<?php
/**
 * WooCommerce Subscriptions Functions
 *
 * @author 		Prospress
 * @category 	Core
 * @package 	WooCommerce Subscriptions/Functions
 * @version     2.0
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly
}

require_once( 'includes/wcs-deprecated-functions.php' );
require_once( 'includes/wcs-conditional-functions.php' );
require_once( 'includes/wcs-formatting-functions.php' );
require_once( 'includes/wcs-cart-functions.php' );
require_once( 'includes/wcs-order-functions.php' );
require_once( 'includes/wcs-time-functions.php' );
require_once( 'includes/wcs-user-functions.php' );
require_once( 'includes/wcs-helper-functions.php' );
require_once( 'includes/wcs-renewal-functions.php' );
require_once( 'includes/wcs-resubscribe-functions.php' );
require_once( 'includes/wcs-switch-functions.php' );

if ( is_admin() ) {
	require_once( 'includes/admin/wcs-admin-functions.php' );
}

/**
 * Check if a given object is a WC_Subscription (or child class of WC_Subscription), or if a given ID
 * belongs to a post with the subscription post type ('shop_subscription')
 *
 * @since  2.0
 * @return boolean true if anything is found
 */
function wcs_is_subscription( $subscription ) {

	if ( is_object( $subscription ) && is_a( $subscription, 'WC_Subscription' ) ) {
		$is_subscription = true;
	} elseif ( is_numeric( $subscription ) && 'shop_subscription' == get_post_type( $subscription ) ) {
		$is_subscription = true;
	} else {
		$is_subscription = false;
	}

	return apply_filters( 'wcs_is_subscription', $is_subscription, $subscription );
}

/**
 * A very simple check. Basically if we have ANY subscriptions in the database, then the user has probably set at
 * least one up, so we can give them the standard message. Otherwise
 *
 * @since  2.0
 * @return boolean 							true if anything is found
 */
function wcs_do_subscriptions_exist() {
	global $wpdb;
	$sql = $wpdb->prepare( "SELECT ID FROM {$wpdb->posts} WHERE post_type = %s LIMIT 1;", 'shop_subscription' );

	// query is the fastest, every other built in method uses this. Plus, the return value is the number of rows found
	$num_rows_found = $wpdb->query( $sql );

	return ( 0 !== $num_rows_found ) ? true: false;
}

/**
 * Main function for returning subscriptions. Wrapper for the wc_get_order() method.
 *
 * @since  2.0
 * @param  mixed $the_subscription Post object or post ID of the order.
 * @return WC_Subscription
 */
function wcs_get_subscription( $the_subscription ) {

	if ( is_object( $the_subscription ) && wcs_is_subscription( $the_subscription ) ) {
		$the_subscription = $the_subscription->id;
	}

	$subscription = WC()->order_factory->get_order( $the_subscription );

	if ( ! wcs_is_subscription( $subscription ) ) {
		$subscription = false;
	}

	return apply_filters( 'wcs_get_subscription', $subscription );
}

/**
 * Create a new subscription
 *
 * Returns a new WC_Subscription object on success which can then be used to add additional data.
 *
 * @return WC_Subscription | WP_Error A WC_Subscription on success or WP_Error object on failure
 * @since  2.0
 */
function wcs_create_subscription( $args = array() ) {

	$order = ( isset( $args['order_id'] ) ) ? wc_get_order( $args['order_id'] ) : null;

	if ( ! empty( $order ) && isset( $order->post->post_date ) ) {
		$default_start_date = ( '0000-00-00 00:00:00' != $order->post->post_date_gmt ) ? $order->post->post_date_gmt : get_gmt_from_date( $order->post->post_date );
	} else {
		$default_start_date = current_time( 'mysql', true );
	}

	$default_args = array(
		'status'             => '',
		'order_id'           => 0,
		'customer_note'      => null,
		'customer_id'        => ( ! empty( $order ) ) ? $order->get_user_id() : null,
		'start_date'         => $default_start_date,
		'created_via'        => ( ! empty( $order ) ) ? $order->created_via : '',
		'order_version'      => ( ! empty( $order ) ) ? $order->order_version : WC_VERSION,
		'currency'           => ( ! empty( $order ) ) ? $order->order_currency : get_woocommerce_currency(),
		'prices_include_tax' => ( ! empty( $order ) ) ? ( ( $order->prices_include_tax ) ? 'yes' : 'no' ) : get_option( 'woocommerce_prices_include_tax' ), // we don't use wc_prices_include_tax() here because WC doesn't use it in wc_create_order(), not 100% sure why it doesn't also check the taxes are enabled, but there could forseeably be a reason
	);

	$args              = wp_parse_args( $args, $default_args );
	$subscription_data = array();

	// validate the start_date field
	if ( ! is_string( $args['start_date'] ) || false === wcs_is_datetime_mysql_format( $args['start_date'] ) ) {
		return new WP_Error( 'woocommerce_subscription_invalid_start_date_format', _x( 'Invalid date. The date must be a string and of the format: "Y-m-d H:i:s".', 'Error message while creating a subscription', 'woocommerce-subscriptions' ) );
	} else if ( strtotime( $args['start_date'] ) > current_time( 'timestamp', true ) ) {
		return new WP_Error( 'woocommerce_subscription_invalid_start_date', _x( 'Subscription start date must be before current day.', 'Error message while creating a subscription', 'woocommerce-subscriptions' ) );
	}

	// check customer id is set
	if ( empty( $args['customer_id'] ) || ! is_numeric( $args['customer_id'] ) || $args['customer_id'] <= 0 ) {
		return new WP_Error( 'woocommerce_subscription_invalid_customer_id', _x( 'Invalid subscription customer_id.', 'Error message while creating a subscription', 'woocommerce-subscriptions' ) );
	}

	// check the billing period
	if ( empty( $args['billing_period'] ) || ! in_array( strtolower( $args['billing_period'] ), array_keys( wcs_get_subscription_period_strings() ) ) ) {
		return new WP_Error( 'woocommerce_subscription_invalid_billing_period', __( 'Invalid subscription billing period given.', 'woocommerce-subscriptions' ) );
	}

	// check the billing interval
	if ( empty( $args['billing_interval'] ) || ! is_numeric( $args['billing_interval'] ) || absint( $args['billing_interval'] ) <= 0 ) {
		return new WP_Error( 'woocommerce_subscription_invalid_billing_interval', __( 'Invalid subscription billing interval given. Must be an integer greater than 0.', 'woocommerce-subscriptions' ) );
	}

	$subscription_data['post_type']     = 'shop_subscription';
	$subscription_data['post_status']   = 'wc-' . apply_filters( 'woocommerce_default_subscription_status', 'pending' );
	$subscription_data['ping_status']   = 'closed';
	$subscription_data['post_author']   = 1;
	$subscription_data['post_password'] = uniqid( 'order_' );
	// translators: Order date parsed by strftime
	$post_title_date = strftime( _x( '%b %d, %Y @ %I:%M %p', 'Used in subscription post title. "Subscription renewal order - <this>"', 'woocommerce-subscriptions' ) );
	// translators: placeholder is order date parsed by strftime
	$subscription_data['post_title']    = sprintf( _x( 'Subscription &ndash; %s', 'The post title for the new subscription', 'woocommerce-subscriptions' ), $post_title_date );
	$subscription_data['post_date_gmt'] = $args['start_date'];
	$subscription_data['post_date']     = get_date_from_gmt( $args['start_date'] );

	if ( $args['order_id'] > 0 ) {
		$subscription_data['post_parent'] = absint( $args['order_id'] );
	}

	if ( ! is_null( $args['customer_note'] ) && ! empty( $args['customer_note'] ) ) {
		$subscription_data['post_excerpt'] = $args['customer_note'];
	}

	// Only set the status if creating a new subscription, use wcs_update_subscription to update the status
	if ( $args['status'] ) {
		if ( ! in_array( 'wc-' . $args['status'], array_keys( wcs_get_subscription_statuses() ) ) ) {
			return new WP_Error( 'woocommerce_invalid_subscription_status', __( 'Invalid subscription status given.', 'woocommerce-subscriptions' ) );
		}
		$subscription_data['post_status']  = 'wc-' . $args['status'];
	}

	$subscription_id = wp_insert_post( apply_filters( 'woocommerce_new_subscription_data', $subscription_data, $args ), true );

	if ( is_wp_error( $subscription_id ) ) {
		return $subscription_id;
	}

	// Default order meta data.
	update_post_meta( $subscription_id, '_order_key', 'wc_' . apply_filters( 'woocommerce_generate_order_key', uniqid( 'order_' ) ) );
	update_post_meta( $subscription_id, '_order_currency', $args['currency'] );
	update_post_meta( $subscription_id, '_prices_include_tax', $args['prices_include_tax'] );
	update_post_meta( $subscription_id, '_created_via', sanitize_text_field( $args['created_via'] ) );

	// add/update the billing
	update_post_meta( $subscription_id, '_billing_period', $args['billing_period'] );
	update_post_meta( $subscription_id, '_billing_interval', absint( $args['billing_interval'] ) );

	update_post_meta( $subscription_id, '_customer_user', $args['customer_id'] );
	update_post_meta( $subscription_id, '_order_version', $args['order_version'] );

	return new WC_Subscription( $subscription_id );
}

/**
 * Return an array of subscription status types, similar to @see wc_get_order_statuses()
 *
 * @since  2.0
 * @return array
 */
function wcs_get_subscription_statuses() {

	$subscription_statuses = array(
		'wc-pending'        => _x( 'Pending', 'Subscription status', 'woocommerce-subscriptions' ),
		'wc-active'         => _x( 'Active', 'Subscription status', 'woocommerce-subscriptions' ),
		'wc-on-hold'        => _x( 'On hold', 'Subscription status', 'woocommerce-subscriptions' ),
		'wc-cancelled'      => _x( 'Cancelled', 'Subscription status', 'woocommerce-subscriptions' ),
		'wc-switched'       => _x( 'Switched', 'Subscription status', 'woocommerce-subscriptions' ),
		'wc-expired'        => _x( 'Expired', 'Subscription status', 'woocommerce-subscriptions' ),
		'wc-pending-cancel' => _x( 'Pending Cancellation', 'Subscription status', 'woocommerce-subscriptions' ),
	);

	return apply_filters( 'wcs_subscription_statuses', $subscription_statuses );
}

/**
 * Get the nice name for a subscription's status
 *
 * @since  2.0
 * @param  string $status
 * @return string
 */
function wcs_get_subscription_status_name( $status ) {

	if ( ! is_string( $status ) ) {
		return new WP_Error( 'woocommerce_subscription_wrong_status_format', __( 'Can not get status name. Status is not a string.', 'woocommerce-subscriptions' ) );
	}

	$statuses = wcs_get_subscription_statuses();

	$sanitized_status_key = wcs_sanitize_subscription_status_key( $status );

	// if the sanitized status key is not in the list of filtered subscription names, return the
	// original key, without the wc-
	$status_name   = isset( $statuses[ $sanitized_status_key ] ) ? $statuses[ $sanitized_status_key ] : $status;

	return apply_filters( 'woocommerce_subscription_status_name', $status_name, $status );
}

/**
 * Helper function to return a localised display name for an address type
 *
 * @param string $address_type the type of address (shipping / billing)
 *
 * @return string
 */
function wcs_get_address_type_to_display( $address_type ) {
	if ( ! is_string( $address_type ) ) {
		return new WP_Error( 'woocommerce_subscription_wrong_address_type_format', __( 'Can not get address type display name. Address type is not a string.', 'woocommerce-subscriptions' ) );
	}

	$address_types = apply_filters( 'woocommerce_subscription_address_types', array(
		'shipping' => __( 'Shipping Address', 'woocommerce-subscriptions' ),
		'billing' => __( 'Billing Address', 'woocommerce-subscriptions' ),
	) );

	// if we can't find the address type, return the raw key
	$address_type_display = isset( $address_types[ $address_type ] ) ? $address_types[ $address_type ] : $address_type;

	return apply_filters( 'woocommerce_subscription_address_type_display', $address_type_display, $address_type );
}

/**
 * Returns an array of subscription dates
 *
 * @since  2.0
 * @return array
 */
function wcs_get_subscription_date_types() {

	$dates = array(
		'start'        => _x( 'Start Date', 'table heading', 'woocommerce-subscriptions' ),
		'trial_end'    => _x( 'Trial End', 'table heading', 'woocommerce-subscriptions' ),
		'next_payment' => _x( 'Next Payment', 'table heading', 'woocommerce-subscriptions' ),
		'last_payment' => _x( 'Last Payment', 'table heading', 'woocommerce-subscriptions' ),
		'end'          => _x( 'End Date', 'table heading', 'woocommerce-subscriptions' ),
	);

	return apply_filters( 'woocommerce_subscription_dates', $dates );
}

/**
 * Get the meta key value for storing a date in the subscription's post meta table.
 *
 * @param string $date_type Internally, 'trial_end', 'next_payment' or 'end', but can be any string
 * @since 2.0
 */
function wcs_get_date_meta_key( $date_type ) {
	if ( ! is_string( $date_type ) ) {
		return new WP_Error( 'woocommerce_subscription_wrong_date_type_format', __( 'Date type is not a string.', 'woocommerce-subscriptions' ) );
	} elseif ( empty( $date_type ) ) {
		return new WP_Error( 'woocommerce_subscription_wrong_date_type_format', __( 'Date type can not be an empty string.', 'woocommerce-subscriptions' ) );
	}
	return apply_filters( 'woocommerce_subscription_date_meta_key_prefix', sprintf( '_schedule_%s', $date_type ), $date_type );
}

/**
 * Utility function to standardise status keys:
 * - turns 'pending' into 'wc-pending'.
 * - turns 'wc-pending' into 'wc-pending'
 *
 * @param  string $status_key The status key going in
 * @return string             Status key guaranteed to have 'wc-' at the beginning
 */
function wcs_sanitize_subscription_status_key( $status_key ) {
	if ( ! is_string( $status_key ) || empty( $status_key ) ) {
		return '';
	}
	$status_key = ( 'wc-' === substr( $status_key, 0, 3 ) ) ? $status_key : sprintf( 'wc-%s', $status_key );
	return $status_key;
}

/**
 * A general purpose function for grabbing an array of subscriptions in form of post_id => WC_Subscription
 *
 * The $args parameter is based on the parameter of the same name used by the core WordPress @see get_posts() function.
 * It can be used to choose which subscriptions should be returned by the function, how many subscriptions should be returned
 * and in what order those subscriptions should be returned.
 *
 * @param array $args A set of name value pairs to determine the return value.
 *		'subscriptions_per_page' The number of subscriptions to return. Set to -1 for unlimited. Default 10.
 *		'offset' An optional number of subscription to displace or pass over. Default 0.
 *		'orderby' The field which the subscriptions should be ordered by. Can be 'start_date', 'trial_end_date', 'end_date', 'status' or 'order_id'. Defaults to 'start_date'.
 *		'order' The order of the values returned. Can be 'ASC' or 'DESC'. Defaults to 'DESC'
 *		'customer_id' The user ID of a customer on the site.
 *		'product_id' The post ID of a WC_Product_Subscription, WC_Product_Variable_Subscription or WC_Product_Subscription_Variation object
 *		'order_id' The post ID of a shop_order post/WC_Order object which was used to create the subscription
 *		'subscription_status' Any valid subscription status. Can be 'any', 'active', 'cancelled', 'suspended', 'expired', 'pending' or 'trash'. Defaults to 'any'.
 * @return array Subscription details in post_id => WC_Subscription form.
 * @since  2.0
 */
function wcs_get_subscriptions( $args ) {
	global $wpdb;

	$args = wp_parse_args( $args, array(
			'subscriptions_per_page' => 10,
			'paged'                  => 1,
			'offset'                 => 0,
			'orderby'                => 'start_date',
			'order'                  => 'DESC',
			'customer_id'            => 0,
			'product_id'             => 0,
			'variation_id'           => 0,
			'order_id'               => 0,
			'subscription_status'    => 'any',
			'meta_query_relation'    => 'AND',
		)
	);

	// if order_id is not a shop_order
	if ( 0 !== $args['order_id'] && 'shop_order' !== get_post_type( $args['order_id'] ) ) {
		return array();
	}

	// Make sure status starts with 'wc-'
	if ( ! in_array( $args['subscription_status'], array( 'any', 'trash' ) ) ) {
		$args['subscription_status'] = wcs_sanitize_subscription_status_key( $args['subscription_status'] );
	}

	// Prepare the args for WP_Query
	$query_args = array(
		'post_type'      => 'shop_subscription',
		'post_status'    => $args['subscription_status'],
		'posts_per_page' => $args['subscriptions_per_page'],
		'paged'          => $args['paged'],
		'offset'         => $args['offset'],
		'order'          => $args['order'],
		'fields'         => 'ids',
		'meta_query'     => array(), // just in case we need to filter or order by meta values later
	);

	// Maybe only get subscriptions created by a certain order
	if ( 0 != $args['order_id'] && is_numeric( $args['order_id'] ) ) {
		$query_args['post_parent'] = $args['order_id'];
	}

	// Map subscription specific orderby values to internal/WordPress keys
	switch ( $args['orderby'] ) {
		case 'status' :
			$query_args['orderby'] = 'post_status';
			break;
		case 'start_date' :
			$query_args['orderby'] = 'date';
			break;
		case 'trial_end_date' :
		case 'end_date' :
			// We need to orderby post meta value: http://www.paulund.co.uk/order-meta-query
			$query_args = array_merge( $query_args, array(
				'orderby'   => 'meta_value',
				'meta_key'  => wcs_get_date_meta_key( $args['orderby'] ),
				'meta_type' => 'DATETIME',
			) );
			$query_args['meta_query'][] = array(
				'key'     => wcs_get_date_meta_key( $args['orderby'] ),
				'value'   => 'EXISTS',
				'type'    => 'DATETIME',
			);
			break;
		default :
			$query_args['orderby'] = $args['orderby'];
			break;
	}

	// Maybe filter to a specific user
	if ( 0 != $args['customer_id'] && is_numeric( $args['customer_id'] ) ) {
		$query_args['meta_query'][] = array(
			'key'     => '_customer_user',
			'value'   => $args['customer_id'],
			'type'    => 'numeric',
			'compare' => ( is_array( $args['customer_id'] ) ) ? 'IN' : '=',
		);
	};

	// We need to restrict subscriptions to those which contain a certain product/variation
	if ( ( 0 != $args['product_id'] && is_numeric( $args['product_id'] ) ) || ( 0 != $args['variation_id'] && is_numeric( $args['variation_id'] ) ) ) {
		$query_args['post__in'] = wcs_get_subscriptions_for_product( array( $args['product_id'], $args['variation_id'] ) );
	}

	if ( ! empty( $query_args['meta_query'] ) ) {
		$query_args['meta_query']['relation'] = $args['meta_query_relation'];
	}

	$query_args = apply_filters( 'woocommerce_get_subscriptions_query_args', $query_args, $args );

	$subscription_post_ids = get_posts( $query_args );

	$subscriptions = array();

	foreach ( $subscription_post_ids as $post_id ) {
		$subscriptions[ $post_id ] = wcs_get_subscription( $post_id );
	}

	return apply_filters( 'woocommerce_got_subscriptions', $subscriptions, $args );
}

/**
 * Get subscriptions that contain a certain product, specified by ID.
 *
 * @param  int | array $product_ids Either the post ID of a product or variation or an array of product or variation IDs
 * @param  string $fields The fields to return, either "ids" to receive only post ID's for the match subscriptions, or "subscription" to receive WC_Subscription objects
 * @return array
 * @since  2.0
 */
function wcs_get_subscriptions_for_product( $product_ids, $fields = 'ids' ) {
	global $wpdb;

	// If we have an array of IDs, convert them to a comma separated list and sanatise them to make sure they're all integers
	if ( is_array( $product_ids ) ) {
		$ids_for_query = implode( "', '", array_map( 'absint', array_unique( $product_ids ) ) );
	} else {
		$ids_for_query = absint( $product_ids );
	}

	$subscription_ids = $wpdb->get_col( "
		SELECT DISTINCT order_items.order_id FROM {$wpdb->prefix}woocommerce_order_items as order_items
			LEFT JOIN {$wpdb->prefix}woocommerce_order_itemmeta AS itemmeta ON order_items.order_item_id = itemmeta.order_item_id
			LEFT JOIN {$wpdb->posts} AS posts ON order_items.order_id = posts.ID
		WHERE posts.post_type = 'shop_subscription'
			AND itemmeta.meta_value IN ( '" . $ids_for_query . "' )
			AND itemmeta.meta_key   IN ( '_variation_id', '_product_id' )"
	);

	$subscriptions = array();

	foreach ( $subscription_ids as $post_id ) {
		$subscriptions[ $post_id ] = ( 'ids' !== $fields ) ? wcs_get_subscription( $post_id ) : $post_id;
	}

	return apply_filters( 'woocommerce_subscriptions_for_product', $subscriptions, $product_ids, $fields );
}

/**
 * Get all subscription items which have a trial.
 *
 * @param mixed WC_Subscription|post_id
 * @return array
 * @since 2.0
 */
function wcs_get_line_items_with_a_trial( $subscription_id ) {

	$subscription = ( is_object( $subscription_id ) ) ? $subscription_id : wcs_get_subscription( $subscription_id );
	$trial_items  = array();

	foreach ( $subscription->get_items() as $line_item_id => $line_item ) {

		if ( isset( $line_item['has_trial'] ) ) {
			$trial_items[ $line_item_id ] = $line_item;
		}
	}

	return apply_filters( 'woocommerce_subscription_trial_line_items', $trial_items, $subscription_id );
}

/**
 * Checks if the user can be granted the permission to remove a line item from the subscription.
 *
 * @param WC_Subscription $subscription An instance of a WC_Subscription object
 * @since 2.0
 */
function wcs_can_items_be_removed( $subscription ) {
	$allow_remove = false;

	if ( sizeof( $subscription->get_items() ) > 1 && $subscription->payment_method_supports( 'subscription_amount_changes' ) && $subscription->has_status( array( 'active', 'on-hold', 'pending' ) ) ) {
		$allow_remove = true;
	}

	return apply_filters( 'wcs_can_items_be_removed', $allow_remove, $subscription );
}

/**
 * Get the Product ID for an order's line item (only the product ID, not the variation ID, even if the order item
 * is for a variation).
 *
 * @param int An order item ID
 * @since 2.0
 */
function wcs_get_order_items_product_id( $item_id ) {
	global $wpdb;

	$product_id = $wpdb->get_var( $wpdb->prepare(
		"SELECT meta_value FROM {$wpdb->prefix}woocommerce_order_itemmeta
		 WHERE order_item_id = %d
		 AND meta_key = '_product_id'",
		$item_id
	) );

	return $product_id;
}

/**
 * Get the variation ID for variation items or the product ID for non-variation items.
 *
 * When acting on cart items or order items, Subscriptions often needs to use an item's canonical product ID. For
 * items representing a variation, that means the 'variation_id' value, if the item is not a variation, that means
 * the 'product_id value. This function helps save keystrokes on the idiom to check if an item is to a variation or not.
 *
 * @param array $item Either a cart item or order/subscription line item
 */
function wcs_get_canonical_product_id( $item ) {
	return ( ! empty( $item['variation_id'] ) ) ? $item['variation_id'] : $item['product_id'];
}

/**
 * Return an array statuses used to describe when a subscriptions has been marked as ending or has ended.
 *
 * @return array
 * @since 2.0
 */
function wcs_get_subscription_ended_statuses() {
	return apply_filters( 'wcs_subscription_ended_statuses', array( 'cancelled', 'trash', 'expired', 'switched', 'pending-cancel' ) );
}

/**
 * Returns true when on the My Account > View Subscription front end page.
 *
 * @return bool
 * @since 2.0
 */
function wcs_is_view_subscription_page() {
	global $wp;

	return ( is_page( wc_get_page_id( 'myaccount' ) ) && isset( $wp->query_vars['view-subscription'] ) ) ? true : false;
}