-- Modul für diverse Kalendervorlagen.
-- Grundlegende funktionen sind im Modul:DateTime zu finden.

-- trim: Entfernen aller Zeilenumbrüche, Austausch echter Tabulatoren durch Leerzeichen
-- anschließend Entfernung führender oder abschließender Leerzeichen.
local function trim(s)
	s = mw.ustring.gsub(s,"\n","");
	s = mw.ustring.gsub(s,"\t"," ");
	while mw.ustring.sub(s,1,1) == " " do
		s= mw.ustring.sub(s,2,-1);
	end
	while mw.ustring.sub(s,-1,-1) == " " do
		s= mw.ustring.sub(s,1,-2);
	end
	return s;
end

local Kalender = {};

function Kalender.Jahrhundertnavigation(frame)
	local jh = tonumber(frame.args[1] or "") or 21;
	local Text = '<table style="border:1px solid #000000; width:60ex; text-align:center; box-sizing: border-box; line-height:110%;">\n'
	local jahr = 0;
	local t = '';
	local n = 0;
	if jh > 0 and jh < 22 then
		jahr = (jh - 1) * 100;
		t = '<tr>'
		for i = 0, 4, 1 do
			t = t .. '<td colspan="2">&nbsp;[['.. tostring(jahr + i * 10) ..'er]]&nbsp;</td>'
		end
		t = t .. '</tr>\n'
		Text = Text .. t;
		if jh < 21 then
			t = '<tr>'
			for i = 5, 9, 1 do
				t = t .. '<td colspan="2">&nbsp;[['.. tostring(jahr + i * 10) ..'er]]&nbsp;</td>'
			end
			t = t .. '</tr>\n'
			Text = Text .. t;
		end
		for z = 0,4, 1 do
			t = '<tr>'
			for i = 1, 10, 1 do
				n = z * 10 + i
				t = t .. '<td>&nbsp;[['.. tostring(jahr + n) ..']]&nbsp;</td>';
			end
			t = t .. '</tr>\n'
			Text = Text .. t;
		end
		if jh < 21 then
			for z = 4,9, 1 do
				t = '<tr>'
				for i = 1, 10, 1 do
					n = z * 10 + i
					t = t .. '<td>&nbsp;[['.. tostring(jahr + n) ..']]&nbsp;</td>';
				end
				t = t .. '</tr>\n'
				Text = Text .. t;
			end
		end
		Text = Text .. '</table>\n'
	elseif jh < 0 and jh > -17 then
		jahr =  - (jh+1) * 100;
		t = '<tr>'
		for i = 9, 5, -1 do
			j =  tostring(jahr + i * 10)
			t = t .. '<td colspan="2">&nbsp;[['..j ..'er&nbsp;v.&nbsp;Chr.|'.. j .. 'er]]&nbsp;</td>'
		end
		t = t .. '</tr>\n'
		Text = Text .. t;
		t = '<tr>'
		for i = 4, 0, -1 do
			j =  tostring(jahr + i * 10)
			t = t .. '<td colspan="2">&nbsp;[['.. j ..'er&nbsp;v.&nbsp;Chr.|'.. j .. 'er]]&nbsp;</td>'
		end
		t = t .. '</tr>\n'
		Text = Text .. t;
		Text = Text ..'<tr><td colspan="10">v.&nbsp;Chr.</td></tr>\n'
		for z = 9,0, -1 do
			t = '<tr>'
			for i = 10, 1, -1 do
				n = z * 10 + i
				j =  tostring(jahr + n)
				t = t .. '<td>&nbsp;[['.. j ..'&nbsp;v.&nbsp;Chr.|'.. j .. ']]&nbsp;</td>';
			end
			t = t .. '</tr>\n'
			Text = Text .. t;
		end
		Text = Text .. '</table>\n'
	else
		Text = Text ..'<tr><td class="error">Fehler! Aufruf von [[Vorlage:Jahrhundertnavigation]] mit unerlaubtem Parameterwert!</td></tr></table>\n'
	end
	return Text;	
end

return Kalender