--[[--------------------< A U T H O R _ D A T E _ I D >-----------------------

]]

local function make_author_date_id (refparam, reforigin, a, e, c, year)

    local ref = is_valid_parameter_value (refparam, reforigin, cfg.keywords_lists['ref'], nil, true);	-- nil when |ref=harv; A['Ref'] else  
 	if 'none' == cfg.keywords_xlate[(ref.val and ref.val:lower()) or ''] then
        return nil;
    elseif ref then
        return ref;
    end
       
    local author_date = '';
  
	local namelist_t = {};								-- holds selected contributor, author, editor name list

	if #c > 0 then										-- if there is a contributor list
		namelist_t = c;									-- select it
	elseif #a > 0 then									-- or an author list
		namelist_t = a;
	elseif #e > 0 then									-- or an editor list
		namelist_t = e;
	else
        return '';
    end

    local names={};					                    -- a table for the one to four names and year
    for i,v in ipairs (namelist_t) do	                -- loop through the list and take up to the first four last names
        names[i] = v.last
        if i == 4 then break 
    end			                                        -- if four then done
        
    table.insert (names, year);				            -- add the year at the end
    author_date = table.concat(names);			        -- concatenate names and year
			
    if mw.uri.anchorEncode (author_date) == ((ref and mw.uri.anchorEncode (ref)) or '') then -- Ref may already be encoded (by {{sfnref}}) so citeref_id must be encoded before comparison
	    utilities.set_message ('maint_ref_duplicates_default');
	end
 	return author_date;
end

--[[--------------------< A U T H O R _ D A T E _ 0 >-----------------------

Create an author-date ID from the parameters passed to CS 1 templates. 

]]

local function authordate0( config, args )
	--[[ 
	Load Input Parameters
	The argument_wrapper facilitates the mapping of multiple aliases to single internal variable.
	]]
	local A = argument_wrapper ( args );

	--[[ AUTHOR ]]---------------------------------------------------------
	local a	= {};																
	do																			
	    local author_etal;
		local selected = select_author_editor_source (A['Vauthors'], A['Authors'], args, 'AuthorList');
		if 1 == selected then
			a, author_etal = extract_names (args, 'AuthorList');			
		elseif 2 == selected then
			a, author_etal = parse_vauthors_veditors (args, A['Vauthors'], 'AuthorList');
		end
	end
    
    --[[ EDITOR ]]---------------------------------------------------------
	local e	= {};														
	do																			
        editor_etal; --- not used
		local selected = select_author_editor_source (A['Veditors'], nil, args, 'EditorList');	
		if 1 == selected then
			e, editor_etal = extract_names (args, 'EditorList');		
		elseif 2 == selected then
			e, editor_etal = parse_vauthors_veditors (args, args.veditors, 'EditorList');
		end
	end

    --[[ CONTRIBUTOR ]]-----------------------------------------------------
	local c = {};			
	if utilities.in_array (config.CitationClass, {"book", "citation"}) and not utilities.is_set (A['Periodical']) then
		c = extract_names (args, 'ContributorList');							
	end

    --[[ DATE AND YEAR ]]---------------------------------------------------
    local anchor_year;
    do
        local Date = A['Date'];
	    local Year = A['Year'];		
	    if not utilities.is_set (Date) then
		    Date = Year;
            Year = nil;
        end															

     	local date_parameters_list = {
			['date'] = {val = Date, name = A:ORIGIN ('Date')},
			['year'] = {val = Year, name = A:ORIGIN ('Year')},
		};

	    local COinS_date = {};	-- not used
        local error_list = {};  -- not used
        local Embargo; --- not used
    	anchor_year, Embargo = validation.dates(date_parameters_list, COinS_date, error_list);

	    anchor_year = first_set ({Year, anchor_year}, 2);		                    -- Year first for legacy citations 
    end

    --[[ AUTHOR-DATE ID ]]----------------------------------------
	local author_date;
    author_date = make_author_date_id (A['Ref'], A:ORIGIN ('Ref'), a, e, c, anchor_year);

     -- Clear the errors?

    return author_date;
end

-- Now enclose the whole thing in a <cite> element
	local options_t = {};
	options_t.class = cite_class_attribute_make (config.CitationClass, Mode);

	local author_date = make_author_date_id (A['Ref'], A:ORIGIN ('Ref'), a, e, c, anchor_year);
    if author_date then 
         options_t.id =  "CITEREF" .. author_date;
    end

	if string.len (text:gsub('%b<>', '')) <= 2 then								-- remove html and html-like tags; then get length of what