add --reverse to history list (#1252)

* wip: add --reverse to history list

* fix: remove print_list being called twice when reverse=true

* chore: update documentation

* feat: Avoid unneeded reverse by iterate forward or backward instead

* feat: Make sure to only iterate once and avoid unneeded reverse call

* feat: It used to be reverse by default. So make it default true here to be backwards compatible

* fix clap

---------

Co-authored-by: Dieter Eickstädt <eickstaedt@deicon.de>

3 files changed, 24 insertions, 5 deletions

diff --git a/atuin/src/command/client/history.rs b/atuin/src/command/client/history.rs
index 3ca6dc4c..6189d05a 100644
--- a/atuin/src/command/client/history.rs
+++ b/atuin/src/command/client/history.rs
@@ -51,6 +51,13 @@ pub enum Cmd {
         #[arg(long)]
         cmd_only: bool,
 
+        #[arg(long, short, default_value = "true")]
+        // accept no value
+        #[arg(num_args(0..=1), default_missing_value("true"))]
+        // accept a value
+        #[arg(action = clap::ArgAction::Set)]
+        reverse: bool,
+
         /// Available variables: {command}, {directory}, {duration}, {user}, {host}, {exit} and {time}.
         /// Example: --format "{time} - [{duration}] - {directory}$\t{command}"
         #[arg(long, short)]
@@ -93,7 +100,7 @@ impl ListMode {
 }
 
 #[allow(clippy::cast_sign_loss)]
-pub fn print_list(h: &[History], list_mode: ListMode, format: Option<&str>) {
+pub fn print_list(h: &[History], list_mode: ListMode, format: Option<&str>, reverse: bool) {
     let w = std::io::stdout();
     let mut w = w.lock();
 
@@ -113,7 +120,13 @@ pub fn print_list(h: &[History], list_mode: ListMode, format: Option<&str>) {
         ListMode::CmdOnly => std::iter::once(ParseSegment::Key("command")).collect(),
     };
 
-    for h in h.iter().rev() {
+    let iterator = if reverse {
+        Box::new(h.iter().rev()) as Box<dyn Iterator<Item = &History>>
+    } else {
+        Box::new(h.iter()) as Box<dyn Iterator<Item = &History>>
+    };
+
+    for h in iterator {
         match writeln!(w, "{}", parsed_fmt.with_args(&FmtHistory(h))) {
             Ok(()) => {}
             // ignore broken pipe (issue #626)
@@ -266,6 +279,7 @@ impl Cmd {
         Ok(())
     }
 
+    #[allow(clippy::too_many_arguments)]
     async fn handle_list(
         db: &mut impl Database,
         settings: &Settings,
@@ -274,6 +288,7 @@ impl Cmd {
         cwd: bool,
         mode: ListMode,
         format: Option<String>,
+        reverse: bool,
     ) -> Result<()> {
         let session = if session {
             Some(env::var("ATUIN_SESSION")?)
@@ -304,7 +319,7 @@ impl Cmd {
             }
         };
 
-        print_list(&history, mode, format.as_deref());
+        print_list(&history, mode, format.as_deref(), reverse);
 
         Ok(())
     }
@@ -320,10 +335,12 @@ impl Cmd {
                 cwd,
                 human,
                 cmd_only,
+                reverse,
                 format,
             } => {
                 let mode = ListMode::from_flags(human, cmd_only);
-                Self::handle_list(db, settings, context, session, cwd, mode, format).await
+                let reverse = reverse;
+                Self::handle_list(db, settings, context, session, cwd, mode, format, reverse).await
             }
 
             Self::Last {
@@ -337,6 +354,7 @@ impl Cmd {
                     last,
                     ListMode::from_flags(human, cmd_only),
                     format.as_deref(),
+                    true,
                 );
 
                 Ok(())
diff --git a/atuin/src/command/client/search.rs b/atuin/src/command/client/search.rs
index bdfa30bd..fd0a2e27 100644
--- a/atuin/src/command/client/search.rs
+++ b/atuin/src/command/client/search.rs
@@ -169,7 +169,7 @@ impl Cmd {
                             .await?;
                 }
             } else {
-                super::history::print_list(&entries, list_mode, self.format.as_deref());
+                super::history::print_list(&entries, list_mode, self.format.as_deref(), true);
             }
         };
         Ok(())
diff --git a/docs/docs/commands/list.md b/docs/docs/commands/list.md
index c48d9d0a..4d4f2a97 100644
--- a/docs/docs/commands/list.md
+++ b/docs/docs/commands/list.md
@@ -11,6 +11,7 @@ title: Listing History
 | `--session`/`-s` | Enable listing history for the current session only (default: false)          |
 | `--human`        | Use human-readable formatting for the timestamp and duration (default: false) |
 | `--cmd-only`     | Show only the text of the command (default: false)                            |
+| `--reverse`      | Reverse the order of the output (default: false)                              |
 | `--format`       | Specify the formatting of a command (see below)                               |
 
 ## Format