Added communication with the Scontrini-Daemon API

api/api.go

@@ -0,0 +1,76 @@
+package api
+
+import (
+	"fmt"
+	"net"
+)
+
+type Pizza struct {
+	Name     string `json:"name"`
+	Price    int    `json:"price"`
+	Quantity int    `json:"quantity"`
+}
+
+/**
+* Send and Receive messages from the API
+ */
+
+func SendPrintCommand(socket *net.TCPConn, text string) (*net.TCPConn, error) {
+	json_command := PrintCommand{Command: "print", Text: text}
+	socket, err := sendJSONToServer(socket, json_command)
+
+	if err != nil {
+		fmt.Println("Error while connecting to the printer server")
+		return nil, err
+	}
+
+	return socket, nil
+}
+
+func SendPizzaCommand(socket *net.TCPConn, pizzas []Pizza) (*net.TCPConn, error) {
+	json_command := PizzaCommand{Command: "pizza", Pizzas: pizzas}
+	socket, err := sendJSONToServer(nil, json_command)
+
+	if err != nil {
+		fmt.Println("Error while connecting to the printer server")
+		return nil, err
+	}
+
+	return socket, nil
+}
+
+func SendGetPizzasCommand(socket *net.TCPConn) (*net.TCPConn, error) {
+	json_command := GetPizzasCommand{Command: "get-pizzas"}
+	socket, err := sendJSONToServer(nil, json_command)
+
+	if err != nil {
+		fmt.Println("Error while connecting to the printer server")
+		return nil, err
+	}
+
+	return socket, nil
+}
+
+func ReceivePizzasCommand(socket *net.TCPConn) (*net.TCPConn, ReceivePizzas, error) {
+	pizzas := ReceivePizzas{}
+	socket, err := receiveJSONFromServer(socket, &pizzas)
+
+	if err != nil {
+		fmt.Println("Error while connecting to the printer server")
+		return nil, pizzas, err
+	}
+
+	return socket, pizzas, nil
+}
+
+func ReceivePriceCommand(socket *net.TCPConn) (*net.TCPConn, ReceivePrice, error) {
+	price := ReceivePrice{}
+	socket, err := receiveJSONFromServer(socket, &price)
+
+	if err != nil {
+		fmt.Println("Error while connecting to the printer server")
+		return nil, price, err
+	}
+
+	return socket, price, nil
+}

api/json_structs.go

@@ -0,0 +1,37 @@
+package api
+
+/**
+* Commands to give to the API
+ */
+type JSONCommand interface {
+	PrintCommand | PizzaCommand | GetPizzasCommand
+}
+
+type PrintCommand struct {
+	Command string `json:"command"`
+	Text    string `json:"text"`
+}
+
+type PizzaCommand struct {
+	Command string  `json:"command"`
+	Pizzas  []Pizza `json:"pizzas"`
+}
+
+type GetPizzasCommand struct {
+	Command string `json:"command"`
+}
+
+/**
+* What to receive from the API
+ */
+type JSONReceived interface {
+	ReceivePizzas | ReceivePrice
+}
+
+type ReceivePizzas struct {
+	Pizzas []Pizza `json:"pizzas"`
+}
+
+type ReceivePrice struct {
+	TotalPrice int `json:"total_price"`
+}

api/protocol.go

@@ -0,0 +1,78 @@
+package api
+
+import (
+	"encoding/binary"
+	"encoding/json"
+	"fmt"
+	"net"
+)
+
+var (
+	printer_server_IP   = net.ParseIP("127.0.0.1")
+	printer_server_port = 4444
+)
+
+/**
+* All messages from and to the API must have the first 4 bytes set to represent
+* the length of the message, followed by the message itself
+ */
+func sendJSONToServer[T JSONCommand](socket *net.TCPConn, json_command T) (*net.TCPConn, error) {
+	json_data, err := json.Marshal(json_command)
+
+	if err != nil {
+		return nil, err
+	}
+
+	// in case a socket doesn't already exist create a new one
+	if socket == nil {
+		socket, err = net.DialTCP("tcp4", nil, &net.TCPAddr{printer_server_IP, printer_server_port, ""})
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	// the first 4 bytes must be the length of the message
+	to_send := make([]byte, 4)
+	binary.LittleEndian.PutUint32(to_send, uint32(len(json_data)))
+
+	to_send = append(to_send, json_data...)
+	socket.Write([]byte(to_send))
+
+	return socket, nil
+}
+
+func receiveJSONFromServer[T JSONReceived](socket *net.TCPConn, json_received *T) (*net.TCPConn, error) {
+	var err error
+
+	// in case a socket doesn't already exist create a new one
+	if socket == nil {
+		fmt.Println("nil")
+		socket, err = net.DialTCP("tcp4", nil, &net.TCPAddr{printer_server_IP, printer_server_port, ""})
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	// the first 4 bytes are the length of the message
+	b := make([]byte, 4)
+	_, err = socket.Read(b[0:])
+
+	if err != nil {
+		return nil, err
+	}
+
+	body_length := binary.LittleEndian.Uint32(b)
+
+	body := make([]byte, body_length)
+	_, err = socket.Read(body[0:])
+
+	err = json.Unmarshal(body, json_received)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return socket, nil
+}

main.go

@@ -3,14 +3,16 @@ package main
 import (
 	"fmt"
 	"os"
+	"strconv"
 	"strings"
 
+	"Scontrini-TUI-Client/api"
+
 	"github.com/gdamore/tcell/v2"
 	"github.com/rivo/tview"
 )
 
 const (
-	USB_SERIAL_PORT = "/dev/ttyUSB0"
 	MAIN_WIDTH  = 240
 	MAIN_HEIGHT = 55
 )
@@ -31,23 +33,18 @@ func main() {
 	}
 }
 
-func writeToPrinter(text string) {
-	// move outside
-	serial_port, err := os.OpenFile(USB_SERIAL_PORT, os.O_WRONLY, 0755)
-	if err != nil {
-		panic(err)
-	}
-
-	fmt.Fprintln(serial_port, text)
-}
-
 /**
-* If text gets piped from terminal, print it
+* If text gets piped from terminal, send it to the API
  */
 func printFromStdIn() {
 	text := ""
-	fmt.Scanf("%s", text)
+	fmt.Scanf("%s", &text)
-	writeToPrinter(text)
+
+	_, err := api.SendPrintCommand(nil, text)
+
+	if err != nil {
+		os.Exit(1)
+	}
 }
 
 func startTui() {
@@ -66,10 +63,10 @@ func startTui() {
 }
 
 /**
-* Return a page with a TextView used to print
+* Return a page with a TextView used to print text
  */
 func createPrintPage(width, height int) *tview.Grid {
-	page := tview.NewGrid()
+	print_page := tview.NewGrid()
 
 	textview := tview.NewTextView().
 		SetText("[green]SCRIVI QUELLO CHE VUOI STAMPARE[white]").
@@ -82,7 +79,11 @@ func createPrintPage(width, height int) *tview.Grid {
 
 	print_button := tview.NewButton("Stampa").
 		SetSelectedFunc(func() {
-			writeToPrinter(textarea.GetText())
+			_, err := api.SendPrintCommand(nil, textarea.GetText())
+
+			if err != nil {
+				os.Exit(1) // TODO: add error page
+			}
 		})
 
 	pizza_button := tview.NewButton("Pizza").
@@ -118,14 +119,14 @@ func createPrintPage(width, height int) *tview.Grid {
 		return event
 	})
 
-	page.SetColumns(1/5, 1/5, 1/5, 1/5, 1/5).
+	print_page.SetColumns(1/5, 1/5, 1/5, 1/5, 1/5).
 		SetRows(1/5, 1/5, 1/5, 1/5, 1/5).
 		AddItem(textview, 1, 1, 1, 3, 0, 0, false).
 		AddItem(textarea, 2, 1, 1, 3, 0, 0, true).
 		AddItem(print_button, 3, 1, 1, 1, 0, 0, false).
 		AddItem(pizza_button, 3, 3, 1, 1, 0, 0, false)
 
-	return page
+	return print_page
 }
 
 /**
@@ -140,17 +141,41 @@ func createPizzaPage(width, height int) *tview.Grid {
 		SetDynamicColors(true)
 	setCommonBoxAttributes(textview.Box, "Scontrini")
 
+	// get a list of all the pizzas
+	socket, err := api.SendGetPizzasCommand(nil)
+
+	if err != nil {
+		os.Exit(1) // TODO: error page
+	}
+
+	_, pizzas_json, err := api.ReceivePizzasCommand(socket)
+
 	row_index := 0
 
 	table := tview.NewTable().
-		SetBorders(true).
 		InsertRow(row_index).
 		InsertColumn(0).
-		InsertColumn(1)
+		InsertColumn(1).
-	setCommonBoxAttributes(table.Box, "")
+		InsertColumn(2)
 
-	table.SetCellSimple(0, 0, "Quantità")
+	table.SetCellSimple(0, 0, "Pizza")
-	table.SetCellSimple(0, 1, "Pizza")
+	table.SetCellSimple(0, 1, "Prezzo")
+	table.SetCellSimple(0, 2, "Quantità")
+
+	// make the rows selectable
+	table.SetSelectable(true, false)
+
+	// populate the table
+	for _, v := range pizzas_json.Pizzas {
+		row_index += 1
+
+		table.InsertRow(row_index)
+		table.SetCellSimple(row_index, 0, v.Name)
+		table.SetCellSimple(row_index, 1, strconv.Itoa(v.Price))
+		table.SetCellSimple(row_index, 2, "0")
+	}
+
+	setCommonBoxAttributes(table.Box, "")
 
 	print_button := tview.NewButton("Stampa").
 		SetSelectedFunc(func() {
@@ -159,7 +184,7 @@ func createPizzaPage(width, height int) *tview.Grid {
 
 	pizza_button := tview.NewButton("Pizza").
 		SetSelectedFunc(func() {
-			printPizza(table)
+			sendOrder(table)
 		})
 
 	// define keys and behaviour for selected events
@@ -169,10 +194,26 @@ func createPizzaPage(width, height int) *tview.Grid {
 			return nil
 		}
 
-		if event.Key() == tcell.KeyEnter {
+		// increase/decrease the quantity column of the selected row
-			row_index += 1
+		if event.Rune() == '+' || event.Rune() == '-' {
-			table.InsertRow(row_index)
+			selected_row, _ := table.GetSelection()
-			App.Draw()
+
+			if selected_row == 0 {
+				return event
+			}
+
+			current_quantity, err := strconv.Atoi(table.GetCell(selected_row, 2).Text)
+			if err != nil {
+				os.Exit(1)
+			}
+
+			if event.Rune() == '+' {
+				table.SetCellSimple(selected_row, 2, strconv.Itoa(current_quantity+1))
+			} else {
+				if current_quantity > 0 {
+					table.SetCellSimple(selected_row, 2, strconv.Itoa(current_quantity-1))
+				}
+			}
 			return nil
 		}
 
@@ -208,10 +249,122 @@ func createPizzaPage(width, height int) *tview.Grid {
 }
 
 /**
-* Format the pizza order table and print it
+* Return a page with a Table used to show the pizza order
  */
-func printPizza(table *tview.Table) {
+func createOrderPage(width, height int, pizzas []api.Pizza, price int) *tview.Grid {
-	// TODO
+	order_page := tview.NewGrid()
+
+	textview := tview.NewTextView().
+		SetText("[green]IL TUO ORDINE\n\nPrezzo Totale: [red]" + strconv.Itoa(price) + "€[white]").
+		SetTextAlign(tview.AlignCenter).
+		SetDynamicColors(true)
+	setCommonBoxAttributes(textview.Box, "Scontrini")
+
+	row_index := 0
+
+	table := tview.NewTable().
+		InsertRow(row_index).
+		InsertColumn(0).
+		InsertColumn(1)
+
+	table.SetCellSimple(0, 0, "Pizza")
+	table.SetCellSimple(0, 1, "Quantità")
+
+	// populate the table
+	for _, v := range pizzas {
+		row_index += 1
+
+		table.InsertRow(row_index)
+		table.SetCellSimple(row_index, 0, v.Name)
+		table.SetCellSimple(row_index, 1, strconv.Itoa(v.Quantity))
+	}
+
+	setCommonBoxAttributes(table.Box, "")
+
+	print_button := tview.NewButton("Stampa").
+		SetSelectedFunc(func() {
+			Pages.RemovePage("order")
+			Pages.SwitchToPage("print")
+		})
+
+	pizza_button := tview.NewButton("Pizza").
+		SetSelectedFunc(func() {
+			Pages.RemovePage("order")
+			Pages.SwitchToPage("pizza")
+		})
+
+	// define keys and behaviour for selected events
+	table.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
+		if event.Key() == tcell.KeyTAB {
+			App.SetFocus(print_button)
+			return nil
+		}
+
+		return event
+	})
+
+	print_button.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
+		if event.Key() == tcell.KeyTAB {
+			App.SetFocus(pizza_button)
+			return nil
+		}
+
+		return event
+	})
+
+	pizza_button.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
+		if event.Key() == tcell.KeyTAB {
+			App.SetFocus(table)
+			return nil
+		}
+
+		return event
+	})
+
+	order_page.SetColumns(1/5, 1/5, 1/5, 1/5, 1/5).
+		SetRows(1/5, 1/5, 1/5, 1/5, 1/5).
+		AddItem(textview, 1, 1, 1, 3, 0, 0, false).
+		AddItem(table, 2, 2, 1, 1, 0, 0, true).
+		AddItem(print_button, 3, 1, 1, 1, 0, 0, false).
+		AddItem(pizza_button, 3, 3, 1, 1, 0, 0, false)
+
+	return order_page
+}
+
+/**
+* Format the pizza order from the table and send it to the API
+ */
+func sendOrder(table *tview.Table) {
+	pizzas := make([]api.Pizza, 0)
+
+	// populate the slice with pizzas from the table
+	for i := 1; i < table.GetRowCount(); i++ {
+		name := table.GetCell(i, 0).Text
+		quantity, err := strconv.Atoi(table.GetCell(i, 2).Text)
+
+		if err != nil {
+			os.Exit(1)
+		}
+
+		if quantity > 0 {
+			pizzas = append(pizzas, api.Pizza{name, 0, quantity})
+		}
+	}
+
+	socket, err := api.SendPizzaCommand(nil, pizzas)
+
+	if err != nil {
+		os.Exit(1) // TODO: add error page
+	}
+
+	_, price, err := api.ReceivePriceCommand(socket)
+
+	if err != nil {
+		os.Exit(1) // TODO: add error page
+	}
+
+	order_page := createOrderPage(MAIN_WIDTH, MAIN_HEIGHT, pizzas, price.TotalPrice)
+	Pages.AddAndSwitchToPage("order", order_page, true)
 }
 
 /**