-- This module implements {{find sources}} and other similar templates, and

-- also provides a mechanism to easily create new source-finding templates.



-- Define constants

local ROOT_PAGE = 'Module:Find sources'

local TEMPLATE_ROOT = ROOT_PAGE .. '/templates/' -- for template config modules

local LINK_CONFIG = ROOT_PAGE .. '/links/sandbox' -- for link config modules

local CONFIG_PAGE = ROOT_PAGE .. '/config' -- for global config



-- Load required modules

local checkType = require('libraryUtil').checkType

local cfg = mw.loadData(CONFIG_PAGE)



local p = {}



local function maybeLoadData(page)

	local success, data = pcall(mw.loadData, page)

	return success and data

end



local function substituteParams(msg, ...)

	return mw.message.newRawMessage(msg, ...):plain()

end



local function renderSearchString(searchTerms, separator, transformFunc)

	-- This takes a table of search terms and turns it into a search string

	-- that can be used in a URL or in a display value. The transformFunc

	-- parameter can be used to transform each search term in some way (for

	-- example, URL-encoding them).

	local searchStrings = {}

	for i, s in ipairs(searchTerms) do

		searchStringsi = s

	end

	if transformFunc then

		for i, s in ipairs(searchStrings) do

			searchStringsi = transformFunc(s)

		end

	end

	return table.concat(searchStrings, separator)

end



function p._renderLink(code, searchTerms, display, tooltip)

	-- Renders the external link wikicode for one link, given the link code,

	-- a table of search terms, and an optional display value and tooltip.



	-- Get link config.

	local links = maybeLoadData(LINK_CONFIG)

	local linkCfg = linkscode

	if not linkCfg then

		error(string.format(

			"invalid link code '%s'; no link config found at [[%s]]",

			code,

			LINK_CONFIG

		))

	end



	-- Make URL.

	local url

	do

		local separator = linkCfg.separator or "+"

		local searchString = renderSearchString(

			searchTerms,

			separator,

			mw.uri.encode

		)

		url = substituteParams(linkCfg.url, searchString)

	end

	

	if tooltip then

		return string.format('<span title="%s" style="border-bottom: 1px dotted;">[%s %s]</span>', 

			mw.text.encode(tooltip), url, display or linkCfg.display)

	else

		return string.format('[%s %s]', url, display or linkCfg.display)

	end

end



function p._main(template, args)

	-- The main access point from Lua.

	checkType('_main', 1, template, 'string')

	checkType('_main', 2, args, 'table', true)

	args = args or {}

	local title = mw.title.getCurrentTitle()



	-- Get the template config.

	local templateCfgPage = TEMPLATE_ROOT .. template

	local templateCfg = maybeLoadData(templateCfgPage)

	if not templateCfg then

		error(string.format(

			"invalid template name '%s'; no template config found at [[%s]]",

			template, templateCfgPage

		))

	end



	-- Namespace check.

	if not templateCfg.isUsedInMainspace and title.namespace == 0 then

		local formatString = '<strong class="error">%s</strong>'

		if cfg'namespace-error-category' then

			formatString = formatString .. '[[%s:%s]]'

		end

		return string.format(

			formatString,

			cfg'namespace-error'],

			mw.site.namespaces14].name,

			cfg'namespace-error-category'

		)

	end



	-- Get the search terms from the arguments.

	local searchTerms = {}

	for i, s in ipairs(args) do

		searchTermsi = s

	end

	if not searchTerms1 then

		-- Use the current subpage name as the default search term, unless 

		-- another title is provided. If the page uses a disambiguator like

		-- "Foo (bar)", make "Foo" the first term and "bar" the second.

		local searchTitle = args.title or title.subpageText

		local term, dab = searchTitle:match('^(.*) (%b())$')

		if dab then

			dab = dab:sub(2, -2) -- Remove parens

		end

		if term and dab then

			searchTerms1 = term

			searchTerms2 = dab

		else

			searchTerms1 = searchTitle

		end

	end

	searchTerms1 = '"' .. searchTerms1 .. '"'



	-- Make the intro link

	local introLink

	if templateCfg.introLink then

		local code = templateCfg.introLink.code

		local display = templateCfg.introLink.display or renderSearchString(

			searchTerms,

			'&nbsp;'

		)

		local tooltip = templateCfg.introLink.tooltip

		introLink = p._renderLink(code, searchTerms, display, tooltip)

	else

		introLink = ''

	end



	-- Make the other links

	local links = {}

	local separator = templateCfg.separator or cfg'default-separator'

	local sep = ''

	for i, t in ipairs(templateCfg.links) do

		linksi = sep .. p._renderLink(t.code, searchTerms, t.display, t.tooltip) ..

			(t.afterDisplay or '')

		sep = t.separator or separator

	end

	links = table.concat(links)



	-- Make the blurb.

	local blurb = substituteParams(templateCfg.blurb, introLink, links)

	local span = mw.html.create('span')

	span

		:addClass('plainlinks')

		:addClass(templateCfg.class)

		:cssText(templateCfg.style)

		:wikitext(blurb)



	return tostring(span)

end



setmetatable(p, { __index = function(t, template)

	-- The main access point from #invoke.

	-- Invocations will look like {{#invoke:Find sources|template name}},

	-- where "template name" is a subpage of [[Module:Find sources/templates]].

	local tname = template

	if tname:sub(-8) == '/sandbox' then

		-- This makes {{Find sources/sandbox|Albert Einstein}} work.

		tname = tname:sub(1, -9)

	end

	return function(frame)

		local args = require('Module:Arguments').getArgs(frame, {

			wrappers = mw.site.namespaces10].name .. ':' .. tname

		})

		return t._main(template, args)

	end

end})



return p