-- states/journal.lua — quests, lore, bestiary, knowledge, research, tutorials.
--
-- Two axes move independently: the tab (left/right) and the entry within it
-- (up/down). Both must be announced, and the tab header must lead when it
-- changes, since "Quests" and "Bestiary" list very different things.
--
-- Uses getAnyUpvalue because activeTabIndex, options and selectedOption are
-- touched by different functions here (gotoTab, refreshOptions, keypressed).

local lastTab

return {
	read = function(stateTable, menus)
		local tabIndex = menus.getAnyUpvalue(stateTable, "activeTabIndex")
		local tabsList = menus.getAnyUpvalue(stateTable, "tabsList")
		local options = menus.getAnyUpvalue(stateTable, "options")
		local selected = menus.getAnyUpvalue(stateTable, "selectedOption")

		if type(tabIndex) ~= "number" or type(tabsList) ~= "table" then
			return nil, nil
		end

		local tab = tabsList[tabIndex]
		local tabName = tab and tab.header or ("tab " .. tabIndex)

		local parts = {}

		-- Lead with the tab only when it just changed, so stepping through a long
		-- quest list doesn't repeat "Quests" on every line.
		if tabIndex ~= lastTab then
			lastTab = tabIndex
			parts[#parts + 1] = tabName
		end

		if type(options) == "table" and type(selected) == "number" and options[selected] then
			local entry = options[selected]
			parts[#parts + 1] = entry.title or entry.header or entry.name or "?"
			parts[#parts + 1] = selected .. " of " .. #options
		elseif type(options) == "table" and #options == 0 then
			parts[#parts + 1] = "empty"
		end

		if #parts == 0 then
			return nil, nil
		end

		return table.concat(parts, ", "),
			tostring(tabIndex) .. ":" .. tostring(selected) .. ":" .. tostring(options and #options)
	end,
}