reveal.lua

local revealed_cache = {}


local function item_has_groups(item_groups, groups)
	for i = 1, #groups do
		local group = groups[i]
		if not item_groups[group] then
			return
		end
	end
	return true
end


local function revealed_show_recipe(recipe, playername)
	if not revealed_cache[playername] then
		revealed_cache[playername] = {}
	end
	if revealed_cache[playername][recipe] then
		return true
	end

  local reg_items = minetest.registered_items
	local revealed = doc.data.players[playername].stored_data.revealed
	for _, item in pairs(recipe.items) do
		local is_revealed_item = false
		if item:sub(1,6) == "group:" then
			local groups = item:sub(7):split(",")
			for cid, items in pairs(revealed) do
				for revealed_item in pairs(items) do
					if reg_items[revealed_item] and item_has_groups(reg_items[revealed_item].groups, groups) then
						is_revealed_item = true
						break
					end
				end
				if is_revealed_item then
					break
				end
			end
		else
			for cid, items in pairs(revealed) do
				if items[item] then
					is_revealed_item = true
					break
				end
			end
		end

		if not is_revealed_item then
			return false
		end
	end
	revealed_cache[playername][recipe] = true
	return true
end


local orig_get_usages = sfcg.get_usages
function sfcg.get_usages(data, item)
  local recipes = orig_get_usages(data, item)
  if not recipes then
    return
  end

  local filtered = {}
  for _, recipe in ipairs(recipes) do
    if revealed_show_recipe(recipe, data.playername) then
      table.insert(filtered, recipe)
    end
  end
  if #filtered > 0 then
    return filtered
  end
end


local orig_get_recipes = sfcg.get_recipes
function sfcg.get_recipes(data, item)
  local recipes = orig_get_recipes(data, item)
  if not recipes then
    return
  end

  local filtered = {}
  for _, recipe in ipairs(recipes) do
    if revealed_show_recipe(recipe, data.playername) then
      table.insert(filtered, recipe)
    end
  end
  if #filtered > 0 then
    return filtered
  end
end


local orig_execute_search = sfcg.execute_search
function sfcg.execute_search(data)
  -- Only needed if doc is an optional dependency
  --
  -- if not doc.data.players[data.playername] then
  -- 	-- Hack. craftguide is loaded before doc mod. Therefore doc is not initialized yet
  -- 	data.items = {}
  -- 	minetest.after(0, sfcg.execute_search, data)
  -- 	return
  -- end

  orig_execute_search(data)

  local filtered_items = {}
  for _, item in ipairs(data.items) do
    if sfcg.get_usages(data, item) or
        sfcg.get_recipes(data, item) then
      table.insert(filtered_items, item)
    end
  end
  data.items = filtered_items
end

-- Update sfinv inventory once in globalstep, if something revealed
local async_update_users = {}
local function async_update()
  for playername, _ in pairs(async_update_users) do
    sfcg.update_for_player(playername)
    async_update_users[playername] = nil
  end
end


local orig_mark_entry_as_revealed = doc.mark_entry_as_revealed
function doc.mark_entry_as_revealed(playername, category_id, entry_id)
  -- Temp Fix: `doc.entry_revealed()` crashes on some items like farming:* because they're given the wrong category_id
  -- if not doc.entry_revealed(playername, category_id, entry_id) then
    orig_mark_entry_as_revealed(playername, category_id, entry_id)
    if not next(async_update_users) then
      minetest.after(0, async_update)
      async_update_users[playername] = true
    end
  -- end
end


minetest.register_on_leaveplayer(function(player)
	revealed_cache[player:get_player_name()] = nil
end)