import sys
import os
import shutil

encryptTypes = [ ".json", ".txt", ".text", ".xml", ".js", ".jsc", ".png", ".jpg", ".jpeg", ".tga", ".bmp" ]

class ffEncrypt(object):

    def __init__(self, key ):
        self.mKey  = key

    def build( self, res, dest ):

        keyLength = len(self.mKey)

        if None == self.mKey or 0 == keyLength:
            return False

        if not os.path.exists(res):
            return False

        s = res.lower().replace('\\', '/')
        lastSplit = s.rfind('/')
        if -1 != lastSplit:
            s = s[lastSplit + 1:]

        # Fmt Check
        NeedEncrypt = False
        for suffix in encryptTypes:
            if s.endswith( suffix ):
                NeedEncrypt = True
                break

        if not NeedEncrypt:
            shutil.copy( res, dest )
            return True

        with open(res, 'rb') as f:
            resBytes = f.read()

        resBytesLen = len(resBytes)
        if 0 == resBytesLen:
            return False


        hashVal = ffEncrypt.get_hash(s)
        hashAry = [
            hashVal & 0xff,
            (hashVal >> 8) & 0xff,
            (hashVal >> 16) & 0xff,
            (hashVal >> 24) & 0xff
        ]

        realKey = bytearray()
        for k in range(0,keyLength):
            realKey.append( ord(self.mKey[k] ) ^ hashAry[ k % 4 ] )

        BA = bytearray(resBytes)

        for i in range(0,resBytesLen):
            BA[i] = BA[i] ^ realKey[ i % keyLength]

        with open(dest, 'wb') as f:
            f.write(BA)

        return True

    @staticmethod
    def get_hash(src):
        result    = 0
        srcLength = len(src)
        for i in range(0,srcLength):
            result = int(((result << 5) + result) + ord(src[i])) & 0xffffffff
        return result