-- 版本对比功能
local newRes = {}
local oldRes = {}
-- 读取xml文件
local function readXml(sourceFile, resList)
	local pathName, baseName, ext = string.splitFilename(sourceFile);
	if ext ~= "xml" or baseName == "update.json" then
		return
	end
	
	if resList[baseName] == nil then
		resList[baseName] = {}
	end
	
	-- 读取xml文件
	local fileData = loadfileData(sourceFile)
	-- 解密解压数据
	local romFileData = cc.FilePackage:decrypt(FilePackage.uncompress(fileData))
	
	-- 解析xml文件
	local function onStartElement(name , atts)
		if name == "file" then
			resList[baseName][atts.name] = atts
		end
	end
	local ret, result = tiny.eval(romFileData , onStartElement)
	if ret == nil then
		print("文件" .. sourceFile .. "解析失败", result);
	end
end

-- 比较具体的目录
local function _compareRes(newPath, oldPath, resultPath, resVersion)
	local newResPath = newPath .. "/" .. resVersion
	local oldResPath = oldPath .. "/" .. resVersion
	local resultResPath = resultPath .. "/" .. resVersion
	createDir(newResPath);
	createDir(oldResPath);
	createDir(resultResPath);
	-- 清空下资源
	newRes.resVersion = {}
	oldRes.resVersion = {}
	-- 载入对应目录的xml文件
	visitPath(newResPath, readXml, newRes.resVersion);
	visitPath(oldResPath, readXml, oldRes.resVersion);
	-- 创建一个xml文件
	local versionInfo = xml.new("root");
	-- 需要更新文件的数量
	versionInfo.updateFileCount = 0
	-- 需要更新文件的大小
	versionInfo.updateFileSize = 0
	
	local xmlFileName
	-- 逐个文件对比
	for i, v in pairs(newRes.resVersion) do
		-- 创建一个xml文件
		local fileXml = xml.new("root")
		fileXml.updateFileCount = 0
		fileXml.updateFileSize = 0
		for name, fileInfo in pairs(v) do
			-- 获取老版本对应的资源
			local oldFileInfo
			if oldRes.resVersion[i] == nil then
				oldFileInfo = nil
			else
				oldFileInfo = oldRes.resVersion[i][name]
			end
			if oldFileInfo == nil or fileInfo.md5 ~= oldFileInfo.md5 then
				-- 需要更新这个文件
				local fileItem = xml.new("file")
				fileItem.origin = fileInfo.origin
				fileItem.name = fileInfo.name
				fileItem.md5 = fileInfo.md5
				fileItem.compressedSize = fileInfo.compressedSize
				fileItem.size = fileInfo.size
				fileItem.offset = fileInfo.offset
				table.insert(fileXml, fileItem)
				fileXml.updateFileCount = fileXml.updateFileCount + 1
				fileXml.updateFileSize = fileXml.updateFileSize + fileInfo.compressedSize
			end
		end
		
		-- 保存这个包需要更新的文件
		versionInfo.updateFileCount = versionInfo.updateFileCount + fileXml.updateFileCount
		versionInfo.updateFileSize = versionInfo.updateFileSize + fileXml.updateFileSize
		
		local xmlInfoData = fileXml:toString();
		saveFile(xmlInfoData, resultResPath .. "/" .. i);
	end
	
	-- 保存整个需要更新的文件
	local xmlData = versionInfo:toString()
	saveFile(xmlData, resultResPath .. "/" .. "result.xml");
	
	-- 打印出这次需要更新资源的大小
	local updateSizeStr
	if versionInfo.updateFileSize / 1024 / 1024 >= 1 then
		updateSizeStr = versionInfo.updateFileSize / 1024 / 1024 .. "M"
	else
		updateSizeStr = versionInfo.updateFileSize / 1024 .. "KB"
	end
	print(resVersion .. "需要更新的资源包大小：", updateSizeStr)
end

-- 对比两个目录下的资源版本
function compareVersion(newPath, oldPath, resultPath)
	-- 比较png
	_compareRes(newPath, oldPath, resultPath, "png")
	-- 比较etc
	_compareRes(newPath, oldPath, resultPath, "etc")
	-- 比较pvr
	_compareRes(newPath, oldPath, resultPath, "pvr")
end