Editing Module:Citation/CS1

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' );

-- Checks that parameter name is valid
function validate( name )
    name = tostring( name );
    
    -- Normal arguments
    if whitelist.basic_arguments[ name ] then
        return true;
    end
    
    -- Arguments with numbers in them
    name = name:gsub( "%d+", "#" );
    if whitelist.numbered_arguments[ name ] then
        return true;
    end
    
    -- Not found, argument not supported.
    return false
end

-- Formats a comment for error trapping
function errorcomment( content, hidden )
    if hidden then 
        return '<span style="display:none;font-size:100%" class="error citation-comment">' .. content .. '</span>';
    else
        return '<span style="font-size:100%" class="error">' .. content .. '</span>';
    end        
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, args, raw )
    local error_state = cfg.error_conditions[ error_id ];

    if error_state == nil then
        error( cfg.message_list['undefined_error'] );
    end
    
    if error_state.category ~= nil and error_state.category ~= "" then
        table.insert( z.error_categories, error_state.category );
    end
    
    local message = error_state.message;
    if args ~= nil then
        for k, m in ipairs( args ) do
            m = m:gsub( "%%", "%%%%" );
            message = message:gsub( "$" .. k .. "(%D)", m .. "%1" );
        end
    end

    message = wikiescape(message) .. " ([[" .. cfg.message_list['help page link'] .. 
        "#" .. error_state.anchor .. "|" ..
        cfg.message_list['help page label'] .. "]])";

    z.error_ids[ error_id ] = true;
    if (error_id == 'bare_url_missing_title' or error_id == 'trans_missing_title')
            and z.error_ids['citation_missing_title'] then
        return '', false;
    end
    
    if raw == true then
        return message, error_state.hidden;
    end        
        
    return errorcomment( message, error_state.hidden );
end

-- This returns a string with HTML character entities for wikitext markup characters.
function wikiescape(text)
    text = text:gsub( '[&\'%[%]{|}]', {    
            ['&'] = '&#38;',    
            ["'"] = '&#39;',    
            ['['] = '&#91;',    
            [']'] = '&#93;',    
            ['{'] = '&#123;',    
            ['|'] = '&#124;',	
            ['}'] = '&#125;' } );
    return text;
end

-- Formats a wiki style external link
function externallinkid(options)
    local sep = options.separator or "&nbsp;"
    options.suffix = options.suffix or ""
    local url_string = options.id
    if options.encode == true or options.encode == nil then
        url_string = mw.uri.encode( url_string );
    end
    
    return "[[" .. options.link .. "|" .. options.label .. "]]" .. sep .. "[" .. 
            options.prefix .. url_string .. options.suffix .. " " .. mw.text.nowiki(options.id) .. "]"
end

-- Formats a wiki style internal link
function internallinkid(options)
    local sep = options.separator or "&nbsp;"
    options.suffix = options.suffix or ""
    return "[[" .. options.link .. "|" .. options.label .. "]]" .. sep .. "[[" .. 
            options.prefix .. options.id .. options.suffix .. "|" .. mw.text.nowiki(options.id) .. "]]"
end

-- Format an external link with error checking
function externallink( URL, label )
    local error_str = "";
    if label == nil or label == "" then
        label = URL;
        error_str = seterror( 'bare_url_missing_title' );
    end
    if not checkurl( URL ) then
        error_str = seterror( 'bad_url' ) .. error_str;
    end

    return "[" .. URL .. ' ' .. safeforurl( label ) .. "]" .. error_str;
end

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

-- Formats a DOI and checks for DOI errors.
function doi(id, inactive)
    local cat = ""
    local handler = cfg.id_handlers['DOI'];
    
    local text;
    if ( inactive ~= nil ) then 
        text = "[[" .. handler.link .. "|" .. handler.label .. "]]:" .. id;
        table.insert( z.error_categories, "Pages with DOIs inactive since " .. selectyear(inactive) );        
        inactive = " (" .. cfg.message_list['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

--[[
Determines whether an 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 )
    if url_str:sub(1,2) == "//" then  
        -- Protocol-less URLs
        return true;
    elseif url_str:match( "^[^/]*:" ) ~= nil then   
        -- Look for ":" prefix and assume it is a URI scheme
        return true;
    else
        -- Anything else is an error
        return false;
    end
end

-- Determines whether an ISBN string is valid
function checkisbn( isbn_str )
    isbn_str = isbn_str:gsub("[- ]", ""):upper();
    local len = isbn_str:len();
 
    if len ~= 10 and len ~= 13 then
        return false;
    end
 
    local temp = 0;
    if len == 10 then
        if isbn_str:match( "^%d*X?$" ) == nil then return false; end
        isbn_str = { isbn_str:byte(1, len) };
        for i, v in ipairs( isbn_str ) do
            if v == string.byte( "X" ) then
                temp = temp + 10*( 11 - i );
            else
                temp = temp + tonumber( string.char(v) )*(11-i);
            end
        end
        return temp % 11 == 0;
    else
        if isbn_str:match( "^%d*$" ) == nil then return false; end
        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 [[A|B]] or [[B]] gives B
function removewikilink( str )
    str = str:gsub( "%[%[[^|%]]*|([^%]]*)%]%]", "%1" );
    str = str:gsub( "%[%[([^%]]*)%]%]", "%1" );    
    return str
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]', {    
        ['['] = '&#91;',	
        [']'] = '&#93;',	
        ['\n'] = ' ' } );
end

-- Converts a hyphen to a dash
function hyphentodash( str )
    if str == nil then
        return nil;
    end    
    if 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 <i> 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, <i> and ''
    tend to interact poorly under Mediawiki's HTML tidy. ]]
    
    if str == nil or str == '' then
        return str;
    else
        if str:sub(1,1) == "'" then str = "<span />" .. str; end
        if str:sub(-1,-1) == "'" then str = str .. "<span />"; end
        return str;
    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  

--[[
Return the year portion of a date string, if possible.  
Returns empty string if the argument can not be interpreted
as a year.
]]
function selectyear( str )
    -- Is the input a simple number?
    local num = tonumber( str ); 
    if num ~= nil and num > 0 and num < 2100 and num == math.abs(num) then
        return str;
    else
        -- Use formatDate to interpret more complicated formats
        local lang = mw.getContentLanguage();
        local good, result;
        good, result = pcall( lang.formatDate, lang, 'Y', str )
        if good then 
            return result;
        else
            -- Can't make sense of this input, return blank.
            return "";
        end
    end
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;
    if sep:sub(-1,-1) ~= " " then sep = sep .. " " end
    local namesep = control.namesep
    local format = control.format
    local maximum = control.maximum
    local lastauthoramp = control.lastauthoramp;
    local text = {}
    local etal = false;
    for i,person in ipairs(people) do
        if (person.last ~= nil or person.last ~= "") then
            local mask = person.mask
            local one
            if ( maximum ~= nil and i == maximum + 1 ) then
                etal = true;
                break;
            elseif (mask ~= nil) then
                local n = tonumber(mask)
                if (n ~= nil) then
                    one = string.rep("&mdash;",n)
                else
                    one = mask
                end
            else
                one = person.last
                local first = person.first
                if (first ~= nil and first ~= '') then 
                    if ( "vanc" == format ) then first = reducetoinitials(first) end
                    one = one .. namesep .. first 
                end
                if (person.link ~= nil and person.link ~= "") then one = "[[" .. person.link .. "|" .. one .. "]]" end
            end
            table.insert(text, one)
        end
    end
    local count = #text;
    if count > 1 and lastauthoramp ~= nil and lastauthoramp ~= "" and not etal then
        text[count-1] = text[count-1] .. " & " .. text[count];
        text[count] = nil;
    end    
    local result = table.concat(text, sep) -- construct list
    if etal then 
        local etal_text = cfg.message_list['et al'];
        result = result .. " " .. etal_text;
    end
    
    -- if necessary wrap result in <span> tag to format in Small Caps
    if ( "scap" == format ) then result = 
        '<span class="smallcaps" style="font-variant:small-caps">' .. result .. '</span>';
    end 
    return result, count
end

-- Generates a CITEREF anchor ID.
function anchorid( options )
    return "CITEREF" .. mw.uri.anchorEncode( table.concat( options ) );
end

-- Gets author list from the input arguments
function extractauthors(args)
    local authors = {};
    local i = 1;
    local last;
    while true do
        if i == 1 then 
            last = selectone( args, {"author" .. i .. "-last", "author-last" .. i, 
                "last" .. i, "surname" .. i, "Author" .. i, "author" .. i, 
                "author-last", "last", "surname", "Author", "author", "authors"}, 'redundant_parameters' );
        else
            last = selectone( args, {"author" .. i .. "-last", "author-last" .. i, 
                "last" .. i, "surname" .. i, "Author" .. i, "author" .. i}, 'redundant_parameters' );
        end
        if ( last and "" < last ) then -- just in case someone passed in an empty parameter
            if i == 1 then 
                authors[i] = {
                    last = last,
                    first = selectone( args, {"author" .. i .. "-first", "author-first" .. i, 
                        "first" .. i, "given" .. i, "author-first", 
                        "first", "given"}, 'redundant_parameters' ),
                    link = selectone( args, {"author" .. i .. "-link", "author-link" .. i, 
                        "author" .. i .. "link", "authorlink" .. i, "author-link",  
                        "authorlink"}, 'redundant_parameters' ),
                    mask = selectone( args, {"author" .. i .. "-mask", "author-mask" .. i, 
                        "author" .. i .. "mask", "authormask" .. i, "author-mask", 
                        "authormask" }, 'redundant_parameters' )
                }
            else
                authors[i] = {
                    last = last,
                    first = selectone( args, {"author" .. i .. "-first", "author-first" .. i, 
                        "first" .. i, "given" .. i}, 'redundant_parameters' ),
                    link = selectone( args, {"author" .. i .. "-link", "author-link" .. i, 
                        "author" .. i .. "link", "authorlink" .. i}, 'redundant_parameters' ),
                    mask = selectone( args, {"author" .. i .. "-mask", "author-mask" .. i, 
                        "author" .. i .. "mask", "authormask" .. i}, 'redundant_parameters' )
                }
            end            
        else
            break;
        end
        i = i + 1;
    end
    return authors;
end

-- Gets editor list from the input arguments
function extracteditors(args)
    local editors = {};
    local i = 1;
    local last;
    
    while true do
        if i == 1 then
            last = selectone( args, {"editor" .. i .. "-last", "editor-last" .. i,
                "EditorSurname" .. i, "Editor" .. i, "editor" .. i, "editor-last", 
                "EditorSurname", "Editor", "editor", "editors"}, 'redundant_parameters' );
        else
            last = selectone( args, {"editor" .. i .. "-last", "editor-last" .. i,
                "EditorSurname" .. i, "Editor" .. i, "editor" .. i}, 'redundant_parameters' );
        end        
        if ( last and "" < last ) then -- just in case someone passed in an empty parameter
            if i == 1 then
                editors[i] = {
                    last = last,
                    first = selectone( args, {"editor" .. i .. "-first", 
                        "editor-first" .. i, "EditorGiven" .. i, "editor-first", 
                        "EditorGiven"}, 'redundant_parameters' ),
                    link = selectone( args, {"editor" .. i .. "-link", "editor-link" .. i, 
                        "editor" .. i .. "link", "editorlink" .. i, "editor-link", 
                        "editorlink"}, 'redundant_parameters' ),
                    mask = selectone( args, {"editor" .. i .. "-mask", "editor-mask" .. i, 
                        "editor" .. i .. "mask", "editormask" .. i, "editor-mask",  
                        "editormask"}, 'redundant_parameters' )
                }                
            else
                editors[i] = {
                    last = last,
                    first = selectone( args, {"editor" .. i .. "-first", 
                        "editor-first" .. i, "EditorGiven" .. i}, 'redundant_parameters' ),
                    link = selectone( args, {"editor" .. i .. "-link", "editor-link" .. i, 
                        "editor" .. i .. "link", "editorlink" .. i}, 'redundant_parameters' ),
                    mask = selectone( args, {"editor" .. i .. "-mask", "editor-mask" .. i, 
                        "editor" .. i .. "mask", "editormask" .. i}, 'redundant_parameters' )
                }
            end
        else
            break;
        end
        i = i + 1;
    end
    return editors;
end

-- Populates ID table from arguments using configuration settings
function extractids( args )
    local id_list = {};
    
    for k, v in pairs( cfg.id_handlers ) do    
        id_list[k] = selectone( args, v.parameters, 'redundant_parameters' );
    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 handler;
    local new_list = {};
    
    for k, v in pairs( id_list ) do
        handler = {};
        
        --Becasue cfg is read-only we have to copy it the hard way.
        for k2, v2 in pairs( cfg.id_handlers[k] ) do
            handler[k2] = v2;
        end
        handler['id'] = v;
        
        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
            if 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 == 'ISBN' then
                local ISBN = internallinkid( handler );
                if not checkisbn( v ) and (IgnoreISBN == nil or IgnoreISBN == "") then 
                    ISBN = ISBN .. seterror( 'bad_isbn' );
                end
                table.insert( new_list, {handler.label, ISBN } );                
            else
                error( cfg.message_list['unknown_manual_ID'] );
            end            
        else
            error( cfg.message_list['unknown_ID_mode'] );
        end
    end

    function comp( a, b )
        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 )
    local value = nil;
    local selected = '';
    local error_list = {};
    
    for _, v in ipairs( possible ) do
        if args[v] ~= nil then
            if value ~= nil 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 .. ", " end
            error_str = error_str .. "<code>|" .. k .. "=</code>";
        end
        if #error_list > 1 then
            error_str = error_str .. ", and ";
        else
            error_str = error_str .. " and ";
        end
        error_str = error_str .. "<code>|" .. selected .. "=</code>";
        table.insert( z.message_tail, { seterror( error_condition, {error_str}, true ) } );
    end
            
    return value, selected;
end

--[[
This is the main function foing the majority of the citation
formatting.
]]
function citation0( config, args)
    -- Load Input Parameters

    local i 
    local PPrefix = config.PPrefix or "p.&nbsp;"
    local PPPrefix = config.PPPrefix or "pp.&nbsp;"
    if ( nil ~= args.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 = args.authors
    local a = extractauthors( args );

    local Coauthors = selectone( args, {'coauthors', 'coauthor' }, 'redundant_parameters' );
    local Others = args.others 
    local Editors = args.editors
    local e = extracteditors( args );

    local Year = args.year 
    local PublicationDate = selectone( args, {'publicationdate', 'publication-date' }, 'redundant_parameters' );
    local OrigYear = args.origyear
    local Date = args.date
    local LayDate = args.laydate
    ------------------------------------------------- Get title data
    local Title = args.title or args.encyclopaedia or args.encyclopedia or args.dictionary
    local BookTitle = args.booktitle
    local Conference = args.conference
    local TransTitle = selectone( args, {'trans-title', 'trans_title' }, 'redundant_parameters' );
    local TitleNote = args.department
    local TitleLink = selectone( args, {'titlelink', 'episodelink' }, 'redundant_parameters' );
    local Chapter = selectone( args, {'chapter', 'contribution', 'entry' }, 'redundant_parameters' );
    local ChapterLink = args.chapterlink
    local TransChapter = selectone( args, {'trans-chapter', 'trans_chapter' }, 'redundant_parameters' );
    local TitleType = args.type
    local ArchiveURL = selectone( args, {'archive-url', 'archiveurl' }, 'redundant_parameters' );
    local URL = selectone( args, {'url', 'URL'}, 'redundant_parameters' );
    local ChapterURL = selectone( args, {'chapter-url', 'chapterurl', 'contribution-url', 'contributionurl' }, 'redundant_parameters' );
    local ConferenceURL = selectone( args, {'conference-url', 'conferenceurl' }, 'redundant_parameters' );
    local Periodical = selectone( args, {'journal', 'newspaper', 'magazine', 'work', 'website', 
        'periodical', 'encyclopedia', 'encyclopaedia'}, 'redundant_parameters' );
            
    if ( config.CitationClass == "encyclopaedia" ) then
        if ( args.article and args.article ~= "") then
            if ( Title and Title ~= "") then Periodical = Title end
            Chapter = args.article
            TransChapter = TransTitle
            Title = nil          
            TransTitle = nil
        elseif ( Chapter == nil or Chapter == '' ) then
            if Title ~= args.encyclopedia then 
                Chapter = Title
                TransChapter = TransTitle
                Title = nil 
                TransTitle = nil
            end
        end
        if ( Periodical and Periodical ~= "") then
            if Periodical == Title or Periodical == Chapter then Periodical = nil end
        end
    end
    local Series = selectone( args, {'series', 'version'}, 'redundant_parameters' );
    local Volume = args.volume
    local Issue = selectone( args, {'issue', 'number'}, 'redundant_parameters' );
    local Position = nil
    local Page, Pages, At, page_type;
    
    Page, page_type = selectone( args, {'p', 'page', 'pp', 'pages', 'at'}, 
        'extra_pages' );
    if page_type == 'pp' or page_type == 'pages' then
        Pages = hyphentodash( Page );
        Page = nil;
    elseif page_type == 'at' then
        At = Page;
        Page = nil;
    end
                
    local Edition = args.edition
    local PublicationPlace = selectone( args, {'publication-place', 'publicationplace' }, 'redundant_parameters' ); 
    local Place = selectone( args, {'place', 'location'}, 'redundant_parameters' );
    if PublicationPlace == nil and Place ~= nil then 
        PublicationPlace = Place;
    end
    if PublicationPlace == Place then Place = nil end
    
    local PublisherName = args.publisher
    local SubscriptionRequired = args.subscription
    local Via = args.via
    local AccessDate = selectone( args, {'access-date', 'accessdate' }, 'redundant_parameters' );
    local ArchiveDate = selectone( args, {'archive-date', 'archivedate' }, 'redundant_parameters' );
    local Agency = args.agency
    local DeadURL = args.deadurl or "yes"           -- Only used if ArchiveURL is present.
    local Language = selectone( args, {'language', 'in'}, 'redundant_parameters' );
    local Format = args.format
    local Ref = selectone( args, {'ref', 'Ref'}, 'redundant_parameters' );

    local DoiBroken = selectone( args, {'doi_inactivedate', 'doi_brokendate', 'DoiBroken'}, 'redundant_parameters' );
    local ID = selectone( args, {'id', 'ID', 'docket'}, 'redundant_parameters' );
    local ASINTLD = selectone( args, {'ASIN-TLD', 'asin-tld'}, 'redundant_parameters' );
    local IgnoreISBN = selectone( args, {'ignore-isbn-error', 'ignoreisbnerror'}, 'redundant_parameters' );

    local ID_list = extractids( args );
    
    local Quote = selectone( args, {'quote', 'quotation'}, 'redundant_parameters' );
    local PostScript = args.postscript or "."
    local LaySummary = args.laysummary
    local LaySource = args.laysource
    local Transcript = args.transcript
    local TranscriptURL = selectone( args, {'transcript-url', 'transcripturl'}, 'redundant_parameters' );
    local sepc = args.separator or "."
    local LastAuthorAmp = args.lastauthoramp
    local no_tracking_cats = selectone( args, {"template doc demo", 'nocat', 
        'notracking', "no-tracking"}, 'redundant_parameters' ) or "";

    if ( config.CitationClass == "journal" ) then        
        if (URL == nil or URL == "") then
            if (ID_list['PMC'] ~= nil) then 
                local Embargo = args.embargo or args.Embargo;
                if Embargo ~= nil then
                    local lang = mw.getContentLanguage();
                    local good1, result1, good2, result2;
                    good1, result1 = pcall( lang.formatDate, lang, 'U', Embargo );
                    good2, result2 = pcall( lang.formatDate, lang, 'U' );

                    if good1 and good2 and tonumber( result1 ) < tonumber( result2 ) then 
                        URL = "http://www.ncbi.nlm.nih.gov/pmc/articles/PMC" .. ID_list['PMC'];
                    end
                else
                    URL = "http://www.ncbi.nlm.nih.gov/pmc/articles/PMC" .. ID_list['PMC'];           
                end
            end
        end
    end

    -- 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 {{cite conference}}, before generation of COinS data.
    if ( BookTitle ) then
        Chapter = Title
        ChapterLink = TitleLink
        TransChapter = TransTitle
        Title = BookTitle
        TitleLink = nil
        TransTitle = nil
    end
    -- Account for the oddity that is {{cite episode}}, before generation of COinS data.
    if config.CitationClass == "episode" then
        local AirDate = args.airdate
        local SeriesLink = args.serieslink
        local Season = args.season
        local SeriesNumber = args.seriesnumber or args.seriesno
        local Network = args.network
        local Station = args.station
        local s = {}
        if Issue ~= nil then table.insert(s, cfg.message_list["episode"] .. " " .. Issue) Issue = nil end
        if Season ~= nil then table.insert(s, cfg.message_list["season"] .. " " .. Season) end
        if SeriesNumber ~= nil then table.insert(s, cfg.message_list["series"] .. " " .. SeriesNumber) end
        local n = {}
        if Network ~= nil then table.insert(n, Network) end
        if Station ~= nil then table.insert(n, Station) end
        Date = Date or AirDate
        Chapter = Title
        ChapterLink = TitleLink
        TransChapter = TransTitle
        Title = Series
        TitleLink = SeriesLink
        TransTitle = nil
        local Sep = args["series-separator"] or args["separator"] or ". "
        Series = table.concat(s, Sep)
        ID = table.concat(n, Sep)
    end
    
    -- These data form a COinS tag (see <http://ocoins.info/>) which allows 
    -- automated tools to parse the citation information.
    local OCinSdata = {} -- COinS metadata excluding id, bibcode, doi, etc.
    local ctx_ver = "Z39.88-2004" 
    OCinSdata.rft_val_fmt = "info:ofi/fmt:kev:mtx:book"
    if ( nil ~= Periodical ) then
        OCinSdata.rft_val_fmt = "info:ofi/fmt:kev:mtx:journal"
        OCinSdata["rft.genre"] = "article"
        OCinSdata["rft.jtitle"] = Periodical
        if ( nil ~= Title ) then OCinSdata["rft.atitle"] = Title end
    end
    if ( nil ~= Chapter and "" ~= Chapter) then
        OCinSdata.rft_val_fmt = "info:ofi/fmt:kev:mtx:book"
        OCinSdata["rft.genre"] = "bookitem"
        OCinSdata["rft.btitle"] = Chapter
        if ( nil ~= Title ) then OCinSdata["rft.atitle"] = Title end
    else
        OCinSdata["rft.genre"] = "book"
        if ( nil ~= Title ) then OCinSdata["rft.btitle"] = Title end
    end
    OCinSdata["rft.place"] = PublicationPlace
    OCinSdata["rft.date"] = Date or Year or PublicationDate
    OCinSdata["rft.series"] = Series
    OCinSdata["rft.volume"] = Volume
    OCinSdata["rft.issue"] = Issue
    OCinSdata["rft.pages"] = Page or Pages or At
    OCinSdata["rft.edition"] = Edition
    OCinSdata["rft.pub"] = PublisherName
    
    for k, v in pairs( ID_list ) do
        if string.sub( cfg.id_handlers[k].COinS or "info", 1, 4 ) ~= 'info' then
            OCinSdata[ cfg.id_handlers[k].COinS ] = v;
        end
    end
    
    OCinSdata.rft_id = URL or ChapterURL

    local last, first;
    local OCinSauthors = {};
    for k, v in ipairs( a ) do
        last = v.last;
        first = v.first;
        if k == 1 then
            if last ~= nil then
                OCinSdata["rft.aulast"] = last;
            end
            if first ~= nil then 
                OCinSdata["rft.aufirst"] = first;
            end
        end
        if last ~= nil and first ~= nil then
            table.insert( OCinSauthors, last .. (args.NameSep or ", ") .. first );
    	elseif last ~= nil then
            table.insert( OCinSauthors, last );
        end
    end

    local OCinSids = {} -- COinS data only for id, bibcode, doi, pmid, etc.
    for k, v in pairs( ID_list ) do
        if string.sub( cfg.id_handlers[k].COinS or "", 1, 4 ) == 'info' then
            OCinSids[ cfg.id_handlers[k].COinS ] = v;
        end
    end

    local OCinStitle = "ctx_ver=" .. ctx_ver  -- such as "Z39.88-2004"
    for name,value in pairs(OCinSdata) do
        OCinStitle = OCinStitle .. "&" .. name .. "=" .. mw.uri.encode( removewikilink(value) );
    end
    for _, value in ipairs(OCinSauthors) do
        OCinStitle = OCinStitle .. "&rft.au=" .. mw.uri.encode( removewikilink(value) );
    end
    for name,value in pairs(OCinSids) do
        OCinStitle = OCinStitle .. "&rft_id=" .. mw.uri.encode(name .. "/" .. removewikilink(value) );
    end
    
    local this_page = mw.title.getCurrentTitle();
    OCinStitle = OCinStitle .. "&rfr_id=info:sid/" .. mw.site.server:match( "[^/]*$" ) .. ":"
       .. this_page.prefixedText  -- end COinS data by page's non-encoded pagename

    if (Periodical ~= nil and Periodical ~= "") and
        (Chapter == nil or Chapter == '') and
        (Title ~= nil and Title ~= "") then
            Chapter = Title
            ChapterLink = TitleLink
            TransChapter = TransTitle
            Title = nil
            TitleLink = nil
            TransTitle = nil            
    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 ( Authors == nil ) then 
        local Maximum = tonumber( (selectone( args, {"display-authors", "displayauthors"}, 'redundant_parameters' )) );
        
        -- Preserve old-style implicit et al.
        if Maximum == nil and #a == 9 then 
            Maximum = 8;
            table.insert( z.message_tail, { seterror('implict_etal_author', {}, true ) } );
        elseif Maximum == nil then
            Maximum = #a + 1;
        end
            
        local control = { 
            sep = (args["author-separator"] or ";") .. " ",
            namesep = (args["author-name-separator"] or args["name-separator"] or ",") .. " ",
            format = selectone( args, {"author-format", "authorformat" }, 'redundant_parameters' ),
            maximum = Maximum,
            lastauthoramp = LastAuthorAmp
        }
        
        -- If the coauthor field is also used, prevent ampersand and et al. formatting.
        if Coauthors ~= nil and Coauthors ~= "" then
            control.lastauthoramp = nil;
            control.maximum = #a + 1;
        end
                
        Authors = listpeople(control, a) 
    end
    local EditorCount
    if ( Editors == nil ) then 
        local Maximum = tonumber( (selectone( args, {"display-editors", "displayeditors"}, 'redundant_parameters' )) );

        -- Preserve old-style implicit et al.
        if Maximum == nil and #e == 4 then 
            Maximum = 3;
            table.insert( z.message_tail, { seterror('implict_etal_editor', {}, true) } );
        elseif Maximum == nil then
            Maximum = #e + 1;
        end

        local control = { 
            sep = (args["editor-separator"] or ";") .. " ",
            namesep = (args["editor-name-separator"] or args["name-separator"] or ",") .. " ",
            format = selectone( args, {"editor-format", "editorformat" }, 'redundant_parameters' ),
            maximum = Maximum,
            lastauthoramp = LastAuthorAmp
            }

        Editors, EditorCount = listpeople(control, e) 
    else
        EditorCount = 1;
    end
    if ( Date == nil or Date == "") then
--   there's something hinky with how this adds dashes to perfectly-good free-standing years
--[[        Date = Year
        if ( Date ~= nil ) then
            local Month = args.month
            if ( Month == nil ) then 
                local Began = args.began
                local Ended = args.ended
                if Began ~= nil and Ended ~= nil then
                    Month = Began .. "&ndash;" .. Ended
                else
                    Month = "&ndash;"
                end
            end
            Date = Month .. " " .. Date
            local Day = args.day
            if ( Day ~= nil ) then Date = Day .. " " .. Date end
        end
]] -- so let's use the original version for now
        Date = Year
        if ( Date ~= nil and Date ~="") then
            local Month = args.month
            if ( Month ~= nil and Month ~= "") then 
                Date = Month .. " " .. Date 
                local Day = args.day
                if ( Day ~= nil ) then Date = Day .. " " .. Date end
                else Month = ""
            end
            else Date = ""
        end
    end
    if ( PublicationDate == Date or PublicationDate == Year ) then PublicationDate = nil end
    if( (Date == nil or Date == "") and PublicationDate ~= nil ) then 
        Date = PublicationDate;
        PublicationDate = nil;
    end    

    -- Captures the value for Date prior to adding parens or other textual transformations
    local DateIn = Date
    
    if ( URL == nil or URL == '' ) and
            ( ChapterURL == nil or ChapterURL == '' ) and
            ( ArchiveURL == nil or ArchiveURL == '' ) and                
            ( ConferenceURL == nil or ConferenceURL == '' ) and                
            ( TranscriptURL == nil or 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 ( AccessDate ~= nil and AccessDate ~= '' ) then
            table.insert( z.message_tail, { seterror( 'accessdate_missing_url', {}, true ) } );
            AccessDate = nil;
        end      
    
        -- Test if format is given without giving a URL
        if ( Format ~= nil and Format ~= '' ) then
            Format = Format .. seterror( 'format_missing_url' );
        end        
    end    

    -- Test if citation has no title
    if ( Chapter == nil or Chapter == "" ) and 
            ( Title == nil or Title == "" ) and
            ( Periodical == nil or Periodical == "" ) and
            ( Conference == nil or Conference == "" ) and 
            ( TransTitle == nil or TransTitle == "" ) and
            ( TransChapter == nil or TransChapter == "" ) then
        table.insert( z.message_tail, { seterror( 'citation_missing_title', {}, true ) } );
    end

    if ( Format ~= nil and Format ~="" ) then
        Format = " (" .. Format .. ")" else Format = "" end
    
    local OriginalURL = URL
    DeadURL = DeadURL:lower();
    if ( ArchiveURL and "" < ArchiveURL ) then
        if ( DeadURL ~= "no" ) then
            URL = ArchiveURL
        end
    end

    if ( TransTitle and "" < TransTitle ) then TransTitle = " [" .. TransTitle .. "&#93;" else TransTitle = "" end
    if ( TransChapter and "" < TransChapter ) then TransChapter = " [" .. TransChapter .. "&#93;" else TransChapter = "" end
        
    -- Format chapter / article title
    if ( Chapter ~= nil and Chapter ~= "" ) then
        if ( ChapterLink and "" < ChapterLink ) then Chapter = "[[" .. ChapterLink .. "|" .. Chapter .. "]]" end
        if ( Periodical and "" < Periodical ) and (Title ~= nil and Title ~= "" )
        then
            Chapter = "''" .. safeforitalics(Chapter) .. "''"
        else
            Chapter = "\"" .. Chapter .. "\""
        end
    else
        Chapter = "";
    end
    
    local TransError = ""
    if TransChapter ~= "" and Chapter == "" then
        TransError = " " .. seterror( 'trans_missing_chapter' );
    end
    Chapter = Chapter .. TransChapter
    if Chapter ~= "" then
        if ( ChapterLink == nil ) then
            if ( ChapterURL and "" < ChapterURL ) then                
                Chapter = externallink( ChapterURL, Chapter ) .. TransError;
                if URL == nil or URL == "" then
                    Chapter = Chapter .. Format;
                    Format = "";
                end
            elseif ( URL and "" < URL ) then 
                Chapter = externallink( URL, Chapter ) .. TransError .. Format;
                URL = nil
                Format = ""
            else
                Chapter = Chapter .. TransError;
            end            
        elseif ChapterURL ~= nil and ChapterURL ~= "" then
            Chapter = Chapter .. " " .. externallink( ChapterURL ) .. 
                TransError;
        else
            Chapter = Chapter .. TransError;
        end
        Chapter = Chapter .. sepc .. " " -- with end-space
    elseif ChapterURL ~= nil and ChapterURL ~= "" then
        Chapter = " " .. externallink( ChapterURL ) .. sepc .. " ";
    end        
    
    -- Format main title.
    if ( Title and "" < Title ) then
        if ( TitleLink and "" < TitleLink ) then
            Title = "[[" .. TitleLink .. "|" .. Title .. "]]" end
        if ( Periodical and "" < Periodical ) then
            Title = "\"" .. Title .. "\""
        elseif ( config.CitationClass == "web"
                or config.CitationClass == "news" 
                or config.CitationClass == "pressrelease" ) and 
                Chapter == "" then
            Title = "\"" .. Title .. "\""
        else
            Title = "''" .. safeforitalics(Title) .. "''"
        end
    else
        Title = "";
    end    
    
    local TransError = "";
    if TransTitle ~= "" and Title == "" then
        TransError = " " .. seterror( 'trans_missing_title' );
    end
    Title = Title .. TransTitle
    if Title ~= "" then
        if ( TitleLink == nil and URL and "" < URL ) then 
            Title = externallink( URL, Title ) .. TransError .. Format       
            URL = nil
            Format = ''
        else
            Title = Title .. TransError;
        end
    end

    if ( Place ~= nil and Place ~= "" ) then
        if sepc == '.' then
            Place = " " .. cfg.message_list['written'] .. " " .. Place .. sepc .. " ";
        else
            Place = " " .. cfg.message_list['written']:lower() .. " " .. Place .. sepc .. " ";
        end            
    else
        Place = "";
    end
    
    if ( Conference ~= nil and Conference ~="" ) then
        if ( ConferenceURL ~= nil ) then
            Conference = externallink( ConferenceURL, Conference );
        end
        Conference = " " .. Conference
    elseif ConferenceURL ~= nil and ConferenceURL ~= "" then
        Conference = " " .. externallink( ConferenceURL );
    else
        Conference = "" 
    end
    if ( nil ~= Position or nil ~= Page or nil ~= Pages ) then At = nil end
    if ( nil == Position and "" ~= Position ) then
        local Minutes = args.minutes
        if ( nil ~= Minutes ) then
            Position = " " .. Minutes .. " " .. cfg.message_list['minutes'];
        else
            local Time = args.time
            if ( nil ~= Time ) then
                local TimeCaption = args.timecaption 
                if TimeCaption == nil then
                    TimeCaption = cfg.message_list['event'];
                    if sepc ~= '.' then
                        TimeCaption = TimeCaption:lower();
                    end
                end                
                Position = " " .. TimeCaption .. " " .. Time
            else
                Position = ""
            end
        end
    else
        Position = " " .. Position
    end
    if ( nil == Page or "" == Page ) then 
        Page = "" 
        if ( nil == Pages or "" == Pages) then 
            Pages = ""
        elseif ( Periodical ~= nil and Periodical ~= "" and
                 config.CitationClass ~= "encyclopaedia" and
                 config.CitationClass ~= "web" and
                 config.CitationClass ~= "book" and
                 config.CitationClass ~= "news") then
            Pages = ": " .. Pages
        else
            if ( tonumber(Pages) ~= nil ) then
              Pages = sepc .." " .. PPrefix .. Pages
            else Pages = sepc .." " .. PPPrefix .. Pages
            end
        end
    else
        Pages = ""
        if ( Periodical ~= nil and Periodical ~= "" and
             config.CitationClass ~= "encyclopaedia" and
             config.CitationClass ~= "web" and
             config.CitationClass ~= "book" and
             config.CitationClass ~= "news") then
            Page = ": " .. Page
        else
            Page = sepc .." " .. PPrefix .. Page
        end
    end
    if ( At ~= nil and At ~="") then At = sepc .. " " .. At
    else At = "" end
    if ( Coauthors == nil ) then Coauthors = "" end
    if ( Others ~= nil and Others ~="" ) then
        Others = sepc .. " " .. Others else Others = "" end
    if ( TitleType ~= nil and TitleType ~="" ) then
        TitleType = " (" .. TitleType .. ")" else TitleType = "" end
    if ( TitleNote ~= nil and TitleNote ~="" ) then
        TitleNote = sepc .. " " .. TitleNote else TitleNote = "" end
    if ( Language ~= nil and Language ~="" ) then
        Language = " (" .. cfg.message_list['in'] .. " " .. Language .. ")" else Language = "" end
    if ( Edition ~= nil and Edition ~="" ) then
        Edition = " (" .. Edition .. " " .. cfg.message_list['edition'] .. ")" else Edition = "" end
    if ( Volume ~= nil and Volume ~="" )
    then
        if ( mw.ustring.len(Volume) > 4 )
          then Volume = sepc .." " .. Volume
          else Volume = " <b>" .. hyphentodash(Volume) .. "</b>"
        end
    else Volume = "" end
    if ( Issue ~= nil and Issue ~="" ) then
        Issue = " (" .. Issue .. ")" else Issue = "" end
    if ( Series ~= nil and Series ~="" ) then
        Series = sepc .. " " .. Series else Series = "" end
    if ( OrigYear ~= nil and OrigYear ~="" ) then
        OrigYear = " [" .. OrigYear .. "]" else OrigYear = "" end
    if ( Agency ~= nil and Agency ~="" ) then
        Agency = sepc .. " " .. Agency else Agency = "" end
    ------------------------------------ totally unrelated data
    if ( Date ~= nil ) then Date = Date else Date = "" end
    if ( Via ~= nil and Via ~="" ) then
        Via = " &mdash; " .. cfg.message_list['via'] .. " " .. Via else Via = "" end
    if ( AccessDate ~= nil and AccessDate ~="" )
    then local retrv_text = " " .. cfg.message_list['retrieved'] .. " "
         if (sepc ~= ".") then retrv_text = retrv_text:lower() end
         AccessDate = '<span class="reference-accessdate">' .. sepc
             .. retrv_text .. AccessDate .. '</span>'
    else AccessDate = "" end
    if ( SubscriptionRequired ~= nil and
         SubscriptionRequired ~= "" ) then
        SubscriptionRequired = sepc .. " " .. cfg.message_list['subscription'];
    else
        SubscriptionRequired = ""
    end
    if ( ID ~= nil and ID ~="") then ID = sepc .." ".. ID else ID="" end

    ID_list = buildidlist( ID_list, {DoiBroken = DoiBroken, ASINTLD = ASINTLD, IgnoreISBN = IgnoreISBN} );

    if ( URL ~= nil and URL ~="") then
        URL = " " .. externallink( URL, URL );
        local error_text = seterror( 'bare_url_missing_title' );
        if config.CitationClass == "web" then
            URL = URL .. " " .. seterror( 'cite_web_title' );
        else
            URL = URL .. error_text;
        end       
    else
        URL = ""
    end

    if ( Quote and Quote ~="" ) then 
        if Quote:sub(1,1) == '"' and Quote:sub(-1,-1) == '"' then
            Quote = Quote:sub(2,-2);
        end
        
        Quote = sepc .." \"" .. Quote .. "\"" 
        PostScript = ""
    else 
        if ( PostScript == nil) then PostScript = "" end
        Quote = "" 
    end
    
    local Archived
    if ( nil ~= ArchiveURL and "" ~= ArchiveURL ) then
        if ( ArchiveDate ~= nil and ArchiveDate ~="" ) then
            ArchiveDate = " " .. ArchiveDate
        else 
            ArchiveDate = " " .. seterror('archive_missing_date') .. " "
        end
        local arch_text = cfg.message_list['archived'];
        if (sepc ~= ".") then arch_text = arch_text:lower() end
        if ( "no" == DeadURL ) then
            Archived = sepc .. " " .. externallink( ArchiveURL, arch_text ) .. " " .. 
                cfg.message_list['from'] .. " " .. cfg.message_list['original'] .. " " .. 
                cfg.message_list['on'] .. ArchiveDate
            if OriginalURL == nil or OriginalUrl == '' then
                Archived = Archived .. " " .. seterror('archive_missing_url_not_dead');                               
            end
        else
            if OriginalURL ~= nil and OriginalURL ~= '' then
                Archived = sepc .. " " .. arch_text .. " " .. cfg.message_list['from'] .. 
                    " " .. externallink( OriginalURL, cfg.message_list['original'] ) .. " "
                    .. cfg.message_list['on'] .. ArchiveDate
            else
                if config.CitationClass ~= 'web' then 
                    Archived = sepc .. " " .. arch_text .. " " .. cfg.message_list['from'] .. " " .. 
                    cfg.message_list['original'] .. seterror('archive_missing_url') .. " " .. cfg.message_list['on'] .. ArchiveDate
                else
                    Archived = sepc .. " " .. arch_text .. " " .. cfg.message_list['from'] .. " " .. 
                    cfg.message_list['original'] .. seterror('archive_missing_url_web') .. " " .. cfg.message_list['on'] .. ArchiveDate
                end
            end                
        end
    else
        Archived = ""
    end
    local Lay
    if ( nil ~= LaySummary and "" ~= LaySummary ) then
        if ( LayDate ~= nil ) then LayDate = " (" .. LayDate .. ")" else LayDate = "" end
        if ( LaySource ~= nil ) then 
            LaySource = " &ndash; ''" .. safeforitalics(LaySource) .. "''" 
        else 
            LaySource = "" 
        end
        if sepc == '.' then
            Lay = sepc .. " [" .. LaySummary .. " " .. cfg.message_list['lay summary'] .. "]" .. LaySource .. LayDate
        else
            Lay = sepc .. " [" .. LaySummary .. " " .. cfg.message_list['lay summary']:lower() .. "]" .. LaySource .. LayDate
        end            
    else
        Lay = ""
    end
    if ( nil ~= Transcript and "" ~= Transcript ) then
        if ( TranscriptURL ~= nil ) then Transcript = externallink( TranscriptURL, Transcript ) end
    elseif TranscriptURL ~= nil and TranscriptURL ~= "" then
        Transcript = externallink( TranscriptURL )     
    else
        Transcript = ""
    end
    local Publisher = ""
    if ( Periodical and Periodical ~= "" and
         config.CitationClass ~= "encyclopaedia" and
         config.CitationClass ~= "web" and
         config.CitationClass ~= "pressrelease" ) then
        if ( PublisherName ~= nil and PublisherName ~="" ) then
            if (PublicationPlace ~= nil and PublicationPlace ~= '') then
                Publisher = PublicationPlace .. ": " .. PublisherName;
            else
                Publisher = PublisherName;  
            end            
        elseif (PublicationPlace ~= nil and PublicationPlace ~= '') then 
            Publisher= PublicationPlace;
        else 
            Publisher = "";
        end
        if ( PublicationDate and PublicationDate ~="" ) then
            if Publisher ~= '' then
                Publisher = Publisher .. ", " .. cfg.message_list['published'] .. " " .. PublicationDate;
            else
                Publisher = PublicationDate;
            end
        end
        if Publisher ~= "" then
            Publisher = " (" .. Publisher .. ")";
        end
    else
        if ( PublicationDate and PublicationDate ~="" ) then
            PublicationDate = " (" .. cfg.message_list['published'] .. " " .. PublicationDate .. ")"
        else 
            PublicationDate = ""
        end
        if ( PublisherName ~= nil and PublisherName ~="" ) then
            if (PublicationPlace ~= nil and PublicationPlace ~= '') then
                Publisher = sepc .. " " .. PublicationPlace .. ": " .. PublisherName .. PublicationDate;
            else
                Publisher = sepc .. " " .. PublisherName .. PublicationDate;  
            end            
        elseif (PublicationPlace ~= nil and 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 ( Periodical ~= nil and Periodical ~="" ) then 
        if ( Title and Title ~= "" ) or ( TitleNote and TitleNote ~= "" ) then 
            Periodical = sepc .. " ''" .. safeforitalics(Periodical) .. "''"
        else 
            Periodical = "''" .. safeforitalics(Periodical) .. "''"
        end
    else Periodical = "" 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 ( ( (config.CitationClass == "journal") or (config.CitationClass == "citation") )  and
         Periodical ~= "" ) then
        if (Others ~= "") then Others = Others .. sepc .. " " end
        tcommon = safejoin( {Others, Title, TitleNote, Conference, Periodical, Format, TitleType, Series, 
            Language, Edition, Publisher, Agency, Volume, Issue, Position}, sepc );
    else 
        tcommon = safejoin( {Title, TitleNote, Conference, Periodical, Format, TitleType, Series, Language, 
            Volume, Issue, Others, Edition, Publisher, Agency, Position}, 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 = Page .. Pages .. At
    
    if ( "" ~= Authors ) then
        if (Coauthors ~= "") 
          then Authors = Authors .. "; " .. Coauthors
        end
        if ( "" ~= Date )
          then Date = " ("..Date..")" .. OrigYear .. sepc .. " "
          else
            if ( string.sub(Authors,-1,-1) == sepc) --check end character
              then Authors = Authors .. " "
              else Authors = Authors .. sepc .. " "
            end
        end
        if ( "" ~= Editors) then
            local in_text = " in "
            if (sepc == '.') then in_text = " In " end
            if (string.sub(Editors,-1,-1) == sepc)
                then Editors = in_text .. Editors .. " "
                else Editors = in_text .. Editors .. sepc .. " "
            end
        end
        text = safejoin( {Authors, Date, Chapter, Place, Editors, tcommon }, sepc );
        text = safejoin( {text, pgtext, idcommon}, sepc );
    elseif ( "" ~= Editors) then
        if ( "" ~= Date ) then
            if EditorCount <= 1 then
                Editors = Editors .. ", " .. cfg.message_list['editor'];
            else
                Editors = Editors .. ", " .. cfg.message_list['editors'];
            end
            Date = " (" .. Date ..")" .. OrigYear .. sepc .. " "
        else
            if EditorCount <= 1 then
                Editors = Editors .. " (" .. cfg.message_list['editor'] .. ")" .. sepc .. " "
            else
                Editors = Editors .. " (" .. cfg.message_list['editors'] .. ")" .. sepc .. " "
            end
        end
        text = safejoin( {Editors, Date, Chapter, Place, tcommon}, sepc );
        text = safejoin( {text, pgtext, idcommon}, sepc );
    else
        if ( "" ~= Date ) then
            if ( string.sub(tcommon,-1,-1) ~= sepc )
              then Date = sepc .." " .. Date .. OrigYear
              else Date = " " .. Date .. OrigYear
            end
        end -- endif ""~=Date
        if ( config.CitationClass=="journal" and 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 PostScript ~= '' and PostScript ~= nil 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 <span/> element
    if ( Year == nil ) then
        if ( DateIn ~= nil and DateIn ~= "" ) then 
            Year = selectyear( DateIn )
        elseif( PublicationDate ~= nil and PublicationDate ~= "" ) then
            Year = selectyear( PublicationDate )
        else
            Year = ""
        end
    end
    local classname = "citation"
    if ( config.CitationClass ~= "citation" )
       then classname = "citation " .. (config.CitationClass or "") end
    local options = { class=classname }
    if ( Ref ~= nil ) then 
        local id = Ref
        if ( "harv" == Ref ) then
            local names = {} --table of last names & year
            if ( "" ~= Authors ) then
                for i,v in ipairs(a) do 
                    names[i] = v.last 
                    if i == 4 then break end
                end
            elseif ( "" ~= Editors ) then
                for i,v in ipairs(e) do 
                    names[i] = v.last 
                    if i == 4 then break end                
                end
            end
            names[ #names + 1 ] = Year;
            id = anchorid(names)
        end
        options.id = id;
    end
    
    if string.len(text:gsub("<span[^>/]*>.-</span>", ""):gsub("%b<>","")) <= 2 then
        z.error_categories = {};
        text = seterror('empty_citation');
        z.message_tail = {};
    end
    
    if options.id ~= nil then 
        text = '<span id="' .. wikiescape(options.id) ..'" class="' .. wikiescape(options.class) .. '">' .. text .. "</span>";
    else
        text = '<span class="' .. wikiescape(options.class) .. '">' .. text .. "</span>";
    end        

    local empty_span = '<span style="display:none;">&nbsp;</span>';
    
    -- Note: Using display: none on then COinS span breaks some clients.
    local OCinS = '<span title="' .. wikiescape(OCinStitle) .. '" class="Z3988">' .. empty_span .. '</span>';
    text = text .. OCinS;
    
    if #z.message_tail ~= 0 then
        for i,v in ipairs( z.message_tail ) do
            if v[1] ~= nil and 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
    
    if no_tracking_cats == '' then
        for _, v in ipairs( z.error_categories ) do
            text = text .. '[[Category:' .. v ..']]';
        end
    end
    
    return text
end

-- This is used by templates such as {{cite book}} to create the actual citation text.
function z.citation(frame)
    local pframe = frame:getParent()
    
    local args = {};
    local suggestions = {};
    local error_text, error_state;
    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 k == 'postscript' then
            args[k] = v;
        end        
    end    

    local config = {};
    for k, v in pairs( frame.args ) do
        config[k] = v;
        if args[k] == nil and (v ~= '' or k == 'postscript') then
            args[k] = v;
        end        
    end    
    
    return citation0( config, args)
end

return z
---------------------------------------------------------------------
--NOTES
--
-- NOTE A1: This Lua module was originally designed to handle a mix
--      of citation styles, crossing Vancouver style with Wikipedia's
--      local Citation Style 1 (CS1) from {Template:Citation/core}.
--      However, the conflicting positions of parameters, scattered
--      in twisted locations across this module, led to a separate
--      variation just to untangle the CS1 format of citations.
--
-- NOTE D2: The placement of dots and other separators between the
--      displayed parameters has been a continual headache, to keep
--      coordinated with the data in parentheses "(data)". There
--      has been a need to pre-check for the existence of related
--      options, to keep from putting double-dots ".." in some cases.
--      In particular, the omission of the "title=" parameter has led
--      to several cases of a spurious dot ". ." because the original
--      design had treated the title as a mandatory parameter.
--
------------------------------------------------------------------------
--HISTORY:
--18Oct2012 Fixed lead-space in Chapter by omitting " ".
--18Oct2012 Fixed lead-space in Chapter/Title as end " " of Authors/Date/...
--19Oct2012 Put HISTORY comments to log major changes (not typos).
--19Oct2012 Fixed extra dot ".." in Title by omitting at end of "tcommon=...".
--19Oct2012 For pages, put &nbsp in "p.&nbsp;" etc.
--19Oct2012 Enhanced "pages=" to detect lone page as "p." else "pp." prefix.
--19Oct2012 Fixed to show "." after Periodical name (work, newspaper...).
--19Oct2012 Fixed web-link to have spaces "[...  Archived] from the original".
--19Oct2012 Fixed to show ";" between authors & coauthors.
--19Oct2012 Fixed to omit extra "." after coauthors.
--20Oct2012 Fixed COinS data to not urlencode all, as "ctx_ver=Z39.88-2004"
--20Oct2012 Fixed COinS to not end as "&" but use lead "&rft...=" form.
--20Oct2012 Fixed COinS to not url.encode page's "rfr_id=..." pagename.
--20Oct2012 Fixed COinS data when "web" to default to rft.genre "book".
--05Nov2012 Add a span wrapper even when there is no Ref parameter
--15Feb2013 Added Agency for "agency=xx".
--19Feb2013 Put NOTES comments to explain module operation.
--19Feb2013 Copied as Module:Citation/CS1 to alter to match wp:CS1 form.
--19Feb2013 Changed OrigYear to use [__] for CS1 style.
--19Feb2013 Fixed to not show duplicate Publisher/Agency.
--19Feb2013 Moved page-number parameters to after final date.
--19Feb2013 Fixed to not put double-dots after title again.
--20Feb2013 Changed to omit dot "." if already ends with dot.
--20Feb2013 If class "journal" shows Publisher after Periodical/Series.
--20Feb2013 Shifted Format to after Language, and Others after Volume.
--20Feb2013 Set AccessDate + <span class="reference-accessdate">
--20Feb2013 Fixed url when deadurl=no.
--20Feb2013 Added sepc for separator character between parameters.
--20Feb2013 Put "OCLC" for "Online Computer Library Center".
--20Feb2013 Fix empty "authorlink=" as person.link ~= "".
--20Feb2013 Added space after AuthorSep & AuthorNameSep.
--21Feb2013 Added args.contributor (was missing parameter).
--21Feb2013 Fixed EditorSep (was misspelled "EdithorSep").
--21Feb2013 Set OCinSdata.rft_val_fmt = "info:ofi/fmt:kev:mtx:book"
--21Feb2013 Checked to omit blank codes (asin= | doi= etc.).
--21Feb2013 Set enddot to end line if not config.CitationClass "citation".
--21Feb2013 Fixed to show "issn=x" as the ISSN code.
--21Feb2013 Fixed to show "id=x" after Zbl code.
--21Feb2013 Changed to omit double-dot before date when already dot.
--21Feb2013 Order config.CitationClass "citation": Volume, Issue, Publisher.
--21Feb2013 Put warning "Bad DOI (expected "10."..)" in DOI result.
--21Feb2013 Automatically unbolded volume+comma when > 4 long.
--21Feb2013 Changed to allow lowercase "asin-tld".
--22Feb2013 Fixed ref=harv to extract Year from Date.
--22Feb2013 Set Harvard refer. span id if config.CitationClass "citation".
--22Feb2013 Fixed config.CitationClass "citation" as span class="citation".
--22Feb2013 Capitalized "Archived/Retrieved" only when sepc is dot ".".
--23Feb2013 Fixed author editor for "in" or "In" and put space after sepc.
--23Feb2013 Changed to omit dot in "et al." when sepc is "." separator.
--23Feb2013 Fixed "author1-first" to also get args.given or args.given1.
--23Feb2013 Fixed args.article to set Title, after Periodical is Title.
--23Feb2013 Fixed to allow blank Title (such as "contribution=mytitle").
--23Feb2013 Fixed double-dot ".." at end of Editors list
--26Feb2013 Moved "issue=" data to show before "page=".
--26Feb2013 Moved "type=" data to show after "format=".
--26Feb2013 For "pmc=" link, omitted suffix "/?tool=pmcentrez".
--27Feb2013 For coauthors, omitted extra separator after authors.
--27Feb2013 For date, allowed empty date to use month/day/year.
--27Feb2013 Fixed double-dot ".." at end of authors/coauthors list.
--27Feb2013 Reset editor suffix as ", ed." when date exists.
--27Feb2013 Removed duplicate display of "others=" data.
--27Feb2013 Removed parentheses "( )" around "department" TitleNote.
--05Mar2013 Moved Language to follow Periodical or Series.
--05Mar2013 Fixed Edition to follow Series or Volume.
--05Mar2013 Fixed class encyclopaedia to show article as quoted Chapter.
--05Mar2013 Fixed class encyclopaedia to show page as "pp." or "p.".
--07Mar2013 Changed class encyclopaedia to omit "( )" around publisher.
--07Mar2013 Fixed end double-dot by string.sub(idcommon,-1,-1) was "-1,1".
--13Mar2013 Removed enddot "." after "quote=" parameter.
--13Mar2013 Changed config.CitationClass "news" to use "p." page format.
--13Mar2013 Fixed missing "location=" when "web" or "encyclopaedia".
--14Mar2013 Fixed end double-dot after book/work title.
--14Mar2013 Fixed double-dot before "p." or "pp." page number.
--14Mar2013 Fixed config.CitationClass "book" to use p./pp. page.
--18Mar2013 Fixed "page=" to override "pages=" as in markup-based cites.
--19Mar2013 Fixed date of class=journal Periodical to show after page.
--19Mar2013 Changed null "postscript=" to suppress end-dot of citation.
--20Mar2013 If CitationClass is journal, show "others=" before title.
--20Mar2013 If CitationClass is book, show "others=" before edition.
--20Mar2013 If CitationClass is journal, adjust "others=" to have sepc.
--20Mar2013 For class "journal", use book format unless Periodical set.
--03Apr2013 Changed safejoin() to omit "." after wikilink ".]]" end dot.
--03Apr2013 Changed safejoin() to omit "." after external ".]" end dot.
--03Apr2013 Changed safejoin() to omit "." at italic wikilink ".]]" end.
--03Apr2013 Changed safejoin() to omit "." at italic external ".]" end.
--04Apr2013 Moved sepc before <span class="reference-accessdate"> for "..".
--
--End