feat: add toggle checkbox

home/deepak/neovim/init-vim.nix

@@ -270,5 +270,6 @@
 
   ${builtins.readFile ./lualine.lua}
 
+  ${builtins.readFile ./toggle-checkboxes.lua}
   EOF
 ''

home/deepak/neovim/toggle-checkbox.lua

@@ -0,0 +1,71 @@
+-- stolen from https://github.com/opdavies/toggle-checkbox.nvim/blob/main/lua/toggle-checkbox.lua
+-- Just copying the code because I don't want to import it as a dependency
+
+local checked_character = "x"
+
+local checked_checkbox = "%[" .. checked_character .. "%]"
+local unchecked_checkbox = "%[ %]"
+
+local line_contains_unchecked = function(line)
+	return line:find(unchecked_checkbox)
+end
+
+local line_contains_checked = function(line)
+	return line:find(checked_checkbox)
+end
+
+local line_with_checkbox = function(line)
+	-- return not line_contains_a_checked_checkbox(line) and not line_contains_an_unchecked_checkbox(line)
+	return line:find("^%s*- " .. checked_checkbox)
+		or line:find("^%s*- " .. unchecked_checkbox)
+		or line:find("^%s*%d%. " .. checked_checkbox)
+		or line:find("^%s*%d%. " .. unchecked_checkbox)
+end
+
+local checkbox = {
+	check = function(line)
+		return line:gsub(unchecked_checkbox, checked_checkbox, 1)
+	end,
+
+	uncheck = function(line)
+		return line:gsub(checked_checkbox, unchecked_checkbox, 1)
+	end,
+
+	make_checkbox = function(line)
+		if not line:match("^%s*-%s.*$") and not line:match("^%s*%d%s.*$") then
+			-- "xxx" -> "- [ ] xxx"
+			return line:gsub("(%S+)", "- [ ] %1", 1)
+		else
+			-- "- xxx" -> "- [ ] xxx", "3. xxx" -> "3. [ ] xxx"
+			return line:gsub("(%s*- )(.*)", "%1[ ] %2", 1):gsub("(%s*%d%. )(.*)", "%1[ ] %2", 1)
+		end
+	end,
+}
+
+local M = {}
+
+M.toggle = function()
+	local bufnr = vim.api.nvim_buf_get_number(0)
+	local cursor = vim.api.nvim_win_get_cursor(0)
+	local start_line = cursor[1] - 1
+	local current_line = vim.api.nvim_buf_get_lines(bufnr, start_line, start_line + 1, false)[1] or ""
+
+	-- If the line contains a checked checkbox then uncheck it.
+	-- Otherwise, if it contains an unchecked checkbox, check it.
+	local new_line = ""
+
+	if not line_with_checkbox(current_line) then
+		new_line = checkbox.make_checkbox(current_line)
+	elseif line_contains_unchecked(current_line) then
+		new_line = checkbox.check(current_line)
+	elseif line_contains_checked(current_line) then
+		new_line = checkbox.uncheck(current_line)
+	end
+
+	vim.api.nvim_buf_set_lines(bufnr, start_line, start_line + 1, false, { new_line })
+	vim.api.nvim_win_set_cursor(0, cursor)
+end
+
+vim.api.nvim_create_user_command("ToggleCheckbox", M.toggle, {})
+
+return M