local lang_data =  mw.loadData ('Module:Lang/data/sandbox');					-- language name override and transliteration tool-tip tables

local lang_name_table = lang_data.lang_name_table;								-- language codes, names, regions, scripts, suppressed scripts



local lang_table = lang_name_table.lang;										-- language codes, names

local lang_dep_table = lang_name_table.lang_dep;								-- deprecated language codes, names

local override_table = lang_data.override;



local rev_lang_table = {};														-- same as lang_table reversed so language name is key and language tag is value

local rev_lang_dep_table = {};													-- same as lang_dep_table reversed so language name is key and language tag is value

local rev_override_table = {};													-- same as override_table except reversed

local dedabbed_names_list = {};													-- holds a list of dedabbed name and tags





--[[--------------------------< R E V _ L I S T _ A D D >------------------------------------------------------



local function to add <name> (key) and <tag> (value) pair to <rev_list>



<name>/<tag> pairs where <tag> is ISO 639-1, overwrite all other <name>/<tag> pairs.  When creating overrides,

take care that the <name> is properly disambiguated to avoid improper masking



]]



local function rev_list_add (rev_list, name, tag)

	if rev_listname then														-- if already in <rev_list>

		if 2 == tag:len() then													-- is this is a 2-characater code?

			rev_listname = tag;												-- yes, overwrite 3-characater language <name> and <tag> pair in <rev_list>

		end

	else																		-- here when not yet in <rev_list>

		rev_listname = tag;													-- add language <name> and <tag> (value) pair to <rev_list>

	end

end





--[[--------------------------< D E D A B B E D _ N A M E S _ L I S T _ A D D >--------------------------------



adds <name>/<tag> pairs to the dedabbed_names_list when <name> not already present.  When <name> is present in

the list, unsets the listed <tag> to empty string; cannot have different <name>/<tag> pairs where the table

key (<name>) is shared with another <name>/<tag> pair.



]]



local function dedabbed_names_list_add (dab, name, tag)

	if 0 ~= dab then															-- if dab was removed

		if dedabbed_names_listname then										-- if this dedabbed name is in the table then there are more than one name with different dabs

			dedabbed_names_listname = '';										-- unset but not too unset

		else

			dedabbed_names_listname = tag;									-- add name / tag pair in case this the only dedabbed name

		end

	end

end





--[[--------------------------< D E D A B B E D _ T O _ R E V _ L I S T _ A D D >------------------------------



adds <name>/<tag> pairs to specified <rev_list> when <tag> is not empty string



]]



local function dedabbed_to_rev_list_add (rev_list, name, tag)

	for name, tag in pairs (dedabbed_names_list) do								-- add dedabbed <name>/<tag> pairs to the reversed table

		if '' ~= tag then														-- when <name>/<tag> has not been unset because of multiple dabs

			rev_list_add (rev_list, name, tag);									-- add

		end

	end

end





--[[--------------------------< T A G - F R O M - N A M E   D A T A >------------------------------------------



Creates tag-from-name tables from the data in Module:Lang/data so that templates can get language tags from the

same names as the {{lang}} templates get from those tags.  The conversion prefers ISO 639-1 codes.



Data in these tables are used by tag_from_name() in Module:Lang



When <name> is disambiguated, will create an additional <name> entry without the dab as long as that action won't

conflict with actual undabbed names in the source.



<name> without dab is always added to the list; this rule arises because of the three Marwari language code/name pairs:

	mwr: Marwari																-– not dabbed

these will not have dedabbed entries because of mwr

	rwr: Marwari (India)

	mve: Marwari (Pakistan)



These all share the same base name so there will not not be an dedabbed entry:

	["yaka"] = "axk",															-- this would be wrong for two of these languages

	["yaka (central african republic)"] = "axk",

	["yaka (congo)"] = "iyx",

	["yaka (democratic republic of congo)"] = "yaf",



Say that we find "axk".  It has a dab so we add the dabbed form to rev_lang_table{}.  Then we look in

dedabbed_names_list{} to see if ["yaka"] is already there.  It's not, so we add this:

	["yaka"] = "axk",

Later we find "yaf".  It has a dab so we add the dabbed form to rev_lang_table{}.  Then we look in

dedabbed_names_list{} to see if ["yaka"] is already there.  It is, so that means that more than one language

code could create an dedabbed language name key; there can be only one.  Because ["yaka"] is already in the

dedabbed_names_list{} table we unset the ["yaka"] entry to empty string:

	["yaka"] = '',

later we find "iyx" and add it to rev_lang_table{}.  We look in dedabbed_names_list{} and find ["yaka"] has been

unset to empty string so do nothing.



When done adding names/codes to rev_lang_table{}, spin through dedabbed_names_list{} and add all non-empty-string

name/code pairs to rev_lang_table{}.



This does not catch things like overrides ["pa"] = "Punjabi" and ["pnb"] = "Punjabi".  "pa" and "pnb" are not

synonyms but because the names are the same, will be treated like synonyms ("pnb" promotes to "pa"). To avoid

this, disambiguate the override: ["pnb"] = {"Punjabi"} -> ["pnb"] = {"Punjabi (Western)"}



]]



for tag, name_table in pairs (lang_table) do

	if not override_tabletag then												-- only add names/tags from name_table when tag not present in override table

		local name_raw = name_table1]:lower();									-- there can be multiple names, always take the first name; may have disambiguation

		local name, dab = name_raw:gsub ('%s+%b()', '');						-- remove parenthetical disambiguators or qualifiers from names that have them; <dab> non-zero when disambiguation removed

	

		rev_list_add (rev_lang_table, name_raw, tag);							-- add no-dab-names and names-with-dab here

		dedabbed_names_list_add (dab, name, tag);								-- add to dedabbed_names_list if dabbed

	end

end



dedabbed_to_rev_list_add (rev_lang_table, name, tag);							-- add dedabbed name/tag pairs to the reversed table



dedabbed_names_list = {};														-- reset list of dedabbed names



for tag, name_table in pairs (lang_dep_table) do

	if not override_tabletag then												-- only add names/tags from name_table when tag not present in override table

		local name_raw = name_table1]:lower();									-- there can be multiple names, always take the first name; may have disambiguation

		local name, dab = name_raw:gsub ('%s+%b()', '');						-- remove parenthetical disambiguators or qualifiers from names that have them; <dab> non-zero when disambiguation removed

	

		rev_list_add (rev_lang_dep_table, name_raw, tag);						-- add no-dab-names and names-with-dab here

		dedabbed_names_list_add (dab, name, tag);								-- add to dedabbed_names_list if dabbed

	end

end



dedabbed_to_rev_list_add (rev_lang_dep_table, name, tag);						-- add dedabbed name/tag pairs to the reversed table



dedabbed_names_list = {};														-- reset list of dedabbed names



for tag, name_table in pairs (override_table) do

	local name_raw = name_table1]:lower();										-- there can be multiple names, always take the first name

	local name, dab = name_raw:gsub ('%s+%b()', '');							-- remove parenthetical disambiguators or qualifiers from names that have them



	rev_list_add (rev_override_table, name_raw, tag);

	dedabbed_names_list_add (dab, name, tag);									-- add to dedabbed_names_list if dabbed

end



dedabbed_to_rev_list_add (rev_override_table, name, tag);						-- add dedabbed name/tag pairs to the reversed table



dedabbed_names_list = {};														-- reset list





--[[--------------------------< E X P O R T E D   T A B L E S >------------------------------------------------

]]



return {

	rev_lang_table = rev_lang_table,

	rev_lang_dep_table = rev_lang_dep_table,

	rev_override_table = rev_override_table,

	}