-- Copyright 2025 David Vazgenovich Shakaryan

local util = require('util')

local mp_utils = require('mp.utils')

local cacher = {}

local function wrap_func(obj, opts, func, func_name)
	return function(_, ...)
		local fn = table.concat({opts.prefix, func_name, ...}, '.')
		local path = mp_utils.join_path(opts.directory, fn)
		local f = mp_utils.file_info(path)
		local data

		if not f or os.time() - f.mtime > opts.time then
			data = func(obj, ...)
			if data then
				util.write_json_file(path, data)
			end
		end

		if f and not data then
			print('using cached ' .. fn)
			data = util.read_json_file(path)
		end

		return data
	end
end

function cacher.wrap(obj, opts)
	local proxy = {}

	setmetatable(proxy, {
		__index = function(t, k)
			local v = obj[k]
			if type(v) ~= 'function' or not opts.functions[k] then
				return v
			end

			local fn = wrap_func(obj, opts, v, k)
			t[k] = fn

			return fn
		end,
	})

	return proxy
end

return cacher