local p = {}

local function urlencode(text)
	-- Return equivalent of {{urlencode:text}}.
	local function byte(char)
		return string.format('%%%02X', string.byte(char))
	end
	return text:gsub('[^ %w%-._]', byte):gsub(' ', '+')
end

local function make_link(url, expansion, display_text, after)
	return mw.ustring.format(
		'[%s <abbr title="%s">%s</abbr>]%s',
		url,
		expansion,
		display_text,
		after or ''
	)
end

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

	local search_phrase_encoded = urlencode(args[1] or 'example phrase')
	local short_module_args = {
		class = 'template-search plainlinks',
		make_link('https://en.wikipedia.org/w/index.php?title=Special:Search&search=' .. search_phrase_encoded, 'Wikipedia', 'wp'),
		make_link('https://www.google.com/search?q=' .. search_phrase_encoded, 'Google', 'g'),
		make_link('https://www.bing.com/search?q=' .. search_phrase_encoded, 'Bing', 'b'),
	}
	local long_module_args = {
		class = 'template-search plainlinks',
		make_link('https://en.wikipedia.org/w/index.php?title=Special:Search&search=' .. search_phrase_encoded, 'Wikipedia', 'wp'),
		make_link('https://www.google.com/search?q=site%3Awikipedia.org+' .. search_phrase_encoded, 'Wikipedia over Google', 'gwp'),
		make_link('https://www.google.com/search?q=' .. search_phrase_encoded, 'Google', 'g'),
		make_link('https://www.bing.com/search?q=site%3Awikipedia.org+' .. search_phrase_encoded, 'Wikipedia over Bing', 'bwp'),
		make_link('https://www.bing.com/search?q=' .. search_phrase_encoded, 'Bing', 'b', ' |'),
		make_link('https://www.britannica.com/search?nop&query=' .. search_phrase_encoded, 'Encyclopaedia Britannica', 'eb'),
		make_link('https://www.bartleby.com/cgi-bin/texis/webinator/65search?query=' .. search_phrase_encoded, 'Columbia Encyclopedia', 'co'),
		make_link('https://www.google.com/search?q=site%3Ahttp%3A%2F%2Fwww.pcmag.com%2Fencyclopedia_term%2F+' .. search_phrase_encoded, 'PC Magazine Encyclopedia over Google', 'gct'),
		make_link('https://scienceworld.wolfram.com/search/index.cgi?as_q=' .. search_phrase_encoded, 'World of Science', 'sw'),
		make_link('https://archive.org/search.php?query=' .. search_phrase_encoded, 'Internet Archive', 'arc'),
		make_link('https://babel.hathitrust.org/cgi/ls?field1=ocr;q1=' .. search_phrase_encoded .. ';a=srchls;lmt=ft', 'HathiTrust', 'ht'),	
	}
	
	local long = (args.long or '') ~= ''
	local ubl = require('Module:List').unbulleted
	local list = ubl(long and long_module_args or short_module_args)
	return frame:extensionTag{
		name = 'templatestyles', args = { src = 'Module:Search/styles.css' }
	} .. '(' .. list .. ')'
end

return p