Modul:Wayback

local p = {}

--[[--------------------------< inline_error >-----------------------

Render red error message inline (as opposed to the system error() in large font)
Add article to tracking category.

 ]]

function p.inline_error(arg, msg)
  return '<span style="font-size:100%" class="error citation-comment">Error in wayback template: Check <code style="color:inherit; border:inherit; padding:inherit;">&#124;' .. arg .. '=</code> value. ' .. msg .. '[[Kategori:Sidor med mallen Wayback]]</span>'
end

--[[--------------------------< trimArg >-----------------------

trimArg returns nil if arg is "" while trimArg2 returns 'true' if arg is "" 
trimArg2 is for args that might accept an empty value, as an on/off switch like nolink=

 ]]

function p.trimArg(arg)
  if arg == "" or arg == nil then
    return nil
  else
    return mw.text.trim(arg)
  end
end
function p.trimArg2(arg)
  if arg == nil then
    return nil
  else
    return mw.text.trim(arg)
  end
end

--[[--------------------------< isdf >-----------------------

Given df argument, return "yes" or "no" confirming what it is
Default is "yes". If df is nil or "", return "yes".

 ]]

function isdf(df)

  if df == "yes" or df == "Yes" or df == "YES" or df == "y" or df == "Y" or df == "dmy" or df == "DMY" then
    return "yes"
  elseif df == "iso" or df == "ISO" then
     return "iso"
  end
  return "yes"

end

--[[--------------------------< monthen2sw >-----------------------

Convert English month to Swedish 

 ]]

function p.monthen2sw(month)

  local nmonth

  month = mw.ustring.lower( month )

  if month == "january" then
    nmonth = "januari"
  elseif month == "february" then
    nmonth = "februari"
  elseif month == "march" then
    nmonth = "mars"
  elseif month == "april" then
    nmonth = "april"
  elseif month == "may" then
    nmonth = "maj"
  elseif month == "june" then
    nmonth = "juni"
  elseif month == "july" then
    nmonth = "juli"
  elseif month == "august" then
    nmonth = "augusti"
  elseif month == "september" then
    nmonth = "september"
  elseif month == "october" then
    nmonth = "oktober"
  elseif month == "november" then
    nmonth = "november"
  elseif month == "december" then
    nmonth = "december"
  else
    nmonth = month
  end

  return nmonth
  
end  

--[[--------------------------< makedate >-----------------------

Given a year, month and day, convert into a full date while respecting df (dmy or mdy)

 ]]

function p.makedate(year, month, day, df)

  local nmonth, zmonth, zday

  if not year or year == "" or not month or month == "" or not day or day == "" then
    return nil
  end

  zmonth = month
  month = month:match("0*(%d+)")                                      -- strip leading 0
  if tonumber(month) < 1 or tonumber(month) > 12 then
    return year
  end
  nmonth = os.date("%B", os.time{year=2000, month=month, day=1} )     -- Month in name form   
  if not nmonth then
    return year
  end
  nmonth = p.monthen2sw(nmonth)    

  zday = day
  day = day:match("0*(%d+)")
  if tonumber(day) < 1 or tonumber(day) > 31 then
    return nmonth .. " " .. year
  end                                       

  if df == "yes" then
    return day .. " " .. nmonth .. " " .. year
  elseif df == "iso" then
    return year .. "-" .. zmonth .. "-" .. zday
  else
    return nmonth .. " " .. day .. ", " .. year
  end
 

end


--[[--------------------------< wayback >-----------------------

Main function for Template:wayback

 ]]

function p.wayback(frame)

  local pframe = frame:getParent()
  local args = pframe.args

  local tname = "Wayback"                                 -- name of calling template. Change if template rename.

  local url = nil                                         -- source url (not archive.org url)
  local title = nil                                       -- title argument
  local df = nil                                          -- df argument
  local comma = nil                                       -- "," for mdy or "" for dmy
  local snapdate = nil                                    -- eg. "20160520000000"
  local snapdatelong = nil                                -- 14-digit 0-padded version of snapdate if it is truncated
  local fulldate = nil                                    -- eg. "May 20, 2016"
  local currdate = nil                                    -- today's date
  local urlhead = "https://web.archive.org/web/"
  local tail = nil 
  local nolink = nil
  
                                                          -- URL argument (positional #1)

  url = p.trimArg(args[1]) or p.trimArg(args.url) or p.trimArg(args.site)                -- "site" for {{waybackdate}}
  if not url then
    return p.inline_error("url", "Empty.")
  end
  local safe = url
  local l, count = string.gsub(safe, "archive.org/?w?e?b?/[0-9]+/http", "")              -- Count number of "archive.org" 
  if count > 0 then 
    return p.inline_error("url", "Should be the original URL not an archive.org URL.")
  end 
  local l, count = string.gsub(safe, "archive.org/?w?e?b?/http", "")                     -- Count number of "archive.org" 
  if count > 0 then 
    return p.inline_error("url", "Should be the original URL not an archive.org URL.")
  end 
  
                                                          -- Title argument (positional #2)

  title = p.trimArg(args[2]) or p.trimArg(args.title)

                                                          -- Date argument (positional #3)

  snapdate = p.trimArg(args[3]) or p.trimArg(args.date)
  if not snapdate or snapdate == "*" then
    snapdate = "*"
  else
    local safe = snapdate
    local starcount = 0
    snapdate = string.gsub(safe, "[a-z][a-z]_[0-9]?$", "")              -- Remove any trailing "re_" from date 
    safe = snapdate
    snapdate = string.gsub(safe, "[-]", "")                             -- Remove dashes from date eg. 2015-01-01 
    safe = snapdate
    snapdate, starcount = string.gsub(safe, "[*]$", "")                 -- Remove trailing "*" and re-add below after processing
    if not tonumber(snapdate) then
      return p.inline_error("date", "Should be 14-digit snapshot ID in form YYYYMMDDhhmmss (error code 1)")
    end
    local dlen = string.len(snapdate)
    if dlen < 4 then
      return p.inline_error("date", "Should be 14-digit snapshot ID in form YYYYMMDDhhmmss (error code 2)")
    end
    if dlen < 14 then
      snapdatelong = snapdate .. string.rep("0", 14 - dlen)
    else
      snapdatelong = snapdate
    end
    local year = string.sub(snapdatelong, 1, 4)
    local month = string.sub(snapdatelong, 5, 6)
    local day = string.sub(snapdatelong, 7, 8)
    if not tonumber(year) or not tonumber(month) or not tonumber(day) then
      return p.inline_error("date", "Should be 14-digit snapshot ID in form YYYYMMDDhhmmss (error code 3)")
    end
    if tonumber(month) > 12 or tonumber(day) > 31 or tonumber(month) < 1 then
      return p.inline_error("date", "Date has invalid day or month. (error code 4)")
    end
    currdate = os.date("%Y")
    if tonumber(year) > tonumber(currdate) or tonumber(year) < 1900 then
      return p.inline_error("date", "Date has invalid year. (error code 5)")
    end

    if starcount == 1 then
      snapdate = snapdate .. "*"
    end

    df = isdf( p.trimArg(args.df) )
    if df == "yes" then
      comma = ""
    else
      comma = ","
    end

    fulldate = p.makedate(year, month, day, df)
 
    if not fulldate then
      return p.inline_error("date", "(error code 6)")
    end

  end
                                                          -- Nolink argument 

  nolink = p.trimArg2(args.nolink)
  if not nolink then
    tail = " hämtat från the [[Internet Archive#Wayback Machine|Wayback Machine]]"
  else
    tail = " hämtat från the Wayback Machine"
  end
                                                          -- Render 

  if not title and not fulldate then  -- No title. No date
    return "[" .. urlhead .. snapdate .. "/" .. url .. " Arkivkopia]" .. tail .. "."
  elseif not title and fulldate then  -- No title. Date.
    return "[" .. urlhead .. snapdate .. "/" .. url .. " Arkiverad] " .. fulldate .. comma ..  tail .. "."
  elseif title and not fulldate then  -- Title. No date.
    return "[" .. urlhead .. snapdate .. "/" .. url .. " " .. title .. "]" .. tail .. "."
  elseif title and fulldate then          -- Title. Date.
    return "[" .. urlhead .. snapdate .. "/" .. url .. " " .. title .. "]" .. tail .. "&#32;(arkiverat " .. fulldate .. ")."
  end

  error("Error in [[:Template:"..tname.."]]: Unknown problem. Please report on template talk page (code 7)")

end

return p