local p = {}

local TwitterSnowflake = require('Module:TwitterSnowflake')

local CiteWeb = require('Module:Cite web')[''



local function _if(arg)

	return arg and arg ~= '' or nil

end



p.main = function(frame)

	frame.args = frame:getParent().args

	return p''](frame)

end



p'' = function(frame)

	local args = frame.args

	local cite_args = {

		url 		= 'https://twitter.com/' .. ((args.user and args.number) and (args.user .. '/status/' .. args.number) or ''),

		title		= (args.title or ''):gsub('https*://', ''),

		'script-title' = args'script-title'],

		'trans-title' = args'trans-title'],

		language	= args.language,

		'author-link' = args'author-link' or args.authorlink,

		others		= _if(args.retweet) and ('Retweeted by ' .. args.retweet),

		via 		= args.link == 'no' and 'Twitter' or '[[Twitter]]',

		type		= 'Tweet',

		location	= args.location,

		'access-date' = args'access-date' or args.accessdate,

		'archive-date' = args'archive-date' or args.archivedate,

		'archive-url' = args'archive-url' or args.archiveurl,

		'url-status' = args'url-status' or args'dead-url' or args.deadurl,

		quote	= args.quote,

		ref			= args.ref,

		df			= args.df

	}

	if _if(args.last1 or args.last) then

		cite_args.author = (args.last1 or args.last) ..

			(_if(args.first1 or args.first) and (', ' .. (args.first1 or args.first)) or '') ..

			' [@' .. (args.user or '') .. ']'

	elseif _if(args.author1 or args.author) then

		cite_args.author = (args.author1 or args.author) .. ' [@' .. (args.user or '') .. ']'

	elseif _if(args'author-link']) then

		cite_args.author = args'author-link' .. ' [@' .. (args.user or '') .. ']'

	else

		cite_args.author = '@' .. (args.user or '')

	end

	if cite_args.author:find ('[Tt]witter') then

		cite_args.author = '((' .. cite_args.author .. '))'

	end

	if _if(tonumber(args.number)) then

		cite_args.date = args.date or (_if(args.number) and TwitterSnowflake.snowflakeToDate{ args = {id_str = args.number} })

	else

		cite_args.date = args.date

	end

	

	frame.args = cite_args

	local output = CiteWeb(frame)

	frame.args = args

	

	-- Error checking

	local error_template = '<span class="cs1-visible-error citation-comment">%s</span>'

	local errors = {}

	if not (_if(args.title) or _if(args'script-title']) or args.user or args.number or args.date) then

		-- No title; error message is provided by CS1 module.

		errors1 = ';'

	end

	if not _if(args.user) then

		errors1 + #errors = ' Missing or empty <kbd>&#124;user=</kbd>;'

	end

	if not _if(args.number) then

		errors1 + #errors = ' Missing or empty <kbd>&#124;number=</kbd>;'

	end

	errors1 + #errors = TwitterSnowflake.datecheck{ args = {

		id_str	= args.number or '',

		date	= args.date or '',

		error1	= ' <kbd>&#124;date=</kbd> mismatches calculated date from <kbd>&#124;number=</kbd> by two or more days;',

		error2  = ' Missing or empty <kbd>&#124;date=</kbd>, and posted before November 4, 2010;',

		error3	= ' Invalid <kbd>&#124;number=</kbd> parameter;'

	}}

	if errors1 then

		local last = errors#errors

		errors#errors = last:sub(1, #last - 1) .. ' ([[Template:Cite_tweet#Error_detection|help]])'

		local error_out = error_template:rep(#errors):format(unpack(errors)) 

		if mw.title.getCurrentTitle():inNamespace(0) then

			error_out = error_out .. '[[Category:Cite tweet templates with errors]]'

		end

		output = output .. error_out

	end

	return output

end



return p