local z = {

   error_categories = {};
   error_ids = {};
   message_tail = {};

}

-- Include translation message hooks, ID and error handling configuration settings. local cfg = mw.loadData( 'Module:Citation/CS1/Configuration' );

-- Contains a list of all recognized parameters local whitelist = mw.loadData( 'Module:Citation/CS1/Whitelist' );

-- Whether variable is set or not function is_set( var )

   return not (var == nil or var == );

end

-- First set variable or nil if none function first_set(...)

   local list = {...};
   for _, var in pairs(list) do
       if is_set( var ) then
           return var;
       end
   end

end

-- Whether needle is in haystack function inArray( 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

--[[ Categorize and emit an error message when the citation contains one or more deprecated parameters. Because deprecated parameters (currently |day=, |month=, |coauthor=, and |coauthors=) aren't related to each other and because these parameters may be concatenated into the variables used by |date= and |author#= (and aliases) details of which parameter caused the error message are not provided. Only one error message is emitted regarless of the number of deprecated parameters in the citation. ]] function deprecated_parameter() if true ~= Page_in_deprecated_cat then -- if we haven't been here before then set a Page_in_deprecated_cat=true; -- sticky flag so that if there are more than one deprecated parameter the category is added only once table.insert( z.message_tail, { seterror( 'deprecated_params', {error_message}, true ) } ); -- add error message end end

-- Populates numbered arguments in a message string using an argument table. function substitute( msg, args )

   return args and tostring( mw.message.newRawMessage( msg, args ) ) or msg;

end

-- Wraps a string using a message_list configuration taking one argument function wrap( key, str, lower )

   if not is_set( str ) then
       return "";
   elseif inArray( key, { 'italic-title', 'trans-italic-title' } ) then
       str = safeforitalics( str );
   end
   if lower == true then
       return substitute( cfg.messages[key]:lower(), {str} );
   else
       return substitute( cfg.messages[key], {str} );
   end        

end

--[[ Argument wrapper. This function provides support for argument mapping defined in the configuration file so that multiple names can be transparently aliased to single internal variable. ]] function argument_wrapper( args )

   local origin = {};
   
   return setmetatable({
       ORIGIN = function( self, k )
           local dummy = self[k]; --force the variable to be loaded.
           return origin[k];
       end
   },
   {
       __index = function ( tbl, k )
           if origin[k] ~= nil then
               return nil;
           end
           
           local args, list, v = args, cfg.aliases[k];
           
           if type( list ) == 'table' then
               v, origin[k] = selectone( args, list, 'redundant_parameters' );
               if origin[k] == nil then
                   origin[k] = ; -- Empty string, not nil
               end
           elseif list ~= nil then
               v, origin[k] = args[list], list;
           else
               -- maybe let through instead of raising an error?
               -- v, origin[k] = args[k], k;
               error( cfg.messages['unknown_argument_map'] );
           end
           
           -- Empty strings, not nil;
           if v == nil then
               v = cfg.defaults[k] or ;
               origin[k] = ;
           end
           
           tbl = rawset( tbl, k, v );
           return v;
       end,
   });

end

--[[ Looks for a parameter's name in the whitelist.

Parameters in the whitelist can have three valuse: true - active, supported parameters false - deprecated, supported parameters nil - unsupported parameters ]] function validate( name ) local name = tostring( name ); local state = whitelist.basic_arguments[ name ];

-- Normal arguments if true == state then return true; end -- valid actively supported parameter if false == state then deprecated_parameter (); -- parameter is deprecated but still supported return true; end

-- Arguments with numbers in them name = name:gsub( "%d+", "#" ); -- replace digit(s) with # (last25 becomes last# state = whitelist.numbered_arguments[ name ]; if true == state then return true; end -- valid actively supported parameter if false == state then deprecated_parameter (); -- parameter is deprecated but still supported return true; end

return false; -- Not supported because not found or name is set to nil end

-- Formats a comment for error trapping function errorcomment( content, hidden )

   return wrap( hidden and 'hidden-error' or 'visible-error', content );

end

--[[ 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. ]] function seterror( 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 inArray( 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 errorcomment( message, error_state.hidden );

end

-- Formats a wiki style external link function externallinkid(options)

   local url_string = options.id;
   if options.encode == true or options.encode == nil then
       url_string = mw.uri.encode( url_string );
   end
   return mw.ustring.format( '%s%s[%s%s%s %s]',
       options.link, options.label, options.separator or " ",
       options.prefix, url_string, options.suffix or "",
       mw.text.nowiki(options.id)
   );

end

-- Formats a wiki style internal link function internallinkid(options)

   return mw.ustring.format( '%s%s%s',
       options.link, options.label, options.separator or " ",
       options.prefix, options.id, options.suffix or "",
       mw.text.nowiki(options.id)
   );

end

-- Format an external link with error checking function externallink( URL, label, source )

   local error_str = "";
   if not is_set( label ) then
       label = URL;
       if is_set( source ) then
           error_str = seterror( 'bare_url_missing_title', { wrap( 'parameter', source ) }, false, " " );
       else
           error( cfg.messages["bare_url_no_origin"] );
       end            
   end
   if not checkurl( URL ) then
       error_str = seterror( 'bad_url', {}, false, " " ) .. error_str;
   end
   return table.concat({ "[", URL, " ", safeforurl( label ), "]", error_str });

end

-- Formats a link to Amazon function amazon(id, domain)

   if not is_set(domain) then 
       domain = "com"
   elseif ( "jp" == domain or "uk" == domain ) then
       domain = "co." .. domain
   end
   local handler = cfg.id_handlers['ASIN'];
   return externallinkid({link = handler.link,
       label=handler.label , prefix="//www.amazon."..domain.."/dp/",id=id,
       encode=handler.encode, separator = handler.separator})

end

--[[ Determines if a PMC identifier's online version is embargoed. Compares the date in |embargo= against today's date. If embargo date is in the future, returns true; otherwse, returns false because the embargo has expired or |embargo= not set in this cite. ]] function is_embargoed(embargo) if is_set(embargo) then local lang = mw.getContentLanguage(); local good1, embargo_date, good2, todays_date; good1, embargo_date = pcall( lang.formatDate, lang, 'U', embargo ); good2, todays_date = pcall( lang.formatDate, lang, 'U' );

if good1 and good2 and tonumber( embargo_date ) >= tonumber( todays_date ) then --is embargo date is in the future? return true; -- still embargoed end end return false; -- embargo expired or |embargo= not set end

--[[ Formats a PMC and checks for embargoed articles. The embargo parameter takes a date for a value. If the embargo date is in the future the PMC identifier will not be linked to the article. If the embargo specifies a date in the past, or if it is empty or omitted, then the PMC identifier is linked to the article through the link at cfg.id_handlers['PMC'].prefix. ]] function pmc(id, embargo) local handler = cfg.id_handlers['PMC'];

local text;

if is_embargoed(embargo) then text="" .. handler.label .. ":" .. handler.separator .. id; --still embargoed so no external link else text = externallinkid({link = handler.link, label = handler.label, --no embargo date, ok to link to article prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) end return text; end

-- Formats a DOI and checks for DOI errors. function doi(id, inactive)

   local cat = ""
   local handler = cfg.id_handlers['DOI'];
   
   local text;

if is_set(inactive) then local inactive_year = inactive:match("%d%d%d%d") or ; -- try to get the year portion from the inactive date text = "" .. handler.label .. ":" .. id; if is_set(inactive_year) then table.insert( z.error_categories, "Pages with DOIs inactive since " .. inactive_year ); else table.insert( z.error_categories, "Pages with inactive DOIs" ); -- when inactive doesn't contain a recognizable year end inactive = " (" .. cfg.messages['inactive'] .. " " .. inactive .. ")" else text = externallinkid({link = handler.link, label = handler.label, prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode}) inactive = "" end if ( string.sub(id,1,3) ~= "10." ) then cat = seterror( 'bad_doi' ); end return text .. inactive .. cat end

-- Formats an OpenLibrary link, and checks for associated errors. function openlibrary(id)

   local code = id:sub(-1,-1)
   local handler = cfg.id_handlers['OL'];
   if ( code == "A" ) then
       return externallinkid({link=handler.link, label=handler.label,
           prefix="http://openlibrary.org/authors/OL",id=id, separator=handler.separator,
           encode = handler.encode})
   elseif ( code == "M" ) then
       return externallinkid({link=handler.link, label=handler.label,
           prefix="http://openlibrary.org/books/OL",id=id, separator=handler.separator,
           encode = handler.encode})
   elseif ( code == "W" ) then
       return externallinkid({link=handler.link, label=handler.label,
           prefix= "http://openlibrary.org/works/OL",id=id, separator=handler.separator,
           encode = handler.encode})
   else
       return externallinkid({link=handler.link, label=handler.label,
           prefix= "http://openlibrary.org/OL",id=id, separator=handler.separator,
           encode = handler.encode}) .. 
           ' ' .. seterror( 'bad_ol' );
   end

end

--[[ Validate and format an issn. This code fixes the case where an editor has included an ISSN in the citation but has separated the two groups of four digits with a space. When that condition occurred, the resulting link looked like this:

|issn=0819 4327 gives: 4327 0819 4327 -- can't have spaces in an external link

This code now prevents that by inserting a hyphen at the issn midpoint. It also validates the issn for length and makes sure that the checkdigit agrees with the calculated value. Incorrect length (8 digits), characters other than 0-9 and X, or checkdigit / calculated value mismatch will all cause a check issn error message. The issn is always displayed with a hyphen, even if the issn was given as a single group of 8 digits. ]] function issn(id) local issn_copy = id; -- save a copy of unadulterated issn; use this version for display if issn does not validate local handler = cfg.id_handlers['ISSN']; local text; local valid_issn = true;

id=id:gsub( "[%s-–]", "" ); -- strip spaces, hyphens, and ndashes from the issn

if 8 ~= id:len() or nil == id:match( "^%d*X?$" ) then -- validate the issn: 8 didgits long, containing only 0-9 or X in the last position valid_issn=false; -- wrong length or improper character else valid_issn=is_valid_isxn(id, 8); -- validate issn end

if true == valid_issn then id = string.sub( id, 1, 4 ) .. "-" .. string.sub( id, 5 ); -- if valid, display correctly formatted version else id = issn_copy; -- if not valid, use the show the invalid issn with error message end

text = externallinkid({link = handler.link, label = handler.label, prefix=handler.prefix,id=id,separator=handler.separator, encode=handler.encode})

if false == valid_issn then text = text .. ' ' .. seterror( 'bad_issn' ) -- add an error message if the issn is invalid end

return text end

--[[ This function sets default title types (equivalent to the citation including |type=<default value>) for those citations that have defaults. Also handles the special case where it is desireable to omit the title type from the rendered citation (|type=none). ]] function set_titletype(cite_class, title_type) if is_set(title_type) then if "none" == title_type then title_type = ""; -- if |type=none then type parameter not displayed end return title_type; -- if |type= has been set to any other value use that value end

if "pressrelease" == cite_class then -- if this citation is cite press release return "Press release"; -- display press release annotation

elseif "speech" == cite_class then -- if this citation is cite speech return "Speech"; -- display speech annotation

elseif "techreport" == cite_class then -- if this citation is cite techreport return "Technical report"; -- display techreport annotation

elseif "thesis" == cite_class then -- if this citation is cite thesis (degree option handled after this function returns) return "Thesis"; -- display simple thesis annotation (without |degree= modification) end end

-- returns a number according to the month in a date: 1 for January, etc. If not a valid month, returns 0 function get_month_number (month) local long_months = {['january']=1, ['february']=2, ['march']=3, ['april']=4, ['may']=5, ['june']=6, ['july']=7, ['august']=8, ['september']=9, ['october']=10, ['november']=11, ['december']=12}; local short_months = {['jan']=1, ['feb']=2, ['mar']=3, ['apr']=4, ['may']=5, ['jun']=6, ['jul']=7, ['aug']=8, ['sep']=9, ['oct']=10, ['nov']=11, ['dec']=12}; local temp; temp=long_months[month:lower()]; if temp then return temp; end -- if month is the long-form name temp=short_months[month:lower()]; if temp then return temp; end -- if month is the short-form name return 0; -- misspelled or not a month name end

-- returns true if date has one of the five seasons. Else false. function is_valid_season (season) if inArray( season, {'winter', 'spring', 'summer', 'fall', 'autumn'} ) then return true; end return false; end

--[[ Returns true if day is less than or equal to the number of days in month; else returns false.

Assumes Julian calendar prior to year 1582 and Gregorian calendar thereafter. Accounts for Julian calendar leap years before 1582 and Gregorian leap years after 1582. Where the two calendars overlap (1582 to approximately 1923) dates are assumed to be Gregorian. ]] function is_valid_date (year, month, day) local days_in_month = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; local month_length; if (2==month) then -- if February month_length = 28; -- then 28 days unless if 1582 > tonumber(year) then -- Julian calendar if 0==(year%4) then month_length = 29; end else -- Gregorian calendar if (0==(year%4) and (0~=(year%100) or 0==(year%400))) then -- is a leap year? month_length = 29; -- if leap year then 29 days in February end end else month_length=days_in_month[month]; end

if tonumber (day) > month_length then return false; end return true; end

--Check a pair of months or seasons to see if both are valid members of a month or season pair. --TODO: Check order to make sure that the left month/season properly precedes the right month/season

function is_valid_month_season_range(range_start, range_end) if 0 == get_month_number (range_start:lower()) then -- is this a month range? if true == is_valid_season (range_start:lower()) then -- not a month range, is this a season range? return is_valid_season (range_end:lower()); -- range_start is season; return true if range_end also a season; else false end return false; -- range_start is not a month or a season end if 0 == get_month_number (range_end:lower()) then -- range_start is a month; is range_end also a month? return false; -- not a month range end return true; end

--[[ Check date format to see that it is one of the formats approved by MOS:DATE: MMMM D, YYYY; D MMMM YYYY; MMMM YYYY; YYYY-MM-DD; YYYY. Additionally, check the date to see that it is a real date: no 31 in 30-day months; no 29 February when not a leap year. Months, both long-form and three character abbreviations, and seasons must be spelled correctly.

If the date fails the fomat tests, this function returns false but does not return values for anchor_year and COinS_date. When this happens, the date parameter is used in the COinS metadata and the CITEREF identifier gets its year from the year parameter if present.

Inputs: date_string - date string from date-holding parameters (date, year, accessdate, embargo, archivedate, etc)

Returns: false if date string is not a real date; else true, anchor_year, COinS_date anchor_year can be used in CITEREF anchors COinS_date is date_string without anchor_year disambiguator if any ]] function check_date (date_string) local year; local month; local day; local anchor_year; local coins_date;

if date_string:match("^%d%d%d%d%-%d%d%-%d%d$") then -- Year-initial numerical year month day format coins_date = date_string:match("%d%d%d%d%-%d%d%-%d%d"); year, month, day=string.match(date_string, "(%d%d%d%d)%-(%d%d)%-(%d%d)"); anchor_year = year; month=tonumber(month); if 12 < month or 1 > month then return false; end

elseif date_string:match("^%a+%s*%d%d*%s*,%s*%d%d%d%d%a?$") then -- month-initial: month day, year coins_date = date_string:match("%a+%s*%d%d*%s*,%s*%d%d%d%d"); month, day, anchor_year, year=string.match(date_string, "(%a+)%s*(%d%d*)%s*,%s*((%d%d%d%d)%a?)"); month = get_month_number (month:lower()); if 0 == month then return false; end -- return false if month text isn't one of the twelve months

elseif date_string:match("^%d%d*%s*%a+%s*%d%d%d%d%a?$") then -- date-initial: day month year coins_date = date_string:match("%d%d*%s*%a+%s*%d%d%d%d"); day, month, anchor_year, year=string.match(date_string, "(%d%d*)%s*(%a+)%s*((%d%d%d%d)%a?)"); month = get_month_number (month:lower()); if 0 == month then return false; end -- return false if month text isn't one of the twelve months

elseif mw.ustring.match (date_string, "^%a+%s*[%s%-/–]%s*%a+%s*%d%d%d%d%a?$") then -- month/season range year local month2 coins_date = mw.ustring.match (date_string, "%a+%s*[%s%-/–]%s*%a+%s*%d%d%d%d"); coins_date= mw.ustring.gsub( coins_date, "–", "-" ); -- replace ndash with hyphen month, month2, anchor_year, year=mw.ustring.match (date_string, "(%a+)%s*[%s%-/–]%s*(%a+)%s*((%d%d%d%d)%a?)"); day=0; -- mark day as not used if false == is_valid_month_season_range(month, month2) then return false; end

elseif date_string:match("^%a+%s*%d%d%d%d%a?$") then -- month/season year coins_date = date_string:match("%a+%s*%d%d%d%d"); month, anchor_year, year=string.match(date_string, "(%a+)%s*((%d%d%d%d)%a?)"); day=0; -- mark day as not used local season=month; -- copy month = get_month_number (month:lower()); if month == 0 then -- if month text isn't one of the twelve months, might be a season if false == is_valid_season (season:lower()) then return false; -- return false not a month or one of the five seasons end end

elseif date_string:match("^%d%d%d%d?%a?$") then -- year; here accept either YYY or YYYY coins_date = date_string:match("^%d%d%d%d?"); anchor_year, year=string.match(date_string, "((%d%d%d%d?)%a?)"); month, day = 0, 0; -- mark day and month as not used else return false; -- date format not one of the MOS:DATE approved formats end

if 0~=month and 0~=day then -- check year month day dates for validity if false==is_valid_date(year,month,day) then return false; -- date string is not a real date return false; unset anchor_year and coins_date end end

return true, anchor_year, coins_date; -- format is good and date string represents a real date end

--[[ Cycle the date-holding parameters in passed table date_parameters_list through check_date() to check compliance with MOS:DATE. For all valid dates, check_date() returns true and values for anchor_year (used in CITEREF identifiers) and COinS_date (used in the COinS metadata). The |date= parameter test is unique. This function only accepts anchor_year and COinS_date results from the |date= parameter test and |date= is the only date-holding parameter that is allowed to contain the no-date keywords "n.d." or "nd" (without quotes).

Unlike most error messages created in this module, only one error message is created by this function. Because all of the date holding parameters are processed serially, a single error message is created as the dates are tested. ]]

function dates(date_parameters_list) local anchor_year; -- will return as nil if the date being tested is not |date= local COinS_date; -- will return as nil if the date being tested is not |date= local error_message =""; local good_date=false;

for k, v in pairs(date_parameters_list) do -- for each date-holding parameter in the list if is_set(v) then -- if the parameter has a value if v:match("^c%.%s%d%d%d%d?%a?$") then -- special case for c. year or with or without CITEREF disambiguator - only |date= and |year= if 'date'==k then good_date, anchor_year, COinS_date = true, v:match("((c%.%s%d%d%d%d?)%a?)"); -- anchor year and COinS_date only from |date= parameter elseif 'year'==k then good_date = true; end elseif 'year'==k then -- if the parameter is |year= (but not c. year) if v:match("^%d%d%d%d?%a?$") then -- year with or without CITEREF disambiguator good_date = true; end elseif 'date'==k then -- if the parameter is |date= if v:match("n%.d%.%a?") then -- if |date=n.d. with or without a CITEREF disambiguator good_date, anchor_year, COinS_date = true, v:match("((n%.d%.)%a?)"); --"n.d."; no error when date parameter is set to no date elseif v:match("nd%a?$") then -- if |date=nd with or without a CITEREF disambiguator good_date, anchor_year, COinS_date = true, v:match("((nd)%a?)"); --"nd"; no error when date parameter is set to no date else good_date, anchor_year, COinS_date = check_date (v); -- go test the date end else -- any other date-holding parameter good_date = check_date (v); -- go test the date end if false==good_date then -- assemble one error message so we don't add the tracking category multiple times if is_set(error_message) then -- once we've added the first portion of the error message ... error_message=error_message .. ", "; -- ... add a comma space separator end error_message=error_message .. "|" .. k .. "="; -- add the failed parameter end end end if is_set(error_message) then table.insert( z.message_tail, { seterror( 'bad_date', {error_message}, true ) } ); -- add this error message end

return anchor_year, COinS_date; -- and done end

--[[ Determines whether a URL string is valid

At present the only check is whether the string appears to be prefixed with a URI scheme. It is not determined whether the URI scheme is valid or whether the URL is otherwise well formed. ]] function checkurl( url_str )

   -- Protocol-relative or URL scheme
   return url_str:sub(1,2) == "//" or url_str:match( "^[^/]*:" ) ~= nil;

end

-- Removes irrelevant text and dashes from ISBN number -- Similar to that used for Special:BookSources function cleanisbn( isbn_str )

   return isbn_str:gsub( "[^-0-9X]", "" );

end

--[[ ISBN-10 and ISSN validator code calculates checksum across all isbn/issn digits including the check digit. ISBN-13 is checked in checkisbn(). If the number is valid the result will be 0. Before calling this function, issbn/issn must be checked for length and stripped of dashes, spaces and other non-isxn characters. ]] function is_valid_isxn (isxn_str, len) local temp = 0; isxn_str = { isxn_str:byte(1, len) }; -- make a table of bytes len = len+1; -- adjust to be a loop counter for i, v in ipairs( isxn_str ) do -- loop through all of the bytes and calculate the checksum if v == string.byte( "X" ) then -- if checkdigit is X temp = temp + 10*( len - i ); -- it represents 10 decimal else temp = temp + tonumber( string.char(v) )*(len-i); end end return temp % 11 == 0; -- returns true if calculation result is zero end

-- Determines whether an ISBN string is valid function checkisbn( isbn_str ) if nil ~= isbn_str:match("[^%s-0-9X]") then return false; end -- fail if isbn_str contains anything but digits, hyphens, or the uppercase X isbn_str = isbn_str:gsub( "-", "" ):gsub( " ", "" ); -- remove hyphens and spaces local len = isbn_str:len();

if len ~= 10 and len ~= 13 then return false; end

if len == 10 then if isbn_str:match( "^%d*X?$" ) == nil then return false; end return is_valid_isxn(isbn_str, 10); else local temp = 0; if isbn_str:match( "^97[89]%d*$" ) == nil then return false; end -- isbn13 begins with 978 or 979 isbn_str = { isbn_str:byte(1, len) }; for i, v in ipairs( isbn_str ) do temp = temp + (3 - 2*(i % 2)) * tonumber( string.char(v) ); end return temp % 10 == 0; end end

-- Gets the display text for a wikilink like B or B gives B function removewikilink( str )

   return (str:gsub( "%[%[([^%[%]]*)%]%]", function(l)
       return l:gsub( "^[^|]*|(.*)$", "%1" ):gsub("^%s*(.-)%s*$", "%1");
   end));

end

-- Escape sequences for content that will be used for URL descriptions function safeforurl( str )

   if str:match( "%[%[.-%]%]" ) ~= nil then 
       table.insert( z.message_tail, { seterror( 'wikilink_in_url', {}, true ) } );
   end
   
   return str:gsub( '[%[%]\n]', {    
       ['['] = '[',
       [']'] = ']',
       ['\n'] = ' ' } );

end

-- Converts a hyphen to a dash function hyphentodash( str )

   if not is_set(str) or str:match( "[%[%]{}<>]" ) ~= nil then
       return str;
   end    
   return str:gsub( '-', '–' );

end

-- Protects a string that will be wrapped in wiki italic markup ... function safeforitalics( str )

   --[[ Note: We can not use  for italics, as the expected behavior for
   italics specified by ... in the title is that they will be inverted
   (i.e. unitalicized) in the resulting references.  In addition,  and 
   tend to interact poorly under Mediawiki's HTML tidy. ]]
   
   if not is_set(str) then
       return str;
   else
       if str:sub(1,1) == "'" then str = "" .. str; end
       if str:sub(-1,-1) == "'" then str = str .. ""; end
       
       -- Remove newlines as they break italics.
       return str:gsub( '\n', ' ' );
   end

end

--[[ Joins a sequence of strings together while checking for duplicate separation characters. ]] function safejoin( tbl, duplicate_char )

   --[[
   Note: we use string functions here, rather than ustring functions.
   
   This has considerably faster performance and should work correctly as 
   long as the duplicate_char is strict ASCII.  The strings
   in tbl may be ASCII or UTF8.
   ]]
   
   local str = ;
   local comp = ;
   local end_chr = ;
   local trim;
   for _, value in ipairs( tbl ) do
       if value == nil then value = ; end
       
       if str ==  then
           str = value;
       elseif value ~=  then
           if value:sub(1,1) == '<' then
               -- Special case of values enclosed in spans and other markup.
               comp = value:gsub( "%b<>", "" );
           else
               comp = value;
           end
           
           if comp:sub(1,1) == duplicate_char then
               trim = false;
               end_chr = str:sub(-1,-1);
               -- str = str .. "<HERE(enchr=" .. end_chr.. ")"
               if end_chr == duplicate_char then
                   str = str:sub(1,-2);
               elseif end_chr == "'" then
                   if str:sub(-3,-1) == duplicate_char .. "" then
                       str = str:sub(1, -4) .. "";
                   elseif str:sub(-5,-1) == duplicate_char .. "]]" then
                       trim = true;
                   elseif str:sub(-4,-1) == duplicate_char .. "]" then
                       trim = true;
                   end
               elseif end_chr == "]" then
                   if str:sub(-3,-1) == duplicate_char .. "]]" then
                       trim = true;
                   elseif str:sub(-2,-1) == duplicate_char .. "]" then
                       trim = true;
                   end
               elseif end_chr == " " then
                   if str:sub(-2,-1) == duplicate_char .. " " then
                       str = str:sub(1,-3);
                   end
               end
               if trim then
                   if value ~= comp then 
                       local dup2 = duplicate_char;
                       if dup2:match( "%A" ) then dup2 = "%" .. dup2; end
                       
                       value = value:gsub( "(%b<>)" .. dup2, "%1", 1 )
                   else
                       value = value:sub( 2, -1 );
                   end
               end
           end
           str = str .. value;
       end
   end
   return str;

end

-- Attempts to convert names to initials. function reducetoinitials(first)

   local initials = {}
   for word in string.gmatch(first, "%S+") do
       table.insert(initials, string.sub(word,1,1)) -- Vancouver format does not include full stops.
   end
   return table.concat(initials) -- Vancouver format does not include spaces.

end

-- Formats a list of people (e.g. authors / editors) function listpeople(control, people)

   local sep = control.sep;
   local namesep = control.namesep
   local format = control.format
   local maximum = control.maximum
   local lastauthoramp = control.lastauthoramp;
   local text = {}
   local etal = false;
   
   if sep:sub(-1,-1) ~= " " then sep = sep .. " " end
   if maximum ~= nil and maximum < 1 then return "", 0; end
   
   for i,person in ipairs(people) do
       if is_set(person.last) then
           local mask = person.mask
           local one
           local sep_one = sep;
           if maximum ~= nil and i > maximum then
               etal = true;
               break;
           elseif (mask ~= nil) then
               local n = tonumber(mask)
               if (n ~= nil) then
                   one = string.rep("—",n)
               else
                   one = mask;
                   sep_one = " ";
               end
           else
               one = person.last
               local first = person.first
               if is_set(first) then 
                   if ( "vanc" == format ) then first = reducetoinitials(first) end
                   one = one .. namesep .. first 
               end
               if is_set(person.link) then one = "" .. one .. "" end
           end
           table.insert( text, one )
           table.insert( text, sep_one )
       end
   end
   local count = #text / 2;
   if count > 0 then 
       if count > 1 and is_set(lastauthoramp) and not etal then
           text[#text-2] = " & ";
       end
       text[#text] = nil; 
   end
   
   local result = table.concat(text) -- construct list
   if etal then 
       local etal_text = cfg.messages['et al'];
       result = result .. " " .. etal_text;
   end
   
   -- if necessary wrap result in  tag to format in Small Caps
   if ( "scap" == format ) then result = 
       '' .. result .. '';
   end 
   return result, count

end

-- Generates a CITEREF anchor ID. function anchorid( options )

   return "CITEREF" .. table.concat( options );

end

-- Gets name list from the input arguments function extractnames(args, list_name)

   local names = {};
   local i = 1;
   local last;
   
   while true do
       last = selectone( args, cfg.aliases[list_name .. '-Last'], 'redundant_parameters', i );
       if not is_set(last) then
           -- just in case someone passed in an empty parameter
           break;
       end
       names[i] = {
           last = last,
           first = selectone( args, cfg.aliases[list_name .. '-First'], 'redundant_parameters', i ),
           link = selectone( args, cfg.aliases[list_name .. '-Link'], 'redundant_parameters', i ),
           mask = selectone( args, cfg.aliases[list_name .. '-Mask'], 'redundant_parameters', i )
       };
       i = i + 1;
   end
   return names;

end

-- Populates ID table from arguments using configuration settings function extractids( args )

   local id_list = {};
   for k, v in pairs( cfg.id_handlers ) do    
       v = selectone( args, v.parameters, 'redundant_parameters' );
       if is_set(v) then id_list[k] = v; end
   end
   return id_list;

end

-- Takes a table of IDs and turns it into a table of formatted ID outputs. function buildidlist( id_list, options )

   local new_list, handler = {};
   
   function fallback(k) return { __index = function(t,i) return cfg.id_handlers[k][i] end } end;
   
   for k, v in pairs( id_list ) do
       -- fallback to read-only cfg
       handler = setmetatable( { ['id'] = v }, fallback(k) );
       
       if handler.mode == 'external' then
           table.insert( new_list, {handler.label, externallinkid( handler ) } );
       elseif handler.mode == 'internal' then
           table.insert( new_list, {handler.label, internallinkid( handler ) } );
       elseif handler.mode ~= 'manual' then
           error( cfg.messages['unknown_ID_mode'] );
       elseif k == 'DOI' then
           table.insert( new_list, {handler.label, doi( v, options.DoiBroken ) } );
       elseif k == 'ASIN' then
           table.insert( new_list, {handler.label, amazon( v, options.ASINTLD ) } ); 
       elseif k == 'OL' then
           table.insert( new_list, {handler.label, openlibrary( v ) } );
       elseif k == 'PMC' then
           table.insert( new_list, {handler.label, pmc( v, options.Embargo ) } );
       elseif k == 'ISSN' then
       	table.insert( new_list, {handler.label, issn( v ) } );
       elseif k == 'ISBN' then
           local ISBN = internallinkid( handler );
           if not checkisbn( v ) and not is_set(options.IgnoreISBN) then
               ISBN = ISBN .. seterror( 'bad_isbn', {}, false, " ", "" );
           end
           table.insert( new_list, {handler.label, ISBN } );                
       else
           error( cfg.messages['unknown_manual_ID'] );
       end
   end
   
   function comp( a, b )	-- used in following table.sort()
       return a[1] < b[1];
   end
   
   table.sort( new_list, comp );
   for k, v in ipairs( new_list ) do
       new_list[k] = v[2];
   end
   
   return new_list;

end

-- Chooses one matching parameter from a list of parameters to consider -- Generates an error if more than one match is present. function selectone( args, possible, error_condition, index )

   local value = nil;
   local selected = ;
   local error_list = {};
   
   if index ~= nil then index = tostring(index); end
   
   -- Handle special case of "#" replaced by empty string
   if index == '1' then
       for _, v in ipairs( possible ) do
           v = v:gsub( "#", "" );
           if is_set(args[v]) then
               if value ~= nil and selected ~= v then
                   table.insert( error_list, v );
               else
                   value = args[v];
                   selected = v;
               end
           end
       end        
   end
   
   for _, v in ipairs( possible ) do
       if index ~= nil then
           v = v:gsub( "#", index );
       end
       if is_set(args[v]) then
           if value ~= nil and selected ~=  v then
               table.insert( error_list, v );
           else
               value = args[v];
               selected = v;
           end
       end
   end
   
   if #error_list > 0 then
       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( '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( 'parameter', selected );
       table.insert( z.message_tail, { seterror( error_condition, {error_str}, true ) } );
   end
   
   return value, selected;

end

-- COinS metadata (see <http://ocoins.info/>) allows automated tools to parse -- the citation information. function COinS(data)

   if 'table' ~= type(data) or nil == next(data) then
       return ;
   end
   
   local ctx_ver = "Z39.88-2004";
   
   -- treat table strictly as an array with only set values.
   local OCinSoutput = setmetatable( {}, {
       __newindex = function(self, key, value)
           if is_set(value) then
               rawset( self, #self+1, table.concat{ key, '=', mw.uri.encode( removewikilink( value ) ) } );
           end
       end
   });
   
   if is_set(data.Chapter) then
       OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:book";
       OCinSoutput["rft.genre"] = "bookitem";
       OCinSoutput["rft.btitle"] = data.Chapter;
       OCinSoutput["rft.atitle"] = data.Title;
   elseif is_set(data.Periodical) then
       OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:journal";
       OCinSoutput["rft.genre"] = "article";
       OCinSoutput["rft.jtitle"] = data.Periodical;
       OCinSoutput["rft.atitle"] = data.Title;
   else
       OCinSoutput.rft_val_fmt = "info:ofi/fmt:kev:mtx:book";
       OCinSoutput["rft.genre"] = "book"
       OCinSoutput["rft.btitle"] = data.Title;
   end
   
   OCinSoutput["rft.place"] = data.PublicationPlace;
   OCinSoutput["rft.date"] = data.Date;
   OCinSoutput["rft.series"] = data.Series;
   OCinSoutput["rft.volume"] = data.Volume;
   OCinSoutput["rft.issue"] = data.Issue;
   OCinSoutput["rft.pages"] = data.Pages;
   OCinSoutput["rft.edition"] = data.Edition;
   OCinSoutput["rft.pub"] = data.PublisherName;
   
   for k, v in pairs( data.ID_list ) do
       local id, value = cfg.id_handlers[k].COinS;
       if k == 'ISBN' then value = cleanisbn( v ); else value = v; end
       if string.sub( id or "", 1, 4 ) == 'info' then
           OCinSoutput["rft_id"] = table.concat{ id, "/", v };
       else
           OCinSoutput[ id ] = value;
       end
   end
   
   local last, first;
   for k, v in ipairs( data.Authors ) do
       last, first = v.last, v.first;
       if k == 1 then
           if is_set(last) then
               OCinSoutput["rft.aulast"] = last;
           end
           if is_set(first) then 
               OCinSoutput["rft.aufirst"] = first;
           end
       end
       if is_set(last) and is_set(first) then
           OCinSoutput["rft.au"] = table.concat{ last, ", ", first };
       elseif is_set(last) then
           OCinSoutput["rft.au"] = last;
       end
   end
   
   OCinSoutput.rft_id = data.URL;
   OCinSoutput.rfr_id = table.concat{ "info:sid/", mw.site.server:match( "[^/]*$" ), ":", data.RawPage };
   OCinSoutput = setmetatable( OCinSoutput, nil );
   
   -- sort with version string always first, and combine.
   table.sort( OCinSoutput );
   table.insert( OCinSoutput, 1, "ctx_ver=" .. ctx_ver );  -- such as "Z39.88-2004"
   return table.concat(OCinSoutput, "&");

end

--[[ This is the main function doing the majority of the citation formatting. ]] function citation0( config, args)

   --[[ 
   Load Input Parameters
   The argment_wrapper facillitates the mapping of multiple
   aliases to single internal variable.
   ]]
   local A = argument_wrapper( args );
   local i 
   local PPrefix = A['PPrefix']
   local PPPrefix = A['PPPrefix']
   if is_set( A['NoPP'] ) then PPPrefix = "" PPrefix = "" end
   
   -- Pick out the relevant fields from the arguments.  Different citation templates
   -- define different field names for the same underlying things.    
   local Authors = A['Authors'];
   local a = extractnames( args, 'AuthorList' );
   local Coauthors = A['Coauthors'];
   local Others = A['Others'];
   local Editors = A['Editors'];
   local e = extractnames( args, 'EditorList' );
   local Year = A['Year'];
   local PublicationDate = A['PublicationDate'];
   local OrigYear = A['OrigYear'];
   local Date = A['Date'];
   local LayDate = A['LayDate'];
   ------------------------------------------------- Get title data
   local Title = A['Title'];
   local BookTitle = A['BookTitle'];
   local Conference = A['Conference'];
   local TransTitle = A['TransTitle'];
   local TitleNote = A['TitleNote'];
   local TitleLink = A['TitleLink'];
   local Chapter = A['Chapter'];
   local ChapterLink = A['ChapterLink'];
   local TransChapter = A['TransChapter'];
   local TitleType = A['TitleType'];
   local Degree = A['Degree'];
   local Docket = A['Docket'];
   local ArchiveURL = A['ArchiveURL'];
   local URL = A['URL']
   local URLorigin = A:ORIGIN('URL');
   local ChapterURL = A['ChapterURL'];
   local ChapterURLorigin = A:ORIGIN('ChapterURL');
   local ConferenceURL = A['ConferenceURL'];
   local ConferenceURLorigin = A:ORIGIN('ConferenceURL');
   local Periodical = A['Periodical'];

--[[ Parameter remapping for cite encyclopedia: When the citation has these parameters: |encyclopedia and |title then map |title to |article and |encyclopedia to |title |encyclopedia and |article then map |encyclopedia to |title |encyclopedia then map |encyclopedia to |title

|trans_title maps to |trans_chapter when |title is re-mapped

All other combinations of |encyclopedia, |title, and |article are not modified ]] if ( config.CitationClass == "encyclopaedia" ) then if is_set(Periodical) then -- Periodical is set when |encyclopedia is set if is_set(Title) then if not is_set(Chapter) then Chapter = Title; -- |encyclopedia and |title are set so map |title to |article and |encyclopedia to |title TransChapter = TransTitle; Title = Periodical; Periodical = ; -- redundant so unset TransTitle = ; -- redundant so unset end else -- |title not set Title = Periodical; -- |encyclopedia set and |article set or not set so map |encyclopedia to |title Periodical = ; -- redundant so unset end end end

local Series = A['Series'];

   local Volume = A['Volume'];
   local Issue = A['Issue'];
   local Position = ;
   local Page, Pages, At, page_type;
   
   Page = A['Page'];
   Pages = hyphentodash( A['Pages'] );
   At = A['At'];
   
   if is_set(Page) then
       if is_set(Pages) or is_set(At) then
           Page = Page .. " " .. seterror('extra_pages');
           Pages = ;
           At = ;
       end
   elseif is_set(Pages) then
       if is_set(At) then
           Pages = Pages .. " " .. seterror('extra_pages');
           At = ;
       end
   end    
   
   local Edition = A['Edition'];
   local PublicationPlace = A['PublicationPlace']
   local Place = A['Place'];
   
   if not is_set(PublicationPlace) and is_set(Place) then
       PublicationPlace = Place;
   end
   
   if PublicationPlace == Place then Place = ; end
   
   local PublisherName = A['PublisherName'];
   local RegistrationRequired = A['RegistrationRequired'];
   local SubscriptionRequired = A['SubscriptionRequired'];
   local Via = A['Via'];
   local AccessDate = A['AccessDate'];
   local ArchiveDate = A['ArchiveDate'];
   local Agency = A['Agency'];
   local DeadURL = A['DeadURL']
   local Language = A['Language'];
   local Format = A['Format'];
   local Ref = A['Ref'];
   
   local DoiBroken = A['DoiBroken'];

-- Special case for cite techreport. local ID = A['ID']; if (config.CitationClass == "techreport") then -- special case for cite techreport if is_set(Issue) then -- cite techreport uses 'number', which other citations aliase to 'issue' if not is_set(ID) then -- can we use ID for the "number"? ID = Issue; -- yes, use it Issue = ""; -- unset Issue so that "number" isn't duplicated in the rendered citation or COinS metadata else -- can't use ID so emit error message ID = ID .. " " .. seterror('redundant_parameters', '|id= and |number='); end end end

   local ASINTLD = A['ASINTLD'];
   local IgnoreISBN = A['IgnoreISBN'];
   local Embargo = A['Embargo'];
   local ID_list = extractids( args );
   
   local Quote = A['Quote'];
   local PostScript = A['PostScript'];
   local LayURL = A['LayURL'];
   local LaySource = A['LaySource'];
   local Transcript = A['Transcript'];
   local TranscriptURL = A['TranscriptURL'] 
   local TranscriptURLorigin = A:ORIGIN('TranscriptURL');
   local sepc = A['Separator'];
   local LastAuthorAmp = A['LastAuthorAmp'];
   local no_tracking_cats = A['NoTracking'];
   local use_lowercase = ( sepc ~= '.' );
   local this_page = mw.title.getCurrentTitle();  --Also used for COinS and for language
   
   if not is_set(no_tracking_cats) then
       for k, v in pairs( cfg.uncategorized_namespaces ) do
           if this_page.nsText == v then
               no_tracking_cats = "true";
               break;
           end
       end
   end

local anchor_year; -- used in the CITEREF identifier local COinS_date; -- used in the COinS metadata

-- legacy: promote concatenation of |day=, |month=, and |year= to Date if Date not set; or, promote PublicationDate to Date if neither Date nor Year are set. if not is_set(Date) then Date = Year; -- promote Year to Date Year = nil; -- make nil so Year as empty string isn't used for CITEREF if is_set(Date) then local Month = A['Month']; if is_set(Month) then Date = Month .. " " .. Date; local Day = A['Day'] if is_set(Day) then Date = Day .. " " .. Date end end elseif is_set(PublicationDate) then -- use PublicationDate when |date= and |year= are not set Date = PublicationDate; -- promonte PublicationDate to Date PublicationDate = ; -- unset, no longer needed end end

if PublicationDate == Date then PublicationDate = ; end -- if PublicationDate is same as Date, don't display in rendered citation

-- Go test all of the date-holding parameters for valid MOS:DATE format and make sure that dates are real dates. -- TODO: 2013-10-27: AirDate is nil when dates() is called because it hasn't been set yet. Move the call to dates() or set AirDate earlier. anchor_year, COinS_date = dates({['accessdate']=AccessDate, ['airdate']=AirDate, ['archivedate']=ArchiveDate, ['date']=Date, ['doi_brokendate']=DoiBroken, ['embargo']=Embargo, ['laydate']=LayDate, ['publicationdate']=PublicationDate, ['year']=Year});

-- At this point fields may be nil if they weren't specified in the template use. We can use that fact.

--Account for the oddity that is الگو:Cite journal with |pmc= set and |url= not set if config.CitationClass == "journal" and not is_set(URL) and is_set(ID_list['PMC']) then if not is_embargoed(Embargo) then URL=cfg.id_handlers['PMC'].prefix .. ID_list['PMC']; -- set url to be the same as the PMC external link if not embargoed end end

   -- Account for the oddity that is الگو:Cite conference, before generation of COinS data.
   if is_set(BookTitle) then
       Chapter = Title;
       ChapterLink = TitleLink;
       TransChapter = TransTitle;
       Title = BookTitle;
       TitleLink = ;
       TransTitle = ;
   end
   -- Account for the oddity that is الگو:Cite episode, before generation of COinS data.
   if config.CitationClass == "episode" then
       local AirDate = A['AirDate'];
       local SeriesLink = A['SeriesLink'];
       local Season = A['Season'];
       local SeriesNumber = A['SeriesNumber'];
       local Network = A['Network'];
       local Station = A['Station'];
       local s, n = {}, {};
       local Sep = (first_set(A["SeriesSeparator"], A["Separator"]) or "") .. " ";
       
       if is_set(Issue) then table.insert(s, cfg.messages["episode"] .. " " .. Issue); Issue = ; end
       if is_set(Season) then table.insert(s, cfg.messages["season"] .. " " .. Season); end
       if is_set(SeriesNumber) then table.insert(s, cfg.messages["series"] .. " " .. SeriesNumber); end
       if is_set(Network) then table.insert(n, Network); end
       if is_set(Station) then table.insert(n, Station); end
       
       Date = Date or AirDate;
       Chapter = Title;
       ChapterLink = TitleLink;
       TransChapter = TransTitle;
       Title = Series;
       TitleLink = SeriesLink;
       TransTitle = ;
       
       Series = table.concat(s, Sep);
       ID = table.concat(n, Sep);
   end
   
   -- COinS metadata (see <http://ocoins.info/>) for
   -- automated parsing of citation information.
   local OCinSoutput = COinS{
       ['Periodical'] = Periodical,
       ['Chapter'] = Chapter,
       ['Title'] = Title,
       ['PublicationPlace'] = PublicationPlace,
       ['Date'] = first_set(COinS_date, Date),		-- COinS_date has correctly formatted date if Date is valid; any reason to keep Date here?  Should we be including invalid dates in metadata?
       ['Series'] = Series,
       ['Volume'] = Volume,
       ['Issue'] = Issue,
       ['Pages'] = first_set(Page, Pages, At),
       ['Edition'] = Edition,
       ['PublisherName'] = PublisherName,
       ['URL'] = first_set( URL, ChapterURL ),
       ['Authors'] = a,
       ['ID_list'] = ID_list,
       ['RawPage'] = this_page.prefixedText,
   };
   if is_set(Periodical) and not is_set(Chapter) and is_set(Title) then
       Chapter = Title;
       ChapterLink = TitleLink;
       TransChapter = TransTitle;
       Title = ;
       TitleLink = ;
       TransTitle = ;
   end
   -- Now perform various field substitutions.
   -- We also add leading spaces and surrounding markup and punctuation to the
   -- various parts of the citation, but only when they are non-nil.
   if not is_set(Authors) then
       local Maximum = tonumber( A['DisplayAuthors'] );
       
       -- Preserve old-style implicit et al.
       if not is_set(Maximum) and #a == 9 then 
           Maximum = 8;
           table.insert( z.message_tail, { seterror('implict_etal_author', {}, true ) } );
       elseif not is_set(Maximum) then
           Maximum = #a + 1;
       end
           
       local control = { 
           sep = A["AuthorSeparator"] .. " ",
           namesep = (first_set(A["AuthorNameSeparator"], A["NameSeparator"]) or "") .. " ",
           format = A["AuthorFormat"],
           maximum = Maximum,
           lastauthoramp = LastAuthorAmp
       };
       
       -- If the coauthor field is also used, prevent ampersand and et al. formatting.
       if is_set(Coauthors) then
           control.lastauthoramp = nil;
           control.maximum = #a + 1;
       end
       
       Authors = listpeople(control, a) 
   end

if not is_set(Authors) and is_set(Coauthors) then -- coauthors aren't displayed if one of authors=, authorn=, or lastn= isn't specified table.insert( z.message_tail, { seterror('coauthors_missing_author', {}, true) } ); -- emit error message end

   local EditorCount
   if not is_set(Editors) then
       local Maximum = tonumber( A['DisplayEditors'] );
       -- Preserve old-style implicit et al.
       if not is_set(Maximum) and #e == 4 then 
           Maximum = 3;
           table.insert( z.message_tail, { seterror('implict_etal_editor', {}, true) } );
       elseif not is_set(Maximum) then
           Maximum = #e + 1;
       end
       local control = { 
           sep = A["EditorSeparator"] .. " ",
           namesep = (first_set(A["EditorNameSeparator"], A["NameSeparator"]) or "") .. " ",
           format = A['EditorFormat'],
           maximum = Maximum,
           lastauthoramp = LastAuthorAmp
       };
       Editors, EditorCount = listpeople(control, e);
   else
       EditorCount = 1;
   end
   local Cartography = "";
   local Scale = "";
   if config.CitationClass == "map" then
       if not is_set( Authors ) and is_set( PublisherName ) then
           Authors = PublisherName;
           PublisherName = "";
       end
       Cartography = A['Cartography'];
       if is_set( Cartography ) then
           Cartography = sepc .. " " .. wrap( 'cartography', Cartography, use_lowercase );
       end        
       Scale = A['Scale'];
       if is_set( Scale ) then
           Scale = sepc .. " " .. Scale;
       end        
   end
   
   if  not is_set(URL) and
       not is_set(ChapterURL) and
       not is_set(ArchiveURL) and
       not is_set(ConferenceURL) and
       not is_set(TranscriptURL) then
       
       -- Test if cite web is called without giving a URL
       if ( config.CitationClass == "web" ) then
           table.insert( z.message_tail, { seterror( 'cite_web_url', {}, true ) } );
       end
       
       -- Test if accessdate is given without giving a URL
       if is_set(AccessDate) then
           table.insert( z.message_tail, { seterror( 'accessdate_missing_url', {}, true ) } );
           AccessDate = ;
       end
       
       -- Test if format is given without giving a URL
       if is_set(Format) then
           Format = Format .. seterror( 'format_missing_url' );
       end
   end
   
   -- Test if citation has no title
   if  not is_set(Chapter) and
       not is_set(Title) and
       not is_set(Periodical) and
       not is_set(Conference) and
       not is_set(TransTitle) and
       not is_set(TransChapter) then
       table.insert( z.message_tail, { seterror( 'citation_missing_title', {}, true ) } );
   end
   
   Format = is_set(Format) and " (" .. Format .. ")" or "";
   
   local OriginalURL = URL
   DeadURL = DeadURL:lower();
   if is_set( ArchiveURL ) then
       if ( DeadURL ~= "no" ) then
           URL = ArchiveURL
           URLorigin = A:ORIGIN('ArchiveURL')
       end
   end
   
   -- Format chapter / article title
   if is_set(Chapter) and is_set(ChapterLink) then 
       Chapter = "" .. Chapter .. "";
   end
   if is_set(Periodical) and is_set(Title) then
       Chapter = wrap( 'italic-title', Chapter );
       TransChapter = wrap( 'trans-italic-title', TransChapter );
   else
       Chapter = wrap( 'quoted-title', Chapter );
       TransChapter = wrap( 'trans-quoted-title', TransChapter );
   end
   
   local TransError = ""
   if is_set(TransChapter) then
       if not is_set(Chapter) then
           TransError = " " .. seterror( 'trans_missing_chapter' );
       else
           TransChapter = " " .. TransChapter;
       end
   end
   
   Chapter = Chapter .. TransChapter;
   
   if is_set(Chapter) then
       if not is_set(ChapterLink) then
           if is_set(ChapterURL) then
               Chapter = externallink( ChapterURL, Chapter ) .. TransError;
               if not is_set(URL) then
                   Chapter = Chapter .. Format;
                   Format = "";
               end
           elseif is_set(URL) then 
               Chapter = externallink( URL, Chapter ) .. TransError .. Format;
               URL = "";
               Format = "";
           else
               Chapter = Chapter .. TransError;
           end            
       elseif is_set(ChapterURL) then
           Chapter = Chapter .. " " .. externallink( ChapterURL, nil, ChapterURLorigin ) .. 
               TransError;
       else
           Chapter = Chapter .. TransError;
       end
       Chapter = Chapter .. sepc .. " " -- with end-space
   elseif is_set(ChapterURL) then
       Chapter = " " .. externallink( ChapterURL, nil, ChapterURLorigin ) .. sepc .. " ";
   end        
   
   -- Format main title.
   if is_set(TitleLink) and is_set(Title) then
       Title = "" .. Title .. ""
   end
   
   if is_set(Periodical) then
       Title = wrap( 'quoted-title', Title );
       TransTitle = wrap( 'trans-quoted-title', TransTitle );
   elseif inArray(config.CitationClass, {"web","news","pressrelease","conference"}) and
           not is_set(Chapter) then
       Title = wrap( 'quoted-title', Title );
       TransTitle = wrap( 'trans-quoted-title', TransTitle );
   else
       Title = wrap( 'italic-title', Title );
       TransTitle = wrap( 'trans-italic-title', TransTitle );
   end
   
   TransError = "";
   if is_set(TransTitle) then
       if not is_set(Title) then
           TransError = " " .. seterror( 'trans_missing_title' );
       else
           TransTitle = " " .. TransTitle;
       end
   end
   
   Title = Title .. TransTitle;
   
   if is_set(Title) then
       if not is_set(TitleLink) and is_set(URL) then 
           Title = externallink( URL, Title ) .. TransError .. Format       
           URL = "";
           Format = "";
       else
           Title = Title .. TransError;
       end
   end
   
   if is_set(Place) then
       Place = " " .. wrap( 'written', Place, use_lowercase ) .. sepc .. " ";
   end
   
   if is_set(Conference) then
       if is_set(ConferenceURL) then
           Conference = externallink( ConferenceURL, Conference );
       end
       Conference = sepc .. " " .. Conference
   elseif is_set(ConferenceURL) then
       Conference = sepc .. " " .. externallink( ConferenceURL, nil, ConferenceURLorigin );
   end
   
   if not is_set(Position) then
       local Minutes = A['Minutes'];
       if is_set(Minutes) then
           Position = " " .. Minutes .. " " .. cfg.messages['minutes'];
       else
           local Time = A['Time'];
           if is_set(Time) then
               local TimeCaption = A['TimeCaption']
               if not is_set(TimeCaption) then
                   TimeCaption = cfg.messages['event'];
                   if sepc ~= '.' then
                       TimeCaption = TimeCaption:lower();
                   end
               end
               Position = " " .. TimeCaption .. " " .. Time;
           end
       end
   else
       Position = " " .. Position;
       At = ;
   end
   
   if not is_set(Page) then
       if is_set(Pages) then
           if is_set(Periodical) and
               not inArray(config.CitationClass, {"encyclopaedia","web","book","news"}) then
               Pages = ": " .. Pages;
           elseif tonumber(Pages) ~= nil then
               Pages = sepc .." " .. PPrefix .. Pages;
           else
               Pages = sepc .." " .. PPPrefix .. Pages;
           end
       end
   else
       if is_set(Periodical) and
           not inArray(config.CitationClass, {"encyclopaedia","web","book","news"}) then
           Page = ": " .. Page;
       else
           Page = sepc .." " .. PPrefix .. Page;
       end
   end
   
   At = is_set(At) and (sepc .. " " .. At) or "";
   Position = is_set(Position) and (sepc .. " " .. Position) or "";
   if config.CitationClass == 'map' then
       local Section = A['Section'];
       local Inset = A['Inset'];
       if first_set( Pages, Page, At ) ~= nil or sepc ~= '.' then
           if is_set( Section ) then
               Section = ", " .. wrap( 'section', Section, true );
           end
           if is_set( Inset ) then
               Inset = ", " .. wrap( 'inset', Inset, true );
           end
       else
           if is_set( Section ) then
               Section = sepc .. " " .. wrap( 'section', Section, use_lowercase );
               if is_set( Inset ) then
                   Inset = ", " .. wrap( 'inset', Inset, true );
               end
           elseif is_set( Inset ) then
               Inset = sepc .. " " .. wrap( 'inset', Inset, use_lowercase );
           end            
       end            
       At = At .. Section .. Inset;        
   end    

--[[Look in the list of iso639-1 language codes to see if the value provided in the language parameter matches one of them. If a match is found, use that value; if not, then use the value that was provided with the language parameter.

Categories are assigned in a manner similar to the الگو:Xx icon templates - categorizes only mainspace citations and only when the language code is not 'en' (English). ]] if is_set (Language) then local name = cfg.iso639_1[Language:lower()]; -- get the language name if Language parameter has a valid iso 639-1 code if nil == name then Language=" " .. wrap( 'language', Language ); -- no match, use parameter's value else if 0 == this_page.namespace and 'en' ~= Language:lower() then --found a match; is this page main / article space and English not the language? Language=" " .. wrap( 'language', name .. ); -- in main space and not English: categorize else Language=" " .. wrap( 'language', name ); --not in mainspace or language is English so don't categorize end end else Language=""; -- language not specified so make sure this is an empty string; end

Others = is_set(Others) and (sepc .. " " .. Others) or "";

-- handle type parameter for those CS1 citations that have default values

if inArray(config.CitationClass, {"pressrelease","techreport","thesis", "speech"}) then TitleType = set_titletype (config.CitationClass, TitleType); if is_set(Degree) and "Thesis" == TitleType then -- special case for cite thesis TitleType = Degree .. " thesis"; end end

if is_set(TitleType) then -- if type parameter is specified TitleType = " (" .. TitleType .. ")"; -- display it in parentheses end

TitleNote = is_set(TitleNote) and (sepc .. " " .. TitleNote) or "";

   Edition = is_set(Edition) and (" " .. wrap( 'edition', Edition )) or "";
   Issue = is_set(Issue) and (" (" .. Issue .. ")") or "";
   Series = is_set(Series) and (sepc .. " " .. Series) or "";
   OrigYear = is_set(OrigYear) and (" [" .. OrigYear .. "]") or "";
   Agency = is_set(Agency) and (sepc .. " " .. Agency) or "";
   
   if is_set(Volume) then
       if ( mw.ustring.len(Volume) > 4 )
         then Volume = sepc .." " .. Volume;
         else Volume = " " .. hyphentodash(Volume) .. "";
       end
   end
   
   ------------------------------------ totally unrelated data
   --[[ Loosely mimic الگو:Subscription required template; Via parameter identifies a delivery source that is not the publisher; these sources often, but not always, exist
   behind a registration or paywall.  So here, we've chosen to decouple via from subscription (via has never been part of the registration required template).
   
   Subscription implies paywall; Registration does not.  If both are used in a citation, the subscription required link note is displayed. There are no error messages for this condition.
   ]]
   if is_set(Via) then
       Via = " " .. wrap( 'via', Via );
   end

if is_set(SubscriptionRequired) then

       SubscriptionRequired = sepc .. " " .. cfg.messages['subscription']; --here when 'via' parameter not used but 'subscription' is
   elseif is_set(RegistrationRequired) then
       SubscriptionRequired = sepc .. " " .. cfg.messages['registration']; --here when 'via' and 'subscription' parameters not used but 'registration' is
   end
   if is_set(AccessDate) then
       local retrv_text = " " .. cfg.messages['retrieved']
       if (sepc ~= ".") then retrv_text = retrv_text:lower() end
       AccessDate = '' .. sepc
           .. substitute( retrv_text, {AccessDate} ) .. ''
   end
   
   if is_set(ID) then ID = sepc .." ".. ID; end
  	if "thesis" == config.CitationClass and is_set(Docket) then

ID = sepc .." Docket ".. Docket .. ID; end


   ID_list = buildidlist( ID_list, {DoiBroken = DoiBroken, ASINTLD = ASINTLD, IgnoreISBN = IgnoreISBN, Embargo=Embargo} );
   if is_set(URL) then
       URL = " " .. externallink( URL, nil, URLorigin );
   end
   if is_set(Quote) then
       if Quote:sub(1,1) == '"' and Quote:sub(-1,-1) == '"' then
           Quote = Quote:sub(2,-2);
       end
       Quote = sepc .." " .. wrap( 'quoted-text', Quote ); 
       PostScript = "";
   elseif PostScript:lower() == "none" then
       PostScript = "";
   end
   
   local Archived
   if is_set(ArchiveURL) then
       if not is_set(ArchiveDate) then
           ArchiveDate = seterror('archive_missing_date');
       end
       if "no" == DeadURL then
           local arch_text = cfg.messages['archived'];
           if sepc ~= "." then arch_text = arch_text:lower() end
           Archived = sepc .. " " .. substitute( cfg.messages['archived-not-dead'],
               { externallink( ArchiveURL, arch_text ), ArchiveDate } );
           if not is_set(OriginalURL) then
               Archived = Archived .. " " .. seterror('archive_missing_url');                               
           end
       elseif is_set(OriginalURL) then
           local arch_text = cfg.messages['archived-dead'];
           if sepc ~= "." then arch_text = arch_text:lower() end
           Archived = sepc .. " " .. substitute( arch_text,
               { externallink( OriginalURL, cfg.messages['original'] ), ArchiveDate } );
       else
           local arch_text = cfg.messages['archived-missing'];
           if sepc ~= "." then arch_text = arch_text:lower() end
           Archived = sepc .. " " .. substitute( arch_text, 
               { seterror('archive_missing_url'), ArchiveDate } );
       end
   else
       Archived = ""
   end
   
   local Lay
   if is_set(LayURL) then
       if is_set(LayDate) then LayDate = " (" .. LayDate .. ")" end
       if is_set(LaySource) then 
           LaySource = " – " .. safeforitalics(LaySource) .. "";
       else
           LaySource = "";
       end
       if sepc == '.' then
           Lay = sepc .. " " .. externallink( LayURL, cfg.messages['lay summary'] ) .. LaySource .. LayDate
       else
           Lay = sepc .. " " .. externallink( LayURL, cfg.messages['lay summary']:lower() ) .. LaySource .. LayDate
       end            
   else
       Lay = "";
   end
   
   if is_set(Transcript) then
       if is_set(TranscriptURL) then Transcript = externallink( TranscriptURL, Transcript ); end
   elseif is_set(TranscriptURL) then
       Transcript = externallink( TranscriptURL, nil, TranscriptURLorigin );
   end
   
   local Publisher;
   if is_set(Periodical) and
       not inArray(config.CitationClass, {"encyclopaedia","web","pressrelease"}) then
       if is_set(PublisherName) then
           if is_set(PublicationPlace) then
               Publisher = PublicationPlace .. ": " .. PublisherName;
           else
               Publisher = PublisherName;  
           end
       elseif is_set(PublicationPlace) then
           Publisher= PublicationPlace;
       else 
           Publisher = "";
       end
       if is_set(PublicationDate) then
           if is_set(Publisher) then
               Publisher = Publisher .. ", " .. wrap( 'published', PublicationDate );
           else
               Publisher = PublicationDate;
           end
       end
       if is_set(Publisher) then
           Publisher = " (" .. Publisher .. ")";
       end
   else
       if is_set(PublicationDate) then
           PublicationDate = " (" .. wrap( 'published', PublicationDate ) .. ")";
       end
       if is_set(PublisherName) then
           if is_set(PublicationPlace) then
               Publisher = sepc .. " " .. PublicationPlace .. ": " .. PublisherName .. PublicationDate;
           else
               Publisher = sepc .. " " .. PublisherName .. PublicationDate;  
           end            
       elseif is_set(PublicationPlace) then 
           Publisher= sepc .. " " .. PublicationPlace .. PublicationDate;
       else 
           Publisher = PublicationDate;
       end
   end
   
   -- Several of the above rely upon detecting this as nil, so do it last.
   if is_set(Periodical) then
       if is_set(Title) or is_set(TitleNote) then 
           Periodical = sepc .. " " .. wrap( 'italic-title', Periodical ) 
       else 
           Periodical = wrap( 'italic-title', Periodical )
       end
   end
   -- Piece all bits together at last.  Here, all should be non-nil.
   -- We build things this way because it is more efficient in LUA
   -- not to keep reassigning to the same string variable over and over.
   local tcommon
   if inArray(config.CitationClass, {"journal","citation"}) and is_set(Periodical) then
       if is_set(Others) then Others = Others .. sepc .. " " end
       tcommon = safejoin( {Others, Title, TitleNote, Conference, Periodical, Format, TitleType, Scale, Series, 
           Language, Cartography, Edition, Publisher, Agency, Volume, Issue}, sepc );
   else 
       tcommon = safejoin( {Title, TitleNote, Conference, Periodical, Format, TitleType, Scale, Series, Language, 
           Volume, Issue, Others, Cartography, Edition, Publisher, Agency}, sepc );
   end
   
   if #ID_list > 0 then
       ID_list = safejoin( { sepc .. " ",  table.concat( ID_list, sepc .. " " ), ID }, sepc );
   else
       ID_list = ID;
   end
   
   local idcommon = safejoin( { ID_list, URL, Archived, AccessDate, Via, SubscriptionRequired, Lay, Quote }, sepc );
   local text;
   local pgtext = Position .. Page .. Pages .. At;
   
   if is_set(Authors) then
       if is_set(Coauthors) then
           Authors = Authors .. A['AuthorSeparator'] .. " " .. Coauthors
       end
       if is_set(Date) then
           Date = " ("..Date..")" .. OrigYear .. sepc .. " "
       elseif string.sub(Authors,-1,-1) == sepc then
           Authors = Authors .. " "
       else
           Authors = Authors .. sepc .. " "
       end
       if is_set(Editors) then
           local in_text = " ";
           local post_text = "";
           if is_set(Chapter) then
               in_text = in_text .. cfg.messages['in'] .. " "
           else
               if EditorCount <= 1 then
                   post_text = ", " .. cfg.messages['editor'];
               else
                   post_text = ", " .. cfg.messages['editors'];
               end
           end 
           if (sepc ~= '.') then in_text = in_text:lower() end
           Editors = in_text .. Editors .. post_text;
           if (string.sub(Editors,-1,-1) == sepc)
               then Editors = Editors .. " "
               else Editors = Editors .. sepc .. " "
           end
       end
       text = safejoin( {Authors, Date, Chapter, Place, Editors, tcommon }, sepc );
       text = safejoin( {text, pgtext, idcommon}, sepc );
   elseif is_set(Editors) then
       if is_set(Date) then
           if EditorCount <= 1 then
               Editors = Editors .. ", " .. cfg.messages['editor'];
           else
               Editors = Editors .. ", " .. cfg.messages['editors'];
           end
           Date = " (" .. Date ..")" .. OrigYear .. sepc .. " "
       else
           if EditorCount <= 1 then
               Editors = Editors .. " (" .. cfg.messages['editor'] .. ")" .. sepc .. " "
           else
               Editors = Editors .. " (" .. cfg.messages['editors'] .. ")" .. sepc .. " "
           end
       end
       text = safejoin( {Editors, Date, Chapter, Place, tcommon}, sepc );
       text = safejoin( {text, pgtext, idcommon}, sepc );
   else
       if is_set(Date) then
           if ( string.sub(tcommon,-1,-1) ~= sepc )
             then Date = sepc .." " .. Date .. OrigYear
             else Date = " " .. Date .. OrigYear
           end
       end
       if config.CitationClass=="journal" and is_set(Periodical) then
           text = safejoin( {Chapter, Place, tcommon}, sepc );
           text = safejoin( {text, pgtext, Date, idcommon}, sepc );
       else
           text = safejoin( {Chapter, Place, tcommon, Date}, sepc );
           text = safejoin( {text, pgtext, idcommon}, sepc );
       end
   end
   
   if is_set(PostScript) and PostScript ~= sepc then
       text = safejoin( {text, sepc}, sepc );  --Deals with italics, spaces, etc.
       text = text:sub(1,-2); --Remove final seperator    
   end    
   
   text = safejoin( {text, PostScript}, sepc );
   -- Now enclose the whole thing in a  element
   local options = {};
   
   if is_set(config.CitationClass) and config.CitationClass ~= "citation" then
       options.class = "citation " .. config.CitationClass;
   else
       options.class = "citation";
   end
   
   if is_set(Ref) and Ref:lower() ~= "none" then
       local id = Ref
       if ( "harv" == Ref ) then
           local names = {} --table of last names & year
           if #a > 0 then
               for i,v in ipairs(a) do 
                   names[i] = v.last 
                   if i == 4 then break end
               end
           elseif #e > 0 then
               for i,v in ipairs(e) do 
                   names[i] = v.last 
                   if i == 4 then break end                
               end
           end

names[ #names + 1 ] = first_set(Year, anchor_year); -- Year first for legacy citations -- names[ #names + 1 ] = Year or anchor_year; -- Year first for legacy citations

           id = anchorid(names)
       end
       options.id = id;
   end
   
   if string.len(text:gsub("<span[^>/]*>.-", ""):gsub("%b<>","")) <= 2 then
       z.error_categories = {};
       text = seterror('empty_citation');
       z.message_tail = {};
   end
   
   if is_set(options.id) then 
       text = '' .. text .. "";
   else
       text = '' .. text .. "";
   end        
   local empty_span = ' ';
   
   -- Note: Using display: none on then COinS span breaks some clients.
   local OCinS = '' .. empty_span .. '';
   text = text .. OCinS;
   
   if #z.message_tail ~= 0 then
       text = text .. " ";
       for i,v in ipairs( z.message_tail ) do
           if is_set(v[1]) then
               if i == #z.message_tail then
                   text = text .. errorcomment( v[1], v[2] );
               else
                   text = text .. errorcomment( v[1] .. "; ", v[2] );
               end
           end
       end
   end
   
   no_tracking_cats = no_tracking_cats:lower();
   if inArray(no_tracking_cats, {"", "no", "false", "n"}) then
       for _, v in ipairs( z.error_categories ) do
           text = text .. ;
       end
   end
   
   return text

end

-- This is used by templates such as خطای لوآ در خط 55: bad argument #1 to 'message.newRawMessage' (string expected, got nil). to create the actual citation text. function z.citation(frame)

   local pframe = frame:getParent()
   
   local args = {};
   local suggestions = {};
   local error_text, error_state;
   local config = {};
   for k, v in pairs( frame.args ) do
       config[k] = v;
       args[k] = v;       
   end    
   for k, v in pairs( pframe.args ) do
       if v ~=  then
           if not validate( k ) then            
               error_text = "";
               if type( k ) ~= 'string' then
                   -- Exclude empty numbered parameters
                   if v:match("%S+") ~= nil then
                       error_text, error_state = seterror( 'text_ignored', {v}, true );
                   end
               elseif validate( k:lower() ) then 
                   error_text, error_state = seterror( 'parameter_ignored_suggest', {k, k:lower()}, true );
               else
                   if #suggestions == 0 then
                       suggestions = mw.loadData( 'Module:Citation/CS1/Suggestions' );
                   end
                   if suggestions[ k:lower() ] ~= nil then
                       error_text, error_state = seterror( 'parameter_ignored_suggest', {k, suggestions[ k:lower() ]}, true );
                   else
                       error_text, error_state = seterror( 'parameter_ignored', {k}, true );
                   end
               end                  
               if error_text ~=  then
                   table.insert( z.message_tail, {error_text, error_state} );
               end                
           end
           args[k] = v;
       elseif args[k] ~= nil or (k == 'postscript') then
           args[k] = v;
       end        
   end    
   
   return citation0( config, args)

end

return z