5 files changed, 19 insertions, 32 deletions
diff --git a/lua/muwiki/config.lua b/lua/muwiki/config.lua
index d9b6661..2a89427 100644
--- a/lua/muwiki/config.lua
+++ b/lua/muwiki/config.lua
@@ -52,7 +52,8 @@ function M.setup(opts)
   end
 end
 
-function M.get_wiki_path(name)
+-- Lookup wiki path by name (e.g., "default" -> "~/wiki/")
+function M.wiki_path(name)
   if not M.options.dirs or #M.options.dirs == 0 then
     vim.notify('MuWiki: No dirs configured. See :help muwiki-configuration', vim.log.levels.ERROR)
     return nil
@@ -70,40 +71,26 @@ function M.get_wiki_path(name)
   return M.options.dirs[1].path
 end
 
-function M.get_wiki_root_for_file(filepath)
-  if not M.options.dirs or #M.options.dirs == 0 then
-    return nil
+-- Find which wiki contains this buffer's file (cached per-buffer)
+function M.wiki_root(bufnr)
+  bufnr = bufnr or 0
+
+  if vim.b[bufnr].muwiki_root ~= nil then
+    return vim.b[bufnr].muwiki_root or nil
   end
 
-  local normalized_path = vim.fs.normalize(filepath)
+  local filepath = vim.api.nvim_buf_get_name(bufnr)
+  local normalized = vim.fs.normalize(filepath)
 
-  for _, dir in ipairs(M.options.dirs) do
-    if vim.startswith(normalized_path, dir.path) then
+  for _, dir in ipairs(M.options.dirs or {}) do
+    if vim.startswith(normalized, dir.path) then
+      vim.b[bufnr].muwiki_root = dir.path
       return dir.path
     end
   end
 
+  vim.b[bufnr].muwiki_root = false
   return nil
 end
 
-function M.get_wiki_root_for_buffer(bufnr)
-  bufnr = bufnr or 0
-  local ok, cached = pcall(vim.api.nvim_buf_get_var, bufnr, 'muwiki_root')
-  if ok then
-    return cached
-  end
-
-  local root = M.get_wiki_root_for_file(vim.api.nvim_buf_get_name(bufnr))
-  if root then
-    pcall(vim.api.nvim_buf_set_var, bufnr, 'muwiki_root', root)
-  end
-  return root
-end
-
-function M.is_wiki_buffer(bufnr)
-  bufnr = bufnr or 0
-  return vim.bo[bufnr].filetype == 'markdown'
-    and M.get_wiki_root_for_buffer(bufnr) ~= nil
-end
-
 return M
diff --git a/lua/muwiki/files.lua b/lua/muwiki/files.lua
index 851feb4..6ec2bc2 100644
--- a/lua/muwiki/files.lua
+++ b/lua/muwiki/files.lua
@@ -26,7 +26,7 @@ function M.open_external(url)
 end
 
 function M.open_index(name)
-  local wiki_path = config.get_wiki_path(name)
+  local wiki_path = config.wiki_path(name)
   if not wiki_path then
     return
   end
@@ -70,7 +70,7 @@ function M.open_wiki_file(filepath)
   local exists = fs.file_exists(filepath)
 
   if not exists and config.options.create_missing_dirs then
-    local wiki_root = config.get_wiki_root_for_file(vim.api.nvim_buf_get_name(0))
+    local wiki_root = config.wiki_root(0)
     if wiki_root then
       local mode = config.options.create_missing_dirs
 
diff --git a/lua/muwiki/init.lua b/lua/muwiki/init.lua
index 6dc088f..a898c88 100644
--- a/lua/muwiki/init.lua
+++ b/lua/muwiki/init.lua
@@ -4,7 +4,7 @@ local M = {}
 local config = require('muwiki.config')
 
 local function wiki_buffer()
-  return config.is_wiki_buffer(0)
+  return config.wiki_root(0) ~= nil
 end
 
 M.setup = function(opts)
diff --git a/lua/muwiki/links/creation.lua b/lua/muwiki/links/creation.lua
index 0b31b10..81c45a6 100644
--- a/lua/muwiki/links/creation.lua
+++ b/lua/muwiki/links/creation.lua
@@ -52,7 +52,7 @@ function M.create_link()
   vim.api.nvim_buf_set_text(0, start_row, start_col, end_row, end_col, { link_text })
   vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes('<Esc>', true, false, true), 'n', false)
 
-  local wiki_root = config.get_wiki_root_for_file(vim.api.nvim_buf_get_name(0))
+  local wiki_root = config.wiki_root(0)
   if not wiki_root then
     vim.notify('Not in a wiki buffer', vim.log.levels.ERROR)
     return
diff --git a/lua/muwiki/links/open.lua b/lua/muwiki/links/open.lua
index 5afec53..c8a1233 100644
--- a/lua/muwiki/links/open.lua
+++ b/lua/muwiki/links/open.lua
@@ -7,7 +7,7 @@ local url_handlers = require('muwiki.links.url_handlers')
 local M = {}
 
 local function get_wiki_root_or_notify()
-  local wiki_root = config.get_wiki_root_for_buffer(0)
+  local wiki_root = config.wiki_root(0)
   if not wiki_root then
     vim.notify('Not in a wiki buffer', vim.log.levels.ERROR)
     return nil