feat(cli): readline history

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
+    }
 }