Module:Navigation by countries

-- =============================================================================
-- Prepare a list of countries for the inclusion into a category description
-- template.
-- =============================================================================

local langSwitch           = require "Module:LangSwitch"
local wdStatements         = require "Module:Wikidata statements"
local navbox               = require "Module:Navbox"
local navigationByWikidata = require "Module:Navigation by Wikidata"

local p = {}

-- -----------------------------------------------------------------------------
-- Main routine
-- -----------------------------------------------------------------------------

function p.navigationBlock(frame)
	-- Compare the "Country" property of the Wikidata item with itself to find
	-- out whether it actually is a country. If it isn't, just return nothing.
	if wdStatements.getOneItemId(frame.args.item, "P17") ~= frame.args.item then
		return nil
	end
	-- Find out the user's language.
	local lang = frame:callParserFunction("int", "lang")
	-- Loop through all continents this country is located in. For each of them,
	-- build a Navbox subgroup:
	local result = ""
	for index, continentId in ipairs(wdStatements.getItemIdList(frame.args.item, "P30")) do
		-- First, add the name of the continent as a title of the subgroup.
		result = result .. "; " .. navigationByWikidata._getLink(continentId, frame.args.pattern, frame.args.the, false) or mw.wikibase.getLabel(continentId) .. "\n"
		-- Next, load the submodule of Module:Countries with the country list.
		local module = "Module:Countries/" .. mw.wikibase.getLabelByLang(continentId, "en")
		local status, data = pcall(require, module)
		assert(status, "Data could not be loaded from [[" .. module .."]]")
		-- Now, build the Navbox subgroup:
		local boxargs = {
			border = "subgroup"
		}
		-- Iterate through the various secions in the country list and create a
		-- Navbox group for each of them:
		local count = 1
		for index, section in ipairs{"main", "specific", "limited", "other"} do
			-- Not all sections exist in all continents.
			if data.titles[section] then
				-- Find out the group title for the user's language.
				boxargs["group" .. tostring(count)] = langSwitch._langSwitch(data.titles[section], lang)
				-- Let "Module:Navigation by Wikidata" do the actual hard work
				-- of compiling the link list:
				local listargs = {
					sort = "label",
					pattern = frame.args.pattern,
					the = frame.args.the,
					redlinks = frame.args.redlinks
				}
				-- Convert the data list from the Countries submodule into a
				-- simple list of Wikidata item IDs, possibly augmented with a
				-- marker.
				for code in data.lists[section].automatic:gmatch('%S+') do
					local info = data.countries[code]
					table.insert(listargs, info.qid .. (info.mark and ":after=⁽¹⁾" or ""))
				end
				-- Actually run the "Module:Navigation by Wikidata" magic.
				boxargs["list" .. tostring(count)] = navigationByWikidata._navigationList(listargs)
				count = count + 1
			end
		end
		-- As a separate group at the end of the Navbox subgroup, add an
		-- explanation for the markers.
		boxargs["group" .. tostring(count)] = ""
		boxargs["list" .. tostring(count)] = "* " .. "⁽¹⁾ " .. langSwitch._langSwitch(data.titles["partly"], lang)
		-- Actually build the Navbox subgroup.
		result = result .. navbox._navbox(boxargs) .. "\n" 
	end
	return result
end

return p