local str = {}

-- Function: len -- -- This function returns the length of the target string. -- -- Usage: -- Script error: No such module "Echo". -- OR -- Script error: No such module "Echo". -- -- Parameters -- s: The string whose length to report -- -- If invoked using named parameters, Mediawiki will automatically -- remove any leading/trailing whitespace from the target string.

function str.len( frame )

   local new_args = str._getParameters( frame.args, {'s'} );
   local s = new_args['s'] or ;
   return mw.ustring.len( s )

end

-- Function: echo -- -- This function returns the contents of the target string. -- -- Usage: -- Script error: No such module "Echo". -- OR -- Script error: No such module "Echo". -- -- Parameters -- s: The string whose contents to display -- -- If invoked using named parameters, Mediawiki will automatically -- remove any leading/trailing whitespace from the target string.

function str.echo( frame )

   local new_args = str._getParameters( frame.args, {'s'} );
   local s = new_args['s'] or ;
   return s

end

-- Function: cite -- -- This function displays cite parameters. -- -- Usage: -- Script error: No such module "Echo". -- -- Parameters -- author, title, url, date: strings to display

function str.cite( frame )

   -- local args = str._getParameters( frame.args,
   --    {'author','last','first','last1','first1','title','url','date'} );
   local p1 = frame.args[1] or 'web';
   local author = frame.args['author'] or ;
   local last  = frame.args['last'] or ;
   local last1 = frame.args['last1'] or ;
   local first = frame.args['first'] or ;
   local first1 = frame.args['first1'] or ;
   local title = frame.args['title'] or ;
   local url = frame.args['url'] or ;
   local date = frame.args['date'] or ;

   local work = frame.args['work'] or ;
   local periodical = frame.args['periodical'] or ;
   local newspaper = frame.args['newspaper'] or ;
   local journal = frame.args['journal'] or ;

   local day  = frame.args['day'] or ;
   local month = frame.args['month'] or ;
   local year = frame.args['year'] or ;
   local accessdate = frame.args['accessdate'] or ;
   local agency = frame.args['agency'] or ;
   local publisher = frame.args['publisher'] or ;
   local location = frame.args['location'] or ;
   local place = frame.args['place'] or ;
   local volume = frame.args['volume'] or ;
   local edition = frame.args['edition'] or ;
   local issue = frame.args['issue'] or ;
   local number = frame.args['number'] or ;
   local pages = frame.args['pages'] or ;
   local page = frame.args['page'] or ;
   local at = frame.args['at'] or ;
   local archivedate = frame.args['archivedate'] or ;
   local archiveurl = frame.args['archiveurl'] or ;

   local text = author
   if author ~= or last ~= or last1 ~=  then
     if last ~= or last1 ~=  then
        text = text .. last ..last1 ..', '.. first ..first1
     end
     if date ~=  then
         text = text .. " (" ..date .."). "
     else
         if year ~=  then
             text = text .. " (" ..day ..month ..year .."). "
         else
             if string.sub(text,-1,-1) == '.' then
               text = text .. ' '
             else
               text = text .. '. '
             end
         end
     end --endif-else date
   end

Title

   local type = '"'
   if p1=='book' then type = "" end
   if url ~=  then
      text = text .. '[' ..url .. ' ' ..type ..title ..type .. ']'
   else
      text = text .. type ..title .. type
   end
   if periodical ~=  then text = text .. ". " ..periodical .. "" end
   if newspaper ~=  then text = text .. ". " ..newspaper .. "" end
   if journal ~=  then text = text .. ". " ..journal .. "" end
   if work ~= then text = text .. ". " ..work.."" end

Pub/location/volume

   if journal ~=  or work~= or newspaper~= then
     if location ~=  or place ~= then
         text = text ..' (' .. location .. place
         if publisher ~=  or agency ~= then
           text = text ..': ' ..publisher .. agency
         end
         text = text ..')'
     else
         if publisher ~=  or agency ~= then
           text = text ..'. ' .. publisher .. agency
         end
     end -- endif-else location/place
   else -- else not journal/work/newspaper
     if agency ~= then
         text = text .. '. ' .. agency
     end
     if location ~=  or place ~= then
         text = text ..'. ' .. location .. place
         if publisher ~=  then
           text = text ..': ' .. publisher
         end
     else
         if publisher ~=  then
           text = text .. '. ' .. publisher
         end
     end -- endif-else location/place #2
   end --endif-else journal/newspaper
   if volume ~=  then
     if string.len(volume) > 4 then
         text = text .. '. ' .. volume
         text = text .. " " .. volume .. ""
     end --endif volume #len > 4
   end
   if issue ~=  or number ~=  then
     text = text .. ' (' ..issue ..number ..')'
   end --if issue/number
   if edition ~=  then
     text = text .. ' (' ..edition ..' ed.)'
   end --if edition

Date/year

   if last ~= or author ~= or last1 ~= or editor~= then
       -- then omit date here --
   else --show date/year
     if date ~=  then
         text = text .. '. ' ..date
     else
         if year ~=  then
             text = text .. '. ' ..day ..month ..year
         end
     end --endif-else date
   end --endif-else last/author/last1..

Pages/page

   if pages ~=  then
       if p1 == 'journal' then
           text = text .. ": " ..pages
       else
           text = text .. ". pp. " ..pages
       end
   else 
       if page ~=  then
           if p1 == 'journal' then
               text = text .. ": " ..page
           else
               text = text .. ". p. " ..page
           end
       end
   end --endif-else pages
   if at ~=  then
       text = text .. ". " ..at
   end

Access date

   if accessdate ~=  then
       text = text .. ". Retrieved " ..accessdate
   end

   text = text .. "."
   return text

end

-- Helper function that populates the argument list given that user -- may need to use a mix of named and unnamed parameters. This is -- relevant because named parameters are not identical to unnamed -- parameters due to string trimming, and when dealing with strings, -- there can be a need to either preserve or remove that whitespace -- depending on the application.

function str._getParameters( frame_args, arg_list )

   local new_args = {};
   local index = 1;
   local value;
   
   for i,arg in ipairs( arg_list ) do
       value = frame_args[arg]
       if value == nil then
           value = frame_args[index];
           index = index + 1;
       end
       new_args[arg] = value;
   end
   
   return new_args;

end

return str