-- This module implements {{search link}}



local p = {}



local searchProfiles = {

	-- "advanced" is not included, as we automatically use the advanced profile

	-- if individual namespaces are specified.

	default = true,

	images = true,

	all = true

}



local function escapeTemplate(s)

	s = s:gsub('[{}|=]', function(match)

		return mw.text.nowiki(match)

	end)

	return s

end



local function parseNamespaceList(ns)

	-- s can be a search profile, a comma-separated list of namespaces, or a

	-- Lua array.

	-- Items in the list can be any valid key to mw.site.namespaces.

	-- We return either a profile string or a table of namespace numbers.



	-- Check for no input or search profile strings.

	local default = 'default'

	if not ns then

		return default

	elseif searchProfilesns then

		return ns

	end

	

	-- Parse the string for valid namespaces

	local ret = {}

	local keys

	if type(ns) == 'table' then

		keys = ns

	else

		keys = mw.text.split(ns, '%s*,%s*')

	end

	for _, key in ipairs(keys) do

		key = tonumber(key) or key

		if type(key) == 'string' and key:lower() == 'main' then

			key = 0

		end

		if mw.site.namespaceskey then

			ret#ret + 1 = mw.site.namespaceskey].id

		end

	end



	-- Check that we were passed at least one namespace, and return the table.

	if #ret < 1 then

		return default

	else

		return ret

	end

end



local function makeLink(searchString, display, ns)

	-- Normalise the input.

	if not searchString then

		-- Show the correct syntax if we are not passed a search string.

		return '<code>' ..

			escapeTemplate("{{search link|''search string''|''link text''}}") ..

			'</code>'

	end

	display = display or searchString

	ns = parseNamespaceList(ns)



	-- Build the query table

	local query = {

		search = searchString,

		fulltext = 'Search'

	}

	if searchProfilesns then

		query.profile = ns

	else

		query.profile = 'advanced'

		for _, nsid in ipairs(ns) do

			query'ns' .. tostring(nsid)] = '1'

		end

	end

	

	-- Make the URL.

	local url = mw.uri.fullUrl('Special:Search', query)

	url = tostring(url)

	

	-- Add the span tags and display value.

	return string.format(

		'<span class="plainlinks">[%s %s]</span>',

		url,

		display

	)

end



local function makeNamespaceWarningBanner(title)

	if title.namespace == 0 then

		return require('Module:Message box').main('mbox', {

			type = 'content',

			text = mw.text.nowiki('{{') ..

				'[[Template:Search link|Search link]]' ..

				mw.text.nowiki('}}') ..

				' ' ..

				'should not be used in [[WP:WIAA|articles]] as links to ' ..

				'"search result pages" are among the ' ..

				'[[WP:LINKSTOAVOID|links normally to be avoided]].',

			textstyle = 'text-align: center'

		})

	else

		return ''

	end

end



function p._main(searchString, display, ns, title)

	title = title or mw.title.getCurrentTitle()

	return makeLink(searchString, display, ns) .. makeNamespaceWarningBanner(title)

end



function p.main(frame)

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

		wrappers = 'Template:Search link'

	})

	local searchString = args1

	local display = args2

	local ns = args.ns

	return p._main(searchString, display, ns)

end



return p