frappe.ui.form.on("Sales Invoice", {
    refresh(frm) {
        if (frm.doc.docstatus !== 1) return; // submitted only

        frm.add_custom_button("Run Payment", () => {
            run_payment_flow(frm);
        });
    }
});

function run_payment_flow(frm) {
    frappe.call({
        method: "ns_app.api.payments.check_autopay",
        args: {
            customer: frm.doc.customer
        },
        callback(r) {
            if (!r.message) return;

            if (r.message.autopay_enabled) {
                run_autopay(frm, r.message.autopay_id);
            } else {
                open_manual_payment_form(frm);
            }
        }
    });


function run_autopay(frm, autopay_id) {
    frappe.confirm(
        `Run AutoPay for $${frm.doc.grand_total}?`,
        () => {
            frappe.call({
                method: "ns_app.api.payments.run_autopay_payment",
                args: {
                    invoice: frm.doc.name,
                    autopay_id: autopay_id,
                    amount: frm.doc.grand_total
                },
                callback(r) {
                    frappe.msgprint(r.message || "Payment processed");
                    frm.reload_doc();
                }
            });
        }
    );
}


function open_manual_payment_form(frm) {
    const dialog = new frappe.ui.Dialog({
        title: "Enter Payment",
        fields: [
            {
                fieldtype: "HTML",
                fieldname: "payment_form",
                options: `<iframe
                    src="https://payments.yourprovider.com/pay?invoice=${frm.doc.name}&amount=${frm.doc.grand_total}"
                    style="width:100%;height:500px;border:none;"
                ></iframe>`
            }    
        ]
    });

    dialog.show();
}

}