require('strict');
local getArgs = require ('Module:Arguments').getArgs;


--[[--------------------------< I S _ C J K _ C O D E >--------------------------------------------------------

return true if code is one of the listed Chinese, Japanese, Korean ISO 639 codes, false else.

]]

local function is_cjk_code (code)
local cjk =
		{
		['zh'] = true, ['cdo'] = true, ['cjy'] = true, ['cmn'] = true,			-- Chinese language codes
		['cpi'] = true, ['cpx'] = true, ['czh'] = true, ['czo'] = true,
		['gan'] = true, ['hak'] = true, ['hsn'] = true, ['ltc'] = true,
		['lzh'] = true, ['mnp'] = true, ['nan'] = true, ['och'] = true,
		['wuu'] = true, ['yue'] = true, ['zhx'] = true,
		['ja'] = true, ['jpx'] = true, ['ojp'] = true,							-- Japanese language codes
		['ko'] = true, ['okm'] = true, ['oko'] = true,							-- Korean language codes
		}

	return cjk[code] or false;
end


--[[--------------------------< S E T _ I T A L I C S >--------------------------------------------------------

Created for use with Template:Infobox book and Template:Infobox document and perhaps others to replace hard-coded
italic markup in the call to {{lang}}.  This module attempts to make sure that {{lang}} correctly applies italic
markup according to MOS:FOREIGNITALIC.

|italics={{#invoke:Infobox/utilities|set_italics|{{{orig_lang_code|}}}|{{{title_orig}}}}}}}

]]

local function set_italics (frame)
	local args=getArgs(frame); 
	local code = args[1] or args['code'] or '';									-- empty string causes 'yes' return; {{lang}} will handle the missing code error
	local text = args[2] or args['text'] or '';									-- empty string causes 'yes' return; {{lang}} will handle the missing text error

	local is_latn = require ("Module:Unicode data").is_Latin;
	
	if is_cjk_code (code) and not is_latn (text) then							-- is_latn() is in Module:Unicode data
		return  'no';															-- only case for 'no' 
	end
	return 'yes';																-- everything else is yes
end


--[[--------------------------< C O M P >----------------------------------------------------------------------

compare function for result{} table descending sort

]]

local function comp (a, b)
	return tonumber (a[1]) > tonumber (b[1]);
end
	

--[[--------------------------< S O R T _ C O M M O N >--------------------------------------------------------

common function to render sorted distribution, ethnicity, and occupation lists.

inputs:
	result - table of percentages and labels
	ref - value from |distribution ref=, |ethnicity ref=, or |occupation ref= as appropriate
	frame - calling frame required for expandTemplate()
	
returns sorted list on success; empty string else

]]

local function sort_common (result, ref, frame)
	for i=#result, 1, -1 do
		if not tonumber (result[i][1]) then										-- if cannot be converted to a number
			table.remove (result, i);											-- delete
		end
	end
	
	if 0 == #result then														-- if we get here and the result table is empty
		return '';																-- abandon returning empty string
	end
	
	table.sort (result, comp);													-- sort what remains

	for i, v in ipairs (result) do
		result[i] = table.concat (result[i]);									-- make each table in result{} a string
	end

	result[1] = table.concat ({result[1], ref and ref or ''});					-- add reference(s) from |<list> ref= to first item in the list
	
	return frame:expandTemplate { title = 'Unbulleted list', args = result};	-- render the unbulleted list
end


--[[--------------------------< D I S R I B U T I O N _ S O R T >----------------------------------------------

{{#invoke:Infobox/utilities|distribution_sort|{{{percent urban|}}}|{{{percent rural|}}}|{{{distribution ref|}}} }}

]]

local function distribution_sort (frame)
	local args=getArgs(frame);
	
	local result = {															-- initialize; table will be sorted according to values in result[n][1]
		{args[1], '% urban'},
		{args[2], '% rural'},
	};
	
	return sort_common (result, args[#result+1], frame);
end


--[[--------------------------< E T H N I C I T Y _ S O R T >--------------------------------------------------

{{#invoke:Infobox/utilities|ethnicity_sort|{{{percent white|}}}|{{{percent black|}}}|{{{percent asian|}}}|{{{percent hispanic|}}}|{{{percent native american|}}}|{{{percent native hawaiian|}}}|{{{percent more than one race|}}}|{{{percent other race|}}}|{{{ethnicity ref|}}} }}

]]

local function ethnicity_sort (frame)
	local args=getArgs(frame);
	
	local result = {															-- initialize; table will be sorted according to values in result[n][1]
		{args[1], '% [[White Americans|White]]'},
		{args[2], '% [[African Americans|Black]]'},
		{args[3], '% [[Asian Americans|Asian]]'},
		{args[4], '% [[Hispanic and Latino Americans|Hispanic]]'},
		{args[5], '% [[Native Americans in the United States|Native American]]'},
		{args[6], '% [[Pacific Islander Americans]]'},
		{args[7], '% [[Multiracial Americans|Two or more races]]'},
		{args[8], '% other'},													-- TODO: make other always last?
	};
	
	return sort_common (result, args[#result+1], frame);
end


--[[--------------------------< O C C U P A T I O N _ S O R T >------------------------------------------------

{{#invoke:Infobox/utilities|distribution_sort|{{{percent blue collar|}}}|{{{percent white collar|}}}|{{{percent grey collar|}}}|{{{occupation ref|}}} }}

]]

local function occupation_sort (frame)
	local args=getArgs(frame);
	
	local result = {															-- initialize; table will be sorted according to values in result[n][1]
		{args[1], '% [[Blue-collar worker|Blue-collar]]'},
		{args[2], '% [[White-collar worker|White-collar]]'},
		{args[3], '% [[Gray-collar]]'},
	};
	
	return sort_common (result, args[#result+1], frame)
end


--[[--------------------------< E X P O R T E D   F U N C T I O N S >------------------------------------------

]]

return {
	distribution_sort = distribution_sort,										-- {{Infobox U.S. congressional district}}
	ethnicity_sort = ethnicity_sort,
	occupation_sort = occupation_sort,
	
	set_italics = set_italics,													-- {{Infobox book}}
	}