1 files changed, 132 insertions, 0 deletions
diff --git a/src/client/shell/preferences.rs b/src/client/shell/preferences.rs
new file mode 100644
index 00000000..dc6cc1ac
--- /dev/null
+++ b/src/client/shell/preferences.rs
@@ -0,0 +1,132 @@
+use std::{
+    path::{Path, PathBuf},
+    sync::atomic::{AtomicU64, Ordering},
+};
+
+static NEXT_TEMP_FILE: AtomicU64 = AtomicU64::new(1);
+
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Debug, Default, Deserialize, Serialize)]
+pub(super) struct ClientChromePreferences {
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub(super) sidebar_width: Option<u16>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub(super) sidebar_section_split: Option<f32>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub(super) sidebar_collapsed: Option<bool>,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub(super) agent_panel_sort: Option<crate::config::AgentPanelSortConfig>,
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub(super) collapsed_groups: Vec<String>,
+}
+
+pub(super) fn path_for_local_endpoint(socket_path: &Path) -> PathBuf {
+    let mut hash = 0xcbf29ce484222325u64;
+    for byte in socket_path.to_string_lossy().as_bytes() {
+        hash ^= u64::from(*byte);
+        hash = hash.wrapping_mul(0x100000001b3);
+    }
+    crate::config::state_dir()
+        .join("client-shell")
+        .join(format!("local-{hash:016x}.json"))
+}
+
+pub(super) fn load(path: &Path) -> Option<ClientChromePreferences> {
+    let content = std::fs::read_to_string(path).ok()?;
+    serde_json::from_str(&content).ok()
+}
+
+pub(super) fn store(path: &Path, preferences: ClientChromePreferences) -> Result<(), String> {
+    let parent = path
+        .parent()
+        .ok_or_else(|| format!("invalid client shell state path: {}", path.display()))?;
+    std::fs::create_dir_all(parent)
+        .map_err(|error| format!("failed to create client shell state directory: {error}"))?;
+    let content = serde_json::to_vec_pretty(&preferences)
+        .map_err(|error| format!("failed to encode client shell state: {error}"))?;
+    let sequence = NEXT_TEMP_FILE.fetch_add(1, Ordering::Relaxed);
+    let mut temp_name = path
+        .file_name()
+        .ok_or_else(|| format!("invalid client shell state path: {}", path.display()))?
+        .to_os_string();
+    temp_name.push(format!(".tmp-{}-{sequence}", std::process::id()));
+    let temp_path = parent.join(temp_name);
+    std::fs::write(&temp_path, content)
+        .map_err(|error| format!("failed to write client shell state: {error}"))?;
+    crate::platform::replace_file(&temp_path, path).map_err(|error| {
+        let _ = std::fs::remove_file(&temp_path);
+        format!("failed to replace client shell state: {error}")
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn endpoint_paths_are_stable_and_distinct() {
+        let first = path_for_local_endpoint(Path::new("/run/herdr/one.sock"));
+        let again = path_for_local_endpoint(Path::new("/run/herdr/one.sock"));
+        let second = path_for_local_endpoint(Path::new("/run/herdr/two.sock"));
+        assert_eq!(first, again);
+        assert_ne!(first, second);
+    }
+
+    #[test]
+    fn concurrent_stores_leave_complete_preferences() {
+        let path = std::env::temp_dir().join(format!(
+            "herdr-shell-concurrent-preferences-{}.json",
+            std::process::id()
+        ));
+        let _ = std::fs::remove_file(&path);
+        let writers = (20..28)
+            .map(|width| {
+                let path = path.clone();
+                std::thread::spawn(move || {
+                    store(
+                        &path,
+                        ClientChromePreferences {
+                            sidebar_width: Some(width),
+                            ..ClientChromePreferences::default()
+                        },
+                    )
+                })
+            })
+            .collect::<Vec<_>>();
+        for writer in writers {
+            writer.join().expect("preference writer").expect("store");
+        }
+        assert!(load(&path)
+            .and_then(|saved| saved.sidebar_width)
+            .is_some_and(|width| (20..28).contains(&width)));
+        std::fs::remove_file(path).expect("remove preferences");
+    }
+
+    #[test]
+    fn repeated_store_replaces_existing_preferences() {
+        let path = std::env::temp_dir().join(format!(
+            "herdr-shell-preferences-{}.json",
+            std::process::id()
+        ));
+        let _ = std::fs::remove_file(&path);
+        store(
+            &path,
+            ClientChromePreferences {
+                sidebar_width: Some(24),
+                ..ClientChromePreferences::default()
+            },
+        )
+        .expect("first preference store");
+        store(
+            &path,
+            ClientChromePreferences {
+                sidebar_width: Some(32),
+                ..ClientChromePreferences::default()
+            },
+        )
+        .expect("replacement preference store");
+        assert_eq!(load(&path).and_then(|saved| saved.sidebar_width), Some(32));
+        std::fs::remove_file(path).expect("remove preferences");
+    }
+}