package main import ( "chat2/pb" "context" "fmt" "io" "strings" "time" "github.com/gdamore/tcell/v2" "github.com/rivo/tview" "github.com/status-im/go-waku/waku/v2/node" ) // ChatUI is a Text User Interface (TUI) for a ChatRoom. // The Run method will draw the UI to the terminal in "fullscreen" // mode. You can quit with Ctrl-C, or by typing "/quit" into the // chat prompt. type ChatUI struct { app *tview.Application chat *Chat msgW io.Writer inputCh chan string doneCh chan struct{} ctx context.Context } // NewChatUI returns a new ChatUI struct that controls the text UI. // It won't actually do anything until you call Run(). func NewChatUI(ctx context.Context, chat *Chat) *ChatUI { chatUI := new(ChatUI) app := tview.NewApplication() // make a NewChatUI text view to contain our chat messages msgBox := tview.NewTextView() msgBox.SetDynamicColors(true) msgBox.SetBorder(true) msgBox.SetTitle("chat2 example") // text views are io.Writers, but they don't automatically refresh. // this sets a change handler to force the app to redraw when we get // new messages to display. msgBox.SetChangedFunc(func() { app.Draw() }) // an input field for typing messages into inputCh := make(chan string, 32) input := tview.NewInputField(). SetLabel(chat.nick + " > "). SetFieldWidth(0). SetFieldBackgroundColor(tcell.ColorBlack) // the done func is called when the user hits enter, or tabs out of the field input.SetDoneFunc(func(key tcell.Key) { if key != tcell.KeyEnter { // we don't want to do anything if they just tabbed away return } line := input.GetText() if len(line) == 0 { // ignore blank lines return } input.SetText("") // bail if requested if line == "/quit" { app.Stop() return } // add peer if strings.HasPrefix(line, "/connect ") { peer := strings.TrimPrefix(line, "/connect ") go func(peer string) { chatUI.displayMessage("Connecting to peer...") err := chat.node.DialPeer(peer) if err != nil { chatUI.displayMessage(err.Error()) } else { chatUI.displayMessage("Peer connected succesfully") } }(peer) return } // list peers if line == "/peers" { peers := chat.node.PubSub().ListPeers(string(node.DefaultWakuTopic)) if len(peers) == 0 { chatUI.displayMessage("No peers available") } for _, p := range peers { chatUI.displayMessage("- " + p.Pretty()) } return } // change nick if strings.HasPrefix(line, "/nick ") { newNick := strings.TrimSpace(strings.TrimPrefix(line, "/nick ")) chat.nick = newNick input.SetLabel(chat.nick + " > ") return } if line == "/help" { chatUI.displayMessage(` Available commands: /connect multiaddress - dials a node adding it to the list of connected peers /peers - list of peers connected to this node /nick newNick - change the user's nickname /quit - closes the app `) return } // send the line onto the input chan and reset the field text inputCh <- line }) chatPanel := tview.NewFlex(). AddItem(msgBox, 0, 1, false) // flex is a vertical box with the chatPanel on top and the input field at the bottom. flex := tview.NewFlex(). SetDirection(tview.FlexRow). AddItem(chatPanel, 0, 1, false). AddItem(input, 1, 1, true) app.SetRoot(flex, true) chatUI.app = app chatUI.msgW = msgBox chatUI.chat = chat chatUI.ctx = ctx chatUI.inputCh = inputCh chatUI.doneCh = make(chan struct{}, 1) for _, addr := range chat.node.ListenAddresses() { chatUI.displayMessage(fmt.Sprintf("Listening on %s", addr)) } return chatUI } // Run starts the chat event loop in the background, then starts // the event loop for the text UI. func (ui *ChatUI) Run() error { ui.displayMessage("\nWelcome, " + ui.chat.nick) ui.displayMessage("type /help to see available commands \n") go ui.handleEvents() defer ui.end() return ui.app.Run() } // end signals the event loop to exit gracefully func (ui *ChatUI) end() { ui.doneCh <- struct{}{} } // displayChatMessage writes a ChatMessage from the room to the message window, // with the sender's nick highlighted in green. func (ui *ChatUI) displayChatMessage(cm *pb.Chat2Message) { t := time.Unix(int64(cm.Timestamp), 0) prompt := withColor("green", fmt.Sprintf("<%s> %s:", t.Format("Jan 02, 15:04"), cm.Nick)) fmt.Fprintf(ui.msgW, "%s %s\n", prompt, cm.Payload) } // displayMessage writes a blue message to output func (ui *ChatUI) displayMessage(msg string) { fmt.Fprintf(ui.msgW, "%s\n", withColor("grey", msg)) } // handleEvents runs an event loop that sends user input to the chat room // and displays messages received from the chat room. It also periodically // refreshes the list of peers in the UI. func (ui *ChatUI) handleEvents() { for { select { case input := <-ui.inputCh: err := ui.chat.Publish(input) if err != nil { printErr("publish error: %s", err) } case m := <-ui.chat.Messages: // when we receive a message from the chat room, print it to the message window ui.displayChatMessage(m) case <-ui.ctx.Done(): return case <-ui.doneCh: return } } } // withColor wraps a string with color tags for display in the messages text box. func withColor(color, msg string) string { return fmt.Sprintf("[%s]%s[-]", color, msg) }