feat: add todo list

2 files changed, 137 insertions, 0 deletions

diff --git a/lua/muwiki/init.lua b/lua/muwiki/init.lua
index f9d8f23..f9f7187 100644
--- a/lua/muwiki/init.lua
+++ b/lua/muwiki/init.lua
@@ -12,5 +12,6 @@ M.get_link = function() return require('muwiki.links').get_link() end
 M.open_with_menu = function(handlers, link) require('muwiki.links').open_with_menu(handlers, link) end
 M.open_index = function(name) require('muwiki.utils').open_index(name) end
 M.wiki_root = function(bufnr) return require('muwiki.utils').wiki_root(bufnr) end
+M.toggle_checkbox = function() require('muwiki.todo').toggle_checkbox() end
 
 return M
diff --git a/lua/muwiki/todo.lua b/lua/muwiki/todo.lua
new file mode 100644
index 0000000..6978c54
--- /dev/null
+++ b/lua/muwiki/todo.lua
@@ -0,0 +1,136 @@
+local M = {}
+
+---Toggle checkbox at cursor position and all children
+-- Uses treesitter to find markdown list items with checkboxes
+function M.toggle_checkbox()
+  local bufnr = vim.api.nvim_get_current_buf()
+  local cursor = vim.api.nvim_win_get_cursor(0)
+  local cursor_row = cursor[1] - 1 -- 0-indexed
+  local cursor_col = cursor[2]
+
+  -- Get markdown parser
+  local ok, parser = pcall(vim.treesitter.get_parser, bufnr, 'markdown')
+  if not ok or not parser then
+    vim.notify('Markdown parser not available', vim.log.levels.WARN)
+    return
+  end
+
+  -- Parse and get tree
+  local trees = parser:parse()
+  if not trees or #trees == 0 then
+    return
+  end
+
+  local tree = trees[1]
+  local root = tree:root()
+
+  -- Find list_item node at cursor position
+  local target_node = nil
+  for node in root:iter_children() do
+    if node:range() then
+      local start_row, start_col, end_row, end_col = node:range()
+      -- end_row is exclusive, so use < not <=
+      if cursor_row >= start_row and cursor_row < end_row then
+        -- Check if this is a list_item or contains one
+        target_node = M.find_list_item_at(node, cursor_row, cursor_col)
+        if target_node then
+          break
+        end
+      end
+    end
+  end
+
+  if not target_node then
+    return
+  end
+
+  -- Toggle the target and its children
+  local new_state = M.toggle_list_item(bufnr, target_node)
+  if new_state then
+    M.toggle_children(bufnr, target_node, new_state)
+  end
+end
+
+---Find list_item node containing cursor position
+-- Searches children first to return the deepest matching node
+function M.find_list_item_at(node, cursor_row, cursor_col)
+  -- Check children first to find the deepest match
+  for child in node:iter_children() do
+    local result = M.find_list_item_at(child, cursor_row, cursor_col)
+    if result then
+      return result
+    end
+  end
+
+  -- Then check this node
+  if node:type() == 'list_item' then
+    local start_row, start_col, end_row, end_col = node:range()
+    -- end_row is exclusive, so use < not <=
+    if cursor_row >= start_row and cursor_row < end_row then
+      return node
+    end
+  end
+
+  return nil
+end
+
+---Toggle a single list item's checkbox
+-- Returns the new state ('x' or ' ') or nil if not a task
+function M.toggle_list_item(bufnr, node)
+  -- Find task_list_marker
+  for child in node:iter_children() do
+    local child_type = child:type()
+    if child_type == 'task_list_marker_unchecked' then
+      -- Replace [ ] with [x]
+      local start_row, start_col, end_row, end_col = child:range()
+      vim.api.nvim_buf_set_text(bufnr, start_row, start_col, end_row, end_col, { '[x]' })
+      return 'x'
+    elseif child_type == 'task_list_marker_checked' then
+      -- Replace [x] with [ ]
+      local start_row, start_col, end_row, end_col = child:range()
+      vim.api.nvim_buf_set_text(bufnr, start_row, start_col, end_row, end_col, { '[ ]' })
+      return ' '
+    end
+  end
+
+  return nil
+end
+
+---Toggle all child list items to match parent state
+function M.toggle_children(bufnr, parent_node, target_state)
+  -- Find nested list
+  for child in parent_node:iter_children() do
+    if child:type() == 'list' then
+      -- Iterate through list_items in the nested list
+      for list_item in child:iter_children() do
+        if list_item:type() == 'list_item' then
+          -- Force this child to target state
+          M.force_list_item_state(bufnr, list_item, target_state)
+          -- Recursively handle grandchildren
+          M.toggle_children(bufnr, list_item, target_state)
+        end
+      end
+      break
+    end
+  end
+end
+
+---Force a list item to specific state without toggling
+function M.force_list_item_state(bufnr, node, target_state)
+  for child in node:iter_children() do
+    local child_type = child:type()
+    if child_type == 'task_list_marker_unchecked' and target_state == 'x' then
+      -- Need to check it
+      local start_row, start_col, end_row, end_col = child:range()
+      vim.api.nvim_buf_set_text(bufnr, start_row, start_col, end_row, end_col, { '[x]' })
+      return
+    elseif child_type == 'task_list_marker_checked' and target_state == ' ' then
+      -- Need to uncheck it
+      local start_row, start_col, end_row, end_col = child:range()
+      vim.api.nvim_buf_set_text(bufnr, start_row, start_col, end_row, end_col, { '[ ]' })
+      return
+    end
+  end
+end
+
+return M