From 9b75cb6144cf50ed9750a8bcf4689cb218df375b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kha=C3=AFs=20COLIN?= <khais.colin@gmail.com>
Date: Sat, 10 May 2025 10:20:26 +0200
Subject: [PATCH] feat(cli): readline history

---
 notes.org   | 12 ++++++------
 src/cli.rs  | 45 +++++++++++++++++++++++++++++++++++++++++++--
 src/main.rs | 10 +++++++++-
 3 files changed, 58 insertions(+), 9 deletions(-)

diff --git a/notes.org b/notes.org
index 6db9d88..3286ee1 100644
--- a/notes.org
+++ b/notes.org
@@ -189,24 +189,24 @@ CLOCK: [2025-05-04 dim. 14:01]--[2025-05-04 dim. 14:14] =>  0:13
 
 * DONE remove old FromStr parser implementation
 
-* TODO use a better readline impl
+* DONE use a better readline impl
 
 ** DONE inform myself on the different alternatives and decide on one
 i will use rustyline, since it seems like the most feature-complete
 
 ** DONE do the impl
 
-** TODO make history work
+** DONE make history work
 
 *** DONE have the rl instance be spawned from main
 
-*** TODO figure out how to locate the app data directory on linux
+*** DONE figure out how to locate the app data directory on linux
 
-*** TODO create our own app data directory
+*** DONE create our own app data directory
 
-*** TODO load and save the history from a file in this directory
+*** DONE load and save the history from a file in this directory
 
-* TODO handle non-interactive input better
+* DONE handle non-interactive input better
 
 * TODO cli tests using insta-cmd
 https://insta.rs/docs/cmd/
diff --git a/src/cli.rs b/src/cli.rs
index e44b26f..4aa33d0 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -1,5 +1,46 @@
-use rustyline::{Editor, history::FileHistory};
+use std::path::PathBuf;
+
+use rustyline::{history::FileHistory, Editor};
+
+fn xdg_state_dir() -> Option<PathBuf> {
+    if let Ok(dir) = std::env::var("XDG_STATE_DIR") {
+        Some(PathBuf::from(dir))
+    } else if let Ok(home) = std::env::var("HOME") {
+        if home.is_empty() {
+            None
+        } else {
+            Some(PathBuf::from(home).join(".local/state"))
+        }
+    } else {
+        None
+    }
+}
+
+fn state_dir() -> Option<PathBuf> {
+    if let Some(dir) = xdg_state_dir() {
+        let dir = dir.join("osdb");
+        std::fs::create_dir_all(&dir).ok()?;
+        Some(dir)
+    } else {
+        None
+    }
+}
+
+pub fn history_file() -> Option<std::path::PathBuf> {
+    if let Some(state) = state_dir() {
+        Some(state.join("cli_history"))
+    } else {
+        eprintln!("Warning: failed to find or create XDG_STATE_DIR for osdb.");
+        eprintln!("Warning: either set XDG_STATE_DIR or HOME, and ensure osdb has write permissions to that directory.");
+        None
+    }
+}
 
 pub fn read_input(rl: &mut Editor<(), FileHistory>) -> Option<String> {
-    rl.readline("osdb> ").ok()
+    if let Ok(result) = rl.readline("osdb> ") {
+        let _ = rl.add_history_entry(&result);
+        Some(result)
+    } else {
+        None
+    }
 }
diff --git a/src/main.rs b/src/main.rs
index 6691c8f..9085a97 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,10 +1,14 @@
 use osdb::branding::startup_msg;
-use osdb::cli::read_input;
+use osdb::cli::{history_file, read_input};
 use osdb::error_display::OSDBError as _;
 use osdb::parser::parse;
 
 fn main() {
     let mut rl = rustyline::DefaultEditor::new().expect("failed to create stdin reader");
+    let history_file = history_file();
+    if let Some(history_file) = &history_file {
+        let _ = rl.load_history(history_file);
+    }
 
     println!("{}", startup_msg());
 
@@ -29,5 +33,9 @@ fn main() {
         }
     }
 
+    if let Some(history_file) = &history_file {
+        let _ = rl.save_history(history_file);
+    }
+
     println!("Good-bye");
 }