--Extracts all files from an NPK archive to a specified output directory.
--[[
npkFileName  The path to the NPK archive file to be extracted.
outputPath    The path to the output directory where files will be extracted.
return true if extraction succeeds; false otherwise.
--]]
local M={}
function  M.extract_npk_files(npkFileName, outputPath)
	local npk = createNPKFile();
	
	local ret = npk:openPakFile(npkFileName)
	if(not ret) then
		return false
	end

	local counts = npk:getFileCounts()
	for i=0, counts-1, 1 do
		local baseInfo = npk:getFileNode(i)
		
		local fileStream = npk:openFileStream(baseInfo:keyName())
		
		print("keyName=" .. fileStream:name() .. "\n")
		
		local diskFileName = outputPath .. "/" .. baseInfo:keyName()
		ret = forceCreatePathForFile(diskFileName);
		if(not ret) then
			print("CreatePathForFile failed: " .. diskFileName)
			npk:closeFileStream(fileStream)
			break
		end
		
		ret = fileStream:writeToDiskFile(diskFileName)
		if(not ret) then
			print("dump file failed: " .. baseInfo:keyName())
			print("LastErrorMsg=" .. getLastErrorMessage())
			npk:closeFileStream(fileStream)
			break
		end	
		npk:closeFileStream(fileStream)
	end
	
	npk:closePakFile()
	destroyNPKFile(npk)
	return true
end


return M;