feat: initial nuwiki Rust workspace (core, lsp, ls)

crates/nuwiki-lsp/src/wiki.rs

@@ -0,0 +1,80 @@
+//! `Wiki` aggregate — per-wiki state, even when there's only one.
+//!
+//! The single `Arc<RwLock<WorkspaceIndex>>` on `Backend` is lifted into a
+//! `Wiki` aggregate so multi-wiki support only changes config shape, not
+//! data flow. Handlers always operate on a `Wiki`; in practice the `wikis`
+//! `Vec` has one entry until multi-wiki support lands.
+
+use std::path::Path;
+use std::sync::{Arc, RwLock};
+
+use tower_lsp::lsp_types::Url;
+
+use crate::config::WikiConfig;
+use crate::index::WorkspaceIndex;
+
+#[derive(Debug, Clone, Copy, Eq, PartialEq, Hash, Default)]
+pub struct WikiId(pub u32);
+
+#[derive(Clone)]
+pub struct Wiki {
+    pub id: WikiId,
+    // `Arc` so cloning a `Wiki` (done on every handler entry that picks a
+    // wiki out of the list) is a refcount bump, not a deep copy of the whole
+    // config — color_dic, templates, header strings, and so on.
+    pub config: Arc<WikiConfig>,
+    pub index: Arc<RwLock<WorkspaceIndex>>,
+}
+
+impl Wiki {
+    pub fn new(id: WikiId, config: WikiConfig) -> Self {
+        let index = WorkspaceIndex::new(Some(config.root.clone()))
+            .with_diary_rel_path(Some(config.diary_rel_path.clone()))
+            .with_file_extension(Some(config.file_extension.clone()));
+        let index = Arc::new(RwLock::new(index));
+        Self {
+            id,
+            config: Arc::new(config),
+            index,
+        }
+    }
+
+    /// True when `uri` resolves to a file under this wiki's root.
+    pub fn contains(&self, uri: &Url) -> bool {
+        let Ok(path) = uri.to_file_path() else {
+            return false;
+        };
+        path.starts_with(&self.config.root)
+    }
+
+    /// Length of the wiki's root path (component count) — used to break
+    /// ties in nested-root layouts.
+    pub fn root_depth(&self) -> usize {
+        self.config.root.components().count()
+    }
+
+    pub fn root(&self) -> &Path {
+        &self.config.root
+    }
+}
+
+/// Pick the wiki whose root is the longest prefix of `uri`. Returns the
+/// wiki id, not a guard, so callers can release the read lock before
+/// awaiting.
+pub fn resolve_uri_to_wiki(wikis: &[Wiki], uri: &Url) -> Option<WikiId> {
+    wikis
+        .iter()
+        .filter(|w| w.contains(uri))
+        .max_by_key(|w| w.root_depth())
+        .map(|w| w.id)
+}
+
+/// Build the initial `Vec<Wiki>` from a list of `WikiConfig`s. Always
+/// assigns ids by position so `WikiId(0)` is the default wiki.
+pub fn build_wikis(configs: &[WikiConfig]) -> Vec<Wiki> {
+    configs
+        .iter()
+        .enumerate()
+        .map(|(i, cfg)| Wiki::new(WikiId(i as u32), cfg.clone()))
+        .collect()
+}