fix(config): pick macOS db dir by database mtimes

src/config.rs

@@ -233,6 +233,11 @@ fn detect_db_dir_impl() -> Option<PathBuf> {
     let home = sudo_user_home_dir().or_else(dirs::home_dir)?;
 
     let base = home.join("Library/Containers/com.tencent.xinWeChat/Data/Documents/xwechat_files");
+    detect_db_dir_under(&base)
+}
+
+#[cfg(target_os = "macos")]
+fn detect_db_dir_under(base: &Path) -> Option<PathBuf> {
     if !base.exists() {
         return None;
     }
@@ -245,11 +250,7 @@ fn detect_db_dir_impl() -> Option<PathBuf> {
             }
         }
     }
-    candidates.sort_by_key(|p| {
-        std::fs::metadata(p)
-            .and_then(|m| m.modified())
-            .unwrap_or(std::time::SystemTime::UNIX_EPOCH)
-    });
+    candidates.sort_by_key(|p| latest_db_mtime(p).unwrap_or(std::time::SystemTime::UNIX_EPOCH));
     candidates.into_iter().next_back()
 }
 
@@ -284,7 +285,7 @@ fn detect_db_dir_impl() -> Option<PathBuf> {
     candidates.into_iter().next_back()
 }
 
-#[cfg(any(target_os = "linux", target_os = "windows"))]
+#[cfg(any(target_os = "macos", target_os = "linux", target_os = "windows"))]
 /// 递归查找 db_storage 目录下所有 .db 文件的最新 mtime
 fn latest_db_mtime(dir: &Path) -> Option<std::time::SystemTime> {
     let mut latest = None;
@@ -416,8 +417,8 @@ fn detect_db_dir_impl() -> Option<PathBuf> {
 #[cfg(test)]
 mod tests {
     use super::{
-        config_path_in_dir, default_config_path, find_existing_config_path, home_config_path,
-        resolve_cli_home,
+        config_path_in_dir, default_config_path, detect_db_dir_under, find_existing_config_path,
+        home_config_path, resolve_cli_home,
     };
     #[cfg(target_os = "windows")]
     use super::{known_documents_dir, resolve_windows_data_root};
@@ -480,6 +481,34 @@ mod tests {
         assert_eq!(path, cwd.join("config.json"));
     }
 
+    #[cfg(target_os = "macos")]
+    #[test]
+    fn auto_detect_db_dir_prefers_latest_db_file_mtime_over_directory_mtime() {
+        let home = temp_dir("macos-home");
+
+        let base = home.join("Library/Containers/com.tencent.xinWeChat/Data/Documents/xwechat_files");
+        let active_db_dir = base.join("wxid_active/db_storage");
+        let stale_db_dir = base.join("wxid_stale/db_storage");
+        let active_db_file = active_db_dir.join("message/session.db");
+        let stale_db_file = stale_db_dir.join("message/session.db");
+
+        fs::create_dir_all(active_db_file.parent().unwrap()).unwrap();
+        fs::write(&active_db_file, b"active").unwrap();
+        fs::create_dir_all(stale_db_file.parent().unwrap()).unwrap();
+        fs::write(&stale_db_file, b"stale").unwrap();
+        set_file_mtime(
+            &active_db_file,
+            SystemTime::now()
+                .checked_add(std::time::Duration::from_secs(3600))
+                .unwrap(),
+        );
+
+        let detected = detect_db_dir_under(&base).unwrap();
+        assert_eq!(detected, active_db_dir);
+
+        fs::remove_dir_all(home).unwrap();
+    }
+
     #[cfg(target_os = "windows")]
     #[test]
     fn resolve_windows_data_root_passes_through_absolute_path() {
@@ -499,4 +528,28 @@ mod tests {
             assert_eq!(resolved, docs, "keyword {keyword:?}");
         }
     }
+
+    #[cfg(unix)]
+    fn set_file_mtime(path: &std::path::Path, mtime: SystemTime) {
+        use std::ffi::CString;
+        use std::os::unix::ffi::OsStrExt;
+        use std::time::Duration;
+
+        let dur = mtime
+            .duration_since(UNIX_EPOCH)
+            .unwrap_or(Duration::from_secs(0));
+        let times = [
+            libc::timeval {
+                tv_sec: dur.as_secs() as libc::time_t,
+                tv_usec: dur.subsec_micros() as libc::suseconds_t,
+            },
+            libc::timeval {
+                tv_sec: dur.as_secs() as libc::time_t,
+                tv_usec: dur.subsec_micros() as libc::suseconds_t,
+            },
+        ];
+        let c_path = CString::new(path.as_os_str().as_bytes()).unwrap();
+        let rc = unsafe { libc::utimes(c_path.as_ptr(), times.as_ptr()) };
+        assert_eq!(rc, 0, "failed to update mtime for {}", path.display());
+    }
 }