feat: Correctly handle change of cwd automatically and via API

closes https://github.com/dmtrKovalenko/fff.nvim/issues/20

This allows to use

```
require('fff.main').find_files_in_dir('/Users/neogoose/dev/lightsource')
```

to change cwd and start the picker immediately to choose the file.

lua/fff/file_picker/image.lua

@@ -127,7 +127,7 @@ end
 function M.display_image_info(file_path, bufnr, reason)
   local info = {}
 
-  local stat = vim.loop.fs_stat(file_path)
+  local stat = vim.uv.fs_stat(file_path)
   if stat then
     table.insert(info, string.format('📁 File: %s', vim.fn.fnamemodify(file_path, ':t')))
     table.insert(info, string.format('📏 Size: %d bytes', stat.size))

lua/fff/file_picker/preview.lua

@@ -157,7 +157,7 @@ end
 --- @param file_path string Path to the file
 --- @return table File information
 function M.get_file_info(file_path)
-  local stat = vim.loop.fs_stat(file_path)
+  local stat = vim.uv.fs_stat(file_path)
   if not stat then return nil end
 
   local info = {
@@ -554,7 +554,7 @@ function M.preview(file_path, bufnr, file)
   M.state.current_file = file_path
   M.state.bufnr = bufnr
 
-  local stat = vim.loop.fs_stat(file_path)
+  local stat = vim.uv.fs_stat(file_path)
   if not stat then
     M.clear_buffer_completely(bufnr)
     safe_set_buffer_lines(bufnr, 0, -1, false, {

lua/fff/fuzzy.lua

@@ -15,6 +15,7 @@ M.get_keyword_range = rust_module.get_keyword_range
 M.guess_edit_range = rust_module.guess_edit_range
 M.get_words = rust_module.get_words
 M.init_file_picker = rust_module.init_file_picker
+M.restart_index_in_path = rust_module.restart_index_in_path
 M.scan_files = rust_module.scan_files
 M.get_cached_files = rust_module.get_cached_files
 M.fuzzy_search_files = rust_module.fuzzy_search_files

lua/fff/main.lua

@@ -126,7 +126,7 @@ function M.setup_global_file_tracking()
       if file_path and file_path ~= '' and not vim.startswith(file_path, 'term://') then
         -- never block the UI
         vim.schedule(function()
-          local stat = vim.loop.fs_stat(file_path)
+          local stat = vim.uv.fs_stat(file_path)
           if stat and stat.type == 'file' then
             local relative_path = vim.fn.fnamemodify(file_path, ':.')
             pcall(fuzzy.access_file, relative_path)
@@ -136,6 +136,26 @@ function M.setup_global_file_tracking()
     end,
     desc = 'Track file access for FFF frecency',
   })
+
+  -- make sure that this won't work correctly if autochdir plugins are enabled
+  -- using a pure :cd command but will work using lua api or :e command
+  vim.api.nvim_create_autocmd('DirChanged', {
+    group = group,
+    callback = function()
+      local new_cwd = vim.v.event.cwd
+      if M.is_initialized() and new_cwd and new_cwd ~= M.config.base_path then
+        vim.schedule(function()
+          local ok, err = pcall(M.change_indexing_directory, new_cwd)
+          if not ok then
+            vim.notify('FFF: Failed to change indexing directory: ' .. tostring(err), vim.log.levels.ERROR)
+          else
+            M.config.base_path = new_cwd
+          end
+        end)
+      end
+    end,
+    desc = 'Automatically sync FFF directory changes',
+  })
 end
 
 function M.setup_commands()
@@ -234,12 +254,7 @@ function M.find_in_git_root()
     return
   end
 
-  local picker_ok, picker_ui = pcall(require, 'fff.picker_ui')
-  if picker_ok then
-    picker_ui.open({ title = 'Git Files', cwd = git_root })
-  else
-    vim.notify('Failed to load picker UI', vim.log.levels.ERROR)
-  end
+  M.find_files_in_dir(git_root)
 end
 
 --- Trigger rescan of files in the current directory
@@ -331,76 +346,6 @@ function M.get_preview(file_path)
   return table.concat(lines, '\n')
 end
 
-function M.debug_file_ordering()
-  print('FFF Debug File Ordering')
-  print('=======================')
-
-  if not M.is_initialized() then
-    print('File picker not initialized. Run :FFFScan first.')
-    return
-  end
-
-  local picker = M.picker or M.core
-  print('Getting top 10 files with debug info...')
-
-  -- Enable debug mode temporarily
-  local old_debug = M.config.debug.show_scores
-  M.config.debug.show_scores = true
-
-  -- Search with empty query to get default ordering
-  local files = picker.search_files('', 10)
-
-  print('🏆 TOP FILES (in order they appear):')
-  print('=' .. string.rep('=', 70))
-
-  for i, file in ipairs(files) do
-    local frecency_stars = ''
-    if file.frecency_score > 0 then frecency_stars = ' ⭐' .. file.frecency_score end
-
-    -- Extract directory information
-    local dir = vim.fn.fnamemodify(file.relative_path, ':h')
-    local filename = vim.fn.fnamemodify(file.relative_path, ':t')
-    local dir_display = (dir == '.' or dir == '') and 'root' or dir
-
-    -- Get score information for this file
-    local score = picker.get_file_score(i)
-
-    print(string.format('%2d. %s%s', i, filename, frecency_stars))
-    print(string.format('    Path: %s/', dir_display))
-    print(string.format('    Debug: %s', score and score.match_type or 'no debug info'))
-    if score then
-      print(
-        string.format(
-          '    Total Score: %d (base=%d, name_bonus=%d, special_bonus=%d, frec=%d, dist=%d)',
-          score.total,
-          score.base_score,
-          score.filename_bonus,
-          score.special_filename_bonus,
-          score.frecency_boost,
-          score.distance_penalty
-        )
-      )
-    else
-      print('    Total Score: N/A (no score data)')
-    end
-
-    local now = os.time()
-    local age_hours = math.floor((now - file.modified) / 3600)
-    local age_days = math.floor(age_hours / 24)
-    print(string.format('    Age: %d hours (%d days) since last modified', age_hours, age_days))
-    print('')
-  end
-
-  print('💡 EXPLANATION:')
-  print('• Files are sorted by FRECENCY first (⭐ score), then by modification time')
-  print('• Frecency combines how often AND how recently you accessed files')
-  print('• The file at #1 has either:')
-  print('  - Highest frecency score, OR')
-  print('  - Same frecency as others but most recent modification')
-
-  M.config.debug.show_scores = old_debug
-end
-
 function M.health_check()
   local health = {
     ok = true,
@@ -460,4 +405,48 @@ end
 
 function M.is_initialized() return M.state and M.state.initialized or false end
 
+--- Find files in a specific directory
+--- @param directory string Directory path to search in
+function M.find_files_in_dir(directory)
+  if not directory then
+    vim.notify('Directory path required for find_files_in_dir', vim.log.levels.ERROR)
+    return
+  end
+
+  M.change_indexing_directory(directory)
+
+  local picker_ok, picker_ui = pcall(require, 'fff.picker_ui')
+  if picker_ok then
+    picker_ui.open({ title = 'Files in ' .. vim.fn.fnamemodify(directory, ':t') })
+  else
+    vim.notify('Failed to load picker UI', vim.log.levels.ERROR)
+  end
+end
+
+--- Change the base directory for the file picker
+--- @param new_path string New directory path to use as base
+--- @return boolean `true` if successful, `false` otherwise
+function M.change_indexing_directory(new_path)
+  if not new_path or new_path == '' then
+    vim.notify('Directory path is required', vim.log.levels.ERROR)
+    return false
+  end
+
+  local expanded_path = vim.fn.expand(new_path)
+
+  if vim.fn.isdirectory(expanded_path) ~= 1 then
+    vim.notify('Directory does not exist: ' .. expanded_path, vim.log.levels.ERROR)
+    return false
+  end
+
+  local ok, result = pcall(fuzzy.restart_index_in_path, expanded_path)
+  if not ok then
+    vim.notify('Failed to change directory: ' .. result, vim.log.levels.ERROR)
+    return false
+  end
+
+  M.config.base_path = expanded_path
+  return true
+end
+
 return M

lua/fff/picker_ui.lua

@@ -930,7 +930,6 @@ function M.scroll_preview_down()
   preview.scroll(scroll_lines)
 end
 
---- Select current item
 function M.select(action)
   if not M.state.active then return end
 
@@ -960,7 +959,6 @@ function M.select(action)
   end
 end
 
---- Close picker
 function M.close()
   if not M.state.active then return end
 

lua/fff/rust/lib.rs

@@ -46,6 +46,37 @@ pub fn init_file_picker(_: &Lua, base_path: String) -> LuaResult<bool> {
     Ok(true)
 }
 
+fn reinit_file_picker_internal(path: std::path::PathBuf) -> Result<(), Error> {
+    let mut file_picker = FILE_PICKER.write().map_err(|_| Error::AcquireItemLock)?;
+
+    // drop should clean it anyway but just to be extra sure
+    if let Some(picker) = file_picker.take() {
+        picker.stop_background_monitor();
+    }
+
+    let new_picker = FilePicker::new(path.to_string_lossy().to_string())?;
+    *file_picker = Some(new_picker);
+
+    Ok(())
+}
+
+pub fn restart_index_in_path(_: &Lua, new_path: String) -> LuaResult<bool> {
+    let path = std::path::PathBuf::from(&new_path);
+    if !path.exists() {
+        return Err(LuaError::RuntimeError(format!(
+            "Path does not exist: {}",
+            new_path
+        )));
+    }
+
+    let canonical_path = path.canonicalize().map_err(|e| {
+        LuaError::RuntimeError(format!("Failed to canonicalize path '{}': {}", new_path, e))
+    })?;
+
+    reinit_file_picker_internal(canonical_path)?;
+    Ok(true)
+}
+
 pub fn scan_files(_: &Lua, _: ()) -> LuaResult<()> {
     let file_picker = FILE_PICKER.read().map_err(|_| Error::AcquireItemLock)?;
     let picker = file_picker
@@ -163,6 +194,10 @@ fn create_exports(lua: &Lua) -> LuaResult<LuaTable> {
     exports.set("init_db", lua.create_function(init_db)?)?;
     exports.set("destroy_db", lua.create_function(destroy_db)?)?;
     exports.set("init_file_picker", lua.create_function(init_file_picker)?)?;
+    exports.set(
+        "restart_index_in_path",
+        lua.create_function(restart_index_in_path)?,
+    )?;
     exports.set("scan_files", lua.create_function(scan_files)?)?;
     exports.set("get_cached_files", lua.create_function(get_cached_files)?)?;
     exports.set(