[ADD] tui: interactive terminal UI for resolving duplicates

The tool could only act on duplicates non-interactively or through a
line-oriented per-group prompt. Add a full-screen terminal UI (--tui) for
browsing and resolving them visually.

The UI is a two-pane master/detail view: a list of duplicate groups and,
for the selected group, its files with per-file deletion marks. Files can
be marked individually or in bulk by a keep-strategy (newest/oldest/first/
last/shortest/shallowest, reused from the resolver) applied to the current
group or to all groups at once. A footer tracks how many files are marked
and how much space would be reclaimed. Deletion is gated behind an explicit
confirmation, a group always keeps at least one file, and the highlighted
file can be opened in the system default application.

The design keeps the interaction logic pure and independently testable: an
App model translates an abstract key event into an outcome, so navigation,
marking, strategy application, and post-deletion model updates are all unit
tested without a terminal. Rendering (ratatui) and the destructive file I/O
live in the event loop, which restores the terminal on both normal exit and
panic so a crash never leaves it broken. --tui is mutually exclusive with
--keep and --interactive.

Cargo.toml

@@ -26,8 +26,10 @@ globwalk = "0.9.1"
 gxhash = { version = "3.4.1", default-features = false }
 indicatif = { version = "0.18.0", features = ["rayon"] }
 memmap2 = "0.9.7"
+open = "5.4.0"
 pathdiff = "0.2.1"
 prettytable-rs = "0.10.0"
+ratatui = "0.30.2"
 rayon = "1.6.1"
 unicode-segmentation = "1.12.0"
 

src/main.rs

@@ -7,6 +7,7 @@ mod pipeline;
 mod processor;
 mod resolver;
 mod scanner;
+mod tui;
 
 use self::{formatter::Formatter, interactive::Interactive};
 use anyhow::Result;
@@ -17,12 +18,11 @@ fn main() -> Result<()> {
     let params = Params::parse();
     let report = pipeline::run(&params)?;
 
-    match params.keep {
-        Some(strategy) => resolver::run(&report, strategy, params.force, &params)?,
-        None => match params.interactive {
-            true => Interactive::init(&report.groups, &params)?,
-            false => Formatter::print(&report, &params),
-        },
+    match (params.tui, params.keep, params.interactive) {
+        (true, _, _) => tui::run(report, &params)?,
+        (false, Some(strategy), _) => resolver::run(&report, strategy, params.force, &params)?,
+        (false, None, true) => Interactive::init(&report.groups, &params)?,
+        (false, None, false) => Formatter::print(&report, &params),
     }
 
     Ok(())

src/params.rs

@@ -48,6 +48,9 @@ pub struct Params {
     /// Use a specific cache file instead of the default location
     #[arg(long, value_name = "PATH")]
     pub cache_file: Option<PathBuf>,
+    /// Browse and resolve duplicates in an interactive terminal UI
+    #[arg(long, conflicts_with_all = ["keep", "interactive"])]
+    pub tui: bool,
 }
 
 impl Params {

src/tui/app.rs

@@ -0,0 +1,499 @@
+use std::path::PathBuf;
+
+use crate::fileinfo::FileInfo;
+use crate::pipeline::DuplicateGroup;
+use crate::resolver::{select_keeper, KeepStrategy};
+
+pub const STRATEGIES: [KeepStrategy; 6] = [
+    KeepStrategy::Newest,
+    KeepStrategy::Oldest,
+    KeepStrategy::First,
+    KeepStrategy::Last,
+    KeepStrategy::Shortest,
+    KeepStrategy::Shallowest,
+];
+
+pub fn strategy_label(strategy: KeepStrategy) -> &'static str {
+    match strategy {
+        KeepStrategy::Newest => "newest",
+        KeepStrategy::Oldest => "oldest",
+        KeepStrategy::First => "first",
+        KeepStrategy::Last => "last",
+        KeepStrategy::Shortest => "shortest",
+        KeepStrategy::Shallowest => "shallowest",
+    }
+}
+
+#[derive(Clone, Copy, PartialEq)]
+pub enum Focus {
+    Groups,
+    Files,
+}
+
+#[derive(Clone, Copy, PartialEq)]
+pub enum StrategyScope {
+    CurrentGroup,
+    AllGroups,
+}
+
+#[derive(Clone, Copy, PartialEq)]
+pub enum Popup {
+    None,
+    Strategy { scope: StrategyScope },
+    ConfirmDelete,
+}
+
+pub enum Key {
+    Up,
+    Down,
+    Tab,
+    Space,
+    Enter,
+    Esc,
+    Char(char),
+}
+
+pub enum Outcome {
+    Continue,
+    Quit,
+    Delete,
+    Open(PathBuf),
+}
+
+pub struct Group {
+    pub files: Vec<FileInfo>,
+    pub marked: Vec<bool>,
+}
+
+impl Group {
+    pub fn size(&self) -> u64 {
+        self.files.first().map(|f| f.size).unwrap_or(0)
+    }
+}
+
+pub struct App {
+    pub groups: Vec<Group>,
+    pub group_cursor: usize,
+    pub file_cursor: usize,
+    pub focus: Focus,
+    pub popup: Popup,
+    pub strategy_cursor: usize,
+    pub status: Option<String>,
+    pub should_quit: bool,
+}
+
+fn clamp_add(cur: usize, delta: isize, max: usize) -> usize {
+    (cur as isize + delta).clamp(0, max as isize) as usize
+}
+
+impl App {
+    pub fn from_groups(groups: Vec<DuplicateGroup>) -> Self {
+        let groups = groups
+            .into_iter()
+            .map(|g| Group {
+                marked: vec![false; g.files.len()],
+                files: g.files,
+            })
+            .collect();
+
+        Self {
+            groups,
+            group_cursor: 0,
+            file_cursor: 0,
+            focus: Focus::Files,
+            popup: Popup::None,
+            strategy_cursor: 0,
+            status: None,
+            should_quit: false,
+        }
+    }
+
+    pub fn move_group(&mut self, delta: isize) {
+        if self.groups.is_empty() {
+            return;
+        }
+        self.group_cursor = clamp_add(self.group_cursor, delta, self.groups.len() - 1);
+        let len = self.groups[self.group_cursor].files.len();
+        self.file_cursor = self.file_cursor.min(len.saturating_sub(1));
+    }
+
+    pub fn move_file(&mut self, delta: isize) {
+        if let Some(g) = self.groups.get(self.group_cursor) {
+            self.file_cursor = clamp_add(self.file_cursor, delta, g.files.len().saturating_sub(1));
+        }
+    }
+
+    pub fn toggle_mark(&mut self) {
+        let fc = self.file_cursor;
+        if let Some(g) = self.groups.get_mut(self.group_cursor) {
+            if fc >= g.marked.len() {
+                return;
+            }
+            if !g.marked[fc] && g.marked.iter().filter(|m| !**m).count() <= 1 {
+                return;
+            }
+            g.marked[fc] = !g.marked[fc];
+        }
+    }
+
+    pub fn apply_strategy(&mut self, strategy: KeepStrategy, scope: StrategyScope) {
+        let indices: Vec<usize> = match scope {
+            StrategyScope::CurrentGroup => vec![self.group_cursor],
+            StrategyScope::AllGroups => (0..self.groups.len()).collect(),
+        };
+        for gi in indices {
+            if let Some(g) = self.groups.get_mut(gi) {
+                if g.files.len() < 2 {
+                    continue;
+                }
+                let keeper = select_keeper(&g.files, strategy);
+                for i in 0..g.marked.len() {
+                    g.marked[i] = i != keeper;
+                }
+            }
+        }
+    }
+
+    pub fn marked_count(&self) -> usize {
+        self.groups
+            .iter()
+            .flat_map(|g| g.marked.iter())
+            .filter(|m| **m)
+            .count()
+    }
+
+    pub fn reclaimable_bytes(&self) -> u64 {
+        self.groups
+            .iter()
+            .flat_map(|g| g.files.iter().zip(&g.marked))
+            .filter(|(_, m)| **m)
+            .map(|(f, _)| f.size)
+            .sum()
+    }
+
+    pub fn marked_paths(&self) -> Vec<PathBuf> {
+        self.groups
+            .iter()
+            .flat_map(|g| g.files.iter().zip(&g.marked))
+            .filter(|(_, m)| **m)
+            .map(|(f, _)| f.path.to_path_buf())
+            .collect()
+    }
+
+    pub fn apply_deletion(&mut self, deleted: &[PathBuf]) {
+        use std::collections::HashSet;
+        let removed: HashSet<&std::path::Path> = deleted.iter().map(|p| p.as_path()).collect();
+
+        for g in &mut self.groups {
+            let mut files = Vec::new();
+            let mut marked = Vec::new();
+            for (i, f) in g.files.iter().enumerate() {
+                if !removed.contains(&*f.path) {
+                    files.push(f.clone());
+                    marked.push(g.marked[i]);
+                }
+            }
+            g.files = files;
+            g.marked = marked;
+        }
+
+        self.groups.retain(|g| g.files.len() >= 2);
+
+        if self.groups.is_empty() {
+            self.should_quit = true;
+            self.group_cursor = 0;
+            self.file_cursor = 0;
+            return;
+        }
+
+        self.group_cursor = self.group_cursor.min(self.groups.len() - 1);
+        let len = self.groups[self.group_cursor].files.len();
+        self.file_cursor = self.file_cursor.min(len.saturating_sub(1));
+    }
+
+    pub fn handle_key(&mut self, key: Key) -> Outcome {
+        match self.popup {
+            Popup::Strategy { scope } => self.handle_strategy_key(key, scope),
+            Popup::ConfirmDelete => self.handle_confirm_key(key),
+            Popup::None => self.handle_main_key(key),
+        }
+    }
+
+    fn handle_main_key(&mut self, key: Key) -> Outcome {
+        self.status = None;
+        match key {
+            Key::Char('q') | Key::Esc => {
+                self.should_quit = true;
+                Outcome::Quit
+            }
+            Key::Tab => {
+                self.focus = match self.focus {
+                    Focus::Groups => Focus::Files,
+                    Focus::Files => Focus::Groups,
+                };
+                Outcome::Continue
+            }
+            Key::Up | Key::Char('k') => {
+                self.move_in_focus(-1);
+                Outcome::Continue
+            }
+            Key::Down | Key::Char('j') => {
+                self.move_in_focus(1);
+                Outcome::Continue
+            }
+            Key::Space => {
+                if self.focus == Focus::Files {
+                    self.toggle_mark();
+                }
+                Outcome::Continue
+            }
+            Key::Char('s') => {
+                self.open_strategy(StrategyScope::CurrentGroup);
+                Outcome::Continue
+            }
+            Key::Char('S') => {
+                self.open_strategy(StrategyScope::AllGroups);
+                Outcome::Continue
+            }
+            Key::Char('o') => self.open_current(),
+            Key::Char('d') => {
+                if self.marked_count() > 0 {
+                    self.popup = Popup::ConfirmDelete;
+                } else {
+                    self.status = Some("nothing marked".to_string());
+                }
+                Outcome::Continue
+            }
+            _ => Outcome::Continue,
+        }
+    }
+
+    fn handle_strategy_key(&mut self, key: Key, scope: StrategyScope) -> Outcome {
+        match key {
+            Key::Up | Key::Char('k') => {
+                self.strategy_cursor = self.strategy_cursor.saturating_sub(1);
+            }
+            Key::Down | Key::Char('j') => {
+                self.strategy_cursor = (self.strategy_cursor + 1).min(STRATEGIES.len() - 1);
+            }
+            Key::Enter => {
+                let strategy = STRATEGIES[self.strategy_cursor];
+                self.apply_strategy(strategy, scope);
+                self.popup = Popup::None;
+            }
+            Key::Esc => self.popup = Popup::None,
+            _ => {}
+        }
+        Outcome::Continue
+    }
+
+    fn handle_confirm_key(&mut self, key: Key) -> Outcome {
+        match key {
+            Key::Char('y') => {
+                self.popup = Popup::None;
+                Outcome::Delete
+            }
+            Key::Char('n') | Key::Esc => {
+                self.popup = Popup::None;
+                Outcome::Continue
+            }
+            _ => Outcome::Continue,
+        }
+    }
+
+    fn move_in_focus(&mut self, delta: isize) {
+        match self.focus {
+            Focus::Groups => self.move_group(delta),
+            Focus::Files => self.move_file(delta),
+        }
+    }
+
+    fn open_strategy(&mut self, scope: StrategyScope) {
+        self.strategy_cursor = 0;
+        self.popup = Popup::Strategy { scope };
+    }
+
+    fn open_current(&self) -> Outcome {
+        match self.groups.get(self.group_cursor).and_then(|g| g.files.get(self.file_cursor)) {
+            Some(f) => Outcome::Open(f.path.to_path_buf()),
+            None => Outcome::Continue,
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::fileinfo::FileInfo;
+    use crate::pipeline::DuplicateGroup;
+    use std::path::PathBuf;
+    use std::time::{Duration, UNIX_EPOCH};
+
+    fn file(path: &str, size: u64, mtime_secs: u64) -> FileInfo {
+        FileInfo {
+            path: PathBuf::from(path).into_boxed_path(),
+            size,
+            modified: UNIX_EPOCH + Duration::from_secs(mtime_secs),
+        }
+    }
+
+    fn group(files: Vec<FileInfo>) -> DuplicateGroup {
+        DuplicateGroup { hash: 0, files }
+    }
+
+    fn sample() -> App {
+        App::from_groups(vec![
+            group(vec![file("/a/x", 10, 100), file("/a/y", 10, 200)]),
+            group(vec![file("/b/p", 5, 50), file("/b/q", 5, 60), file("/b/r", 5, 70)]),
+        ])
+    }
+
+    #[test]
+    fn move_group_clamps_at_bounds() {
+        let mut app = sample();
+        app.move_group(-1);
+        assert_eq!(app.group_cursor, 0);
+        app.move_group(1);
+        assert_eq!(app.group_cursor, 1);
+        app.move_group(5);
+        assert_eq!(app.group_cursor, 1);
+    }
+
+    #[test]
+    fn move_group_reclamps_file_cursor() {
+        let mut app = sample();
+        app.group_cursor = 1;
+        app.file_cursor = 2;
+        app.move_group(-1);
+        assert_eq!(app.group_cursor, 0);
+        assert_eq!(app.file_cursor, 1);
+    }
+
+    #[test]
+    fn move_file_clamps() {
+        let mut app = sample();
+        app.move_file(-1);
+        assert_eq!(app.file_cursor, 0);
+        app.move_file(10);
+        assert_eq!(app.file_cursor, 1);
+    }
+
+    #[test]
+    fn toggle_mark_blocks_marking_the_last_survivor() {
+        let mut app = sample();
+        app.group_cursor = 0;
+        app.file_cursor = 0;
+        app.toggle_mark();
+        assert!(app.groups[0].marked[0]);
+        app.file_cursor = 1;
+        app.toggle_mark();
+        assert!(!app.groups[0].marked[1]);
+    }
+
+    #[test]
+    fn toggle_mark_allows_unmark() {
+        let mut app = sample();
+        app.file_cursor = 0;
+        app.toggle_mark();
+        app.toggle_mark();
+        assert!(!app.groups[0].marked[0]);
+    }
+
+    #[test]
+    fn apply_strategy_current_group_marks_all_but_keeper() {
+        let mut app = sample();
+        app.group_cursor = 0;
+        app.apply_strategy(KeepStrategy::Newest, StrategyScope::CurrentGroup);
+        assert_eq!(app.groups[0].marked, vec![true, false]);
+        assert_eq!(app.groups[1].marked, vec![false, false, false]);
+    }
+
+    #[test]
+    fn apply_strategy_all_groups() {
+        let mut app = sample();
+        app.apply_strategy(KeepStrategy::Oldest, StrategyScope::AllGroups);
+        assert_eq!(app.groups[0].marked, vec![false, true]);
+        assert_eq!(app.groups[1].marked, vec![false, true, true]);
+    }
+
+    #[test]
+    fn totals_sum_marked_only() {
+        let mut app = sample();
+        app.apply_strategy(KeepStrategy::Newest, StrategyScope::AllGroups);
+        assert_eq!(app.marked_count(), 3);
+        assert_eq!(app.reclaimable_bytes(), 20);
+    }
+
+    #[test]
+    fn marked_paths_lists_marked_files() {
+        let mut app = sample();
+        app.group_cursor = 0;
+        app.file_cursor = 0;
+        app.toggle_mark();
+        assert_eq!(app.marked_paths(), vec![PathBuf::from("/a/x")]);
+    }
+
+    #[test]
+    fn apply_deletion_removes_files_and_drops_small_groups() {
+        let mut app = sample();
+        app.apply_deletion(&[PathBuf::from("/a/x")]);
+        assert_eq!(app.groups.len(), 1);
+        assert_eq!(app.groups[0].files.len(), 3);
+    }
+
+    #[test]
+    fn apply_deletion_emptying_everything_sets_quit() {
+        let mut app = App::from_groups(vec![group(vec![file("/a/x", 1, 1), file("/a/y", 1, 2)])]);
+        app.apply_deletion(&[PathBuf::from("/a/x")]);
+        assert!(app.groups.is_empty());
+        assert!(app.should_quit);
+    }
+
+    #[test]
+    fn handle_key_quits_on_q() {
+        let mut app = sample();
+        assert!(matches!(app.handle_key(Key::Char('q')), Outcome::Quit));
+        assert!(app.should_quit);
+    }
+
+    #[test]
+    fn handle_key_space_marks_in_files_focus() {
+        let mut app = sample();
+        app.focus = Focus::Files;
+        app.handle_key(Key::Space);
+        assert!(app.groups[0].marked[0]);
+    }
+
+    #[test]
+    fn handle_key_strategy_popup_apply_flow() {
+        let mut app = sample();
+        app.handle_key(Key::Char('S'));
+        assert!(matches!(app.popup, Popup::Strategy { .. }));
+        app.handle_key(Key::Enter);
+        assert!(matches!(app.popup, Popup::None));
+        assert_eq!(app.groups[0].marked, vec![true, false]);
+    }
+
+    #[test]
+    fn handle_key_delete_requires_marks_then_confirms() {
+        let mut app = sample();
+        app.handle_key(Key::Char('d'));
+        assert!(matches!(app.popup, Popup::None));
+        app.focus = Focus::Files;
+        app.handle_key(Key::Space);
+        app.handle_key(Key::Char('d'));
+        assert!(matches!(app.popup, Popup::ConfirmDelete));
+        assert!(matches!(app.handle_key(Key::Char('y')), Outcome::Delete));
+        assert!(matches!(app.popup, Popup::None));
+    }
+
+    #[test]
+    fn handle_key_open_returns_path() {
+        let mut app = sample();
+        app.focus = Focus::Files;
+        match app.handle_key(Key::Char('o')) {
+            Outcome::Open(p) => assert_eq!(p, PathBuf::from("/a/x")),
+            _ => panic!("expected Open"),
+        }
+    }
+}

src/tui/mod.rs

@@ -0,0 +1,129 @@
+pub mod app;
+mod ui;
+
+use std::io::{self, Stdout};
+
+use anyhow::Result;
+use ratatui::backend::CrosstermBackend;
+use ratatui::crossterm::event::{self, Event, KeyCode, KeyEvent, KeyEventKind};
+use ratatui::crossterm::execute;
+use ratatui::crossterm::terminal::{
+    disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen,
+};
+use ratatui::Terminal;
+
+use crate::params::Params;
+use crate::pipeline::DedupReport;
+use app::{App, Key, Outcome};
+
+type Tui = Terminal<CrosstermBackend<Stdout>>;
+
+pub fn run(report: DedupReport, params: &Params) -> Result<()> {
+    if report.groups.is_empty() {
+        println!("No duplicates found matching your search criteria.");
+        return Ok(());
+    }
+
+    let mut app = App::from_groups(report.groups);
+    let mut terminal = setup_terminal()?;
+    let result = event_loop(&mut terminal, &mut app, params);
+    restore_terminal(&mut terminal)?;
+    result
+}
+
+fn setup_terminal() -> Result<Tui> {
+    install_panic_hook();
+    enable_raw_mode()?;
+    let mut stdout = io::stdout();
+    execute!(stdout, EnterAlternateScreen)?;
+    Ok(Terminal::new(CrosstermBackend::new(stdout))?)
+}
+
+fn restore_terminal(terminal: &mut Tui) -> Result<()> {
+    let _ = disable_raw_mode();
+    let _ = execute!(terminal.backend_mut(), LeaveAlternateScreen);
+    let _ = terminal.show_cursor();
+    Ok(())
+}
+
+fn install_panic_hook() {
+    let original = std::panic::take_hook();
+    std::panic::set_hook(Box::new(move |info| {
+        let _ = disable_raw_mode();
+        let _ = execute!(io::stdout(), LeaveAlternateScreen);
+        original(info);
+    }));
+}
+
+fn event_loop(terminal: &mut Tui, app: &mut App, params: &Params) -> Result<()> {
+    loop {
+        terminal.draw(|frame| ui::draw(frame, app, params))?;
+        if app.should_quit {
+            break;
+        }
+
+        if let Event::Key(key) = event::read()? {
+            if key.kind != KeyEventKind::Press {
+                continue;
+            }
+            if let Some(translated) = translate(key) {
+                match app.handle_key(translated) {
+                    Outcome::Quit => {}
+                    Outcome::Continue => {}
+                    Outcome::Delete => perform_deletion(app),
+                    Outcome::Open(path) => {
+                        if let Err(err) = open::that(&path) {
+                            app.status = Some(format!("open failed: {err}"));
+                        }
+                    }
+                }
+            }
+        }
+
+        if app.should_quit {
+            break;
+        }
+    }
+    Ok(())
+}
+
+fn translate(key: KeyEvent) -> Option<Key> {
+    Some(match key.code {
+        KeyCode::Up => Key::Up,
+        KeyCode::Down => Key::Down,
+        KeyCode::Tab => Key::Tab,
+        KeyCode::Enter => Key::Enter,
+        KeyCode::Esc => Key::Esc,
+        KeyCode::Char(' ') => Key::Space,
+        KeyCode::Char(c) => Key::Char(c),
+        _ => return None,
+    })
+}
+
+fn perform_deletion(app: &mut App) {
+    let paths = app.marked_paths();
+    let mut deleted = Vec::new();
+    let mut freed: u64 = 0;
+    let mut failures: u64 = 0;
+
+    for path in &paths {
+        let size = std::fs::metadata(path).map(|m| m.len()).unwrap_or(0);
+        match std::fs::remove_file(path) {
+            Ok(_) => {
+                deleted.push(path.clone());
+                freed += size;
+            }
+            Err(_) => failures += 1,
+        }
+    }
+
+    app.apply_deletion(&deleted);
+    app.status = Some(match failures {
+        0 => format!("deleted {}, freed {}", deleted.len(), bytesize::ByteSize::b(freed)),
+        _ => format!(
+            "deleted {}, {failures} failed, freed {}",
+            deleted.len(),
+            bytesize::ByteSize::b(freed)
+        ),
+    });
+}

src/tui/ui.rs

@@ -0,0 +1,211 @@
+use ratatui::layout::{Constraint, Direction, Layout, Rect};
+use ratatui::style::Style;
+use ratatui::text::Line;
+use ratatui::widgets::{Block, Borders, Clear, List, ListItem, ListState, Paragraph};
+use ratatui::Frame;
+
+use crate::params::Params;
+use crate::formatter::Formatter;
+
+use super::app::{strategy_label, App, Focus, Popup, StrategyScope, STRATEGIES};
+
+pub fn draw(frame: &mut Frame, app: &App, params: &Params) {
+    let rows = Layout::default()
+        .direction(Direction::Vertical)
+        .constraints([Constraint::Min(1), Constraint::Length(1)])
+        .split(frame.area());
+
+    let panes = Layout::default()
+        .direction(Direction::Horizontal)
+        .constraints([Constraint::Percentage(35), Constraint::Percentage(65)])
+        .split(rows[0]);
+
+    draw_groups(frame, app, panes[0]);
+    draw_files(frame, app, params, panes[1]);
+    draw_footer(frame, app, rows[1]);
+
+    match app.popup {
+        Popup::Strategy { scope } => draw_strategy_popup(frame, app, scope),
+        Popup::ConfirmDelete => draw_confirm_popup(frame, app),
+        Popup::None => {}
+    }
+}
+
+fn pane_block(title: &str, focused: bool) -> Block<'_> {
+    let block = Block::default().borders(Borders::ALL).title(title.to_string());
+    match focused {
+        true => block.border_style(Style::new().yellow()),
+        false => block,
+    }
+}
+
+fn draw_groups(frame: &mut Frame, app: &App, area: Rect) {
+    let items: Vec<ListItem> = app
+        .groups
+        .iter()
+        .enumerate()
+        .map(|(i, g)| {
+            ListItem::new(format!(
+                "{:>3}  {} files  {}",
+                i + 1,
+                g.files.len(),
+                bytesize::ByteSize::b(g.size())
+            ))
+        })
+        .collect();
+
+    let list = List::new(items)
+        .block(pane_block("Groups", app.focus == Focus::Groups))
+        .highlight_style(Style::new().reversed());
+
+    let mut state = ListState::default();
+    state.select(Some(app.group_cursor));
+    frame.render_stateful_widget(list, area, &mut state);
+}
+
+fn draw_files(frame: &mut Frame, app: &App, params: &Params, area: Rect) {
+    let title = format!(
+        "Group {}/{}",
+        (app.group_cursor + 1).min(app.groups.len().max(1)),
+        app.groups.len()
+    );
+
+    let items: Vec<ListItem> = match app.groups.get(app.group_cursor) {
+        Some(g) => g
+            .files
+            .iter()
+            .enumerate()
+            .map(|(i, f)| {
+                let box_char = if g.marked[i] { "[x]" } else { "[ ]" };
+                let path = Formatter::human_path(f, params, 0).unwrap_or_default();
+                let size = Formatter::human_filesize(f).unwrap_or_default();
+                let mtime = Formatter::human_mtime(f).unwrap_or_default();
+                let line = format!("{box_char} {}  {}  {}", path.trim_end(), size.trim_start(), mtime);
+                match g.marked[i] {
+                    true => ListItem::new(Line::from(line).style(Style::new().red())),
+                    false => ListItem::new(line),
+                }
+            })
+            .collect(),
+        None => Vec::new(),
+    };
+
+    let list = List::new(items)
+        .block(pane_block(&title, app.focus == Focus::Files))
+        .highlight_style(Style::new().reversed());
+
+    let mut state = ListState::default();
+    state.select(Some(app.file_cursor));
+    frame.render_stateful_widget(list, area, &mut state);
+}
+
+fn draw_footer(frame: &mut Frame, app: &App, area: Rect) {
+    let hints = "[Tab]pane [Space]mark [s]group [S]all [o]pen [d]elete [q]uit";
+    let left = match &app.status {
+        Some(s) => s.clone(),
+        None => format!(
+            "marked {} · reclaim {}",
+            app.marked_count(),
+            bytesize::ByteSize::b(app.reclaimable_bytes())
+        ),
+    };
+    let text = format!("{left}   {hints}");
+    frame.render_widget(Paragraph::new(text), area);
+}
+
+fn centered_rect(width: u16, height: u16, area: Rect) -> Rect {
+    let x = area.x + area.width.saturating_sub(width) / 2;
+    let y = area.y + area.height.saturating_sub(height) / 2;
+    Rect {
+        x,
+        y,
+        width: width.min(area.width),
+        height: height.min(area.height),
+    }
+}
+
+fn draw_strategy_popup(frame: &mut Frame, app: &App, scope: StrategyScope) {
+    let title = match scope {
+        StrategyScope::CurrentGroup => "Keep in this group",
+        StrategyScope::AllGroups => "Keep in ALL groups",
+    };
+    let items: Vec<ListItem> = STRATEGIES
+        .iter()
+        .map(|s| ListItem::new(strategy_label(*s)))
+        .collect();
+
+    let area = centered_rect(28, (STRATEGIES.len() as u16) + 2, frame.area());
+    frame.render_widget(Clear, area);
+
+    let list = List::new(items)
+        .block(Block::default().borders(Borders::ALL).title(title))
+        .highlight_style(Style::new().reversed());
+
+    let mut state = ListState::default();
+    state.select(Some(app.strategy_cursor));
+    frame.render_stateful_widget(list, area, &mut state);
+}
+
+fn draw_confirm_popup(frame: &mut Frame, app: &App) {
+    let area = centered_rect(48, 3, frame.area());
+    frame.render_widget(Clear, area);
+    let text = format!(
+        "Delete {} files, reclaim {}? [y/N]",
+        app.marked_count(),
+        bytesize::ByteSize::b(app.reclaimable_bytes())
+    );
+    frame.render_widget(
+        Paragraph::new(text).block(Block::default().borders(Borders::ALL).title("Confirm")),
+        area,
+    );
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::fileinfo::FileInfo;
+    use crate::pipeline::DuplicateGroup;
+    use crate::tui::app::App;
+    use ratatui::backend::TestBackend;
+    use ratatui::Terminal;
+    use std::path::PathBuf;
+    use std::time::{Duration, UNIX_EPOCH};
+
+    fn sample_app() -> App {
+        let files = vec![
+            FileInfo {
+                path: PathBuf::from("/tmp/report.pdf").into_boxed_path(),
+                size: 4_000_000,
+                modified: UNIX_EPOCH + Duration::from_secs(1_700_000_000),
+            },
+            FileInfo {
+                path: PathBuf::from("/tmp/report-copy.pdf").into_boxed_path(),
+                size: 4_000_000,
+                modified: UNIX_EPOCH + Duration::from_secs(1_700_100_000),
+            },
+        ];
+        App::from_groups(vec![DuplicateGroup { hash: 0, files }])
+    }
+
+    #[test]
+    fn draw_renders_without_panic_and_shows_content() {
+        let app = sample_app();
+        let params = crate::params::Params::default();
+        let backend = TestBackend::new(100, 24);
+        let mut terminal = Terminal::new(backend).unwrap();
+
+        terminal.draw(|f| draw(f, &app, &params)).unwrap();
+
+        let text: String = terminal
+            .backend()
+            .buffer()
+            .content()
+            .iter()
+            .map(|cell| cell.symbol())
+            .collect();
+
+        assert!(text.contains("Groups"));
+        assert!(text.contains("report"));
+        assert!(text.contains("marked"));
+    }
+}