1 files changed, 99 insertions, 0 deletions
diff --git a/src/ui.rs b/src/ui.rs
new file mode 100644
index 0000000..4d197bc
--- /dev/null
+++ b/src/ui.rs
@@ -0,0 +1,99 @@
+use crossterm::{
+    event::{self, Event, KeyCode},
+    terminal::{disable_raw_mode, enable_raw_mode, EnterAlternateScreen, LeaveAlternateScreen},
+    ExecutableCommand,
+};
+use nix::unistd::Pid;
+use ratatui::{prelude::*, widgets::*};
+use std::io::{self, stdout};
+
+struct UI {
+    height: usize,
+    max_lines: usize,
+    scroll: usize,
+}
+
+impl UI {
+    fn new() -> UI {
+        UI {
+            height: 0,
+            max_lines: 0,
+            scroll: 0,
+        }
+    }
+}
+
+fn handle_events(ui: &mut UI) -> io::Result<bool> {
+    if event::poll(std::time::Duration::from_millis(50))? {
+        if let Event::Key(key) = event::read()? {
+            if key.kind == event::KeyEventKind::Press {
+                match key.code {
+                    KeyCode::Char('q') => {
+                        return Ok(true);
+                    }
+                    KeyCode::Char('j') | KeyCode::Down => {
+                        if ui.scroll < (ui.max_lines - ui.height + 1) {
+                            ui.scroll += 1;
+                        }
+                    }
+                    KeyCode::Char('J') | KeyCode::Char('G') => {
+                        ui.scroll = ui.max_lines - ui.height + 1;
+                    }
+                    KeyCode::Char('k') | KeyCode::Up => {
+                        if ui.scroll > 1 {
+                            ui.scroll -= 1;
+                        }
+                    }
+                    KeyCode::Char('K') | KeyCode::Char('0') => {
+                        ui.scroll = ui.height;
+                    }
+                    _ => {}
+                }
+            }
+        }
+    }
+    Ok(false)
+}
+
+pub fn run_tui(pid: Pid, lines: &str) -> anyhow::Result<()> {
+    enable_raw_mode()?;
+    stdout().execute(EnterAlternateScreen)?;
+    let mut terminal = Terminal::new(CrosstermBackend::new(stdout()))?;
+
+    let mut ui = UI::new();
+    ui.max_lines = lines.split('\n').count() + 1;
+
+    let mut should_quit = false;
+    while !should_quit {
+        ui.height = terminal.get_frame().size().height as usize;
+        terminal.draw(move |frame| {
+            let size = frame.size();
+            frame.render_widget(
+                Paragraph::new(lines)
+                    .block(
+                        Block::default()
+                            .border_style(Style::default().fg(Color::Yellow))
+                            .title(format!("[{pid}]"))
+                            .title(
+                                block::Title::from(format!(
+                                    "[lines {}-{}]",
+                                    ui.scroll,
+                                    ui.scroll + ui.height
+                                ))
+                                .position(block::Position::Bottom)
+                                .alignment(Alignment::Right),
+                            )
+                            .borders(Borders::ALL),
+                    )
+                    .scroll((ui.scroll as u16, 0)),
+                size,
+            );
+        })?;
+        should_quit = handle_events(&mut ui)?;
+    }
+
+    disable_raw_mode()?;
+    stdout().execute(LeaveAlternateScreen)?;
+
+    Ok(())
+}