feat: add working prototype

lua/lualine/components/harpoon.lua

@@ -0,0 +1,49 @@
+local ok, harpoon = pcall(require, "harpoon")
+local Path = require("plenary.path")
+local function normalize_path(buf_name, root)
+	return Path:new(buf_name):make_relative(root)
+end
+
+--- [TODO:description]
+---@return table {current}
+local function get_status()
+	if not ok then
+		return { current = nil, total = 0 }
+	end
+
+	local list = harpoon:list()
+	local total = list:length()
+
+	local bufname = normalize_path(vim.api.nvim_buf_get_name(0), list.config.get_root_dir())
+	local _, idx = list:get_by_value(bufname)
+	if type(idx) ~= "number" or idx < 1 or idx > total then
+		return { current = nil, total = total }
+	end
+	return { current = idx, total = total }
+end
+
+--- Draw function called by lualine
+---@return string
+local function draw()
+	local st = get_status()
+	if st.total == 0 then
+		return ""
+	end
+	local idx = st.current and tostring(st.current) or "?"
+	return string.format("[%s/%d]", idx, st.total)
+end
+
+--- Only show when there is at least one mark
+---@return boolean
+local function cond()
+	return get_status().total > 0
+end
+
+return function(opts)
+	return draw()
+	-- return {
+	-- 	draw = draw,
+	-- 	cond = opts.cond or cond,
+	-- 	color = opts.color or { fg = "#89b4fa", gui = "bold" },
+	-- }
+end