模組:UnwrapConversion

local p = {}
local getArgs = require('Module:Arguments').getArgs

local validVariantMap = {}
for _, variant in ipairs({
	'zh',
	'zh-hans',
	'zh-hant',
	'zh-cn',
	'zh-hk',
	'zh-mo',
	'zh-my',
	'zh-sg',
	'zh-tw',
}) do
	validVariantMap[variant] = true
end

local function validateFlag(input)
	local ret = {}
	local split = mw.text.split(input, ';')
	for _, item in ipairs(split) do
		item = mw.text.trim(item)
		if validVariantMap[item] then
			table.insert(ret, item)
		end
	end
	return #ret > 0 and table.concat(ret, ';') or nil
end

function p._main(args)
	local text = args.text or args[1]
	local convFlag = args.flag or args[2]
	if convFlag then
		convFlag = validateFlag(convFlag)
	end

	local source = {}
	for cp in mw.ustring.gcodepoint(text) do
		table.insert(source, mw.ustring.char(cp))
	end
	local result = {}
	local strlen = #source
	local i=1
	while i <= strlen do
		if source[i] == "-" and source[i + 1] == "{" then
			-- 跳掉轉換標籤
			if source[i + 2] == "}" and source[i + 3] == "-" then
				-- 無視 -{}-（畢竟最後輸出後這個 -{}- 的位置就會變成轉換標記邊界）
				i = i + 4
			else
				i = i + 2
				
				local depth = 1 -- 處理可能由其他模板引入的嵌套轉換標籤

				table.insert(result, "-{")

				while i <= strlen do
					if source[i] == "-" and source[i + 1] == "{" then
						-- 嵌套開始
						depth = depth + 1
						table.insert(result, "-{")
						i = i + 2
					elseif source[i] == "}" and source[i + 1] == "-" then
						-- 嵌套結束
						depth = depth - 1
						if depth == 0 then
							i = i + 2
							break
						end
						table.insert(result, "}-")
						i = i + 2
					else
						table.insert(result, source[i])
						i = i + 1
					end
				end

				table.insert(result, "}-")
			end
		else
			-- 在轉換標籤外，加上轉換標籤
			local buffer = {}

			while i <= strlen and not (source[i] == "-" and source[i + 1] == "{") do
				table.insert(buffer, source[i])
				i = i + 1
			end

			if #buffer > 0 then
				if convFlag then
					table.insert(
						result,
						"-{" .. convFlag .. "|" .. table.concat(buffer) .. "}-"
					)
				else
					table.insert(
						result,
						"-{" .. table.concat(buffer) .. "}-"
					)
				end
			end
		end
	end

	return table.concat(result)
end

function p.main(frame)
	local args = getArgs(frame)
	return p._main(args)
end

return p