-- This module implements {{for loop}}.



local getArgs = require('Module:Arguments').getArgs

local yesno = require('Module:Yesno')

local p = {}



function p.main(frame)

	local args = getArgs(frame, {

		trim = false,

		removeBlanks = false

	})

	return p._main(args)

end



function p._main(args)

	local template = args'call' or 'void'

	local calltemplates = yesno(args.substall or "", true) or not mw.isSubsting()

	local variableParam = args.pv

	variableParam = tonumber(variableParam) or variableParam or 1 -- fix for positional parameters

	local variableValPrefix = args.prefix or ''

	local variableValPostfix = args.postfix or ''

	local sep = args1 or ''

	local constantArgs = p.getConstants(args)

	local variableVals = p.getVariableVals(args)



	local result = ''

	local addSeparator = false;

	for _, v in ipairs(variableVals) do

		v = mw.text.trim(v)

		if #v > 0 or not yesno(args.skipBlanks) then

			if addSeparator then

				result = result .. sep

			end

			addSeparator = true;

			local targs = constantArgs

			targsvariableParam = variableValPrefix .. v .. variableValPostfix

			if calltemplates then

				local output = p.callTemplate(template, targs)

				if #mw.text.trim(output) == 0 then

					addSeparator = false

				end

				result = result .. output

			else

				local makeTemplate = require('Module:Template invocation').invocation

				result = result .. makeTemplate(template, targs)

			end

		end

	end

	return result

end



function p.getConstants(args)

	local constantArgNums = p.getArgNums(args, 'pc', 'n')

	local constantArgs = {}

	for _, num in ipairs(constantArgNums) do

		local keyArg = 'pc' .. tostring(num) .. 'n'

		local valArg = 'pc' .. tostring(num) .. 'v'

		local key = argskeyArg

		key = tonumber(key) or key

		local value = argsvalArg

		constantArgskey = value

	end

	return constantArgs

end



function p.getVariableVals(args)

	local variableVals = {}

	if args.start or args.stop or args.by then

		if args2 then

			error("Both start/stop/by and numbered parameters specified")

		end

		local start = tonumber(args.start or 1)

		local stop = tonumber(args.stop or 1)

		local by = tonumber(args.by or 1)

		for i = start, stop, by do

			variableVals #variableVals + 1 = i

		end

	else

		for i, v in ipairs(args) do

			if i ~= 1 then

				variableValsi - 1 = v

			end

		end

	end

	return variableVals

end



function p.getArgNums(args, prefix, suffix)

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

	-- for the specified prefix and suffix.

	local nums = {}

	local pattern = '^' .. prefix .. '([1-9]%d*)' .. suffix .. '$'

	for k, _ in pairs(args) do

		local num = tostring(k):match(pattern)

		if num then

			nums#nums + 1 = tonumber(num)

		end

	end

	table.sort(nums)

	return nums

end



function p.callTemplate(template, targs)

	return mw.getCurrentFrame():expandTemplate{title = template, args = targs}

end



return p