Hosta

p = {}

function p.main(frame)
	if frame.args.item == nil then
		return "no item given"
	elseif mw.wikibase.entityExists(frame.args.item) == nil then
		return "not a valid item"
	end
	
	local coordtable = {}
	local usecoordy = nil
	local usecoordx = nil
	local cminy = nil
	local cmaxy = nil
	local closetag = nil
	local i = 0
	-- if far east, west, north, south
	if mw.wikibase.getBestStatements(frame.args.item, "P1334")[1] and mw.wikibase.getBestStatements(frame.args.item, "P1334")[1].mainsnak.datavalue and
	mw.wikibase.getBestStatements(frame.args.item, "P1335")[1] and mw.wikibase.getBestStatements(frame.args.item, "P1335")[1].mainsnak.datavalue and
	mw.wikibase.getBestStatements(frame.args.item, "P1332")[1] and mw.wikibase.getBestStatements(frame.args.item, "P1332")[1].mainsnak.datavalue and
	mw.wikibase.getBestStatements(frame.args.item, "P1333")[1] and mw.wikibase.getBestStatements(frame.args.item, "P1333")[1].mainsnak.datavalue then
		-- getting locations of farthest points in each direction in the area
		local statementa = mw.wikibase.getBestStatements(frame.args.item, "P1334")[1].mainsnak
		table.insert(coordtable, statementa.datavalue.value.longitude)
	
		local statementb = mw.wikibase.getBestStatements(frame.args.item, "P1335")[1].mainsnak
		table.insert(coordtable, statementb.datavalue.value.longitude)
	
		local statementc = mw.wikibase.getBestStatements(frame.args.item, "P1332")[1].mainsnak
		table.insert(coordtable, statementc.datavalue.value.latitude)
	
		local statementd = mw.wikibase.getBestStatements(frame.args.item, "P1333")[1].mainsnak
		table.insert(coordtable, statementd.datavalue.value.latitude)
	
		-- figuring out the center position of the map, but also used for zoom levels
		local cminx = math.min(tonumber(coordtable[1]), tonumber(coordtable[2]))
		local sizex = math.max(tonumber(coordtable[1]), tonumber(coordtable[2])) - cminx
		usecoordx = tonumber(cminx + (sizex / 2))
	
		cminy = math.min(tonumber(coordtable[3]), tonumber(coordtable[4]))
		cmaxy = math.max(tonumber(coordtable[3]), tonumber(coordtable[4]))
		local sizey = cmaxy - cminy
		usecoordy = tonumber(cminy + (sizey / 2))
	
		-- Zoom level: each zoom level is half of the previous zoom level, with the highest being 360 degress (full circle)
		local x = 360
		while math.max(sizex, sizey) < x do
			x = x / 2
			i = i + 1
		end
	-- if either central coordinate or basic coordinate along with instance of
	elseif mw.wikibase.getBestStatements(frame.args.item, "P31")[1] and mw.wikibase.getBestStatements(frame.args.item, "P31")[1].mainsnak.datavalue then
		if mw.wikibase.getBestStatements(frame.args.item, "P15140")[1] and mw.wikibase.getBestStatements(frame.args.item, "P15140")[1].mainsnak.datavalue then
			local statementa = mw.wikibase.getBestStatements(frame.args.item, "P15140")[1].mainsnak
			usecoordx = statementa.datavalue.value.longitude
			usecoordy = statementa.datavalue.value.latitude
			cminy = tonumber(usecoordy)
			cmaxy = tonumber(usecoordy)
		elseif mw.wikibase.getBestStatements(frame.args.item, "P625")[1] and mw.wikibase.getBestStatements(frame.args.item, "P625")[1].mainsnak.datavalue then
			local statementa = mw.wikibase.getBestStatements(frame.args.item, "P625")[1].mainsnak
			usecoordx = statementa.datavalue.value.longitude
			usecoordy = statementa.datavalue.value.latitude
			cminy = tonumber(usecoordy)
			cmaxy = tonumber(usecoordy)
		end
		local statementb = mw.wikibase.getBestStatements(frame.args.item, "P31")[1].mainsnak
		if statementb.datavalue.value.id == "Q6256" then -- Country
			i = 3
		elseif statementb.datavalue.value.id == "Q515" then -- City
			i = 11
		end
	end
	
	-- northern and southern hemisphere have different scaling, due to the earth being round.
	-- in other cases the calculated zoom is a bit tight, so easing that up.
	if cmaxy > 60 or cminy < -30 then
		i = i - 2
	else
		i = i - 1
	end
	if frame.args.closetag then
		closetag = " >"
	else
		closetag = " />"
	end
	
	return frame:preprocess("<mapframe width=250 height=250 zoom=" .. i .. " longitude=" .. usecoordx .. " latitude=" .. usecoordy .. closetag)
end

return p