-- This module implements {{newDYKnomination}}.

local p = {}

local lang = mw.language.getContentLanguage()
local namespace = 'Template:'

-------------------------------------------------------------------------------
-- Output template
-------------------------------------------------------------------------------

-- This template contains the final output of the module. Parameters like
-- ${PARAMETER_NAME} are substituted with the results of the output template
-- parameter functions below.

local OUTPUT_TEMPLATE = [=[
{{DYKsubpage
|monthyear=${MONTH_AND_YEAR} 
|passed=<!--When closing a discussion, enter yes, no, or withdrawn -->
|2=${INPUT_ERRORS}
<noinclude>
{{DYK tools|nominator=${NOMINATOR}}}
</noinclude>
{{DYK header|${HEADING}}}
{{DYK nompage links|nompage=${NOM_SUBPAGE}|${NOMPAGE_LINK_ARGS}}}
${IMAGE}${DYK_LISTEN}${DYK_WATCH}<!--

                   Please do not edit above this line unless you are a DYK volunteer who is closing the discussion.

-->
* ${HOOK}${ALT_HOOKS}${REVIEWED}${COMMENT}
{{smalldiv|1=${STATUS} by ${AUTHORS}.

Number of QPQs required: ${QPQS_REQUIRED}}}
~~~~.
<!--${CHECK_CREDITS_WARNING}
${CREDITS}
-->
* <!-- REPLACE THIS LINE TO WRITE the FIRST COMMENT, KEEPING THE ASTERISK  *   -->

${FILE_BREAK}}}<!--Please do not write below this line or remove this line. Place comments above this line.-->]=]

-------------------------------------------------------------------------------
-- Helper functions
-------------------------------------------------------------------------------

-- Creates a formatted error message that can be used with substitution.
local function formatError(msg)
	return string.format('{{DYK error|1=%s}}', msg)
end

-- Creates a boilerplate error message for invalid titles.
local function formatInvalidTitleError(page, pageType)
	local msg = string.format(
		'"%s" is not a valid %s; check for bad characters',
		page, pageType
	)
	return formatError(msg)
end

-- Make a title object from the given page name. Return nil if the title is
-- invalid.
local function makeTitle(page)
	local title = mw.title.new(page)
	if title and title.text ~= "" then
		return title
	end
end

-- Same as {{ROOTPAGENAME}}. If the page is an invalid title, returns nil.
local function getRootPageText(page)
	local title = makeTitle(page)
	if title and title.rootPageTitle then
		return title.rootPageTitle.text
	end
end

-- Makes template invocations for templates like {{DYK listen}} and
-- {{DYK watch}}.
local function makeFileTemplateInvocation(name, first, second)
	if not first then
		return nil
	end
	local ret = {}
	ret[#ret + 1] = '{{'
	ret[#ret + 1] = name
	ret[#ret + 1] = '|'
	ret[#ret + 1] = first
	if second then
		ret[#ret + 1] = '|'
		ret[#ret + 1] = second
	end
	ret[#ret + 1] = '}}'
	return table.concat(ret)
end

-- Normalize positional parameters for a template invocation. If any of the
-- parameters contain equals signs, the parameters are all prefixed with
-- numbers.
local function normalizeTemplateParameters(params)
	local ret = {}
	local hasEquals = false
	for i, param in ipairs(params) do
		if param:find('=') then
			hasEquals = true
			break
		end
	end
	if hasEquals then
		for i, param in ipairs(params) do
			ret[i] = string.format('%d=%s', i, param)
		end
	else
		for i, param in ipairs(params) do
			ret[i] = param
		end
	end
	return ret
end

-- Makes a link to a user's user page and talk page, like found in a standard
-- signature.
local function makeUserLinks(user)
	return string.format(
		'{{user0|%s}}',
		user
	)
end

-- Returns an array of authors. If the user didn't specify any authors, the
-- first one is the result of {{REVISIONUSER}}.
local function getNormalisedAuthors(data)
	local authors = {}
	for i, author in ipairs(data.authors) do
		authors[i] = author
	end
	authors[1] = authors[1] or data.revisionUser
	return authors
end

-- Removes gaps from sparse arrays. This is used to process numbered arguments
-- like author2 and ALT4.
local compressSparseArray = require("Module:TableTools").compressSparseArray

-- Splits numbered arguments by their prefixes. A table of arguments like this:
--    {foo1 = "foo1", foo2 = "foo2", bar3 = "bar3"}
-- Would be turned into this:
--    {foo = {[1] = "foo1", [2] = "foo2"}, bar = {[3] = "bar3"}}
-- Note that the subtables of the returned tables are not normal arrays, but
-- sparse arrays (there can be gaps between values).
local function splitByPrefix(args)
	local ret = {}
	for key, val in pairs(args) do
		if type(key) == 'string' then
			local prefix, num = key:match('^(.-)([1-9][0-9]*)$')
			if prefix then
				num = tonumber(num)
				ret[prefix] = ret[prefix] or {}
				ret[prefix][num] = val
			end
		end
	end
	return ret
end

-- Returns an array of numbered arguments with the given prefixes. Earlier
-- prefixes have precedence, and args[prefix] will overwrite args[prefix .. 1].
-- For example, for this arguments table:
--   {
--      author = "author",
--      author1 = "author1",
--      author2 = "author2,
--      creator2 = "creator2"
--   }
-- The function call getPrefixedArgs(args, splitArgs, {'creator', 'author'})
-- will produce:
--   {"author", "creator2"}
--
-- Parameters:
-- args - the table of arguments specified by the user
-- splitArgs - the table of arguments as processed by splitByPrefix
-- prefixes - an array of prefixes
local function getPrefixedArgs(args, splitArgs, prefixes)
	local ret = {}
	for i, prefix in ipairs(prefixes) do
		if splitArgs[prefix] then
			for num, val in pairs(splitArgs[prefix]) do
				if not ret[num] then
					ret[num] = val
				end
			end
		end
	end
	-- Allow prefix to overwrite prefix1.
	for _, prefix in ipairs(prefixes) do
		local val = args[prefix]
		if val then
			ret[1] = val
			break
		end
	end
	return compressSparseArray(ret)
end

-------------------------------------------------------------------------------
-- Output template parameter functions
-------------------------------------------------------------------------------

-- The results of these functions are substituted into parameters in the
-- output template. The parameters look like ${PARAMETER_NAME}. Trying to use
-- a parameter that doesn't have a function defined here will result in an
-- error.
--
-- The functions take a data table as a single argument. This table contains
-- the following fields:
-- * errors - a table of formatted error messages that were found when
--     processing the input.
-- * args - the table of arguments supplied by the user.
-- * articles - an array of the article names found in the arguments.
-- * authors - an array of the expanders/creators/writers/authors found in the
--     arguments.
-- * revisionUser - the user that last edited the page. As this module is only
--     substituted, this is always the current user.
-- * alts - an array of the ALT hooks found in the arguments.
-- * title - the mw.title object for the current page.
--
-- Template parameter functions should return a string, false, or nil.
-- Functions returning false or nil will be treated as outputting the empty
-- string "".

local params = {}

-- Renders any errors that were found when processing the input.
function params.INPUT_ERRORS(data)
	local nErrors = #data.errors
	if nErrors > 1 then
		return '\n* ' .. table.concat(data.errors, '\n* ')
	elseif nErrors == 1 then
		return '\n' .. data.errors[1]
	end
end

-- The current month and year, e.g. "March 2015".
function params.MONTH_AND_YEAR()
	return lang:formatDate('F Y')
end

-- The contents of the heading.
function params.HEADING(data)
	return table.concat(data.articles, ', ')
end

function params.NOMINATOR(data)
	return data.revisionUser
end

-- The current subpage name.
function params.NOM_SUBPAGE(data)
	if string.match(data.title.text,"/") then
		return string.gsub(data.title.text,data.title.rootText .. "/","")
	else
		return data.title.text
	end
end

-- Other arguments for the nompage link template, separated by pipes.
function params.NOMPAGE_LINK_ARGS(data)
	local vals = normalizeTemplateParameters(data.articles)
	return table.concat(vals, '|')
end

-- All of the image display code.
function params.IMAGE(data)
	local args = data.args
	if not args.image then
		return nil
	end
	local image = getRootPageText(args.image)
	if not image then
		image = formatInvalidTitleError(args.image, 'image name')
	end
	local caption = args.caption or args.rollover
	local template = [=[
{{main page image/DYK|image=%s|caption=%s}}<!--See [[Template:Main page image/DYK]] for other parameters-->
]=]
	return string.format(
		template,
		image,
		caption or 'CAPTION TEXT GOES HERE'
	)
end

-- The {{DYK listen}} template.
function params.DYK_LISTEN(data)
	local args = data.args
	return makeFileTemplateInvocation(
		'DYK Listen',
		args.sound,
		args.soundcaption
	)
end

-- The {{DYK watch}} template.
function params.DYK_WATCH(data)
	local args = data.args
	return makeFileTemplateInvocation(
		'DYK Watch',
		args.video,
		args.videocaption
	)
end

-- The hook text.
function params.HOOK(data)
	return data.args.hook or "... that ....?"
end

-- All of the ALT hooks that were specified with the ALT1, ALT2, ... etc.
-- parameters.
function params.ALT_HOOKS(data)
	local ret = {}
	for i, alt in ipairs(data.alts) do
		ret[i] = string.format("\n** '''ALT%d''': %s", i, alt)
	end
	return table.concat(ret)
end

-- A note saying which nomination the submitter reviewed.
function params.REVIEWED(data)
	local args = data.args
	local ret = "\n** ''Reviewed'': "
	if args.reviewed then
		local reviewedTitle = makeTitle(
			namespace .. 'Did you know nominations/' .. args.reviewed
		)
		if reviewedTitle and reviewedTitle.exists then
			ret = ret .. string.format(
				'[[%s|%s]]',
				reviewedTitle.prefixedText,
				reviewedTitle.subpageText
			)
		else
			local reviewedTitle = makeTitle(
				'Wikipedia:Did you know nominations/' .. args.reviewed	
			)
			if reviewedTitle and reviewedTitle.exists then
				ret = ret .. string.format(
					'[[%s|%s]]',
					reviewedTitle.prefixedText,
					reviewedTitle.subpageText
				)
			else
				ret = ret .. args.reviewed
			end
		end
	end
	return ret
end

-- A comment.
function params.COMMENT(data)
	if data.args.comment then
		return "\n** ''Comment'': " .. data.args.comment
	end
end

-- The status of the article when it was nominated for DYK.
function params.STATUS(data)
	local status = data.args.status
	status = status and status:lower()

	-- Created
	if status == 'new' then
		return 'Created'
	-- Expanded
	elseif status == 'expanded' or status == 'expansion' then
		return '5x expanded'
	
	-- Moved to mainspace
	elseif status == 'mainspace' or status == 'moved' then
		return 'Moved to mainspace'
	
	-- Converted from a redirect
	elseif status == 'convert'
                or status == 'converted'
                or status == 'redirect'
        then
		return 'Converted from a redirect'

	-- Improved to GA
	elseif status == 'ga' then
		return 'Improved to Good Article status'

	-- Default
	else
		return 'Created/expanded'
	end
end	

-- A list of the authors, with user and user talk links.
function params.AUTHORS(data)
	local authors = getNormalisedAuthors(data)
	for i, author in ipairs(authors) do
		authors[i] = makeUserLinks(author)
	end
	local separator = ', '
	local conjunction
	if #authors > 2 then
		conjunction = ', and '
	else
		conjunction = ' and '
	end
	return mw.text.listToText(authors, separator, conjunction)
end

function params.QPQS_REQUIRED(data)
	local qpqsNeeded, numPriorNoms = p.getRequiredQpqCount(data.revisionUser)
	local totalQpqsNeeded = qpqsNeeded * #data.articles
	if qpqsNeeded == 2 then
		return "'''"..totalQpqsNeeded.."'''. DYK is currently in unreviewed backlog mode and nominator has "..numPriorNoms.." past nominations."
	elseif qpqsNeeded == 1 then
		return "'''"..totalQpqsNeeded.."'''. Nominator has "..numPriorNoms.." past nominations."
	else -- if user has < 5 noms, exact count is unknown as it is not present on the json page
		return "'''0'''. Nominator has fewer than 5 past nominations."
	end
end

-- Warning to check that the credits are correct.
function params.CHECK_CREDITS_WARNING(data)
	if #data.articles > 1 then
		return 'Please check to make sure these auto-generated credits are correct.'
	end
end

-- DYK credits. These are used by the bot to credit people on their talk pages
-- and to tag articles.
function params.CREDITS(data)
	local authors = getNormalisedAuthors(data)
	local articles = data.articles
	local nompage = params.NOM_SUBPAGE(data)
	local nominator = data.revisionUser
	local nominatorIsAuthor = false
	for i, author in ipairs(data.authors) do
		if author == nominator then
			nominatorIsAuthor = true
			break
		end
	end

	local ret = {}

	local function addTemplate(template, article, user, subpage)
		local params = normalizeTemplateParameters{article, user}
		if subpage then
			table.insert(params, 'subpage=' .. subpage)
		end
		ret[#ret + 1] = string.format(
			'* {{%s|%s}}',
			template,
			table.concat(params, '|')
		)
	end

	-- First article, a special case
	do
		local article = articles[1]
		addTemplate(
			'DYKmake',
			article,
			authors[1],
			nompage
		)
		for i = 2, #authors do
			addTemplate('DYKmake', article, authors[i], nompage)
		end
		if not nominatorIsAuthor then
			addTemplate('DYKnom', article, nominator)
		end
	end

	-- Second article and up
	for i = 2, #articles do
		local article = articles[i]
		for j, author in ipairs(authors) do
			addTemplate('DYKmake', article, author, nompage)
		end
		if not nominatorIsAuthor then
			addTemplate('DYKnom', article, nominator)
		end
	end

	return table.concat(ret, '\n')
end

-- If a file was displayed, use the {{-}} template so that it doesn't spill
-- over into the next nomination.
function params.FILE_BREAK(data)
	local args = data.args
	if args.image or args.sound or args.video then
		return '{{-}}'
	end
end

-------------------------------------------------------------------------------
-- Exports
-------------------------------------------------------------------------------

function p._main(args, frame, title)
	-- Subst check.
	-- Check for the frame object as well to make debugging easier from the
	-- debug console.
	if frame and not mw.isSubsting() then
		return '<strong class="error">' ..
			'This template must be [[Wikipedia:Substitution|substituted]]. ' ..
			'Replace <code>{{NewDYKnomination}}</code> with ' ..
			'<code>{{subst:NewDYKnomination}}</code>.</strong>'
	end

	-- Set default arguments.
	frame = frame or mw.getCurrentFrame()
	title = title or mw.title.getCurrentTitle()

	-- Process data from the arguments.
	local splitArgs = splitByPrefix(args)
	local articles = getPrefixedArgs(args, splitArgs, {'article'})
	local authors = getPrefixedArgs(
		args,
		splitArgs,
		{'expander', 'creator', 'writer', 'author'}
	)
	local alts = getPrefixedArgs(args, splitArgs, {'ALT'})

	-- Input sanity checks.
	local errors = {}
	for i, article in ipairs(articles) do
		local articleTitle = makeTitle(article)
		if not articleTitle then
			table.insert(errors, formatInvalidTitleError(
				article,
				'article name'
			))
			articles[i] = ''
		end
	end
	if #articles < 1 then
		articles[1] = title.subpageText
	end
	for i, author in ipairs(authors) do
		authors[i] = getRootPageText(author)
		if not authors[i] then
			table.insert(errors, formatInvalidTitleError(author, 'user name'))
			authors[i] = ''
		end
	end

	-- Substitute the parameters in the output template.
	local data = {
		errors = errors,
		args = args,
		articles = articles,
		authors = authors,
		revisionUser = frame:preprocess('{{safesubst:REVISIONUSER}}'),
		alts = alts,
		title = title,
	}
	local ret = OUTPUT_TEMPLATE:gsub('${([%u_]+)}', function (funcName)
		local func = params[funcName]
		if not func then
			error(string.format(
				"invalid parameter '${%s}' " ..
				"(no corresponding parameter function found)",
				funcName
			))
		end
		return func(data) or ''
	end)
	return ret
end

-- This function is also invoked from the JS wizard. Please do NOT rename or 
-- change the arguments or return format unless the JS wizard is also being 
-- edited concurrently.
function p.getRequiredQpqCount(username) 
	local backlogModeText = mw.title.new('Template:Did you know/Backlog mode?'):getContent()
	local isInBacklogMode = backlogModeText ~= nil and backlogModeText:find('^true') ~= nil
	local nomsCountData = mw.loadJsonData('User:SDZeroBot/DYK nomination counts.json')
	local numPriorNoms = nomsCountData[username] or -1
	local qpqsRequired =
		(isInBacklogMode and numPriorNoms >= 20 and 2) or
		(numPriorNoms >= 5 and 1) or
		0
	return qpqsRequired, numPriorNoms
end

function p.main(frame)
	local args = require('Module:Arguments').getArgs(frame, {
		wrappers = 'Template:NewDYKnomination'
	})
	return p._main(args, frame)
end

return p