Module:ISO 639 name/ISO 639 name to code/make

require('Module:No globals');
local temp = {};


--[[--------------------------< A D D _ L A N G >--------------------------------------------------------------

temp table is a table of tables where the key is the language name and the value is a table listing the ISO 639
codes associated with that language name.

This function adds language name (as index) and its code (as a table element) using an appropriate index number.

<lang> is the language name from the source data
<code> is the associated ISO 639 code from the source data
<part> is 1 for ISO 639-1 language names and codes, 2, 2B, 3, 5.  <part> for the override data is prefixed with 'O'

]]

local function lang_add (lang, code, part)
	part = ({																	-- convert string <part> to a numeric index
		['1']=1, ['2']=2, ['2B']=3, ['3']=4, ['5']=5,							-- for the base ISO 639 parts
		['O1']=6, ['O2']=7, ['O2B']=8, ['O3']=9, ['O5']=10,						-- for the override tables
		})[part];

	lang = mw.ustring.lower (lang);												-- convert to lowercase for use as table index

	if not temp[lang] then														-- when no entry for this language
		temp[lang] = {};														-- make a blank entry
	end

	table.insert (temp[lang], table.concat ({									-- add the code; codes are added in the order that this function is called in iso_639_name_to_code()
		'[',																	-- open the key
		part,																	-- add the index
		']=\"',																	-- close key, add assignment operator and open quote because <code> is a string
		code,																	-- add <code>
		'\"'																	-- close the quote
	}));
end


--[[--------------------------< I S O 6 3 9 _ N A M E _ T O _ C O D E >----------------------------------------

read code-to-name source tables and convert to a name-to-code table.

]]

local function iso_639_name_to_code ()
	local out = {};

	local part_data = mw.loadData ('Module:Language/data/ISO 639-3');			-- ISO 639-3 language codes / names
	for code, v in pairs (part_data) do											-- start with part 3 because it has the most codes
		for _, lang in ipairs (v) do											-- code can have multiple names so for each one
			lang_add (lang, code, '3');											-- create and / or add this name / code pair to the output
		end
	end

	part_data = mw.loadData ('Module:Language/data/ISO 639-5');					-- ISO 639-5 language codes / names
	for code, v in pairs (part_data) do											-- now part 5
		for _, lang in ipairs (v) do
			lang_add (lang, code, '5');
		end
	end

	part_data = mw.loadData ('Module:Language/data/ISO 639-2');					-- ISO 639-2 language codes / names
	for code, v in pairs (part_data) do											-- now part 2
		for _, lang in ipairs (v) do
			lang_add (lang, code, '2');
		end
	end

	part_data = mw.loadData ('Module:Language/data/ISO 639-2B');				-- ISO 639-2B language codes / names
	for code, v in pairs (part_data) do											-- now part 2B
		for _, lang in ipairs (v) do
			lang_add (lang, code, '2B');
		end
	end

	part_data = mw.loadData ('Module:Language/data/iana languages');			-- used only for ISO 639-1 language codes / names');
	for code, v in pairs (part_data) do											-- now part 1
		if 2 == #code then														-- IANA source data includes a mix of 2- and 3-character codes; ISO 639-1 is the 2-character variety
			for _, lang in ipairs (v) do
				lang_add (lang, code, '1');
			end
		end
	end

	part_data = mw.loadData ('Module:Language/data/ISO 639 override');			-- has override data for all parts
	for _, o_part in ipairs ({'1', '2', '2B', '3', '5'}) do						-- for each of the override tables
		local o_part_data = part_data['override_' .. o_part];					-- point to override data
		o_part = 'O' .. o_part;													-- prefix o_part
		for code, v in pairs (o_part_data) do									-- for each code in the data table
			for _, lang in ipairs (v) do										-- and for each language name associated with that code
				lang_add (lang, code, o_part);									-- add
			end
		end
	end

	for lang, codes in pairs (temp) do
		table.sort (codes);														-- codes are added in the order that lang_add() is called above; sort to make pretty
		table.insert (out, table.concat ({'["', lang, '"] = {', table.concat (codes, ', '), '}'}));	-- reformat
	end

	table.sort (out);															-- sort in language name order

	local key_str = table.concat ({
		'--[[--------------------------< I S O _ 6 3 9 _ N A M E _ T O _ C O D E >--------------------------------------<br /><br />',
		'Key:<br />&#9;',
		'[1]=ISO 639-1&#9;&#9;[6]=ISO 639-1 override<br />&#9;',
		'[2]=ISO 639-2&#9;&#9;[7]=ISO 639-2 override<br />&#9;',
		'[3]=ISO 639-2B&#9;&#9;[8]=ISO 639-2B override<br />&#9;',
		'[4]=ISO 639-3&#9;&#9;[9]=ISO 639-3 override<br />&#9;',
		'[5]=ISO 639-5&#9;&#9;[10]=ISO 639-5 override',
		'<br />]]<br /><br />'
		})
	
	return table.concat ({'<pre>', key_str, 'return {<br />&#9;', table.concat (out, ',<br />&#9;'), '<br />&#9;}<br /></pre>'});	-- render
end

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

return {iso_639_name_to_code = iso_639_name_to_code}