Modul:URLutil

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local URLutil = { suite = "URLutil",

                 serial = "2019-11-17",
                 item   = 10859193 }

--[=[ Utilities for URL etc. on www.

  • decode()
  • encode()
  • getAuthority()
  • getFragment()
  • getHost()
  • getLocation()
  • getNormalized()
  • getPath()
  • getPort()
  • getQuery()
  • getQueryTable()
  • getRelativePath()
  • getScheme()
  • getSortkey()
  • getTLD()
  • getTop2domain()
  • getTop3domain()
  • isAuthority()
  • isDomain()
  • isDomainExample()
  • isDomainInt()
  • isHost()
  • isHostPathResource()
  • isIP()
  • isIPlocal()
  • isIPv4()
  • isIPv6()
  • isMailAddress()
  • isMailLink()
  • isProtocolDialog()
  • isProtocolWiki()
  • isResourceURL()
  • isSuspiciousURL()
  • isUnescapedURL()
  • isWebURL()
  • wikiEscapeURL()
  • failsafe()

Only dotted decimal notation for IPv4 expected. Does not support dotted hexadecimal, dotted octal, or single-number formats. IPv6 URL (bracketed) not yet implemented; might need Wikintax escaping anyway. ]=] local Failsafe = URLutil


local decodeComponentProtect = { F = "\"#%<>[\]^`{|}",

                                P = "\"#%<>[\]^`{|}/?",
                                Q = "\"#%<>[\]^`{|}&=+;,",
                                X = "\"#%<>[\]^`{|}&=+;,/?" }


local decodeComponentEscape = function ( averse, adapt )

   return  adapt == 20  or  adapt == 127  or
           decodeComponentProtect[ averse ]:find( string.char( adapt ),
                                                  1,
                                                  true )

end -- decodeComponentEscape()


local decodeComponentML = function ( ask )

   local i = 1
   local j, n, s
   while ( i ) do
       i = ask:find( "&#[xX]%x%x+;", i )
       if i then
           j = ask:find( ";",  i + 3,  true )
           s = ask:sub( i + 2,  j - 1 ):upper()
           n = s:byte( 1, 1 )
           if n == 88 then
               n = tonumber( s:sub( 2 ),  16 )
           elseif s:match( "^%d+$" ) then
               n = tonumber( s )
           else
               n = false
           end
           if n then
               if n >= 128 then
                   s = string.format( "&#%d;", n )
               elseif decodeComponentEscape( "X", n ) then
                   s = string.format( "%%%02X", n )
               else
                   s = string.format( "%c", n )
               end
               j = j + 1
               if i == 1 then
                   ask = s .. ask:sub( j )
               else
                   ask = string.format( "%s%s%s",
                                        ask:sub( 1,  i - 1 ),
                                        s,
                                        ask:sub( j ) )
               end
           end
           i = i + 1
       end
   end -- while i
   return ask

end -- decodeComponentML()


local decodeComponentPercent = function ( ask, averse )

   local i = 1
   local j, k, m, n
   while ( i ) do
       i = ask:find( "%%[2-7]%x", i )
       if i then
           j = i + 1
           k = j + 1
           n = ask:byte( k, k )
           k = k + 1
           m = ( n > 96 )
           if m then
               n = n - 32
               m = n
           end
           if n > 57 then
               n = n - 55
           else
               n = n - 48
           end
           n = ( ask:byte( j, j ) - 48 )  *  16   +   n
           if decodeComponentEscape( averse, n ) then
               if m then
                   ask = string.format( "%s%c%s",
                                        ask:sub( 1, j ),
                                        m,
                                        ask:sub( k ) )
               end
           elseif i == 1 then
               ask = string.format( "%c%s",  n,  ask:sub( k ) )
           else
               ask = string.format( "%s%c%s",
                                    ask:sub( 1,  i - 1 ),
                                    n,
                                    ask:sub( k ) )
           end
           i = j
       end
   end -- while i
   return ask

end -- decodeComponentPercent()


local getTopDomain = function ( url, mode )

   local r = URLutil.getHost( url )
   if r then
       local pattern = "[%w%%%-]+%.%a[%w%-]*%a)$"
       if mode == 3 then
           pattern = "[%w%%%-]+%." .. pattern
       end
       r = mw.ustring.match( "." .. r,  "%.(" .. pattern )
       if not r then
           r = false
       end
   else
       r = false
   end
   return r

end -- getTopDomain()


local getHash = function ( url )

   local r = url:find( "#", 1, true )
   if r then
       local i = url:find( "&#", 1, true )
       if i then
           local s
           while ( i ) do
               s = url:sub( i + 2 )
               if s:match( "^%d+;" ) or s:match( "^x%x+;" ) then
                   r = url:find( "#",  i + 4,  true )
                   if r then
                       i = url:find( "&#",  i + 4,  true )
                   else
                       i = false
                   end
               else
                   r = i + 1
                   i = false
               end
           end -- while i
       end
   end
   return r

end -- getHash()


URLutil.decode = function ( url, enctype )

   local r, s
   if type( enctype ) == "string" then
       s = mw.text.trim( enctype )
       if s == "" then
           s = false
       else
           s = s:upper()
       end
   end
   r = mw.text.encode( mw.uri.decode( url, s ) )
   if r:find( "[%[|%]]" ) then
       local k
       r, k = r:gsub( "%[", "[" )
               :gsub( "|", "|" )
               :gsub( "%]", "]" )
   end
   return r

end -- URLutil.decode()


URLutil.encode = function ( url, enctype )

   local k, r, s
   if type( enctype ) == "string" then
       s = mw.text.trim( enctype )
       if s == "" then
           s = false
       else
           s = s:upper()
       end
   end
   r = mw.uri.encode( url, s )
   k = r:byte( 1, 1 )
   if -- k == 35  or      -- #
         k == 42  or      -- *
         k == 58  or      -- :
         k == 59 then     -- ;
       r = string.format( "%%%X%s", k, r:sub( 2 ) )
   end
   if r:find( "[%[|%]]" ) then
       r, k = r:gsub( "%[", "%5B" )
               :gsub( "|",  "%7C" )
               :gsub( "%]", "%5D" )
   end
   return r

end -- URLutil.encode()


URLutil.getAuthority = function ( url )

   local r
   if type( url ) == "string" then
       local colon, host, port
       local pattern = "^%s*%w*:?//([%w%.%%_-]+)(:?)([%d]*)/"
       local s = mw.text.decode( url )
       local i = s:find( "#", 6, true )
       if i then
           s = s:sub( 1,  i - 1 )  ..  "/"
       else
           s = s .. "/"
       end
       host, colon, port = mw.ustring.match( s, pattern )
       if URLutil.isHost( host ) then
           host = mw.ustring.lower( host )
           if colon == ":" then
               if port:find( "^[1-9]" ) then
                   r = ( host .. ":" .. port )
               end
           elseif #port == 0 then
               r = host
           end
       end
   else
       r = false
   end
   return r

end -- URLutil.getAuthority()


URLutil.getFragment = function ( url, decode )

   local r
   if type( url ) == "string" then
       local i = getHash( url )
       if i then
           r = mw.text.trim( url:sub( i ) ):sub( 2 )
           if type( decode ) == "string" then
               local encoding = mw.text.trim( decode )
               local launch
               if encoding == "%" then
                   launch = true
               elseif encoding == "WIKI" then
                   r = r:gsub( "%.(%x%x)", "%%%1" )
                        :gsub( "_", " " )
                   launch = true
               end
               if launch then
                   r = mw.uri.decode( r, "PATH" )
               end
           end
       else
           r = false
       end
   else
       r = nil
   end
   return r

end -- URLutil.getFragment()


URLutil.getHost = function ( url )

   local r = URLutil.getAuthority( url )
   if r then
       r = mw.ustring.match( r, "^([%w%.%%_%-]+):?[%d]*$" )
   end
   return r

end -- URLutil.getHost()


URLutil.getLocation = function ( url )

   local r
   if type( url ) == "string" then
       r = mw.text.trim( url )
       if r == "" then
           r = false
       else
           local i
           i = getHash( r )
           if i then
               if i == 1 then
                   r = false
               else
                   r = r:sub( 1,  i - 1 )
               end
           end
       end
   else
       r = nil
   end
   return r

end -- URLutil.getLocation()


URLutil.getNormalized = function ( url )

   local r
   if type( url ) == "string" then
       r = mw.text.trim( url )
       if r == "" then
           r = false
       else
           r = decodeComponentML( r )
       end
   else
       r = false
   end
   if r then
       local k = r:find( "//", 1, true )
       if k then
           local j = r:find( "/",  k + 2,  true )
           local sF, sP, sQ
           if r:find( "%%[2-7]%x" ) then
               local i = getHash( r )
               if i then
                   sF = r:sub( i + 1 )
                   r  = r:sub( 1,  i - 1 )
                   if sF == "" then
                       sF = false
                   else
                       sF = decodeComponentPercent( sF, "F" )
                   end
               end
               i = r:find( "?", 1, true )
               if i then
                   sQ = r:sub( i )
                   r  = r:sub( 1,  i - 1 )
                   sQ = decodeComponentPercent( sQ, "Q" )
               end
               if j then
                   if #r > j then
                       sP = r:sub( j + 1 )
                       sP = decodeComponentPercent( sP, "P" )
                   end
                   r = r:sub( 1,  j - 1 )
               end
           elseif j then
               local n = #r
               if r:byte( n, n ) == 35 then    -- '#'
                   n = n - 1
                   r = r:sub( 1, n )
               end
               if n > j then
                   sP = r:sub( j + 1 )
               end
               r = r:sub( 1,  j - 1 )
           end
           r = mw.ustring.lower( r ) .. "/"
           if sP then
               r = r .. sP
           end
           if sQ then
               r = r .. sQ
           end
           if sF then
               r = string.format( "%s#%s", r, sF )
           end
       end
       r = r:gsub( " ",  "%%20" )
            :gsub( "%[", "%%5B" )
            :gsub( "|",  "%%7C" )
            :gsub( "%]", "%%5D" )
            :gsub( "%<", "%%3C" )
            :gsub( "%>", "%%3E" )
   end
   return r

end -- URLutil.getNormalized()


URLutil.getPath = function ( url )

   local r = URLutil.getRelativePath( url )
   if r then
       local s = r:match( "^([^%?]*)%?" )
       if s then
           r = s
       end
       s = r:match( "^([^#]*)#" )
       if s then
           r = s
       end
   end
   return r

end -- URLutil.getPath()


URLutil.getPort = function ( url )

   local r = URLutil.getAuthority( url )
   if r then
       r = r:match( ":([1-9][0-9]*)$" )
       if r then
           r = tonumber( r )
       else
           r = false
       end
   end
   return r

end -- URLutil.getPort()


URLutil.getQuery = function ( url, key, separator )

   local r = URLutil.getLocation( url )
   if r then
       r = r:match( "^[^%?]*%?(.+)$" )
       if r then
           if type( key ) == "string" then
               local single = mw.text.trim( key )
               local sep = "&"
               local s, scan
               if type( separator ) == "string" then
                   s = mw.text.trim( separator )
                   if s:match( "^[&;,/]$" ) then
                       sep = s
                   end
               end
               s = string.format( "%s%s%s", sep, r, sep )
               scan = string.format( "%s%s=([^%s]*)%s",
                                     sep, key, sep, sep )
               r = s:match( scan )
           end
       end
       if not r then
           r = false
       end
   end
   return r

end -- URLutil.getQuery()


URLutil.getQueryTable = function ( url, separator )

   local r = URLutil.getQuery( url )
   if r then
       local sep = "&"
       local n, pairs, s, set
       if type( separator ) == "string" then
           s = mw.text.trim( separator )
           if s:match( "^[&;,/]$" ) then
               sep = s
           end
       end
       pairs = mw.text.split( r, sep, true )
       n = #pairs
       r = { }
       for i = 1, n do
           s = pairs[ i ]
           if s:find( "=", 2, true ) then
               s, set = s:match( "^([^=]+)=(.*)$" )
               if s then
                   r[ s ] = set
               end
           else
               r[ s ] = false
           end
       end -- for i
   end
   return r

end -- URLutil.getQueryTable()


URLutil.getRelativePath = function ( url )

   local r
   if type( url ) == "string" then
       local s = url:match( "^%s*[a-zA-Z]*://(.*)$" )
       if s then
           s = s:match( "[^/]+(/.*)$" )
       else
           local x
           x, s = url:match( "^%s*(/?)(/.*)$" )
           if x == "/" then
               s = s:match( "/[^/]+(/.*)$" )
           end
       end
       if s then
           r = mw.text.trim( s )
       elseif URLutil.isResourceURL( url ) then
           r = "/"
       else
           r = false
       end
   else
       r = nil
   end
   return r

end -- URLutil.getRelativePath()


URLutil.getScheme = function ( url )

   local r
   if type( url ) == "string" then
       local pattern = "^%s*([a-zA-Z]*)(:?)(//)"
       local prot, colon, slashes = url:match( pattern )
       r = false
       if slashes == "//" then
           if colon == ":" then
               if #prot > 2 then
                   r = prot:lower() .. "://"
               end
           elseif #prot == 0 then
               r = "//"
           end
       end
   else
       r = nil
   end
   return r

end -- URLutil.getScheme()


URLutil.getSortkey = function ( url )

   local r = url
   if type( url ) == "string" then
       local i = url:find( "//" )
       if i then
           local scheme
           if i == 0 then
               scheme = ""
           else
               scheme = url:match( "^%s*([a-zA-Z]*)://" )
           end
           if scheme then
               local s = url:sub( i + 2 )
               local comps, site, m, suffix
               scheme = scheme:lower()
               i      = s:find( "/" )
               if i  and  i > 1 then
                   suffix = s:sub( i + 1 )            -- mw.uri.encode()
                   s      = s:sub( 1,  i - 1 )
                   suffix = suffix:gsub( "#", " " )
               else
                   suffix = ""
               end
               site, m = s:match( "^(.+)(:%d+)$" )
               if not m then
                   site = s
                   m    = 0
               end
               comps = mw.text.split( site:lower(), ".", true )
               r = "///"
               for i = #comps, 2, -1 do
                   r =  string.format( "%s%s.", r, comps[ i ] )
               end -- for --i
               r = string.format( "%s%s %d %s: %s",
                                  r, comps[ 1 ], m, scheme, suffix )
           end
       end
   end
   return r

end -- URLutil.getSortkey()


URLutil.getTLD = function ( url )

   local r = URLutil.getHost( url )
   if r then
       r = mw.ustring.match( r, "%w+%.(%a[%w%-]*%a)$" )
       if not r then
           r = false
       end
   end
   return r

end -- URLutil.getTLD()


URLutil.getTop2domain = function ( url )

   return getTopDomain( url, 2 )

end -- URLutil.getTop2domain()


URLutil.getTop3domain = function ( url )

   return getTopDomain( url, 3 )

end -- URLutil.getTop3domain()


URLutil.isAuthority = function ( s )

   local r
   if type( s ) == "string" then
       local pattern = "^%s*([%w%.%%_-]+)(:?)(%d*)%s*$"
       local host, colon, port = mw.ustring.match( s, pattern )
       if colon == ":" then
           port = port:match( "^[1-9][0-9]*$" )
           if type( port ) ~= "string" then
               r = false
           end
       elseif port ~= "" then
           r = false
       end
       r = URLutil.isHost( host )
   else
       r = nil
   end
   return r

end -- URLutil.isAuthority()


URLutil.isDomain = function ( s )

   local r
   if type( s ) == "string" then
       local scan = "^%s*([%w%.%%_-]*%w)%.(%a[%w-]*%a)%s*$"
       local scope
       s, scope = mw.ustring.match( s, scan )
       if type( s ) == "string" then
           if mw.ustring.find( s, "^%w" ) then
               if mw.ustring.find( s, "..", 1, true ) then
                   r = false
               else
                   r = true
               end
           end
       end
   else
       r = nil
   end
   return r

end -- URLutil.isDomain()


URLutil.isDomainExample = function ( url )

   -- RFC 2606: example.com example.net example.org example.edu
   local r = getTopDomain( url, 2 )
   if r then
       local s = r:lower():match( "^example%.([a-z][a-z][a-z])$" )
       if s then
           r = ( s == "com" or
                 s == "edu" or
                 s == "net" or
                 s == "org" )
       else
           r = false
       end
   end
   return r

end -- URLutil.isDomainExample()


URLutil.isDomainInt = function ( url )

   -- Internationalized Domain Name (Punycode)
   local r = URLutil.getHost( url )
   if r then
       if r:match( "^[!-~]+$" ) then
           local s = "." .. r
           if s:find( ".xn--", 1, true ) then
               r = true
           else
               r = false
           end
       else
           r = true
       end
   end
   return r

end -- URLutil.isDomainInt()


URLutil.isHost = function ( s )

   return URLutil.isDomain( s ) or URLutil.isIP( s )

end -- URLutil.isHost()


URLutil.isHostPathResource = function ( s )

   local r = URLutil.isResourceURL( s )
   if not r  and s then
       r = URLutil.isResourceURL( "//" .. mw.text.trim( s ) )
   end
   return r

end -- URLutil.isHostPathResource()


URLutil.isIP = function ( s )

   return URLutil.isIPv4( s ) and 4 or URLutil.isIPv6( s ) and 6

end -- URLutil.isIP()


URLutil.isIPlocal = function ( s )

   -- IPv4 according to RFC 1918, RFC 1122; even any 0.0.0.0 (RFC 5735)
   local r = false
   local num = s:match( "^ *([01][0-9]*)%." )
   if num then
       num = tonumber( num )
       if num == 0 then
           r = s:match( "^ *0+%.[0-9]+%.[0-9]+%.[0-9]+ *$" )
       elseif num == 10  or  num == 127 then
           -- loopback; private/local host: 127.0.0.1
           r = URLutil.isIPv4( s )
       elseif num == 169 then
           -- 169.254.*.*
       elseif num == 172 then
           -- 172.(16...31).*.*
           num = s:match( "^ *0*172%.([0-9]+)%." )
           if num then
               num = tonumber( num )
               if num >= 16  and  num <= 31 then
                   r = URLutil.isIPv4( s )
               end
           end
       elseif beg == 192 then
           -- 192.168.*.*
           num = s:match( "^ *0*192%.([0-9]+)%." )
           if num then
               num = tonumber( num )
               if num == 168 then
                   r = URLutil.isIPv4( s )
               end
           end
       end
   end
   if r then
       r = true
   end
   return r

end -- URLutil.isIPlocal()


URLutil.isIPv4 = function ( s )

   local function legal( n )
             return ( tonumber( n ) < 256 )
         end
   local r = false
   if type( s ) == "string" then
       local p1, p2, p3, p4 = s:match( "^%s*([1-9][0-9]?[0-9]?)%.([12]?[0-9]?[0-9])%.([12]?[0-9]?[0-9])%.([12]?[0-9]?[0-9])%s*$" )
       if p1 and p2 and p3 and p4 then
           r = legal( p1 ) and legal( p2 ) and legal( p3 ) and legal( p4 )
       end
   end
   return r

end -- URLutil.isIPv4()


URLutil.isIPv6 = function ( s )

   local dcolon, groups
   if type( s ) ~= "string"
       or s:len() == 0
       or s:find( "[^:%x]" ) -- only colon and hex digits are legal chars
       or s:find( "^:[^:]" ) -- can begin or end with :: but not with single :
       or s:find( "[^:]:$" )
       or s:find( ":::" )
   then
       return false
   end
   s = mw.text.trim( s )
   s, dcolon = s:gsub( "::", ":" )
   if dcolon > 1 then
       return false
   end -- at most one ::
   s = s:gsub( "^:?", ":" ) -- prepend : if needed, upper
   s, groups = s:gsub( ":%x%x?%x?%x?", "" ) -- remove valid groups, and count them
   return ( ( dcolon == 1 and groups < 8 ) or
            ( dcolon == 0 and groups == 8 ) )
       and ( s:len() == 0 or ( dcolon == 1 and s == ":" ) ) -- might be one dangling : if original ended with ::

end -- URLutil.isIPv6()


URLutil.isMailAddress = function ( s )

   if type( s ) == "string" then
       s = mw.ustring.match( s, "^%s*[%w%.%%_-]+@([%w%.%%-]+)%s*$" )
       return URLutil.isDomain( s )
   end
   return false

end -- URLutil.isMailAddress()


URLutil.isMailLink = function ( s )

   if type( s ) == "string" then
       local addr
       s, addr = mw.ustring.match( s, "^%s*([Mm][Aa][Ii][Ll][Tt][Oo]):(%S[%w%.%%_-]*@[%w%.%%-]+)%s*$" )
       if type( s ) == "string" then
           if s:lower() == "mailto" then
               return URLutil.isMailAddress( addr )
           end
       end
   end
   return false

end -- URLutil.isMailLink()


local function isProtocolAccepted( prot, supplied )

   if type( prot ) == "string" then
       local scheme, colon, slashes = mw.ustring.match( prot, "^%s*([a-zA-Z]*)(:?)(/?/?)%s*$" )
       if slashes ~= "/" then
           if scheme == "" then
               if colon ~= ":" and slashes == "//" then
                   return true
               end
            elseif colon == ":" or slashes == "" then
               local s = supplied:match( " " .. scheme:lower() .. " " )
               if type( s ) == "string" then
                   return true
               end
           end
       end
   end
   return false

end -- isProtocolAccepted()


URLutil.isProtocolDialog = function ( prot )

   return isProtocolAccepted( prot, " mailto irc ircs ssh telnet " )

end -- URLutil.isProtocolDialog()


URLutil.isProtocolWiki = function ( prot )

   return isProtocolAccepted( prot,
                              " ftp ftps git http https nntp sftp svn worldwind " )

end -- URLutil.isProtocolWiki()


URLutil.isResourceURL = function ( url )

   local scheme = URLutil.getScheme( url )
   if scheme then
       local s = " // http:// https:// ftp:// sftp:// "
       s = s:find( string.format( " %s ", scheme ) )
       if s then
           if URLutil.getAuthority( url ) then
               if not url:match( "%S%s+%S" ) then
                   local s1, s2 = url:match( "^([^#]+)(#.*)$" )
                   if s2 then
                       if url:match( "^%s*[a-zA-Z]*:?//(.+)/" ) then
                           return true
                       end
                   else
                       return true
                   end
               end
           end
       end
   end
   return false

end -- URLutil.isResourceURL()


URLutil.isSuspiciousURL = function ( url )

   if URLutil.isResourceURL( url ) then
       local s = URLutil.getAuthority( url )
       local pat = "[%[|%]" ..
                   mw.ustring.char( 8201, 45, 8207,
                                    8234, 45, 8239,
                                    8288 )
                   .. "]"
       if s:find( "@" )
          or url:find( "" )
          or url:find( pat )
          or url:find( "[%.,]$" ) then
           return true
       end
       -- TODO  zero width character ??
       return false
   end
   return true

end -- URLutil.isSuspiciousURL()


URLutil.isUnescapedURL = function ( url, trailing )

   if type( trailing ) ~= "string" then
       if URLutil.isWebURL( url ) then
           if url:match( "[%[|%]]" ) then
               return true
           end
       end
   end
   return false

end -- URLutil.isUnescapedURL()


URLutil.isWebURL = function ( url )

   if URLutil.getScheme( url ) and URLutil.getAuthority( url ) then
       if not url:find( "%S%s+%S" )  and
          not url:find( "", 1, true ) then
           return true
       end
   end
   return false

end -- URLutil.isWebURL()


URLutil.wikiEscapeURL = function ( url )

   if url:find( "[%[|%]]" ) then
       local n
       url, n = url:gsub( "%[", "[" )
                   :gsub( "|", "|" )
                   :gsub( "%]", "]" )
   end
   return url

end -- URLutil.wikiEscapeURL()


Failsafe.failsafe = function ( atleast )

   -- Retrieve versioning and check for compliance
   -- Precondition:
   --     atleast  -- string, with required version or "wikidata" or "~"
   --                 or false
   -- Postcondition:
   --     Returns  string  -- with queried version, also if problem
   --              false   -- if appropriate
   -- 2019-10-15
   local last  = ( atleast == "~" )
   local since = atleast
   local r
   if last  or  since == "wikidata" then
       local item = Failsafe.item
       since = false
       if type( item ) == "number"  and  item > 0 then
           local entity = mw.wikibase.getEntity( string.format( "Q%d",
                                                                item ) )
           if type( entity ) == "table" then
               local seek = Failsafe.serialProperty or "P348"
               local vsn  = entity:formatPropertyValues( seek )
               if type( vsn ) == "table"  and
                  type( vsn.value ) == "string"  and
                  vsn.value ~= "" then
                   if last  and  vsn.value == Failsafe.serial then
                       r = false
                   else
                       r = vsn.value
                   end
               end
           end
       end
   end
   if type( r ) == "nil" then
       if not since  or  since <= Failsafe.serial then
           r = Failsafe.serial
       else
           r = false
       end
   end
   return r

end -- Failsafe.failsafe()


local function Template( frame, action, amount )

   -- Run actual code from template transclusion
   -- Precondition:
   --     frame   -- object
   --     action  -- string, with function name
   --     amount  -- number, of args if > 1
   -- Postcondition:
   --     Return string or not
   local n = amount or 1
   local v = { }
   local r, s
   for i = 1, n do
       s = frame.args[ i ]
       if s then
            s = mw.text.trim( s )
            if s ~= "" then
                v[ i ] = s
            end
        end
   end -- for i
   if v[ 1 ] then
        r = URLutil[ action ](  v[ 1 ], v[ 2 ], v[ 3 ] )
   end
   return r

end -- Template()


local p = {}

function p.decode( frame )

   return Template( frame, "decode", 2 ) or ""

end function p.encode( frame )

   return Template( frame, "encode", 2 ) or ""

end function p.getAuthority( frame )

   return Template( frame, "getAuthority" ) or ""

end function p.getFragment( frame )

   local r = Template( frame, "getFragment", 2 )
   if r then
       r = "#" .. r
   else
       r = ""
   end
   return r

end function p.getHost( frame )

   return Template( frame, "getHost" ) or ""

end function p.getLocation( frame )

   return Template( frame, "getLocation" ) or ""

end function p.getNormalized( frame )

   return Template( frame, "getNormalized" ) or ""

end function p.getPath( frame )

   return Template( frame, "getPath" ) or ""

end function p.getPort( frame )

   return Template( frame, "getPort" ) or ""

end function p.getQuery( frame )

   local r = Template( frame, "getQuery", 3 )
   if r then
       local key = frame.args[ 2 ]
       if key then
           key = mw.text.trim( key )
           if key == "" then
               key = nil
           end
       end
       if not key then
           r = "?" .. r
       end
   else
       r = ""
   end
   return r

end function p.getRelativePath( frame )

   return Template( frame, "getRelativePath" ) or ""

end function p.getScheme( frame )

   return Template( frame, "getScheme" ) or ""

end function p.getSortkey( frame )

   return Template( frame, "getSortkey" ) or ""

end function p.getTLD( frame )

   return Template( frame, "getTLD" ) or ""

end function p.getTop2domain( frame )

   return Template( frame, "getTop2domain" ) or ""

end function p.getTop3domain( frame )

   return Template( frame, "getTop3domain" ) or ""

end function p.isAuthority( frame )

   return Template( frame, "isAuthority" ) and "1" or ""

end function p.isDomain( frame )

   return Template( frame, "isDomain" ) and "1" or ""

end function p.isDomainExample( frame )

   return Template( frame, "isDomainExample" ) and "1" or ""

end function p.isDomainInt( frame )

   return Template( frame, "isDomainInt" ) and "1" or ""

end function p.isHost( frame )

   return Template( frame, "isHost" ) and "1" or ""

end function p.isHostPathResource( frame )

   return Template( frame, "isHostPathResource" ) and "1" or ""

end function p.isIP( frame )

   return Template( frame, "isIP" ) and "1" or ""

end function p.isIPlocal( frame )

   return Template( frame, "isIPlocal" ) and "1" or ""

end function p.isIPv4( frame )

   return Template( frame, "isIPv4" ) and "1" or ""

end function p.isIPv6( frame )

   return Template( frame, "isIPv6" ) and "1" or ""

end function p.isMailAddress( frame )

   return Template( frame, "isMailAddress" ) and "1" or ""

end function p.isMailLink( frame )

   return Template( frame, "isMailLink" ) and "1" or ""

end function p.isProtocolDialog( frame )

   return Template( frame, "isProtocolDialog" ) and "1" or ""

end function p.isProtocolWiki( frame )

   return Template( frame, "isProtocolWiki" ) and "1" or ""

end function p.isResourceURL( frame )

   return Template( frame, "isResourceURL" ) and "1" or ""

end function p.isSuspiciousURL( frame )

   return Template( frame, "isSuspiciousURL" ) and "1" or ""

end function p.isUnescapedURL( frame )

   return Template( frame, "isUnescapedURL", 2 ) and "1" or ""

end function p.isWebURL( frame )

   return Template( frame, "isWebURL" ) and "1" or ""

end function p.wikiEscapeURL( frame )

   return Template( frame, "wikiEscapeURL" )

end p.failsafe = function ( frame )

   local s = type( frame )
   local since
   if s == "table" then
       since = frame.args[ 1 ]
   elseif s == "string" then
       since = frame
   end
   if since then
       since = mw.text.trim( since )
       if since == "" then
           since = false
       end
   end
   return Failsafe.failsafe( since ) or ""

end function p.URLutil()

   return URLutil

end

return p