Add a terminal-based client as example

Cargo.toml

@@ -6,7 +6,14 @@ edition = "2021"
 license = "LGPL-3.0-or-later"
 authors = ["Paul-Christian Volkmer"]
 
+[[example]]
+name = "arsnova-client-tui"
+
 [dependencies]
+clap = { version = "4.4", features = ["std", "help", "usage", "derive", "error-context"], default-features = false }
+ratatui = "0.25"
+crossterm = "0.27"
+
 futures-util = "0.3"
 reqwest = { version = "0.11", features = ["json", "rustls-tls"], default-features = false }
 serde = { version = "1.0", features = ["derive"] }

README.md

@@ -50,3 +50,14 @@ let (tx, rx) = tokio::sync::mpsc::channel::<Feedback>(10);
 
 client.on_feedback_changed( & cli.room, FeedbackHandler::Sender(tx.clone())).await;
 ```
+
+## Example
+
+See [`examples/arsnova-client-tui.rs`](examples/arsnova-client-tui.rs) for a simple terminal-based feedback client
+application.
+
+```bash
+arsnova-client-tui 23269388
+```
+
+![arsnova-client-tui](examples/arsnova-client.gif)

examples/arsnova-client-tui.rs

@@ -0,0 +1,212 @@
+/*
+ * This file is part of arsnova-client
+ *
+ * Copyright (C) 2023  Paul-Christian Volkmer
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+use std::io::{stdout, Stdout};
+
+use clap::Parser;
+use crossterm::event::{KeyCode, KeyEventKind};
+use crossterm::terminal::{
+    disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen,
+};
+use crossterm::{event, ExecutableCommand};
+use ratatui::backend::CrosstermBackend;
+use ratatui::layout::{Alignment, Constraint, Direction, Layout};
+use ratatui::style::Stylize;
+use ratatui::text::{Line, Span};
+use ratatui::widgets::Paragraph;
+use ratatui::Terminal;
+use tokio::select;
+use tokio::sync::mpsc::Receiver;
+
+use arsnova_client::{Client, Feedback, FeedbackHandler};
+
+#[derive(Parser)]
+#[command(author, version, about = "Terminal-based ARSnova live feedback client", long_about = None)]
+#[command(arg_required_else_help(true))]
+pub struct Cli {
+    #[arg(help = "Raum")]
+    room: String,
+    #[arg(
+        short = 'u',
+        long = "url",
+        help = "API-URL",
+        default_value = "https://ars.particify.de/api"
+    )]
+    url: String,
+}
+
+#[tokio::main(worker_threads = 3)]
+async fn main() -> Result<(), ()> {
+    let cli = Cli::parse();
+
+    let mut client = match Client::new(&cli.url) {
+        Ok(client) => client,
+        Err(_) => return Err(()),
+    };
+
+    if client.guest_login().await.is_err() {
+        return Err(());
+    }
+
+    stdout().execute(EnterAlternateScreen).map_err(|_| ())?;
+    enable_raw_mode().map_err(|_| ())?;
+    let mut terminal = Terminal::new(CrosstermBackend::new(stdout())).map_err(|_| ())?;
+    terminal.clear().map_err(|_| ())?;
+
+    let (tx, rx) = tokio::sync::mpsc::channel::<Feedback>(10);
+
+    let l1 = client.on_feedback_changed(&cli.room, FeedbackHandler::Sender(tx.clone()));
+
+    let _ = tx
+        .clone()
+        .send(client.get_feedback(&cli.room).await.unwrap())
+        .await;
+
+    let room_info = client.get_room_info(&cli.room).await.map_err(|_| ())?;
+    let title = format!("Live Feedback: {} ({})", room_info.name, room_info.short_id);
+
+    let l2 = create_ui(&mut terminal, &title, rx);
+
+    let l3 = tokio::spawn(async {
+        loop {
+            if event::poll(std::time::Duration::from_millis(16))
+                .map_err(|_| ())
+                .is_ok()
+            {
+                if let event::Event::Key(key) = event::read().map_err(|_| ()).unwrap() {
+                    if key.kind == KeyEventKind::Press && key.code == KeyCode::Esc {
+                        break;
+                    }
+                }
+            }
+        }
+    });
+
+    select! {
+        _ = l1 => {},
+        _ = l2 => {},
+        _ = l3 => {},
+    }
+
+    let _ = stdout().execute(LeaveAlternateScreen).map_err(|_| ());
+    let _ = disable_raw_mode().map_err(|_| ()).map_err(|_| ());
+
+    Ok(())
+}
+
+async fn create_ui(
+    terminal: &mut Terminal<CrosstermBackend<Stdout>>,
+    title: &str,
+    mut rx: Receiver<Feedback>,
+) -> Result<(), ()> {
+    fn feedback_paragraph(feedback: &Feedback, idx: usize, width: usize) -> Paragraph<'static> {
+        let value = match idx {
+            0 => feedback.very_good,
+            1 => feedback.good,
+            2 => feedback.bad,
+            3 => feedback.very_bad,
+            _ => 0,
+        };
+
+        let icon = match idx {
+            0 => "Super       ",
+            1 => "Gut         ",
+            2 => "Nicht so gut",
+            3 => "Schlecht    ",
+            _ => "            ",
+        };
+
+        let width = width - 24;
+
+        let l = ((value as f32 / feedback.count_votes() as f32) * width as f32) as usize;
+
+        match idx {
+            0..=3 => Paragraph::new(Line::from(vec![
+                Span::raw(format!("{} : ", icon)),
+                Span::raw(format!("[{: >5}] ", value)).dim(),
+                Span::raw("■".to_string().repeat(l).to_string())
+                    .green()
+                    .on_black(),
+                Span::raw(" ".to_string().repeat(width - l).to_string()).on_black(),
+            ])),
+            _ => Paragraph::default(),
+        }
+    }
+
+    loop {
+        let feedback = match rx.recv().await {
+            Some(feedback) => feedback,
+            _ => continue,
+        };
+
+        let _ = terminal.draw(|frame| {
+            let layout = Layout::default()
+                .direction(Direction::Vertical)
+                .constraints(vec![
+                    Constraint::Max(1),
+                    Constraint::Max(6),
+                    Constraint::Min(1),
+                    Constraint::Max(1),
+                ])
+                .split(frame.size());
+
+            frame.render_widget(
+                Paragraph::new(title)
+                    .white()
+                    .on_blue()
+                    .bold()
+                    .alignment(Alignment::Center),
+                layout[0],
+            );
+
+            frame.render_widget(
+                Paragraph::new(format!("{} Antworten", feedback.count_votes()))
+                    .white()
+                    .bold()
+                    .alignment(Alignment::Center),
+                layout[2],
+            );
+
+            frame.render_widget(
+                Paragraph::new("Beenden mit <Esc>")
+                    .on_blue()
+                    .alignment(Alignment::Left),
+                layout[3],
+            );
+
+            let feedback_layout = Layout::default()
+                .direction(Direction::Vertical)
+                .constraints(vec![
+                    Constraint::Max(1),
+                    Constraint::Max(1),
+                    Constraint::Max(1),
+                    Constraint::Max(1),
+                ])
+                .margin(1)
+                .split(layout[1]);
+
+            [0usize, 1, 2, 3].iter().for_each(|&idx| {
+                frame.render_widget(
+                    feedback_paragraph(&feedback, idx, feedback_layout[idx].width as usize),
+                    feedback_layout[idx],
+                )
+            });
+        });
+    }
+}