functions.sol

// function to send order
function sendOrder(string memory burgerMenu, uint quantity) payable public {				
  // only the customer can use this function
  require(msg.sender == customerAddress);

  // increase the order index
  orderseq++;

  // create the order
  orders[orderseq] = Order(orderseq, burgerMenu, quantity, 0, 0, 0, 0, true);

  // trigger OrderSent event
  emit OrderSent(msg.sender, burgerMenu, quantity, orderseq);
}

// function to check orders
function checkOrder(uint ID) view public returns (address customer, string memory burgerMenu, uint quantity, uint price, uint safePayment) {		
  // check the order exists
  require(orders[ID].created);

  // return the order
  return(customerAddress, orders[ID].burgerMenu, orders[ID].quantity, orders[ID].price, orders[ID].safePayment);
}

// function to send price
function sendPrice(uint orderNo, uint price) payable public {		
  // only the owner can use this function
  require(msg.sender == owner);

  // check the order exists
  require(orders[orderNo].created);

  // set the order price
  orders[orderNo].price = price;

  // trigger PriceSent event
  emit PriceSent(customerAddress, orderNo, price);
}

// function to send safe payment
function sendSafePayment(uint orderNo) payable public {
  // only the customer can use this function
  require(customerAddress == msg.sender);

  // check the order exists
  require(orders[orderNo].created);			

  // payout
  orders[orderNo].safePayment = msg.value;

  // trigger SafePaymentSent event
  emit SafePaymentSent(msg.sender, orderNo, msg.value, now);
}

// function to send invoice
function sendInvoice(uint orderNo, uint order_date) payable public {
  // only the owner can use this function
  require(owner == msg.sender);

  // check the order exists
  require(orders[orderNo].created);

  // increase the invoice index
  invoiceseq++;

  // create the invoice
  invoices[invoiceseq] = Invoice(invoiceseq, orderNo, true);

  //  set the order date
  orders[orderNo].orderDate = order_date;

  // trigger InvoiceSent event
  emit InvoiceSent(customerAddress, invoiceseq, orderNo, order_date);
}

// function to get invoice
function getInvoice(uint invoiceID) view public returns (address customer, uint orderNo, uint invoice_date){
  // check the invoice exists
  require(invoices[invoiceID].created);

  // get the related invoice info
  Invoice storage _invoice = invoices[invoiceID];
  // get the related order info
  Order storage _order     = orders[_invoice.orderNo];		

  // return the invoice
  return (customerAddress, _order.ID, _order.orderDate);
}

// function to mark the order as delivered
function markOrderDelivered(uint invoiceID, uint delivery_date) payable public {
  // only the customer can use this function
  require(customerAddress == msg.sender);

  // check the invoice exists
  require(invoices[invoiceID].created);

  // get the related invoice info
  Invoice storage _invoice = invoices[invoiceID];
  // get the related order info
  Order storage _order     = orders[_invoice.orderNo];	

  // set the delivery date
  _order.deliveryDate = delivery_date;

  // trigger OrderDelivered event
  emit OrderDelivered(customerAddress, invoiceID, _order.ID, delivery_date);

  // payout
  owner.transfer(_order.safePayment);
}