AyeCode / invoicing

includes/class-wpinv-ajax.php

<?php
/**
 * Contains the ajax handlers.
 *
 * @since 1.0.0
 * @package Invoicing
 */

defined( 'ABSPATH' ) || exit;

/**
 * WPInv_Ajax class.
 */
class WPInv_Ajax {

    /**
	 * Hook in ajax handlers.
	 */
	public static function init() {
		add_action( 'init', array( __CLASS__, 'define_ajax' ), 0 );
		add_action( 'template_redirect', array( __CLASS__, 'do_wpinv_ajax' ), 0 );
		self::add_ajax_events();
    }

    /**
	 * Set GetPaid AJAX constant and headers.
	 */
	public static function define_ajax() {

		if ( ! empty( $_GET['wpinv-ajax'] ) ) {
			getpaid_maybe_define_constant( 'DOING_AJAX', true );
			getpaid_maybe_define_constant( 'WPInv_DOING_AJAX', true );
			if ( ! WP_DEBUG || ( WP_DEBUG && ! WP_DEBUG_DISPLAY ) ) {
				/** @scrutinizer ignore-unhandled */ @ini_set( 'display_errors', 0 );
			}
			$GLOBALS['wpdb']->hide_errors();
		}

    }

    /**
	 * Send headers for GetPaid Ajax Requests.
	 *
	 * @since 1.0.18
	 */
	private static function wpinv_ajax_headers() {
		if ( ! headers_sent() ) {
			send_origin_headers();
			send_nosniff_header();
			nocache_headers();
			header( 'Content-Type: text/html; charset=' . get_option( 'blog_charset' ) );
			header( 'X-Robots-Tag: noindex' );
			status_header( 200 );
		}
    }

    /**
	 * Check for GetPaid Ajax request and fire action.
	 */
	public static function do_wpinv_ajax() {
		global $wp_query;

		if ( ! empty( $_GET['wpinv-ajax'] ) ) {
			$wp_query->set( 'wpinv-ajax', sanitize_text_field( wp_unslash( $_GET['wpinv-ajax'] ) ) );
		}

		$action = $wp_query->get( 'wpinv-ajax' );

		if ( $action ) {
			self::wpinv_ajax_headers();
			$action = sanitize_text_field( $action );
			do_action( 'wpinv_ajax_' . $action );
			wp_die();
		}

    }

    /**
	 * Hook in ajax methods.
	 */
    public static function add_ajax_events() {

        // array( 'event' => is_frontend )
        $ajax_events = array(
            'add_note'                      => false,
            'delete_note'                   => false,
            'get_states_field'              => true,
            'get_aui_states_field'          => true,
            'payment_form'                  => true,
            'get_payment_form'              => true,
            'get_payment_form_states_field' => true,
            'get_invoicing_items'           => false,
            'get_customers'                 => false,
            'get_invoice_items'             => false,
            'add_invoice_items'             => false,
            'admin_add_invoice_item'        => false,
            'recalculate_full_prices'       => false,
            'edit_invoice_item'             => false,
            'create_invoice_item'           => false,
            'remove_invoice_item'           => false,
            'get_billing_details'           => false,
            'recalculate_invoice_totals'    => false,
            'check_new_user_email'          => false,
            'run_tool'                      => false,
            'payment_form_refresh_prices'   => true,
            'file_upload'                   => true,
        );

        foreach ( $ajax_events as $ajax_event => $nopriv ) {
            add_action( 'wp_ajax_wpinv_' . $ajax_event, array( __CLASS__, $ajax_event ) );
            add_action( 'wp_ajax_getpaid_' . $ajax_event, array( __CLASS__, $ajax_event ) );

            if ( $nopriv ) {
                add_action( 'wp_ajax_nopriv_wpinv_' . $ajax_event, array( __CLASS__, $ajax_event ) );
                add_action( 'wp_ajax_nopriv_getpaid_' . $ajax_event, array( __CLASS__, $ajax_event ) );
                add_action( 'wpinv_ajax_' . $ajax_event, array( __CLASS__, $ajax_event ) );
            }
        }
    }

    public static function add_note() {
        check_ajax_referer( 'add-invoice-note', '_nonce' );

        $post_id   = absint( $_POST['post_id'] );
        $note      = wp_kses_post( trim( stripslashes( $_POST['note'] ) ) );
        $note_type = sanitize_text_field( $_POST['note_type'] );

        if ( ! wpinv_current_user_can( 'invoice_add_note', array( 'invoice_id' => $post_id, 'note_type' => $note_type ) ) ) {
            die( -1 );
        }

        $is_customer_note = $note_type == 'customer' ? 1 : 0;

        if ( $post_id > 0 ) {
            $note_id = wpinv_insert_payment_note( $post_id, $note, $is_customer_note );

            if ( $note_id > 0 && ! is_wp_error( $note_id ) ) {
                wpinv_get_invoice_note_line_item( $note_id );
            }
        }

        die();
    }

    public static function delete_note() {
        check_ajax_referer( 'delete-invoice-note', '_nonce' );

        $note_id = (int)$_POST['note_id'];

        if ( ! wpinv_current_user_can( 'invoice_delete_note', array( 'note_id' => $note_id ) ) ) {
            die( -1 );
        }

        if ( $note_id > 0 ) {
            wp_delete_comment( $note_id, true );
        }

        die();
    }

    public static function get_states_field() {
        wpinv_get_states_field();

        die();
    }

    /**
     * Retrieves a given user's billing address.
     */
    public static function get_billing_details() {
        // Verify nonce.
        check_ajax_referer( 'wpinv-nonce' );

        // Do we have a user id?
        $user_id = (int) $_GET['user_id'];
        $invoice_id = ! empty( $_REQUEST['post_id'] ) ? (int) $_REQUEST['post_id'] : 0;

        if ( empty( $user_id ) || ! is_numeric( $user_id ) ) {
            die( -1 );
        }

        // Can the user manage the plugin?
        if ( ! wpinv_current_user_can( 'invoice_get_billing_details', array( 'user_id' => $user_id, 'invoice_id' => $invoice_id ) ) ) {
            die( -1 );
        }

        // Fetch the billing details.
        $billing_details    = wpinv_get_user_address( $user_id );
        $billing_details    = apply_filters( 'wpinv_ajax_billing_details', $billing_details, $user_id );

        // unset the user id and email.
        $to_ignore = array( 'user_id', 'email' );

        foreach ( $to_ignore as $key ) {
            if ( isset( $billing_details[ $key ] ) ) {
                unset( $billing_details[ $key ] );
            }
        }

        wp_send_json_success( $billing_details );

    }

    /**
     * Checks if a new users email is valid.
     */
    public static function check_new_user_email() {
        // Verify nonce.
        check_ajax_referer( 'wpinv-nonce' );

        $invoice_id = ! empty( $_REQUEST['post_id'] ) ? absint( $_REQUEST['post_id'] ) : 0;

        if ( empty( $invoice_id ) ) {
            die( -1 );
        }

        // Can the user manage the plugin?
        if ( ! wpinv_current_user_can( 'invoice_check_new_user_email', array( 'invoice_id' => $invoice_id ) ) ) {
            die( -1 );
        }

        // We need an email address.
        if ( empty( $_GET['email'] ) ) {
            esc_html_e( "Provide the new user's email address", 'invoicing' );
            exit;
        }

        // Ensure the email is valid.
        $email = sanitize_email( $_GET['email'] );
        if ( ! is_email( $email ) ) {
            esc_html_e( 'Invalid email address', 'invoicing' );
            exit;
        }

        // And it does not exist.
        $id = email_exists( $email );
        if ( $id ) {
            wp_send_json_success( compact( 'id' ) );
        }

        wp_send_json_success( true );
    }

    public static function run_tool() {
        check_ajax_referer( 'wpinv-nonce', '_nonce' );

        if ( ! wpinv_current_user_can_manage_invoicing() ) {
            die( -1 );
        }

        $tool = sanitize_text_field( $_POST['tool'] );

        do_action( 'wpinv_run_tool' );

        if ( ! empty( $tool ) ) {
            do_action( 'wpinv_tool_' . $tool );
        }
    }

    /**
     * Retrieves the markup for a payment form.
     */
    public static function get_payment_form() {
        global $getpaid_force_checkbox;

        // Is the request set up correctly?
		if ( empty( $_GET['form'] ) && empty( $_GET['item'] ) && empty( $_GET['invoice'] ) ) {
			aui()->alert(
				array(
					'type'    => 'warning',
					'content' => __( 'No payment form or item provided', 'invoicing' ),
                ),
                true
            );
            exit;
        }

        // Payment form or button?
		if ( ! empty( $_GET['form'] ) ) {
            $form = sanitize_text_field( urldecode( $_GET['form'] ) );

            if ( false !== strpos( $form, '|' ) ) {
                $form_pos = strpos( $form, '|' );
                $_items   = getpaid_convert_items_to_array( substr( $form, $form_pos + 1 ) );
                $form     = substr( $form, 0, $form_pos );

                // Retrieve appropriate payment form.
                $payment_form = new GetPaid_Payment_Form( $form );
                $payment_form = $payment_form->exists() ? $payment_form : new GetPaid_Payment_Form( wpinv_get_default_payment_form() );

                $items    = array();
                $item_ids = array();

                foreach ( $_items as $item_id => $qty ) {
                    if ( ! in_array( $item_id, $item_ids ) ) {
                        $item = new GetPaid_Form_Item( $item_id );
                        $item->set_quantity( $qty );

                        if ( 0 == $qty ) {
                            $item->set_allow_quantities( true );
                            $item->set_is_required( false );
                            $getpaid_force_checkbox = true;
                        }

                        $item_ids[] = $item->get_id();
                        $items[]    = $item;
                    }
                }

                if ( ! $payment_form->is_default() ) {

                    foreach ( $payment_form->get_items() as $item ) {
                        if ( ! in_array( $item->get_id(), $item_ids ) ) {
                            $item_ids[] = $item->get_id();
                            $items[]    = $item;
                        }
                    }
                }

                $payment_form->set_items( $items );
                $extra_items     = esc_attr( getpaid_convert_items_to_string( $_items ) );
                $extra_items_key = md5( NONCE_KEY . AUTH_KEY . $extra_items );
                $extra_items     = "<input type='hidden' name='getpaid-form-items' value='$extra_items' />";
                $extra_items    .= "<input type='hidden' name='getpaid-form-items-key' value='$extra_items_key' />";
                $payment_form->display( $extra_items );
                $getpaid_force_checkbox = false;

            } else {
                getpaid_display_payment_form( $form );
            }
} elseif ( ! empty( $_GET['invoice'] ) ) {
		    getpaid_display_invoice_payment_form( (int) urldecode( $_GET['invoice'] ) );
        } else {
			$items = getpaid_convert_items_to_array( sanitize_text_field( urldecode( $_GET['item'] ) ) );
		    getpaid_display_item_payment_form( $items );
        }

        exit;

    }

    /**
     * Payment forms.
     *
     * @since 1.0.18
     */
    public static function payment_form() {

        // ... form fields...
        if ( empty( $_POST['getpaid_payment_form_submission'] ) ) {
            esc_html_e( 'Error: Reload the page and try again.', 'invoicing' );
            exit;
        }

        // Process the payment form.
        $checkout_class = apply_filters( 'getpaid_checkout_class', 'GetPaid_Checkout' );
        $checkout       = new $checkout_class( new GetPaid_Payment_Form_Submission() );
        $checkout->process_checkout();

        exit;
    }

    /**
     * Payment forms.
     *
     * @since 1.0.18
     */
    public static function get_payment_form_states_field() {

        if ( empty( $_GET['country'] ) || empty( $_GET['form'] ) ) {
            exit;
        }

        $elements = getpaid_get_payment_form_elements( (int) $_GET['form'] );

        if ( empty( $elements ) ) {
            exit;
        }

        $address_fields = array();
        foreach ( $elements as $element ) {
            if ( 'address' === $element['type'] ) {
                $address_fields = $element;
                break;
            }
        }

        if ( empty( $address_fields ) ) {
            exit;
        }

        foreach ( $address_fields['fields'] as $address_field ) {

            if ( 'wpinv_state' == $address_field['name'] ) {

                $wrap_class  = getpaid_get_form_element_grid_class( $address_field );
                $wrap_class  = esc_attr( "$wrap_class getpaid-address-field-wrapper" );
                $placeholder = empty( $address_field['placeholder'] ) ? '' : esc_attr( $address_field['placeholder'] );
                $description = empty( $address_field['description'] ) ? '' : wp_kses_post( $address_field['description'] );
                $value       = is_user_logged_in() ? get_user_meta( get_current_user_id(), '_wpinv_state', true ) : '';
                $label       = empty( $address_field['label'] ) ? '' : wp_kses_post( $address_field['label'] );

                if ( ! empty( $address_field['required'] ) ) {
                    $label .= "<span class='text-danger'> *</span>";
                }

                $html = getpaid_get_states_select_markup(
                    sanitize_text_field( $_GET['country'] ),
                    $value,
                    $placeholder,
                    $label,
                    $description,
                    ! empty( $address_field['required'] ),
                    $wrap_class,
                    sanitize_text_field( $_GET['name'] )
                );

                wp_send_json_success( $html );
                exit;

            }
}

        exit;
    }

    /**
     * Recalculates invoice totals.
     */
    public static function recalculate_invoice_totals() {
        // Verify nonce.
        check_ajax_referer( 'wpinv-nonce' );

        $invoice_id = ! empty( $_POST['post_id'] ) ? absint( $_POST['post_id'] ) : 0;

        if ( empty( $invoice_id ) ) {
            die( -1 );
        }

        // Can the user manage the plugin?
        if ( ! wpinv_current_user_can( 'invoice_recalculate_totals', array( 'invoice_id' => $invoice_id ) ) ) {
            die( -1 );
        }

        // Fetch the invoice.
        $invoice = new WPInv_Invoice( $invoice_id );

        // Ensure it exists.
        if ( ! $invoice->get_id() ) {
            exit;
        }

        // Maybe set the country, state, currency.
        foreach ( array( 'country', 'state', 'currency', 'vat_number', 'discount_code' ) as $key ) {
            if ( isset( $_POST[ $key ] ) ) {
                $method = "set_$key";
                $invoice->$method( sanitize_text_field( $_POST[ $key ] ) );
            }
        }

        // Maybe disable taxes.
        $invoice->set_disable_taxes( ! empty( $_POST['taxes'] ) );

        // Discount code.
        if ( ! $invoice->is_paid() && ! $invoice->is_refunded() ) {
            $discount = new WPInv_Discount( $invoice->get_discount_code() );
            if ( $discount->exists() ) {
                $invoice->add_discount( getpaid_calculate_invoice_discount( $invoice, $discount ) );
            } else {
                $invoice->remove_discount( 'discount_code' );
            }
        }

        // Recalculate totals.
        $invoice->recalculate_total();

        $total        = wpinv_price( $invoice->get_total(), $invoice->get_currency() );
        $suscriptions = getpaid_get_invoice_subscriptions( $invoice );
        if ( is_a( $suscriptions, 'WPInv_Subscription' ) && $invoice->is_recurring() && $invoice->is_parent() && $invoice->get_total() != $invoice->get_recurring_total() ) {
            $recurring_total = wpinv_price( $invoice->get_recurring_total(), $invoice->get_currency() );
            $total          .= '<small class="form-text text-muted">' . sprintf( __( 'Recurring Price: %s', 'invoicing' ), $recurring_total ) . '</small>';
        }

        $totals = array(
            'subtotal' => wpinv_price( $invoice->get_subtotal(), $invoice->get_currency() ),
            'discount' => wpinv_price( $invoice->get_total_discount(), $invoice->get_currency() ),
            'tax'      => wpinv_price( $invoice->get_total_tax(), $invoice->get_currency() ),
            'total'    => $total,
        );

        $totals = apply_filters( 'getpaid_invoice_totals', $totals, $invoice );

        wp_send_json_success( compact( 'totals' ) );
    }

    /**
     * Get items belonging to a given invoice.
     */
    public static function get_invoice_items() {
        // Verify nonce.
        check_ajax_referer( 'wpinv-nonce' );

        $invoice_id = ! empty( $_POST['post_id'] ) ? absint( $_POST['post_id'] ) : 0;

        if ( empty( $invoice_id ) ) {
            exit;
        }

        // Can the user manage the plugin?
        if ( ! wpinv_current_user_can( 'invoice_get_items', array( 'invoice_id' => $invoice_id ) ) ) {
            exit;
        }

        // Fetch the invoice.
        $invoice = new WPInv_Invoice( $invoice_id );

        // Ensure it exists.
        if ( ! $invoice->get_id() ) {
            exit;
        }

        // Return an array of invoice items.
        $items = array();

        foreach ( $invoice->get_items() as $item ) {
            $items[] = $item->prepare_data_for_invoice_edit_ajax( $invoice->get_currency(), $invoice->is_renewal() );
        }

        wp_send_json_success( compact( 'items' ) );
    }

    /**
     * Edits an invoice item.
     */
    public static function edit_invoice_item() {
        // Verify nonce.
        check_ajax_referer( 'wpinv-nonce' );

        // We need an invoice and item details.
        if ( empty( $_POST['post_id'] ) || empty( $_POST['data'] ) ) {
            exit;
        }

        $invoice_id = absint( $_POST['post_id'] );

        if ( empty( $invoice_id ) ) {
            exit;
        }

        // Can the user manage the plugin?
        if ( ! wpinv_current_user_can( 'invoice_edit_item', array( 'invoice_id' => $invoice_id ) ) ) {
            exit;
        }

        // Fetch the invoice.
        $invoice = new WPInv_Invoice( $invoice_id );

        // Ensure it exists and its not been paid for.
        if ( ! $invoice->get_id() || $invoice->is_paid() || $invoice->is_refunded() ) {
            exit;
        }

        // Format the data.
        $data = wp_kses_post_deep( wp_unslash( wp_list_pluck( $_POST['data'], 'value', 'field' ) ) );

        // Ensure that we have an item id.
        if ( empty( $data['id'] ) ) {
            exit;
        }

        // Abort if the invoice does not have the specified item.
        $item = $invoice->get_item( (int) $data['id'] );

        if ( empty( $item ) ) {
            exit;
        }

        // Update the item.
        $item->set_price( getpaid_standardize_amount( $data['price'] ) );
        $item->set_name( sanitize_text_field( $data['name'] ) );
        $item->set_description( wp_kses_post( $data['description'] ) );
        $item->set_quantity( floatval( $data['quantity'] ) );

        // Add it to the invoice.
        $error = $invoice->add_item( $item );
        $alert = false;
        if ( is_wp_error( $error ) ) {
            $alert = $error->get_error_message();
        }

        // Update totals.
        $invoice->recalculate_total();

        // Save the invoice.
        $invoice->save();

        // Return an array of invoice items.
        $items = array();

        foreach ( $invoice->get_items() as $item ) {
            $items[] = $item->prepare_data_for_invoice_edit_ajax( $invoice->get_currency() );
        }

        wp_send_json_success( compact( 'items', 'alert' ) );
    }

    /**
     * Creates an invoice item.
     */
    public static function create_invoice_item() {
        // Verify nonce.
        check_ajax_referer( 'wpinv-nonce' );

        // We need an invoice and item details.
        if ( empty( $_POST['invoice_id'] ) || empty( $_POST['_wpinv_quick'] ) ) {
            exit;
        }

        $invoice_id = absint( $_POST['invoice_id'] );

        if ( empty( $invoice_id ) ) {
            exit;
        }

        if ( ! wpinv_current_user_can( 'invoice_create_item', array( 'invoice_id' => $invoice_id ) ) ) {
            exit;
        }

        // Fetch the invoice.
        $invoice = new WPInv_Invoice( $invoice_id );

        // Ensure it exists and its not been paid for.
        if ( ! $invoice->get_id() || $invoice->is_paid() || $invoice->is_refunded() ) {
            exit;
        }

        // Format the data.
        $data = wp_kses_post_deep( wp_unslash( $_POST['_wpinv_quick'] ) );

        $item = new WPInv_Item();
        $item->set_price( getpaid_standardize_amount( $data['price'] ) );
        $item->set_name( sanitize_text_field( $data['name'] ) );
        $item->set_description( wp_kses_post( $data['description'] ) );
        $item->set_type( sanitize_text_field( $data['type'] ) );
        $item->set_vat_rule( sanitize_text_field( $data['vat_rule'] ) );
        $item->set_vat_class( sanitize_text_field( $data['vat_class'] ) );
        $item->set_status( 'publish' );
        $item->save();

        if ( ! $item->exists() ) {
            $alert = __( 'Could not create invoice item. Please try again.', 'invoicing' );
            wp_send_json_success( compact( 'alert' ) );
        }

        if ( ! empty( $data['one-time'] ) ) {
            update_post_meta( $item->get_id(), '_wpinv_one_time', 'yes' );
        }

        $item = new GetPaid_Form_Item( $item->get_id() );
        $item->set_quantity( floatval( $data['qty'] ) );

        // Add it to the invoice.
        $error = $invoice->add_item( $item );
        $alert = false;

        if ( is_wp_error( $error ) ) {
            $alert = $error->get_error_message();
            wp_send_json_success( compact( 'alert' ) );
         }

        // Update totals.
        $invoice->recalculate_total();

        // Save the invoice.
        $invoice->save();

        // Save the invoice.
        $invoice->recalculate_total();
        $invoice->save();
        ob_start();
        GetPaid_Meta_Box_Invoice_Items::output_row( GetPaid_Meta_Box_Invoice_Items::get_columns( $invoice ), $item, $invoice );
        $row = ob_get_clean();
        wp_send_json_success( compact( 'row' ) );
    }

    /**
     * Deletes an invoice item.
     */
    public static function remove_invoice_item() {
        // Verify nonce.
        check_ajax_referer( 'wpinv-nonce' );

        // We need an invoice and item.
        $invoice_id = ! empty( $_POST['post_id'] ) ? absint( $_POST['post_id'] ) : 0;
        $item_id = ! empty( $_POST['item_id'] ) ? absint( $_POST['item_id'] ) : 0;

        if ( empty( $invoice_id ) || empty( $item_id ) ) {
            exit;
        }

        // Can the user manage the plugin?
        if ( ! wpinv_current_user_can( 'invoice_remove_item', array( 'invoice_id' => $invoice_id, 'item_id' => $item_id ) ) ) {
            exit;
        }

        // Fetch the invoice.
        $invoice = new WPInv_Invoice( $invoice_id );

        // Ensure it exists and its not been paid for.
        if ( ! $invoice->get_id() || $invoice->is_paid() || $invoice->is_refunded() ) {
            exit;
        }

        // Abort if the invoice does not have the specified item.
        $item = $invoice->get_item( $item_id );

        if ( empty( $item ) ) {
            exit;
        }

        $invoice->remove_item( $item_id );

        // Update totals.
        $invoice->recalculate_total();

        // Save the invoice.
        $invoice->save();

        // Return an array of invoice items.
        $items = array();

        foreach ( $invoice->get_items() as $item ) {
            $items[] = $item->prepare_data_for_invoice_edit_ajax( $invoice->get_currency() );
        }

        wp_send_json_success( compact( 'items' ) );
    }

    /**
     * Adds an item to an invoice.
     */
    public static function recalculate_full_prices() {
        // Verify nonce.
        check_ajax_referer( 'wpinv-nonce' );

        $invoice_id = ! empty( $_POST['post_id'] ) ? absint( $_POST['post_id'] ) : 0;

        if ( empty( $invoice_id ) ) {
            exit;
        }

        if ( ! wpinv_current_user_can( 'invoice_recalculate_full_prices', array( 'invoice_id' => $invoice_id ) ) ) {
            exit;
        }

        // Fetch the invoice.
        $invoice = new WPInv_Invoice( $invoice_id );
        $alert   = false;

        // Ensure it exists and its not been paid for.
        if ( ! $invoice->get_id() || $invoice->is_paid() || $invoice->is_refunded() ) {
            exit;
        }

        $invoice->set_items( array() );

        if ( ! empty( $_POST['getpaid_items'] ) ) {

            foreach ( wp_kses_post_deep( wp_unslash( $_POST['getpaid_items'] ) ) as $item_id => $args ) {
                $item = new GetPaid_Form_Item( $item_id );

                if ( $item->exists() ) {
                    $item->set_price( getpaid_standardize_amount( $args['price'] ) );
                    $item->set_quantity( floatval( $args['quantity'] ) );
                    $item->set_name( sanitize_text_field( $args['name'] ) );
                    $item->set_description( wp_kses_post( $args['description'] ) );
                    $invoice->add_item( $item );
                }
            }
        }

        $invoice->set_disable_taxes( ! empty( $_POST['disable_taxes'] ) );

        // Maybe set the country, state, currency.
        foreach ( array( 'wpinv_country', 'wpinv_state', 'wpinv_currency', 'wpinv_vat_number', 'wpinv_discount_code' ) as $key ) {
            if ( isset( $_POST[ $key ] ) ) {
                $_key   = str_replace( 'wpinv_', '', $key );
                $method = "set_$_key";
                $invoice->$method( sanitize_text_field( $_POST[ $key ] ) );
            }
        }

        $discount = new WPInv_Discount( $invoice->get_discount_code() );
        if ( $discount->exists() ) {
            $invoice->add_discount( getpaid_calculate_invoice_discount( $invoice, $discount ) );
        } else {
            $invoice->remove_discount( 'discount_code' );
        }

        // Save the invoice.
        $invoice->recalculate_total();
        $invoice->save();
        ob_start();
        GetPaid_Meta_Box_Invoice_Items::output( get_post( $invoice->get_id() ), $invoice );
        $table = ob_get_clean();
        wp_send_json_success( compact( 'table' ) );
    }

    /**
     * Adds an item to an invoice.
     */
    public static function admin_add_invoice_item() {
        // Verify nonce.
        check_ajax_referer( 'wpinv-nonce' );

        // We need an invoice and item.
        $invoice_id = ! empty( $_POST['post_id'] ) ? absint( $_POST['post_id'] ) : 0;
        $item_id = ! empty( $_POST['item_id'] ) ? absint( $_POST['item_id'] ) : 0;

        if ( empty( $invoice_id ) || empty( $item_id ) ) {
            exit;
        }

        // Can the user manage the plugin?
        if ( ! wpinv_current_user_can( 'invoice_add_item', array( 'invoice_id' => $invoice_id, 'item_id' => $item_id ) ) ) {
            exit;
        }

        // Fetch the invoice.
        $invoice = new WPInv_Invoice( $invoice_id );
        $alert   = false;

        // Ensure it exists and its not been paid for.
        if ( ! $invoice->get_id() || $invoice->is_paid() || $invoice->is_refunded() ) {
            exit;
        }

        // Add the item.
        $item  = new GetPaid_Form_Item( $item_id );

        $error = $invoice->add_item( $item );

        if ( is_wp_error( $error ) ) {
            $alert = $error->get_error_message();
            wp_send_json_success( compact( 'alert' ) );
        }

        // Save the invoice.
        $invoice->recalculate_total();
        $invoice->save();
        ob_start();
        GetPaid_Meta_Box_Invoice_Items::output_row( GetPaid_Meta_Box_Invoice_Items::get_columns( $invoice ), $item, $invoice );
        $row = ob_get_clean();
        wp_send_json_success( compact( 'row' ) );
    }

    /**
     * Adds a items to an invoice.
     */
    public static function add_invoice_items() {
        // Verify nonce.
        check_ajax_referer( 'wpinv-nonce' );

        $invoice_id = ! empty( $_POST['post_id'] ) ? absint( $_POST['post_id'] ) : 0;

        // We need an invoice and items.
        if ( empty( $invoice_id ) || empty( $_POST['items'] ) ) {
            exit;
        }

        // Can the user manage the plugin?
        if ( ! wpinv_current_user_can( 'invoice_add_items', array( 'invoice_id' => $invoice_id ) ) ) {
            exit;
        }

        // Fetch the invoice.
        $invoice = new WPInv_Invoice( $invoice_id );
        $alert   = false;

        // Ensure it exists and its not been paid for.
        if ( ! $invoice->get_id() || $invoice->is_paid() || $invoice->is_refunded() ) {
            exit;
        }

        // Add the items.
        foreach ( wp_kses_post_deep( wp_unslash( $_POST['items'] ) ) as $data ) {

            $item = new GetPaid_Form_Item( (int) $data['id'] );

            if ( is_numeric( $data['qty'] ) && (float) $data['qty'] > 0 ) {
                $item->set_quantity( floatval( $data['qty'] ) );
            }

            if ( $item->get_id() > 0 ) {
                $error = $invoice->add_item( $item );

                if ( is_wp_error( $error ) ) {
                    $alert = $error->get_error_message();
                }
}
}

        // Save the invoice.
        $invoice->recalculate_total();
        $invoice->save();

        // Return an array of invoice items.
        $items = array();

        foreach ( $invoice->get_items() as $item ) {
            $items[] = $item->prepare_data_for_invoice_edit_ajax( $invoice->get_currency() );
        }

        wp_send_json_success( compact( 'items', 'alert' ) );
    }

    /**
     * Retrieves items that should be added to an invoice.
     */
    public static function get_invoicing_items() {
        // Verify nonce.
        check_ajax_referer( 'wpinv-nonce' );

        // Can the user manage the plugin?
        if ( ! wpinv_current_user_can( 'get_invoicing_items' ) ) {
            exit;
        }

        // We need a search term.
        if ( empty( $_GET['search'] ) ) {
            wp_send_json_success( array() );
        }

        // Retrieve items.
        $item_args = array(
            'post_type'      => 'wpi_item',
            'orderby'        => 'title',
            'order'          => 'ASC',
            'posts_per_page' => -1,
            'post_status'    => array( 'publish' ),
            's'              => sanitize_text_field( urldecode( $_GET['search'] ) ),
            'meta_query'     => array(
                array(
                    'key'     => '_wpinv_type',
                    'compare' => '!=',
                    'value'   => 'package',
                ),
                array(
                    'key'     => '_wpinv_one_time',
                    'compare' => 'NOT EXISTS',
                ),
            ),
        );

        if ( ! empty( $_GET['ignore'] ) ) {
            $item_args['exclude'] = wp_parse_id_list( sanitize_text_field( $_GET['ignore'] ) );
        }

        $items = get_posts( apply_filters( 'getpaid_ajax_invoice_items_query_args', $item_args ) );
        $data  = array();

        $is_payment_form = ( ! empty( $_GET['post_id'] ) && 'wpi_payment_form' == get_post_type( (int) $_GET['post_id'] ) );

        foreach ( $items as $item ) {
            $item      = new GetPaid_Form_Item( $item );
            $data[] = array(
                'id'        => (int) $item->get_id(),
                'text'      => strip_tags( $item->get_name() ),
                'form_data' => $is_payment_form ? $item->prepare_data_for_use( false ) : '',
            );
        }

        wp_send_json_success( $data );

    }

    /**
     * Retrieves items that should be added to an invoice.
     */
    public static function get_customers() {
        // Verify nonce.
        check_ajax_referer( 'wpinv-nonce' );

        $invoice_id = ! empty( $_REQUEST['post_id'] ) ? (int) $_REQUEST['post_id'] : 0;

        // Can the user manage the plugin?
        if ( ! wpinv_current_user_can( 'invoice_get_customers', array( 'invoice_id' => $invoice_id ) ) ) {
            die( -1 );

Using exit here is not recommended.

        }

        // We need a search term.
        if ( empty( $_GET['search'] ) ) {
            wp_send_json_success( array() );
        }

        // Retrieve customers.

        $customer_args = array(
            'fields'         => array( 'ID', 'user_email', 'display_name' ),
            'orderby'        => 'display_name',
            'search'         => '*' . sanitize_text_field( $_GET['search'] ) . '*',
            'search_columns' => array( 'user_login', 'user_email', 'display_name' ),
        );

        $customers = get_users( apply_filters( 'getpaid_ajax_invoice_customers_query_args', $customer_args ) );
        $data      = array();

        foreach ( $customers as $customer ) {
            $data[] = array(
                'id'   => (int) $customer->ID,
                'text' => strip_tags( sprintf( _x( '%1$s (%2$s)', 'user dropdown', 'invoicing' ), $customer->display_name, $customer->user_email ) ),
            );
        }

        wp_send_json_success( $data );

    }

    /**
     * Retrieves the states field for AUI forms.
     */
    public static function get_aui_states_field() {

        // We need a country.
        if ( empty( $_GET['country'] ) ) {
            exit;
        }

        $states = wpinv_get_country_states( sanitize_text_field( $_GET['country'] ) );
        $state  = isset( $_GET['state'] ) ? sanitize_text_field( $_GET['state'] ) : wpinv_get_default_state();
        $name   = isset( $_GET['name'] ) ? sanitize_text_field( $_GET['name'] ) : 'wpinv_state';
        $class  = isset( $_GET['class'] ) ? sanitize_text_field( $_GET['class'] ) : 'form-control-sm';

        if ( empty( $states ) ) {

            $html = aui()->input(
                array(
                    'type'        => 'text',
                    'id'          => 'wpinv_state',
                    'name'        => $name,
                    'label'       => __( 'State', 'invoicing' ),
                    'label_type'  => 'vertical',
                    'placeholder' => __( 'State', 'invoicing' ),
                    'class'       => $class,
                    'value'       => $state,
                )
            );

        } else {

            $html = aui()->select(
                array(
                    'id'               => 'wpinv_state',
                    'name'             => $name,
                    'label'            => __( 'State', 'invoicing' ),
                    'label_type'       => 'vertical',
                    'placeholder'      => __( 'Select a state', 'invoicing' ),
                    'class'            => $class,
                    'value'            => $state,
                    'options'          => $states,
                    'data-allow-clear' => 'false',
                    'select2'          => true,
                )
            );

        }

        wp_send_json_success(
            array(
                'html'   => $html,
                'select' => ! empty( $states ),
            )
        );

    }

    /**
     * Refresh prices.
     *
     * @since 1.0.19
     */
    public static function payment_form_refresh_prices() {

        // ... form fields...
        if ( empty( $_POST['getpaid_payment_form_submission'] ) ) {
            esc_html_e( 'Error: Reload the page and try again.', 'invoicing' );
            exit;
        }

        // Load the submission.
        $submission = new GetPaid_Payment_Form_Submission();

        // Do we have an error?
        if ( ! empty( $submission->last_error ) ) {
            wp_send_json_error(
                array(
                    'code'  => $submission->last_error_code,
                    'error' => $submission->last_error,
                )
            );
        }

        // Prepare the response.
        $response = new GetPaid_Payment_Form_Submission_Refresh_Prices( $submission );

        // Filter the response.
        $response = apply_filters( 'getpaid_payment_form_ajax_refresh_prices', $response->response, $submission );

        wp_send_json_success( $response );
    }

    /**
	 * Handles file uploads.
	 *
	 * @since       1.0.0
	 * @return      void
	 */
	public static function file_upload() {

        // Check nonce.
        check_ajax_referer( 'getpaid_form_nonce' );

        if ( empty( $_POST['form_id'] ) || empty( $_POST['field_name'] ) || empty( $_FILES['file'] ) ) {
            wp_die( esc_html_e( 'Bad Request', 'invoicing' ), 400 );
        }

        // Fetch form.
        $form = new GetPaid_Payment_Form( intval( $_POST['form_id'] ) );

        if ( ! $form->is_active() ) {
            wp_send_json_error( __( 'Payment form not active', 'invoicing' ) );
        }

        // Fetch appropriate field.
        $upload_field = current( wp_list_filter( $form->get_elements(), array( 'id' => sanitize_text_field( $_POST['field_name'] ) ) ) );
        if ( empty( $upload_field ) ) {
            wp_send_json_error( __( 'Invalid upload field.', 'invoicing' ) );
        }

        // Prepare allowed file types.
        $file_types = isset( $upload_field['file_types'] ) ? $upload_field['file_types'] : array( 'jpg|jpeg|jpe', 'gif', 'png' );
        $all_types  = getpaid_get_allowed_mime_types();
        $mime_types = array();

        foreach ( $file_types as $file_type ) {
            if ( isset( $all_types[ $file_type ] ) ) {
                $mime_types[] = $all_types[ $file_type ];
            }
        }

        if ( ! in_array( $_FILES['file']['type'], $mime_types ) ) {
            wp_send_json_error( __( 'Unsupported file type.', 'invoicing' ) );
        }

        // Upload file.
        $file_name = explode( '.', strtolower( $_FILES['file']['name'] ) );
        $file_name = uniqid( 'getpaid-' ) . '.' . array_pop( $file_name );

        $uploaded = wp_upload_bits(
            $file_name,
            null,
            file_get_contents( $_FILES['file']['tmp_name'] )
        );

        if ( ! empty( $uploaded['error'] ) ) {
            wp_send_json_error( $uploaded['error'] );
        }

        // Retrieve response.
        $response = sprintf(
            '<input type="hidden" name="%s[%s]" value="%s" />',
            esc_attr( sanitize_text_field( $_POST['field_name'] ) ),
            esc_url( $uploaded['url'] ),
            esc_attr( sanitize_text_field( strtolower( $_FILES['file']['name'] ) ) )
        );

        wp_send_json_success( $response );

	}

}

WPInv_Ajax::init();