local p = {}
local getArgs = require("Module:Arguments").getArgs
local yn = require("Module:Yesno")
local cfg = mw.loadData('Module:If preview/configuration')

--[[
main

This function returns either the first argument or second argument passed to
this module, depending on whether the page is being previewed.

]]
function p.main(frame)
	local args = getArgs(frame)
	if cfg.preview then
		return args[1] or ''
	else
		return args[2] or ''
	end
end

--[[
pmain

This function returns either the first argument or second argument passed to
this module's parent (i.e. template using this module), depending on whether it
is being previewed.

]]
function p.pmain(frame)
	return p.main(frame:getParent())
end

local function warning_text(warning)
	return mw.ustring.format(
		cfg.warning_infrastructure,
		cfg.templatestyles,
		warning
	)
end

function p._warning(args)
	
	local warning = args[1] and args[1]:match('^%s*(.-)%s*$') or ''
	if warning == '' then
		return warning_text(cfg.missing_warning)
	end
	
	if not cfg.preview then return '' end
	
	if yn(args['consolewarning']) then mw.addWarning(args[1] or cfg.missing_warning) end
	return warning_text(warning)
end

--[[
warning

This function returns a "preview warning", which is the first argument marked
up with HTML and some supporting text, depending on whether the page is being previewed.

]]
-- function p.warning(frame)
-- 	mw.addWarning(frame.args[1] or cfg.missing_warning)
-- 	return p._warning(frame.args)
-- end

--[[
warning, but for pass-through templates like {{preview warning}}
]]
function p.pwarning(frame)
	local args = getArgs(frame)
	return p._warning(args)
end

--[[
Does both mw.addWarning and preview warning
]]

function p.warn(text)
	if text == nil or text == "" then return "" end
	mw.addWarning(text)
	return p._warning({text})
end

--[[
Console warning
]]
function p.consoleWarning(frame)
	local args = getArgs(frame)
	mw.addWarning(args[1] or cfg.missing_warning)
	return ''
end

return p