local margs = require('Module:Arguments')

local notblank = function (v) return (v or '') ~= '' end

local function _main(frame, name, mode, key)
	local categories = {
		['Flag icon'] = '[[Category:Flag icons missing country data templates]]' ..
			frame:expandTemplate{title = 'Preview warning', args = {'Unrecognized country in Template:flag icon'}},
		['Flag decoration'] = '[[Category:Flag decoration missing country data templates]]',
	}

    local yesno = require('Module:Yesno')

	--Get input arguments
	local args = margs.getArgs(frame, {
		frameOnly = notblank(frame.args.frameonly), valueFunc =
			function(argkey,value)
				if value then
					value = mw.text.trim(value)
					--Change empty string to nil for all args except 'image' and 'border'
					if argkey=="image" or argkey=="border" or value~="" then
						return value
					end
				end
				return nil
			end
	} )
	
	local preftext, sufftext = "", ""
	
	if name == 'Flag+link' then
		args.pref = args[1]
	elseif name == 'Flag athlete' then
		args.preftext = args[1]
		args[2] = args.code or args[2] or ""
		args.variant = args.variant or args[3]
	elseif name == 'Flag medalist' then
		preftext = (args[1] or "") .. "<br/>"
		args[2] = args.code or args[2] or ""
		args.variant = args.variant or args[3]
	elseif name == 'Flag link' then
		args.suff = args[2]
		args[2] = args[1] or ""
		args.variant = args.variant or args[3]
	elseif key ~= nil then
		args.variant = args.variant or args[1]
		args[2] = key
	else
		local sports = {
			['3x3'] = '3x3',
			bb = 'bb',
			fb = 'fb',
			fbicon = 'fb',
			ru = 'ru',
			fba = 'fba',
			fbw = 'fbw',
			fbaicon = 'fba',
			futsal = 'futsal'
		}
		if sports[name]then
			args.avar = args[1] and sports[name] or nil
			if name == 'fb' and yesno(args.align) == true then
				args.align='c'
			elseif sports[name] == 'fba' then
				if args[1] then
					local list = require("Module:Fba/list")
					local old = notblank(args.old) and "_old" or ""
					local country = args[1]
					local fba = list.fbas[country .. old]
					if not fba then -- look for aliases
						local countryTable = require('Module:CountryData').getcachedtable(frame, country)
						if countryTable and countryTable.alias then
							country = countryTable.alias
							fba = list.fbas[country .. old]
						end
					end
					if args.name == "code" then
						args.name = list.codes[country] or country
					elseif args.name == "full" then
						args.name = fba
					end
					if fba then
						mode = string.gsub(mode, "p", "c")
						args.link = fba
					end
					args.altlink = args.old
				elseif args.name == "code" or args.name == "full" then
					args.name = ""
				end
			end
		elseif name == "Flag team" and (args.code or args[1]) then
			sufftext = '&nbsp;<span style="font-size:90%;">('..(args.code or args[1])..')</span>'
		end
		args.variant = args.variant or args[2]
		args[2] = args[1] or ""
	end

	args[1] = mode .. (args.opts or '')
	args.missingcategory = notblank(args[2]) and categories[name] or nil
	args.noredlink = args.noredlink or 'notext'

	if args.placeholder and yesno(args.placeholder) ~= true then
		args[1] = args[1] .. 'o'
	end

	local check = ''
	
	if name == 'Flag icon' and mw.title.getCurrentTitle().namespace == 0 then
		local unknown = '[[Category:Pages using ' .. mw.ustring.lower(name) .. 
			' template with unknown parameters|_VALUE_' .. frame:getParent():getTitle() .. ']]'
		local opts = {
            unknown=unknown,
            preview='Page using [[Template:' .. name .. ']] with unknown parameter "_VALUE_"',
            ignoreblank='y',
            '1','2','variant','image','size','sz','border','align','al','width',
            'w','alt','ilink','noredlink','missingcategory','name','clink','link',
            'pref','suff','plink','the','section','altvar','avar','age','nalign',
            'nal','text','nodata','opts','placeholder','getParent','frameonly'
		}
		check = require('Module:Check for unknown parameters')._check(opts,args)
	end

	return preftext .. require('Module:Flagg').luaMain(frame,args) .. sufftext .. check
end

local p = {
	['']		= function (frame) return _main(frame, 'Flag',				'unc'   ) end,
	decoration	= function (frame) return _main(frame, 'Flag decoration',	'uxx'   ) end,
	icon		= function (frame) return _main(frame, 'Flag icon',			'cxxl'  ) end,
	link		= function (frame) return _main(frame, 'Flag link',			'unpe'  ) end,
	['+link']	= function (frame) return _main(frame, 'Flag+link',			'unpefo') end,
	u			= function (frame) return _main(frame, 'Flag',				'unu'   ) end,
	country		= function (frame) return _main(frame, 'Flag country',		'unce'  ) end,
	list        = function (frame) return _main(frame, 'Flag list',			'usc'   ) end,
	team		= function (frame) return _main(frame, 'Flag team',			'unce'  ) end,
	athlete		= function (frame) return _main(frame, 'Flag athlete',		'unape' ) end,
	medalist	= function (frame) return _main(frame, 'Flag medalist',		'unce'  ) end,
	['3x3']		= function (frame) return _main(frame, '3x3',				'unpe'  ) end,
	bb			= function (frame) return _main(frame, 'bb',				'unpe'  ) end,
	fb			= function (frame) return _main(frame, 'fb',				'unpe'  ) end,
	fba			= function (frame) return _main(frame, 'fba',				'unpe'  ) end,
	['fb-rt']	= function (frame) return _main(frame, 'fb',				'unpre' ) end,
	fbw			= function (frame) return _main(frame, 'fbw',				'unpe'  ) end,
	['fbw-rt']	= function (frame) return _main(frame, 'fbw',				'unpre' ) end,
	fbicon		= function (frame) return _main(frame, 'fbicon',			'pxxl'  ) end,
	fbaicon		= function (frame) return _main(frame, 'fbaicon',			'pxxl'  ) end,
	futsal		= function (frame) return _main(frame, 'futsal',			'unpe'  ) end,
	['futsal-rt'] = function (frame) return _main(frame, 'futsal',			'unpre' ) end,
	ru			= function (frame) return _main(frame, 'ru',				'unpe'  ) end,
	IOC			= function (frame) return require('Module:Country_alias').flagIOC(frame:newChild{ title = 'Template:Flag IOC' }) end,
	IOC2		= function (frame) return require('Module:Country_alias').flagXYZ(frame:newChild{ title = 'Template:Flag IOC 2', args = {name = margs.getArgs(frame).name or '', type = 'name'} }) end,
	IOCathlete	= function (frame) return require('Module:Country_alias').flagXYZ(frame:newChild{ title = 'Template:Flag IOC athlete', args = {type = 'athlete-O'} }) end,
}

p['deco'] = p.decoration
p['IOC 2'] = p.IOC2
p['IOC athlete'] = p.IOCathlete

return setmetatable (p, {['__index'] =											-- returns table p with the metatable __index set so that, if the table KEY isn't recognized, it returns
	function (_, key)															-- this anonymous function called as function(p, KEY)
		return function (frame) return _main(frame, 'Flag', 'unc', key) end		-- which interprets the module call as {{flag|KEY}} and passes it to _main()
	end
})