Almost done with list display

src/term.rs

@@ -2,10 +2,58 @@ use std::io::{self, BufRead, StdoutLock, Write};
 
 use crossterm::{
     cursor::MoveTo,
+    style::{Color, ResetColor, SetForegroundColor},
     terminal::{Clear, ClearType},
     QueueableCommand,
 };
 
+/// Terminal progress bar to be used when not using Ratataui.
+pub fn progress_bar(
+    stdout: &mut StdoutLock,
+    progress: u16,
+    total: u16,
+    line_width: u16,
+) -> io::Result<()> {
+    debug_assert!(progress <= total);
+
+    const PREFIX: &[u8] = b"Progress: [";
+    const PREFIX_WIDTH: u16 = PREFIX.len() as u16;
+    // Leaving the last char empty (_) for `total` > 99.
+    const POSTFIX_WIDTH: u16 = "] xxx/xx exercises_".len() as u16;
+    const WRAPPER_WIDTH: u16 = PREFIX_WIDTH + POSTFIX_WIDTH;
+    const MIN_LINE_WIDTH: u16 = WRAPPER_WIDTH + 4;
+
+    if line_width < MIN_LINE_WIDTH {
+        return write!(stdout, "Progress: {progress}/{total} exercises");
+    }
+
+    stdout.write_all(PREFIX)?;
+
+    let width = line_width - WRAPPER_WIDTH;
+    let filled = (width * progress) / total;
+
+    stdout.queue(SetForegroundColor(Color::Green))?;
+    for _ in 0..filled {
+        stdout.write_all(b"#")?;
+    }
+
+    if filled < width {
+        stdout.write_all(b">")?;
+    }
+
+    let width_minus_filled = width - filled;
+    if width_minus_filled > 1 {
+        let red_part_width = width_minus_filled - 1;
+        stdout.queue(SetForegroundColor(Color::Red))?;
+        for _ in 0..red_part_width {
+            stdout.write_all(b"-")?;
+        }
+    }
+
+    stdout.queue(ResetColor)?;
+    write!(stdout, "] {progress:>3}/{total} exercises")
+}
+
 pub fn clear_terminal(stdout: &mut StdoutLock) -> io::Result<()> {
     stdout
         .queue(MoveTo(0, 0))?