( 'ad_column_' . $post_type );

	if( is_array($data) == false || count($data) == 0 || count($columns) == 0 ) {
		return $columns;
	}

	$list = array();

	foreach( $data as $i => $item ) {
		if( $item['after'] == 'first' ) {
			$list[ $item['name'] ] = esc_attr( $item['title'] );
			unset($data[$i]);
		}
	}

	foreach ( $columns as $key => $value ) {
		$list[ $key ] = $value;
	
		foreach( $data as $i => $item ) {
			if( $item['after'] == $key ) {
				$list[ $item['name'] ] = esc_attr( $item['title'] );
				unset($data[$i]);
			}
		}
	}
	
	return $list;
}

function ad_column_custom_list_page()
{
	foreach( ad_column_custom_get_post_types() as $post_type => $title ) {
		add_action( 'manage_'. $post_type .'s_custom_column' , 'ad_column_custom_post_column', 10, 2 );
		add_filter( 'manage_'. $post_type .'s_columns' , 'ad_column_custom_add_post_column', 10, 2);
	}
}
add_action( 'admin_init' , 'ad_column_custom_list_page');

/* Users */

/*
 * Since 1.0.0
 */
function ad_column_custom_add_user_id_column($columns) 
{
	if( is_array($columns) && count($columns) ) {
		$new = array();
		foreach ( $columns as $key => $value ) {
			if( $key == 'email' ) 
			{
				$new['display_name'] = esc_attr( __( 'Display Name', 'admin-column-custom' ) );
			}

			$new[$key] = $value;
		}
		
		$columns = $new;
	}
	
	return $columns;
}
add_filter('manage_users_columns', 'ad_column_custom_add_user_id_column');

/*
 * Since 1.0.0
 */
function ad_column_custom_show_user_id_column_content($value, $column_name, $user_id) 
{
	$user = get_userdata( $user_id );

	if ( $column_name == 'display_name' )
	{
		return esc_attr( $user->display_name );
	}
	else if ( $column_name == 'custom_field' )
	{
		return esc_attr( get_user_meta( $user_id, 'custom_field', true ) );
	}
	
	return $value;
}
add_filter('manage_users_custom_column',  'ad_column_custom_show_user_id_column_content', 10, 3);

/*
 * Since 1.0.1
 */
function ad_column_custom_manage_columns( $columns = array() )
{
	// $columns['url'] = 'URL';

	return $columns;
}
add_filter( 'manage_edit-page_columns', 'ad_column_custom_manage_columns' );

/**
 * Can't hide these for they are special.
 * 
 * wp-admin/includes/class-wp-screen.php
 * 
 * Line 1164 in function `render_list_table_columns_preferences`;
 * 
 */
function ad_column_custom_get_special_columns()
{
	$special = array( '_title', 'cb', 'comment', 'media', 'name', 'title', 'username', 'blogname' );

	return $special;
}

/*
 * Since 1.0.1
 */
function ad_column_custom_get_default_columns( $type = '' )
{
	$columns = array();

	$names = array( 'title', 'author' );

	if( $type == 'post' ) {
		$names = array_merge( $names, array( 'categories', 'tags' ) );
	}

	$names = array_merge( $names, array( 'comments', 'date', 'modified' ) );

	foreach( $names as $name ) {
		$columns[] = array(
			'title' => __($name),
			'name' => $name,
			'default' => 1
		);
	}

	return $columns;
}

/*
 * Since 1.0.1
 */
function ad_column_custom_get_columns( $type = '', $columns = array() )
{
	if( count($columns) == 0 ) {
		$columns = ad_column_custom_get_default_columns( $type );
	}

	$data = get_option( 'ad_column_' . $type );

	if( is_array($data) && count($data) ) {
		$list = array();

		foreach( $data as $i => $item ) {
			if( $item['after'] == 'first' ) {
				$item['default'] = 0;
				$list[] = $item;
				unset($data[$i]);
			}
		}

		foreach( $columns as $column ) {
			$list[] = $column;

			foreach( $data as $i => $item ) {
				if( $item['after'] == $column['name'] ) {
					$item['default'] = 0;
					$list[] = $item;
					unset($data[$i]);
				}
			}
		}

		$columns = $list;
	}

	return $columns;
}

/*
 * Since 1.0.1
 */
function ad_column_custom_get_column( $type = '', $name = '', $key = '' )
{
	global $ad_column;

	if( empty($ad_column_data[ $type ]) ) {
		$ad_column_data[ $type ] = get_option( 'ad_column_' . $type );
	}

	$data = $ad_column_data[ $type ];

	if( is_array($data) && count($data)>0 ) {
		foreach( $data as $item ) {
			if( $item['name'] == $name ) {

				if( $key!='' && isset($item[$key]) ) {
					return $item[$key];
				}

				return $item;
			}
		}

		return $data;
	}

	if( $key!='' ) {
		return '';
	}

	return array();
}