import configparser
from requests import get
import os
import re
import json
import sys

# osSafeName() convertes a string to an OS safe name.
def osSafeName(name):
    return re.sub(r'[^a-zA-Z0-9 -]', '', name).lower().replace(' ', '-').replace('--', '-')

class AudibleBook(object):

    def __init__(self, filePath, activationBytes, targetDir):
        self.filePath = filePath
        self.activationBytes = activationBytes
        self.targetDir = targetDir
        self.metadata = json.loads(os.popen('ffprobe -i {} -show_format \
            -print_format json'.format(filePath)).read())['format']['tags']
        self.chapters = json.loads(os.popen('ffprobe -i {} -print_format json \
            -show_chapters -loglevel error -sexagesimal'.format(self.filePath))
                          .read())['chapters']

    # getPath() returns path to origonal audible file.
    def getPath(self):
        return self.filePath

    # getMetadata() returns audio metadata for a given filepath.
    def getMetadata(self):
        return self.metadata

    # getChapters() returns chapter metadata for a given filepath.
    def getChapters(self):
        return self.chapters

    # getTitle() returns audiobook title.
    def getTitle(self):
        return self.getMetadata()['title']

    def setTargetDir(self, targetDir):
        self.targetDir = targetDir

    def removeDRM(self, fileName):
        filePath = '{}/{}.m4b'.format(self.targetDir, fileName)
        if not os.path.exists(filePath):
            os.system('ffmpeg -activation_bytes {} -i {} -c copy "{}"'
                      .format(self.activationBytes, self.filePath, filePath))
        self.convertedFilePath = filePath

    def splitChapters(self):
        for c in self.getChapters():
            start=c['start_time']
            end=c['end_time']
            title=c['tags']['title']
            outFilePath = '{}-{}.m4a'.format(os.path.splitext(self.convertedFilePath)[0],
                                             osSafeName(title))
            if not os.path.exists(outFilePath):
                os.system('ffmpeg -i {} -acodec copy -vcodec copy -ss {} -t {} {}'.
                          format(self.convertedFilePath, start, end, outFilePath))
        

# getHash() returns the hash of a given file.
def getHash(filePath):
    with open(filePath, 'rb') as f:
        f.seek(653)
        data = f.read(20)
        f.close()
    return data.hex()

# getActivationBytes returns the bytes needed to decrypt a given hash. 
def getActivationBytes(filehash):
    headers = {'User-Agent': 'audible-converter'}
    response = get('https://aax.api.j-kit.me/api/v2/activation/{}'.format(filehash),
                   headers=headers)
    return json.loads(response.text)['activationBytes']

# createConfig() creates a config file.
def createConfig(configFilePath, filePath):
    activationBytes = getActivationBytes(getHash(filePath))
    f = open(configFilePath, 'w')
    f.write('activationBytes={}'.format(activationBytes))
    f.close()
    
configFilePath='./settings.conf'
audibleBookPath=sys.argv[1]
targetDir='.'

# Check if config file exists and creates one if needed.
if not os.path.exists(configFilePath):
    print('Creating config file')
    createConfig(configFilePath, audibleBookPath)
    
configString = '[Settings]\n' + open(configFilePath).read()
configParser = configparser.RawConfigParser()
configParser.read_string(configString)
activationBytes=configParser.get('Settings', 'activationBytes')
    
book = AudibleBook(audibleBookPath, activationBytes, targetDir)

name = osSafeName(book.getTitle())
outputDir = '{}/{}'.format(targetDir, name)
if not os.path.exists(outputDir):
    os.makedirs(outputDir)
book.setTargetDir(outputDir)

book.removeDRM(name)
book.splitChapters()