Add toggle curl feature

Fixes #40

---

For more details, open the [Copilot Workspace session](https://copilot-workspace.githubnext.com/oysandvik94/curl.nvim/issues/40?shareId=XXXX-XXXX-XXXX-XXXX).

lua/curl/api.lua

@@ -142,4 +142,33 @@ M.set_curl_binary = function(binary_name)
 	config.set("curl_binary", binary_name)
 end
 
+M.toggle_curl_tab = function()
+	if M.is_curl_tab_open() then
+		M.close_curl_tab()
+	else
+		M.open_curl_tab()
+	end
+end
+
+M.toggle_global_curl_tab = function()
+	if M.is_curl_tab_open() then
+		M.close_curl_tab()
+	else
+		M.open_global_tab()
+	end
+end
+
+M.is_curl_tab_open = function()
+	for _, tab in ipairs(vim.api.nvim_list_tabpages()) do
+		local success, tab_id = pcall(function()
+			return vim.api.nvim_tabpage_get_var(tab, "id")
+		end)
+
+		if success and tab_id == "curl.nvim.tab" then
+			return true
+		end
+	end
+	return false
+end
+
 return M

lua/curl/init.lua

@@ -81,9 +81,20 @@ local create_filetype = function()
 	})
 end
 
+local create_curl_toggle = function()
+	vim.api.nvim_create_user_command("CurlToggle", function()
+		api.toggle_curl_tab()
+	end, { desc = "Toggle curl tab" })
+
+	vim.api.nvim_create_user_command("CurlToggleGlobal", function()
+		api.toggle_global_curl_tab()
+	end, { desc = "Toggle global curl tab" })
+end
+
 function M.setup(opts)
 	create_curl_open()
 	create_curl_pick()
+	create_curl_toggle()
 
 	create_filetype()
 

tests/api_spec.lua

@@ -64,4 +64,30 @@ describe("Api", function()
 		local new_bufname = vim.api.nvim_buf_get_name(0)
 		assert(new_bufname:find("global") == nil, "Buffer should be closed")
 	end)
+
+	it("can toggle curl tab", function()
+		api.toggle_curl_tab()
+		assert(api.is_curl_tab_open(), "Curl tab should be open")
+
+		api.toggle_curl_tab()
+		assert(not api.is_curl_tab_open(), "Curl tab should be closed")
+	end)
+
+	it("can toggle global curl tab", function()
+		api.toggle_global_curl_tab()
+		assert(api.is_curl_tab_open(), "Global curl tab should be open")
+
+		api.toggle_global_curl_tab()
+		assert(not api.is_curl_tab_open(), "Global curl tab should be closed")
+	end)
+
+	it("can check if curl tab is open", function()
+		assert(not api.is_curl_tab_open(), "Curl tab should be closed initially")
+
+		api.open_curl_tab()
+		assert(api.is_curl_tab_open(), "Curl tab should be open")
+
+		api.close_curl_tab()
+		assert(not api.is_curl_tab_open(), "Curl tab should be closed")
+	end)
 end)