Module:Backwards copy

local MessageBox = require("Module:Message box")
local yesno = require("Module:Yesno")

local p = {}

local function demoCheck(args)
 return yesno(args["demo"]) or yesno(args["nocat"])
end

local function showWarning(text, nocat)
 mw.addWarning(text)
 return nocat and "" or "[[Category:Pages with backwards copy warnings]]"
end

local function delink(text)
 if text == nil then
  return nil
 end
 return string.gsub(string.gsub(require("Module:Delink")._delink{text}, "%[%[", ""), "%]%]", "")
end

local function showError(text, nocat)
 return string.format(
  "%s%s %s",
  nocat and "" or "[[Category:Pages with backwards copy errors]] ",
  tostring(
   mw.html.create("span")
    :css("color", "red")
    :css("font-weight", "bold")
    :wikitext("Error:")
  ),
  text
 )
end

local function row(args, i)
 return mw.html.create("li"):wikitext(rowText)
end

local function bannerText(frame, args)
 local text = ""
 
 local id = args["id"] or args["revid"]
 if id ~= nil then
  text = string.format("Revisions succeeding [[Special:Diff/%s|this version]] of this", id)
 else
  text = "This"
 end
 
 local citations = {}
 local i = 1
 while (
  args[tostring(i)] or 
   (args["articlename" .. i] or (i == 1 and args["articlename"])) or 
   (args["title" .. i] or (i == 1 and args["title"]))
 ) do
  if args[tostring(i)] then
   table.insert(citations, args[tostring(i)])
  else
   local author = args["author" .. i] or (i == 1 and args["author"])
   local date = (args["date" .. i] or (i == 1 and args["date"])) or
    -- legacy way of providing dates
    string.format(
     "%s %s",
     args["monthday" .. i] or (i == 1 and args["monthday"]) or "",
     args["year" .. i] or (i == 1 and args["year"]) or ""
    )
    
   if mw.text.trim(date or "") == "" then
    if string.match(author or "", "(%d%d%d[%d]+)") then
     text = text .. " " .. showWarning(string.format(
      "A <code>year%s</code> or <code>date%s</code> parameter was not found, but a parenthesized year was found in the " ..
      "<code>author%s</code> parameter. Move the provided year to the correct parameter.",
      i, i, i
     ), demoCheck(args))
    else
     text = text .. " " .. showWarning(string.format(
      "Provided <code>title%s</code> must also have a respective <code>year%s</code> or <code>date%s</code> parameter.",
      i, i, i
     ))
    end
   end

   local display_authors = args["display-authors" .. i] or (i == 1 and args["display-authors"]); -- get |display-authors= parameter value for this reference
   if tonumber (display_authors) and (0 ~= tonumber (display_authors)) then  -- for {{backwards copy}} only allowed number is 0 to suppress author name list
    display_authors = 'etal';          -- any other number gets 'etal'; any other text will be rejected by cs1|2
   end
   
   table.insert(citations, frame:expandTemplate{ title = "Citation", args = {
    ref = "none",
    author = author,
    ["display-authors"] = display_authors,
    date = date,
    url = args["url" .. i] or (i == 1 and args["url"]),
    title = (args["articlename" .. i] or (i == 1 and args["articlename"]))
     or args["title" .. i] or (i == 1 and args["title"]),
    publisher = (args["org" .. i] or (i == 1 and args["org"]))
     or args["publisher" .. i] or (i == 1 and args["publisher"])
   } })
  end
  
  i = i + 1
 end

 text = string.format(
  "%s article is substantially duplicated by a piece in an external publication. " ..
  "Please do not flag this article as a copyright violation of the following source",
  text
 )
 local citationCount = #citations
 if citationCount == 0 then
  return showError(
   "No citations were provided. Provide at least one citation using <code>title</code>.", 
   demoCheck(args)
  )
 elseif citationCount > 1 then
  text = string.format("%ss:", text)
 else
  text = string.format("%s:", text)
 end
 
 local ul = mw.html.create("ul")
 for k, v in pairs(citations) do
  ul:node(mw.html.create("li"):wikitext(v))
 end
 
 text = string.format(
  "%s %s %s",
  text,
  tostring(ul),
  args["comments"] and tostring(
   mw.html.create("table")
    :attr("class", "mw-collapsible mw-collapsed")
    :attr("style", "width:100%; background-color: #f8eaba;")
    :node(mw.html.create("tr")
     :node(mw.html.create("th")
      :wikitext("Additional comments")
     )
    )
    :node(mw.html.create("tr"):node(mw.html.create("td")
     :attr("style", "background-color: white; border: 1px solid #c0c090; padding: 0.25em 0.5em;")
     :wikitext(
      args["comments"]
     )
    ))
  ) or ""
 )
 
 return text
end

function p.renderBanner(frame, args)
 return MessageBox.main('tmbox', {
  name = "backwards-copy",
  small = yesno(args["small"]),
  image = '[[File:Newspaper Cover.svg|50px]]',
  text = bannerText(frame, args)
 }) .. ((demoCheck(args) or mw.title.getCurrentTitle().namespace == 10) and
  "" or "[[Category:Wikipedia article talk pages incorporating the backwards copy template]]"
 )
end

function p.main(frame)
 local getArgs = require('Module:Arguments').getArgs
 local args = getArgs(frame, {
  trim = true,
  removeBlanks = true
 })
 return p.renderBanner(frame, args)
end

return p