local p = {}



-- Returns the union of the values of two tables, as a sequence.

local function union(t1, t2)



	local vals = {}

	for k, v in pairs(t1) do

		valsv = true

	end

	for k, v in pairs(t2) do

		valsv = true

	end

	local ret = {}

	for k, v in pairs(vals) do

		table.insert(ret, k)

	end

	return ret

end



-- Returns a table containing the numbers of the arguments that exist

-- for the specified prefix. For example, if the prefix was 'data', and

-- 'data1', 'data2', and 'data5' exist, it would return {1, 2, 5}.

local function get_arg_nums(args, prefix)

	local nums = {}

	for k, v in pairs(args) do

		local num = tostring(k):match('^' .. prefix .. '([1-9]%d*)$')

		if num then table.insert(nums, tonumber(num)) end

	end

	table.sort(nums)

	return nums

end



local function trim_args(args)

	local new_args = {}

	for k,v in pairs(args) do

		new_argsk = mw.text.trim(v)

	end

	return new_args

end



local function responses_have_signatures(response, response_signature)

	return response and response ~= '' and response_signature and response_signature ~= ''

end



local function get_responses(args)

	local response_numbers = union(

		get_arg_nums(args, 'response'),

		get_arg_nums(args, 'response signature')

	)

	table.sort(response_numbers)

	local responses = {}

	local response_signatures = {}

	for _, num in ipairs(response_numbers) do

		local response = args'response' .. num

		local response_signature = args'response signature' .. num

		if not responses_have_signatures(response, response_signature) then

			error('|response' .. num .. '= or |response signature' .. num .. '= is missing')

		end

		table.insert(responses, response)

		table.insert(response_signatures, response_signature)

	end

	return responses, response_signatures

end



local function wordcount(word_limit, statement, signature, responses, response_signatures)

	-- this actually gets the word count. we slightly overcount because this is

	-- wikitext, so things like '\n* ' and elinks will cause an extra word.

	-- we can get a count of the '*' and similar constructs separately if we want.

	-- but parsing wikitext to count links is :(

	-- tables are doomed and probably would just always be better placed on a

	-- different page than the primary statements are.

	-- from https://stackoverflow.com/questions/29133416/how-to-count-the-amount-of-words-in-a-text-file-in-lua

	local _, n_statement = mw.ustring.gsub(statement .. table.concat(responses, '\n'), '%S+', '')

	

	if n_statement > word_limit then error('Too many words') end

	if n_statement <= 0 then error('No words') end



	if not signature or signature == '' then error('No signature') end

	local joined_responses = {

		statement,

		signature

	}

	for k, _ in ipairs(responses) do

		table.insert(joined_responses, responsesk .. '\n' .. response_signaturesk])

	end

	return table.concat(joined_responses)

end



function p.statement(frame)

	local args = trim_args(frame.args)



	local statement = args.statement or ''

	local signature = args.signature or ''

	local added_words = tonumber(args'added words']) or 0

	local word_limit = 500 + added_words

	local responses, response_signatures = get_responses(args)

	

	return wordcount(word_limit, statement, signature, responses, response_signatures)

end



return p