import os

import logger
import tomb
from modules.module import Module
from runcmd import runProcess
import pytsk3


def getInstance():
    return MFTModule()

class MFTModule(Module):

    def __init__(self):
        self.name = "mft"
        self.description = "Extracts NTFS MFT"
        self.requiredVars = ["ntfsvol"]
        self.vars = {}

    def dumpMFT(self,ntfsvol,file):
        img = pytsk3.Img_Info(url=ntfsvol)
        fs = pytsk3.FS_Info(img)
        file_entry = fs.open_meta(inode=0)
        offset = 0
        size = file_entry.info.meta.size
        BUFF_SIZE = 1024*1024
        mft = open(file,'wb')

        while offset < size:
                available_to_read = min(BUFF_SIZE, size - offset)
                data = file_entry.read_random(offset, available_to_read)
                if not data:
                        break

                offset += len(data)
                mft.write(data)

        mft.close()
        img.close()


    def execute(self):
        path = tomb.getPath() + self.name + "/"
        if(not os.path.exists(path)):
            os.mkdir(path)
            logger.msgLog("Extracting MFT from volumes: " + repr(self.vars['ntfsvol'].value), "mft", logger.TYPE_INFO)
        for vol in self.vars['ntfsvol'].value:
            self.dumpMFT("/dev/" + vol,path + vol + ".bin")