Complete Gotcha issue CLI workflow

crates/cli/src/main.rs

@@ -169,20 +169,30 @@ fn print_user(user: &User) {
 }
 
 fn print_repositories(repositories: &[Repository]) {
-    println!("REPOSITORY\tVISIBILITY\tUPDATED\tDESCRIPTION");
-    for repository in repositories {
-        println!(
-            "{}\t{}\t{}\t{}",
-            repository.full_name.as_deref().unwrap_or("unknown"),
-            if repository.private.unwrap_or(false) {
-                "private"
-            } else {
-                "public"
-            },
-            repository.updated_at.as_deref().unwrap_or("-"),
-            repository.description.as_deref().unwrap_or("")
-        );
-    }
+    print_table(
+        &[
+            ("REPOSITORY", 40),
+            ("VISIBILITY", 10),
+            ("UPDATED", 25),
+            ("DESCRIPTION", 60),
+        ],
+        repositories
+            .iter()
+            .map(|repository| {
+                vec![
+                    repository.full_name.as_deref().unwrap_or("unknown").into(),
+                    if repository.private.unwrap_or(false) {
+                        "private"
+                    } else {
+                        "public"
+                    }
+                    .into(),
+                    repository.updated_at.as_deref().unwrap_or("-").into(),
+                    repository.description.as_deref().unwrap_or("").into(),
+                ]
+            })
+            .collect(),
+    );
 }
 
 fn print_repository(repository: &Repository) {
@@ -216,6 +226,93 @@ fn print_json(value: &Value) -> Result<(), serde_json::Error> {
     Ok(())
 }
 
+fn print_table(columns: &[(&str, usize)], rows: Vec<Vec<String>>) {
+    println!("{}", format_table(columns, &rows, terminal_width()));
+}
+
+fn format_table(columns: &[(&str, usize)], rows: &[Vec<String>], width: usize) -> String {
+    let minimums = columns
+        .iter()
+        .map(|(header, _)| header.chars().count())
+        .collect::<Vec<_>>();
+    let mut widths = minimums.clone();
+    for (column, (_, maximum)) in columns.iter().enumerate() {
+        widths[column] = rows
+            .iter()
+            .filter_map(|row| row.get(column))
+            .map(|value| value.chars().count())
+            .max()
+            .unwrap_or_default()
+            .max(widths[column])
+            .min(*maximum);
+    }
+    let separator_width = columns.len().saturating_sub(1) * 2;
+    while widths.iter().sum::<usize>() + separator_width > width {
+        let Some(column) = widths
+            .iter()
+            .zip(&minimums)
+            .enumerate()
+            .filter(|(_, (current, minimum))| current > minimum)
+            .max_by_key(|(_, (current, minimum))| *current - *minimum)
+            .map(|(column, _)| column)
+        else {
+            break;
+        };
+        widths[column] -= 1;
+    }
+
+    let mut lines = Vec::with_capacity(rows.len() + 2);
+    lines.push(table_row(
+        &columns
+            .iter()
+            .map(|(header, _)| (*header).to_owned())
+            .collect::<Vec<_>>(),
+        &widths,
+    ));
+    lines.push(
+        widths
+            .iter()
+            .map(|width| "-".repeat(*width))
+            .collect::<Vec<_>>()
+            .join("  "),
+    );
+    lines.extend(rows.iter().map(|row| table_row(row, &widths)));
+    lines.join("\n")
+}
+
+fn table_row(values: &[String], widths: &[usize]) -> String {
+    values
+        .iter()
+        .zip(widths)
+        .map(|(value, width)| table_cell(value, *width))
+        .collect::<Vec<_>>()
+        .join("  ")
+        .trim_end()
+        .to_owned()
+}
+
+fn table_cell(value: &str, width: usize) -> String {
+    let value = value.lines().next().unwrap_or_default();
+    let length = value.chars().count();
+    if length <= width {
+        return format!("{value}{}", " ".repeat(width - length));
+    }
+    let mut shortened = value
+        .chars()
+        .take(width.saturating_sub(1))
+        .collect::<String>();
+    shortened.push('…');
+    shortened
+}
+
+fn terminal_width() -> usize {
+    env::var("COLUMNS")
+        .ok()
+        .and_then(|value| value.parse().ok())
+        .filter(|width| *width >= 40)
+        .unwrap_or(100)
+}
+
 fn requested_help(command: &[String]) -> Result<Option<&'static str>, String> {
     match command {
         [] => Ok(Some(ROOT_HELP)),
@@ -393,4 +490,23 @@ mod tests {
                 .starts_with("Usage: gotcha repo show")
         );
     }
+
+    #[test]
+    fn formats_bounded_aligned_tables_without_tabs() {
+        let table = format_table(
+            &[("INDEX", 8), ("STATE", 10), ("TITLE", 60)],
+            &[vec![
+                "22".into(),
+                "open".into(),
+                "A deliberately long issue title that must be shortened".into(),
+            ]],
+            40,
+        );
+
+        assert!(!table.contains('\t'));
+        assert!(table.contains('…'));
+        assert_eq!(table.lines().count(), 3);
+        assert!(table.lines().all(|line| line.chars().count() <= 40));
+        assert!(table.lines().next().unwrap().starts_with("INDEX  STATE"));
+    }
 }