Editing Module:Citation/CS1/Utilities

local u = {}

local z = {
	error_categories = {};		-- for categorizing citations that contain errors
	error_ids = {};
	message_tail = {};
	maintenance_cats = {};		-- for categorizing citations that aren't erroneous per se, but could use a little work
	properties_cats = {};		-- for categorizing citations based on certain properties, language of source for instance
};

local cfg = mw.loadData ('Module:Citation/CS1/Configuration/sandbox');

--[[--------------------------< A D D _ M A I N T _ C A T >------------------------------------------------------

Adds a category to z.maintenance_cats using names from the configuration file with additional text if any.
To prevent duplication, the added_maint_cats table lists the categories by key that have been added to z.maintenance_cats.

]]

local added_maint_cats = {}														-- list of maintenance categories that have been added to z.maintenance_cats
local function add_maint_cat (key, arguments)
	if not added_maint_cats [key] then
		added_maint_cats [key] = true;											-- note that we've added this category
		table.insert( z.maintenance_cats, substitute (cfg.maint_cats [key], arguments));	-- make name then add to table
	end
end


--[[--------------------------< I S _ S E T >------------------------------------------------------------------

Returns true if argument is set; false otherwise. Argument is 'set' when it exists (not nil) or when it is not an empty string.
This function is global because it is called from both this module and from Date validation

]]
function is_set( var )
	return not (var == nil or var == '');
end


--[[--------------------------< I N _ A R R A Y >--------------------------------------------------------------

Whether needle is in haystack

]]

local function in_array( needle, haystack )
	if needle == nil then
		return false;
	end
	for n,v in ipairs( haystack ) do
		if v == needle then
			return n;
		end
	end
	return false;
end


--[[--------------------------< S U B S T I T U T E >----------------------------------------------------------

Populates numbered arguments in a message string using an argument table.

]]

local function substitute( msg, args )
	return args and mw.message.newRawMessage( msg, args ):plain() or msg;
end


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

Wraps error messages with css markup according to the state of hidden.

]]
local function error_comment( content, hidden )
	return substitute( hidden and cfg.presentation['hidden-error'] or cfg.presentation['visible-error'], content );
end


--[[--------------------------< S E T _ E R R O R >--------------------------------------------------------------

Sets an error condition and returns the appropriate error message.  The actual placement of the error message in the output is
the responsibility of the calling function.

]]
local function set_error( error_id, arguments, raw, prefix, suffix )
	local error_state = cfg.error_conditions[ error_id ];
	
	prefix = prefix or "";
	suffix = suffix or "";
	
	if error_state == nil then
		error( cfg.messages['undefined_error'] );
	elseif is_set( error_state.category ) then
		table.insert( z.error_categories, error_state.category );
	end
	
	local message = substitute( error_state.message, arguments );
	
	message = message .. " ([[" .. cfg.messages['help page link'] .. 
		"#" .. error_state.anchor .. "|" ..
		cfg.messages['help page label'] .. "]])";
	
	z.error_ids[ error_id ] = true;
	if in_array( error_id, { 'bare_url_missing_title', 'trans_missing_title' } )
			and z.error_ids['citation_missing_title'] then
		return '', false;
	end
	
	message = table.concat({ prefix, message, suffix });
	
	if raw == true then
		return message, error_state.hidden;
	end		
		
	return error_comment( message, error_state.hidden );
end


--[[-------------------------< I S _ A L I A S _ U S E D >-----------------------------------------------------

This function is used by select_one() to determine if one of a list of alias parameters is in the argument list
provided by the template.

Input:
	args – pointer to the arguments table from calling template
	alias – one of the list of possible aliases in the aliases lists from Module:Citation/CS1/Configuration
	index – for enumerated parameters, identifies which one
	enumerated – true/false flag used choose how enumerated aliases are examined
	value – value associated with an alias that has previously been selected; nil if not yet selected
	selected – the alias that has previously been selected; nil if not yet selected
	error_list – list of aliases that are duplicates of the alias already selected

Returns:
	value – value associated with alias we selected or that was previously selected or nil if an alias not yet selected
	selected – the alias we selected or the alias that was previously selected or nil if an alias not yet selected

]]

local function is_alias_used (args, alias, index, enumerated, value, selected, error_list)
	if enumerated then															-- is this a test for an enumerated parameters?
		alias = alias:gsub ('#', index);										-- replace '#' with the value in index
	else
		alias = alias:gsub ('#', '');											-- remove '#' if it exists
	end

	if is_set(args[alias]) then													-- alias is in the template's argument list
		if value ~= nil and selected ~= alias then								-- if we have already selected one of the aliases
			local skip;
			for _, v in ipairs(error_list) do									-- spin through the error list to see if we've added this alias
				if v == alias then
					skip = true;
					break;														-- has been added so stop looking 
				end
			end
			if not skip then													-- has not been added so
				table.insert( error_list, alias );								-- add error alias to the error list
			end
		else
			value = args[alias];												-- not yet selected an alias, so select this one
			selected = alias;
		end
	end
	return value, selected;														-- return newly selected alias, or previously selected alias
end


--[[--------------------------< S E L E C T _ O N E >----------------------------------------------------------

Chooses one matching parameter from a list of parameters to consider.  The list of parameters to consider is just
names.  For parameters that may be enumerated, the position of the numerator in the parameter name is identified
by the '#' so |author-last1= and |author1-last= are represented as 'author-last#' and 'author#-last'.

Because enumerated parameter |<param>1= is an alias of |<param>= we must test for both possibilities.


Generates an error if more than one match is present.

]]

local function select_one( args, aliases_list, error_condition, index )
	local value = nil;															-- the value assigned to the selected parameter
	local selected = '';														-- the name of the parameter we have chosen
	local error_list = {};

	if index ~= nil then index = tostring(index); end

	for _, alias in ipairs( aliases_list ) do									-- for each alias in the aliases list
		if alias:match ('#') then												-- if this alias can be enumerated
			if '1' == index then												-- when index is 1 test for enumerated and non-enumerated aliases
				value, selected = is_alias_used (args, alias, index, false, value, selected, error_list);	-- first test for non-enumerated alias
			end
			value, selected = is_alias_used (args, alias, index, true, value, selected, error_list);		-- test for enumerated alias
		else
			value, selected = is_alias_used (args, alias, index, false, value, selected, error_list);		--test for non-enumerated alias
		end
	end

	if #error_list > 0 and 'none' ~= error_condition then						-- for cases where this code is used outside of extract_names()
		local error_str = "";
		for _, k in ipairs( error_list ) do
			if error_str ~= "" then error_str = error_str .. cfg.messages['parameter-separator'] end
			error_str = error_str .. wrap_style ('parameter', k);
		end
		if #error_list > 1 then
			error_str = error_str .. cfg.messages['parameter-final-separator'];
		else
			error_str = error_str .. cfg.messages['parameter-pair-separator'];
		end
		error_str = error_str .. wrap_style ('parameter', selected);
		table.insert( z.message_tail, { set_error( error_condition, {error_str}, true ) } );
	end
	
	return value, selected;
end


return {																		-- return exported functions and tables
	is_set = is_set,
	in_array = in_array,
	substitute = substitute,
	error_comment = error_comment,
	set_error = set_error,
	select_one = select_one,
	add_maint_cat = add_maint_cat,
	z = z,
	}