local yesno = require('Module:Yesno')
local makeMessageBox = require('Module:Message box').main

-- may not need these. lazily initalize
local makeToolbar, getPagetype, effectiveProtectionLevel
local modulesLoaded = false

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

local function makeWikilink(page, display)
	if display then
		return mw.ustring.format('[[%s|%s]]', page, display)
	else
		return mw.ustring.format('[[%s]]', page)
	end
end

----------------------------------------------------------------------
-- Title class
----------------------------------------------------------------------

-- This is basically the mw.title class with some extras thrown in.

local title = {}
title.__index = title

function title.getProtectionLevelText(protectionLevel)
	-- Gets the text to use in anchors and urn links.
	local levels = {unprotected = 'editunprotected', autoconfirmed = 'editsemiprotected', templateeditor = 'edittemplateprotected', sysop = 'editprotected'}
	return levels[protectionLevel]
end

function title.new(...)
	local success, obj = pcall(mw.title.new, ...)
	if not (success and obj) then return end

	-- Add a protectionLevel property.
	obj.protectionLevel = effectiveProtectionLevel(obj.exists and 'edit' or 'create', obj)
	if obj.protectionLevel == '*' then
		-- Make unprotected pages return "unprotected".
		obj.protectionLevel = 'unprotected'
	elseif obj.protectionLevel == 'user' then
		-- If we just need to be registered, pretend we need to be autoconfirmed, since it's the closest thing we have.
		obj.protectionLevel = 'autoconfirmed'
	elseif obj.protectionLevel == 'accountcreator' then
		-- Lump titleblacklisted pages in with template-protected pages, since templateeditors can do both.
		obj.protectionLevel = 'templateeditor'
	end

	-- Add a pagetype property.
	obj.pagetype = getPagetype{page = obj.prefixedText, defaultns = 'all'}
	
	-- Add link-making methods.
	function obj:makeUrlLink(query, display)
		return mw.ustring.format('[%s %s]', self:fullUrl(query), display)
	end

	function obj:makeViewLink(display)
		return self:makeUrlLink({redirect = 'no'}, display)
	end

	function obj:makeEditLink(display)
		return self:makeUrlLink({action = 'edit'}, display)
	end

	function obj:makeHistoryLink(display)
		return self:makeUrlLink({action = 'history'}, display)
	end

	function obj:makeLastEditLink(display)
		return self:makeUrlLink({diff = 'cur', oldid = 'prev'}, display)
	end

	function obj:makeWhatLinksHereLink(display)
		return makeWikilink('Special:WhatLinksHere/' .. self.prefixedText, display)
	end

	function obj:makeCompareLink(otherTitle, display)
		display = display or 'diff'
		local comparePagesTitle = title.new('Special:ComparePages')
		return comparePagesTitle:makeUrlLink({page1 = self.prefixedText, page2 = otherTitle.prefixedText}, display)
	end

	function obj:makeLogLink(logType, display)
		local logTitle = title.new('Special:Log')
		return logTitle:makeUrlLink({type = logType, page = self.prefixedText}, display)
	end

	function obj:urlEncode()
		return mw.uri.encode(self.prefixedText, 'WIKI')
	end

	function obj:makeUrnLink(boxProtectionLevel)
		-- Outputs a urn link. The protection level is taken from the template, rather than detected from page itself,
		-- as the detection may be inaccurate for cascade-protected and title-blacklisted pages as of Nov 2013.
		local protectionLinkText = title.getProtectionLevelText(boxProtectionLevel)
		return mw.ustring.format('[urn:x-wp-%s:%s <span/>]', protectionLinkText, self:urlEncode())
	end

	-- Get a subpage title object, but go through pcall rather than use the unprotected mw.title:subPageTitle.
	function obj:getSubpageTitle(subpage)
		return title.new(self.prefixedText .. '/' .. subpage)
	end
	
	return obj
end

----------------------------------------------------------------------
-- TitleTable class
----------------------------------------------------------------------

local titleTable = {}
titleTable.__index = titleTable

function titleTable.new(args)
	-- Get numerical arguments and make title objects for each of them. 
	local nums = {}
	for k, v in pairs(args) do
		if type(k) == 'number' then
			table.insert(nums, k)
		end
	end
	table.sort(nums)
	local titles = {}
	for _, num in ipairs(nums) do
		local title = title.new(args[num])
		table.insert(titles, title)
	end
	-- Get the current title, and get the subject title if no titles were specified.
	titles.currentTitle = mw.title.getCurrentTitle()
	if #titles < 1 then
		local currentTitle = titles.currentTitle
		local subjectNs = currentTitle.subjectNsText
		if subjectNs ~= '' then
			subjectNs = subjectNs .. ':'
		end
		titles.subjectTitle = title.new(subjectNs .. currentTitle.text)
	end
	-- Set the metatable.
	setmetatable(titles, titleTable)
	return titles
end

function titleTable:memoize(memoField, func, ...)
	if self[memoField] ~= nil then
		return self[memoField]
	else
		self[memoField] = func(...)
		return self[memoField]
	end
end

function titleTable:titleIterator()
	local i = 0
	local n = #self
	return function()
		i = i + 1
		if i == 1 and n < 1 then
			return self.subjectTitle
		else
			if i <= n then
				return self[i]
			end
		end
	end
end

function titleTable:hasSameProperty(memoField, getPropertyFunc)
	-- If the titles table has more than one title in it, check if they have the same property.
	-- The property is found using the getPropertyFunc function, which takes a title object as its single argument.
	if #self <= 1 then return end
	
	local function hasSameProperty(getPropertyFunc)
		local properties = {}
		for i, obj in ipairs(self) do
			local property = getPropertyFunc(obj)
			if i == 1 or property ~= properties[#properties] then
				table.insert(properties, property)
			end
		end
		if #properties == 1 then
			return true
		elseif #properties > 1 then
			return false
		end
	end

	return self:memoize(memoField, hasSameProperty, getPropertyFunc)
end	

function titleTable:hasSameExistenceStatus()
	-- Returns true if all the titles exist, or if they all don't exist. Returns false if there is a mixture of existence statuses,
	-- and returns nil if there is one title or less.
	return self:hasSameProperty('sameExistenceStatus', function (title) return title.exists end)
end

function titleTable:hasSameProtectionStatus()
	-- Checks if all the titles have the same protection status (either for creation protection or for edit-protection - the two are not mixed).
	local sameExistenceStatus = self:hasSameExistenceStatus()
	if sameExistenceStatus then
		return self:hasSameProperty('sameProtectionStatus', function (title) return title.protectionLevel end)
	else
		return sameExistenceStatus
	end
end

function titleTable:hasSamePagetype()
	-- Checks if all the titles have the same pagetype.
	return self:hasSameProperty('samePagetype', function (title) return title.pagetype end)
end

function titleTable:propertyExists(memoField, getPropertyFunc)
	-- Checks if a title with a certain property exists.
	-- The property is found using the getPropertyFunc function, which takes a title object as its single argument
	-- and should return a boolean value.
	local function propertyExists(getPropertyFunc)
		for titleObj in self:titleIterator() do
			if getPropertyFunc(titleObj) then
				return true
			end
		end
		return false
	end
	return self:memoize(memoField, propertyExists, getPropertyFunc)
end

function titleTable:hasNonInterfacePage()
	return self:propertyExists('nonInterfacePage', function (titleObj) return titleObj.namespace ~= 8 end)
end

function titleTable:hasTemplateOrModule()
	return self:propertyExists('templateOrModule', function (titleObj) return titleObj.namespace == 10 or titleObj.namespace == 828 end)
end

function titleTable:hasNonTemplateOrModule()
	return self:propertyExists('nontemplateormodule', function (titleobj) return titleobj.namespace ~= 10 and titleobj.namespace ~= 828 end)
end

function titleTable:hasOtherProtectionLevel(level)
	for titleObj in self:titleIterator() do
		if titleObj.protectionLevel ~= level then
			return true
		end
	end
	return false
end

function titleTable:getProtectionLevels()
	local function getProtectionLevels()
		local levels = {}
		for titleObj in self:titleIterator() do
			local level = titleObj.protectionLevel
			levels[level] = true
		end
		return levels
	end
	return self:memoize('protectionLevels', getProtectionLevels)
end

----------------------------------------------------------------------
-- Blurb class definition
----------------------------------------------------------------------

local blurb = {}
blurb.__index = blurb

function blurb.new(titleTable, boxProtectionLevel)
	local obj = {}
	obj.titles = titleTable
	obj.boxProtectionLevel = boxProtectionLevel
	obj.linkCount = 0 -- Counter for the number of total items in the object's link lists. 
	setmetatable(obj, blurb)
	return obj
end

-- Static methods --

function blurb.makeParaText(name, val)
	local pipe = mw.text.nowiki('|')
	local equals = mw.text.nowiki('=')
	val = val and ("''" .. val .. "''") or ''
	return mw.ustring.format('<code style="white-space: nowrap;">%s%s%s%s</code>', pipe, name, equals, val)
end

function blurb.makeTemplateLink(s)
	return mw.ustring.format('%s[[Template:%s|%s]]%s', mw.text.nowiki('{{'), s,	s, mw.text.nowiki('}}'))
end

function blurb:makeProtectionText()
	local boxProtectionLevel = self.boxProtectionLevel
	local levels = {unprotected = 'unprotected', autoconfirmed = 'semi-protected', templateeditor = 'template-protected', sysop = 'fully protected'}
	for level, protectionText in pairs(levels) do
		if level == boxProtectionLevel then
			return mw.ustring.format('[[Help:Protection|%s]]', protectionText)
		end
	end
end

function blurb.getPagetypePlural(title)
	local pagetype = title.pagetype
	if pagetype == 'category' then
		return 'categories'
	else
		return pagetype .. 's'
	end
end

-- Normal methods --

function blurb:makeLinkList(title, showViewLink)
	local tbargs = {} -- The argument list to pass to Module:Toolbar
	tbargs.style = 'font-size: smaller;'
	tbargs.separator = 'dot'
	-- Show view link if the option is set.
	if showViewLink then
		table.insert(tbargs, title:makeViewLink('view'))
	end
	-- Page links.
	table.insert(tbargs, title:makeEditLink('edit'))
	table.insert(tbargs, title:makeHistoryLink('history'))
	table.insert(tbargs, title:makeLastEditLink('last'))
	table.insert(tbargs, title:makeWhatLinksHereLink('links'))
	-- Sandbox links.
	local sandboxTitle = title:getSubpageTitle('sandbox')
	if sandboxTitle and sandboxTitle.exists then
		table.insert(tbargs, sandboxTitle:makeViewLink('sandbox'))
		table.insert(tbargs, sandboxTitle:makeEditLink('edit sandbox'))
		table.insert(tbargs, sandboxTitle:makeHistoryLink('sandbox history'))
		table.insert(tbargs, sandboxTitle:makeLastEditLink('sandbox last edit'))
		table.insert(tbargs, title:makeCompareLink(sandboxTitle, 'sandbox diff'))
	end
	-- Test cases links.
	local testcasesTitle = title:getSubpageTitle('testcases')
	if testcasesTitle and testcasesTitle.exists then
		table.insert(tbargs, testcasesTitle:makeViewLink('test cases'))
	end
	-- Transclusion count link.
	if title.namespace == 10 or title.namespace == 828 then -- Only add the transclusion count link for templates and modules.
		title.fragment = 'mw-pageinfo-transclusions'
		table.insert(tbargs, title:makeUrlLink({action='info'}, 'transclusion count'))
		title.fragment = ''
	end
	-- Protection log link.
	if title.namespace ~= 8 then -- MediaWiki pages don't have protection log entries.
		table.insert(tbargs, title:makeLogLink('protect', 'protection log'))
	end
	self.linkCount = self.linkCount + #tbargs -- Keep track of the number of total links created by the object.
	return makeToolbar(tbargs)
end

function blurb:makeLinkLists()
	local titles = self.titles
	if #titles < 1 then
		return self:makeLinkList(titles.subjectTitle, true) 
	elseif #titles == 1 then
		return self:makeLinkList(titles[1]) -- The page name is included in the "at" link, so we don't need to include the view link here.
	else
		local ret = {}
		table.insert(ret, '<ul>')
		for i, titleObj in ipairs(titles) do
			table.insert(ret, mw.ustring.format('<li>%s %s</li>', titleObj:makeViewLink(titleObj.prefixedText), self:makeLinkList(titleObj)))
		end
		table.insert(ret, '</ul>')
		return table.concat(ret)
	end
end

function blurb:makeIntro()
	local titles = self.titles
	local requested = 'It is [[Wikipedia:Edit requests|requested]] that'
	local protectionText
	if titles:hasNonInterfacePage() then
		protectionText = ' ' .. self:makeProtectionText()
	else
		protectionText = '' -- Interface pages cannot be unprotected, so we don't need to explicitly say they are protected.
	end
	-- Deal with cases where we are passed multiple titles.
	if #titles > 1 then
		local pagetype
		if titles:hasSamePagetype() then
			pagetype = blurb.getPagetypePlural(titles[1])
		else
			pagetype = 'pages'
		end
		return mw.ustring.format("'''%s edits be made to the following%s %s''':", requested, protectionText, pagetype)
	end
	-- Deal with cases where we are passed only one title.
	local title = titles[1]
	if not title then
		title = titles.subjectTitle
	end
	local stringToFormat
	if title.exists then
		stringToFormat = '%s an edit be made to %s%s %s%s.'
	else
		stringToFormat = '%s %s%s %s%s be created.'
	end
	stringToFormat = "'''" .. stringToFormat .. "'''"
	local atLink, theOrThis
	if #titles == 1 then
		atLink = mw.ustring.format(' at %s', title:makeViewLink(title.prefixedText))
		theOrThis = 'the'
	else -- #titles < 1 
		atLink = ''
		theOrThis = 'this'
	end
	return mw.ustring.format(stringToFormat, requested, theOrThis, protectionText, title.pagetype, atLink)
end

function blurb:makeBody()
	local titles = self.titles
	local protectionLevels = titles:getProtectionLevels()
	local boxProtectionLevel = self.boxProtectionLevel
	local hasNonInterfacePage = titles:hasNonInterfacePage()
	local isPlural = false
	if #titles > 1 then
		isPlural = true
	end

	local descriptionText = "This template must be followed by a '''complete and specific description''' of the request, "
	if boxProtectionLevel == 'sysop' or boxProtectionLevel == 'templateeditor' then
		local editText = 'edit'
		if isPlural then
			editText = editText .. 's'
		end
		local descriptionCompleteText = mw.ustring.format('so that an editor unfamiliar with the subject matter could complete the requested %s immediately.', editText)
		descriptionText = descriptionText .. descriptionCompleteText
	else
		descriptionText = descriptionText .. 'that is, specify what text should be removed and a verbatim copy of the text that should replace it. '
			.. [["Please change ''X''" is '''not acceptable''' and will be rejected; the request '''must''' be of the form "please change ''X'' to ''Y''".]]
	end

	local smallText = ''
	if boxProtectionLevel == 'sysop' or boxProtectionLevel == 'templateeditor' then
		local templateFullText
		if boxProtectionLevel == 'sysop' then
			templateFullText = 'fully protected'
		elseif boxProtectionLevel == 'templateeditor' then
			templateFullText = 'template-protected'
		end
		smallText =	'Edit requests to ' .. templateFullText	.. " pages should only be used for edits that are either '''uncontroversial''' or supported by [[Wikipedia:Consensus|consensus]]."
			.. " If the proposed edit might be controversial, discuss it on the protected page's talk page '''before''' using this template."
	else
		local userText
		if boxProtectionLevel == 'autoconfirmed' then
			userText = '[[Wikipedia:User access levels#Autoconfirmed|autoconfirmed]] user'
		else
			userText = 'user'
		end
		local answeredPara = blurb.makeParaText('answered', 'no')
		local stringToFormat =	'The edit may be made by any %s. '
			.. [[Remember to change the %s parameter to "'''yes'''" when the request has been accepted, rejected or on hold awaiting user input. ]]
			.. "This is so that inactive or completed requests don't needlessly fill up the edit requests category. "
			.. 'You may also wish to use the %s template in the response.'
		smallText = mw.ustring.format(stringToFormat, userText, answeredPara, blurb.makeTemplateLink('ESp'))
	end
	if hasNonInterfacePage then
		smallText = smallText .. ' To request that a page be protected or unprotected, make a [[Wikipedia:Requests for page protection|protection request]].'
	end
	if boxProtectionLevel == 'sysop' or boxProtectionLevel == 'templateeditor' then
		smallText = smallText .. ' When the request has been completed or denied, please add the ' .. blurb.makeParaText('answered', 'yes') .. ' parameter to deactivate the template.'
	end
	return mw.ustring.format('%s\n<p style="font-size:smaller; line-height:1.3em;">\n%s\n</p>', descriptionText, smallText)
end

function blurb:export()
	local intro = self:makeIntro()
	local linkLists = self:makeLinkLists()
	local body = self:makeBody()
	-- Start long links lists on a new line.
	local linkListSep = ' '
	if self.linkCount > 5 then
		linkListSep = '<br />'
	end
	return mw.ustring.format('%s%s%s\n\n%s', intro, linkListSep, linkLists, body)
end

----------------------------------------------------------------------
-- Box class definition
----------------------------------------------------------------------

local box = {}
box.__index = box

function box.new(protectionType, args)
	local obj = {}
	obj.tmboxArgs = {} -- Used to store arguments to be passed to tmbox by the box:export method.
	-- Set data fields.
	local answered = args.answered or args.ans
	obj.answered = yesno(answered, true) or false
	if not obj.answered then
		if not modulesLoaded then
			-- We know we'll need these now, so go ahead and load them
			modulesLoaded = true
			makeToolbar = require('Module:Toolbar')._main
			getPagetype = require('Module:Pagetype')._main
			effectiveProtectionLevel = require('Module:Effective protection level').main
		end
		local boxProtectionLevels = {semi = 'autoconfirmed', template = 'templateeditor', full = 'sysop'}
		obj.boxProtectionLevel = boxProtectionLevels[protectionType]
		obj.demo = yesno(args.demo)
		-- Set dependent objects.
		obj.titles = titleTable.new(args)
		if not yesno(args.force) and obj.titles:hasSameProperty('sameProtectionStatus', function (title) return title.protectionLevel end) ~= false and (obj.titles[1] or obj.titles.subjectTitle).protectionLevel ~= 'unprotected' then
			obj.boxProtectionLevel = (obj.titles[1] or obj.titles.subjectTitle).protectionLevel
		end
		obj.blurb = blurb.new(obj.titles, obj.boxProtectionLevel)
	end
	setmetatable(obj, box)
	return obj
end

function box:setArg(key, value)
	-- This sets a value to be passed to tmbox.
	if key then
		self.tmboxArgs[key] = value
	end
end

function box:setImage()
	local titles = self.titles
	local boxProtectionLevel = self.boxProtectionLevel
	local padlock
	if boxProtectionLevel == 'sysop' and not titles:hasNonTemplateOrModule() then
		padlock = 'Padlock-red.svg'
	elseif boxProtectionLevel == 'sysop' then
		padlock = 'Padlock.svg'
	elseif boxProtectionLevel == 'templateeditor' then
		padlock = 'Padlock-pink.svg'
	elseif boxProtectionLevel == 'autoconfirmed' then
		padlock = 'Padlock-silver.svg'
	else
		padlock = 'Padlock-bronze-open.svg'
	end
	local stringToFormat = '[[File:%s|%dpx|alt=|link=]]'
	local smallPadlock = mw.ustring.format(stringToFormat, padlock, 25)
	local largePadlock = mw.ustring.format(stringToFormat, padlock, 60)
	self:setArg('smallimage', smallPadlock)
	self:setArg('image', largePadlock)
end

function box:setBlurbText()
	local blurbText = self.blurb:export()
	self:setArg('text', blurbText)
end

function box:setAnsweredText()
	local answeredText = mw.ustring.format(
		"This [[Wikipedia:Edit requests|edit request]] has been answered. Set the %s or %s parameter to '''no''' to reactivate your request.",
		blurb.makeParaText('answered'), blurb.makeParaText('ans')
	)
	self:setArg('smalltext', answeredText)
end

function box:exportAnchors()
	local anchorText = title.getProtectionLevelText(self.boxProtectionLevel)
	return mw.ustring.format('<span id="%s"></span>', anchorText)
end

function box:exportRequestTmbox()
	self:setImage()
	self:setBlurbText()
	self:setArg('class', 'editrequest')
	return makeMessageBox('tmbox', self.tmboxArgs)
end

function box:exportAnsweredTmbox()
	self:setAnsweredText()
	self:setArg('small', true)
	self:setArg('class', 'editrequest')
	return makeMessageBox('tmbox', self.tmboxArgs)
end	

function box:exportRequestCategories()
	local cats = {}
	local boxProtectionLevel = self.boxProtectionLevel
	local function addCat(cat)
		table.insert(cats, mw.ustring.format('[[Category:%s]]', cat))
	end
	local protectionCats = {
		autoconfirmed = 'Wikipedia semi-protected edit requests',
		templateeditor = 'Wikipedia template-protected edit requests',
		sysop = 'Wikipedia protected edit requests'
	}
	addCat(protectionCats[boxProtectionLevel])
	if self.titles:hasOtherProtectionLevel(boxProtectionLevel) then
		addCat('Wikipedia edit requests possibly using incorrect templates')
	end
	return table.concat(cats)
end

function box:exportUrnLinks()
	local ret = {}
	local boxProtectionLevel = self.boxProtectionLevel
	for titleObj in self.titles:titleIterator() do
		table.insert(ret, titleObj:makeUrnLink(boxProtectionLevel))
	end
	return mw.ustring.format('<span class="plainlinks" style="display:none">%s</span>', table.concat(ret))
end

function box:export()
	local ret = {}
	if self.answered then
		table.insert(ret, self:exportAnsweredTmbox())
	elseif self.titles.currentTitle.isTalkPage or self.demo then
		table.insert(ret, self:exportAnchors())
		table.insert(ret, self:exportRequestTmbox())
		table.insert(ret, self:exportUrnLinks())
		if not self.demo then
			table.insert(ret, self:exportRequestCategories())
		end
	else
		table.insert(ret, '<span class="error">Error: Protected edit requests can only be made on the talk page.</span>[[Category:Non-talk pages requesting an edit to a protected page]]')
	end
	return table.concat(ret)
end

----------------------------------------------------------------------
-- Process arguments and initialise objects
----------------------------------------------------------------------

local p = {}

function p.main(protectionType, args)
	local requestBox = box.new(protectionType, args)
	return requestBox:export()
end

local function makeWrapper(protectionType)
	return function (frame)
		-- If called via #invoke, use the args passed into the invoking template, or the args passed to #invoke if any exist.
		-- Otherwise assume args are being passed directly in from the debug console or from another Lua module.
		local origArgs
		if frame == mw.getCurrentFrame() then
			origArgs = frame:getParent().args
			for k, v in pairs(frame.args) do
				origArgs = frame.args
				break
			end
		else
			origArgs = frame
		end
		-- Trim whitespace and remove blank arguments.
		local args = {}
		for k, v in pairs(origArgs) do
			if type(v) == 'string' then
				v = mw.text.trim(v)
			end
			if v ~= '' then
				args[k] = v
			end
		end
		return p.main(protectionType, args)
	end
end

local funcNames = {'semi', 'template', 'full'}
for _, funcName in ipairs(funcNames) do
	p[funcName] = makeWrapper(funcName)
end

return p