feat: add remove TODO markup functionality

lua/todoer/init.lua

@@ -7,7 +7,7 @@ local defaults = {
 }
 
 -- Helper: Parses line details for a given line number (1-based)
--- Returns table: { line = str, indent = str, marker = str|nil, content = str, is_todo = bool } or nil
+-- Returns table: { line = str, indent = str, marker = str|nil, content = str, is_todo = bool, prefix_len = number } or nil
 local function get_line_details(lnum)
   -- Use nvim_buf_get_lines which is 0-indexed for ranges
   local lines = vim.api.nvim_buf_get_lines(0, lnum - 1, lnum, false)
@@ -22,19 +22,25 @@ local function get_line_details(lnum)
   -- Matches lines like: "- [ ] task", "* [x] task", "+ [ ] task"
   local todo_pattern = "^(%s*[%-%*%+]%s+)%[([ x])%]%s*" -- Capture prefix before checkbox
 
-  local _, marker_match, _ = string.match(line, marker_pattern)
+  local prefix_match, marker_match, space_match = string.match(line, marker_pattern)
   local is_todo = (string.match(line, todo_pattern) ~= nil)
   local content = ""
+  local prefix_len = 0 -- Length of the string before the content starts
 
   if is_todo then
     -- Content is everything after "[x] " or "[ ] " (including leading space)
+    local todo_prefix = string.match(line, todo_pattern) -- The part like "- [ ] "
     content = string.match(line, todo_pattern .. "(.*)") or ""
+    prefix_len = #todo_prefix
   elseif marker_match then
     -- Content is everything after "- " / "* " / "+ "
+    local list_prefix = prefix_match .. marker_match .. space_match -- The part like "- "
     content = string.match(line, marker_pattern .. "(.*)") or ""
+    prefix_len = #list_prefix
   else
     -- No list marker, just the trimmed line content
     content = vim.trim(line)
+    prefix_len = #indent -- Length before the trimmed content
   end
 
   return {
@@ -43,19 +49,21 @@ local function get_line_details(lnum)
     marker = marker_match, -- '-', '*', '+', or nil
     content = content,
     is_todo = is_todo,
+    prefix_len = prefix_len, -- Store the calculated prefix length
   }
 end
 
--- Helper: Gets details for the current line
+-- Helper: Gets details for the current line including cursor position
-local function get_current_line_details()
+local function get_current_line_details_with_cursor()
     local cursor_pos = vim.api.nvim_win_get_cursor(0)
     local lnum = cursor_pos[1] -- 1-based line number
-    return get_line_details(lnum), lnum
+    local col = cursor_pos[2] -- 0-based byte column
+    return get_line_details(lnum), lnum, col
 end
 
 -- <leader>ti: Convert line to TODO, cursor after "] " (Normal mode)
 local function add_todo_insert_mode()
-    local details, lnum = get_current_line_details()
+    local details, lnum = get_current_line_details_with_cursor() -- Use basic helper is fine
     -- Don't convert if already a TODO or if getting details failed
     if not details or details.is_todo then return end
 
@@ -74,7 +82,7 @@ end
 
 -- <leader>ta: Convert line to TODO, cursor at end of line (Normal mode)
 local function add_todo_append_mode()
-    local details, lnum = get_current_line_details()
+    local details, lnum = get_current_line_details_with_cursor() -- Use basic helper is fine
     if not details or details.is_todo then return end
 
     local use_marker = details.marker or "-"
@@ -92,7 +100,7 @@ end
 
 -- <leader>to: Insert new TODO line below, cursor after "] " (Normal mode)
 local function add_todo_new_line_mode()
-    local details, lnum = get_current_line_details()
+    local details, lnum = get_current_line_details_with_cursor() -- Use basic helper is fine
     if not details then return end -- Should not happen usually, but check anyway
 
     -- Determine indent and marker based on current line, default to '-' if no marker
@@ -109,11 +117,50 @@ local function add_todo_new_line_mode()
     vim.api.nvim_win_set_cursor(0, { lnum + 1, cursor_col_bytes })
 end
 
+-- <leader>td: Remove TODO markup from the current line (Normal mode)
+local function remove_todo_markup()
+    local details, lnum, original_col = get_current_line_details_with_cursor()
+    if not details or not details.is_todo then return end -- Only act on TODO lines
+
+    -- Construct the new line without the TODO markup "[ ] " or "[x] "
+    local new_line = details.indent .. details.marker .. " " .. details.content
+
+    -- Calculate the position where the markup started
+    -- This is the length of the indent + marker + one space
+    local markup_start_col = #(details.indent .. details.marker .. " ")
+
+    -- The markup itself is 4 characters: '[', ' ' or 'x', ']', ' '
+    local markup_len = 4
+
+    -- Update the line content
+    vim.api.nvim_buf_set_lines(0, lnum - 1, lnum, false, { new_line })
+
+    -- Calculate the new cursor column
+    local new_col
+    if original_col < markup_start_col then
+        -- Cursor was before the markup, keep its position
+        new_col = original_col
+    elseif original_col >= markup_start_col and original_col < markup_start_col + markup_len then
+        -- Cursor was inside the markup, move it to the start of where the markup was
+        new_col = markup_start_col
+    else
+        -- Cursor was after the markup, shift it left by the length of the removed markup
+        new_col = original_col - markup_len
+    end
+
+    -- Ensure the column is not negative (shouldn't happen here, but good practice)
+    new_col = math.max(0, new_col)
+
+    -- Set the new cursor position
+    vim.api.nvim_win_set_cursor(0, { lnum, new_col })
+end
+
+
 -- Internal function to set up buffer-local keymaps
 local function setup_buffer_keymaps()
 	-- Handles Enter key press in Insert mode
 	local function press_enter()
-        local details, lnum = get_current_line_details()
+        local details, lnum = get_current_line_details_with_cursor() -- Use basic helper is fine
         if not details then
             -- Getting details failed, do nothing and let Neovim handle Enter.
             return
@@ -259,6 +306,9 @@ local function setup_buffer_keymaps()
 	vim.keymap.set("n", "<leader>ti", add_todo_insert_mode, { desc = "Todoer: Add TODO (cursor after marker)", buffer = 0, silent = true })
 	vim.keymap.set("n", "<leader>ta", add_todo_append_mode, { desc = "Todoer: Add TODO (cursor at end)", buffer = 0, silent = true })
 	vim.keymap.set("n", "<leader>to", add_todo_new_line_mode, { desc = "Todoer: Add new TODO line below", buffer = 0, silent = true })
+    -- Mapping for removing TODO markup
+    vim.keymap.set("n", "<leader>td", remove_todo_markup, { desc = "Todoer: Remove TODO markup", buffer = 0, silent = true })
+
 
 	-- Optional: Notify that keymaps are set for this buffer
 	-- vim.notify("Todoer keymaps activated for this buffer", vim.log.levels.INFO)