Use $XDG_STATE_HOME to store history.db

Cargo.toml

@@ -19,7 +19,7 @@ debug = true
 chrono = "0.4"
 csv = "1"
 humantime = "2.1"
-directories-next = "2.0"
+etcetera = "0.8"
 itertools = "0.10"
 libc = "0.2"
 rand = "0.8"

README.md

@@ -341,7 +341,10 @@ Note that only single-character-prompts are allowed. setting `MCFLY_PROMPT` to `
 
 ### Database Location
 
-McFly stores its SQLite database in the standard location for the OS. On OS X, this is in `~/Library/Application Support/McFly` and on Linux it is in `$XDG_DATA_DIR/mcfly/history.db` (default would be `~/.local/share/mcfly/history.db`). For legacy support, if `~/.mcfly/` exists, it is used instead.
+McFly stores its SQLite database & cache according to the [`XDG Base Directory Specification`](https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html)
+i.e. in `$XDG_STATE_DIR/mcfly/history.db` (default would be `~/.local/state/mcfly/history.db`).
+For legacy support, if `~/.mcfly/history.db` or `$XDG_DATA_HOME/mcfly/history.db` or `~/Library/Application Support/McFly/history.db` (on macOS) exists,
+then it will automatically be migrated to the above location.
 
 ### Slow startup
 

src/history/history.rs

@@ -80,7 +80,7 @@ impl History {
         let history = if db_path.exists() {
             History::from_db_path(db_path)
         } else {
-            History::from_shell_history(history_format)
+            History::from_shell_history(db_path, history_format)
         };
         schema::migrate(&history.connection);
         history
@@ -755,8 +755,8 @@ impl History {
         }
     }
 
-    fn from_shell_history(history_format: HistoryFormat) -> History {
-        print!(
+    fn from_shell_history(mcfly_db_path: PathBuf, history_format: HistoryFormat) -> History {
+        println!(
             "McFly: Importing shell history for the first time. This may take a minute or two..."
         );
         io::stdout()
@@ -767,14 +767,11 @@ impl History {
         let commands =
             shell_history::full_history(&shell_history::history_file_path(), history_format);
 
-        // Use ~/.mcfly if it already exists, or create 'mcfly' folder in XDG_DATA_DIR
-        let mcfly_db_path = Settings::mcfly_db_path();
+        // Create 'mcfly' folder in XDG_STATE_DIR, if it doesn't exit
         let mcfly_db_dir = mcfly_db_path.parent().unwrap();
-
         fs::create_dir_all(mcfly_db_dir)
             .unwrap_or_else(|_| panic!("Unable to create {:?}", mcfly_db_dir));
 
-        // Make ~/.mcfly/history.db
         let mut connection = Connection::open(&mcfly_db_path)
             .unwrap_or_else(|_| panic!("Unable to create history DB at {:?}", &mcfly_db_path));
 

src/settings.rs

@@ -1,12 +1,13 @@
 use crate::cli::{Cli, SubCommand};
 use crate::shell_history;
 use clap::Parser;
-use directories_next::{ProjectDirs, UserDirs};
-use std::env;
-use std::path::PathBuf;
+use etcetera::base_strategy::Xdg;
+use etcetera::BaseStrategy;
+use std::path::{Path, PathBuf};
 use std::str::FromStr;
 use std::time::SystemTime;
 use std::time::UNIX_EPOCH;
+use std::{env, fs};
 
 #[derive(Debug)]
 pub enum Mode {
@@ -372,35 +373,56 @@ impl Settings {
         settings
     }
 
-    // Use ~/.mcfly only if it already exists, otherwise create 'mcfly' folder in XDG_CACHE_DIR
+    // Use or create the 'mcfly' folder in `$XDG_CACHE_DIR`
     pub fn mcfly_training_cache_path() -> PathBuf {
-        let cache_dir = Settings::mcfly_xdg_dir().cache_dir().to_path_buf();
-
-        Settings::mcfly_base_path(cache_dir).join(PathBuf::from("training-cache.v1.csv"))
+        Settings::xdg_base_strategy()
+            .cache_dir()
+            .join(PathBuf::from("mcfly/training-cache.v1.csv"))
     }
 
-    // Use ~/.mcfly only if it already exists, otherwise create 'mcfly' folder in XDG_DATA_DIR
+    // Use or migrate to the 'mcfly' folder in `$XDG_STATE_DIR`
     pub fn mcfly_db_path() -> PathBuf {
-        let data_dir = Settings::mcfly_xdg_dir().data_dir().to_path_buf();
-
-        Settings::mcfly_base_path(data_dir).join(PathBuf::from("history.db"))
-    }
-
-    fn mcfly_xdg_dir() -> ProjectDirs {
-        ProjectDirs::from("", "", "McFly").unwrap()
+        let basedirs = Settings::xdg_base_strategy();
+        let path = basedirs
+            .state_dir()
+            .unwrap()
+            .join(PathBuf::from("mcfly/history.db"));
+        if !path.exists() {
+            println!("McFly: history.db not found: `{}`", path.display());
+            let old = basedirs.data_dir().join(PathBuf::from("mcfly/history.db"));
+            if !Settings::migrate_old_path(old, &path) {
+                let old = basedirs.home_dir().join(PathBuf::from(".mcfly/history.db"));
+                if !Settings::migrate_old_path(old, &path) {
+                    #[cfg(target_os = "macos")]
+                    {
+                        let old = etcetera::base_strategy::Apple::new()
+                            .unwrap()
+                            .data_dir()
+                            .join(PathBuf::from("McFly/history.db"));
+                        Settings::migrate_old_path(old, &path);
+                    }
+                }
+            }
+        }
+        path
     }
 
-    fn mcfly_base_path(base_dir: PathBuf) -> PathBuf {
-        Settings::mcfly_dir_in_home().unwrap_or(base_dir)
+    fn xdg_base_strategy() -> impl BaseStrategy {
+        Xdg::new().unwrap()
     }
 
-    fn mcfly_dir_in_home() -> Option<PathBuf> {
-        let user_dirs_file = UserDirs::new()
-            .unwrap()
-            .home_dir()
-            .join(PathBuf::from(".mcfly"));
-
-        user_dirs_file.exists().then_some(user_dirs_file)
+    fn migrate_old_path(old: PathBuf, new: &Path) -> bool {
+        println!("McFly: Checking old history.db: `{}`", old.display());
+        let ret = old.exists();
+        if ret {
+            fs::create_dir_all(new.parent().unwrap()).unwrap();
+            fs::copy(&old, new).unwrap();
+            println!(
+                "McFly: history.db migrated.\nYou can now delete the old directory: `rm -r '{}'`",
+                old.parent().unwrap().display()
+            );
+        }
+        ret
     }
 }