local p = {}



--creates a frame object that cannot access any of the parent's args

--unless a table containing a list keys of not to inherit is provided

function disinherit(frame, onlyTheseKeys)

	local parent = frame:getParent() or frame

	local orphan = parent:newChild{}

	orphan.getParent = parent.getParent --returns nil

	orphan.args = {}

	if onlyTheseKeys then

		local family = {parent, frame}

		for f = 1, 2 do

			for k, v in pairs(familyf and familyf].args or {}) do

				orphan.argsk = orphan.argsk or v

			end

		end

		parent.args = mw.clone(orphan.args)

		setmetatable(orphan.args, nil)

		for _, k in ipairs(onlyTheseKeys) do

			rawset(orphan.args, k, nil)

		end

	end

	return orphan, parent

end



function getSeparator(args, default)

	local br = tonumber(args.br) and ('<br>'):rep(args.br) or args.br

	local sep = args.sep or br or default

	return #sep > 0 and ' ' .. sep .. ' ' or sep

end



function p.get(frame, arg, passArgs)

	local orphan, frame = disinherit(frame, passArgs and {arg or 1})

	local code = frame.argsarg or 1 or ''

	if code:match'UNIQ%-%-nowiki' then

		code = mw.text.unstripNoWiki(code)

			:gsub('&lt;', '<')

			:gsub('&gt;', '>')

			:gsub('&quot;', '"')

			-- Replace `&#125;%-` with `}-` because of some server quirk leading to

			-- =mw.text.unstripNoWiki(mw.getCurrentFrame():preprocess('<nowiki>}-</nowiki>'))

			-- outputting `&#125;-` instead of `}-`, while it's ok with `<nowiki>} -</nowiki>`

			:gsub('&#125;%-', '}-')

			-- The same with `-&#123;`

			:gsub('%-&#123;', '-{')

	end

	local kill_categories = frame.args.demo_kill_categories or frame.args.nocat

	return {

		source = code,

		output = orphan:preprocess(code):gsub(kill_categories and '%[%[Category.-%]%]' or '', ''),

		frame = frame

	}

end



function p.main(frame, demoTable)

	local show = demoTable or p.get(frame)

	local args = show.frame.args

	if showargs.result_arg then

		return showargs.result_arg

	end

	local yesno = require('Module:Yesno')

	args.reverse = yesno(args.reverse, false)

	args.sep = getSeparator(args, '')

	local source = frame:extensionTag{

		name = 'syntaxhighlight',

		args = {

			lang = 'wikitext',

			style = args.style

		},

		content = show.source

	}

	return args.reverse and

		show.output .. args.sep .. source or

		source .. args.sep .. show.output

end



-- Alternate function to return an inline result

function p.inline(frame, demoTable)

	local show = demoTable or p.get(frame)

	local args = show.frame.args

	if showargs.result_arg then

		return showargs.result_arg

	end

	local yesno = require('Module:Yesno')

	args.reverse = yesno(args.reverse, false)

	args.sep = getSeparator(args, args.reverse and '←' or '→')

	local source =  frame:extensionTag{

		name = 'syntaxhighlight',

		args = {

			lang = 'wikitext',

			inline = true,

			style = args.style

		},

		content = show.source

	}

	return args.reverse and

		show.output .. args.sep .. source or

		source .. args.sep .. show.output

end



--passing of args into other module without preprocessing

function p.module(frame)

	local orphan, frame = disinherit(frame, {

		'demo_template',

		'demo_module',

		'demo_module_func',

		'demo_main',

		'demo_sep',

		'demo_br',

		'demo_result_arg',

		'demo_kill_categories',

		'nocat'

	})

	local template = frame.args.demo_template and 'Template:'..frame.args.demo_template

	local demoFunc = frame.args.demo_module_func or 'main\n'

	local demoModule = require('Module:' .. frame.args.demo_module)[demoFunc:match('^%s*(.-)%s*$')]

	frame.args.br, frame.args.result_arg = frame.args.demo_sep or frame.args.demo_br, frame.args.demo_result_arg

	local kill_categories = frame.args.demo_kill_categories or frame.args.nocat

	if demoModule then

		local named = {insert = function(self, ...) table.insert(self, ...) return self end}

		local source = {insert = named.insert, '{{', frame.args.demo_template or frame.args.demo_module, '\n'}

		if not template then

			source:insert(2, '#invoke:'):insert(4, '|'):insert(5, demoFunc)

		end

		local insertNamed = #source + 1

		for k, v in pairs(orphan.args) do

			local nan, insert = type(k) ~= 'number', {v}

			local target = nan and named or source

			target:insert'|'

			if nan then

				target:insert(k):insert'=':insert'\n'

				table.insert(insert, 1, #target)

			end

			target:insert(unpack(insert))

			local nowiki = v:match('nowiki')

			if nowiki or v:match('{{.-}}') then

				orphan.argsk = frame:preprocess(nowiki and mw.text.unstripNoWiki(v) or v)

			end

		end

		source:insert'}}'

		table.insert(source, insertNamed, table.concat(named))

		return p.main(orphan, {

			source = table.concat(source), "<>'|=~",

			output = tostring(demoModule(orphan)):gsub(kill_categories and '%[%[Category.-%]%]' or '', ''),

			frame = frame

		})

	else

		return "ERROR: Invalid module function: "..demoFunc

	end

end



return p