import subprocess
import binascii

from zope.interface import implements

from lbrynet.lbryfile.StreamDescriptor import save_sd_info
from lbrynet.cryptstream.client.CryptStreamDownloader import CryptStreamDownloader
from lbrynet.core.client.StreamProgressManager import FullStreamProgressManager
from lbrynet.interfaces import IStreamDownloaderFactory
from lbrynet.lbryfile.client.LBRYFileMetadataHandler import LBRYFileMetadataHandler
import os
from twisted.internet import defer, threads, reactor
from twisted.python.procutils import which


class LBRYFileDownloader(CryptStreamDownloader):
    """Classes which inherit from this class download LBRY files"""

    def __init__(self, stream_hash, peer_finder, rate_limiter, blob_manager,
                 stream_info_manager, payment_rate_manager, wallet, upload_allowed):
        CryptStreamDownloader.__init__(self, peer_finder, rate_limiter, blob_manager,
                                       payment_rate_manager, wallet, upload_allowed)
        self.stream_hash = stream_hash
        self.stream_info_manager = stream_info_manager
        self.suggested_file_name = None
        self._calculated_total_bytes = None

    def set_stream_info(self):
        if self.key is None:
            d = self.stream_info_manager.get_stream_info(self.stream_hash)

            def set_stream_info(stream_info):
                key, stream_name, suggested_file_name = stream_info
                self.key = binascii.unhexlify(key)
                self.stream_name = binascii.unhexlify(stream_name)
                self.suggested_file_name = binascii.unhexlify(suggested_file_name)

            d.addCallback(set_stream_info)
            return d
        else:
            return defer.succeed(True)

    def stop(self, err=None):
        d = self._close_output()
        d.addCallback(lambda _: CryptStreamDownloader.stop(self, err=err))
        return d

    def _get_progress_manager(self, download_manager):
        return FullStreamProgressManager(self._finished_downloading, self.blob_manager, download_manager)

    def _start(self):
        d = self._setup_output()
        d.addCallback(lambda _: CryptStreamDownloader._start(self))
        return d

    def _setup_output(self):
        pass

    def _close_output(self):
        pass

    def get_total_bytes(self):
        if self._calculated_total_bytes is None or self._calculated_total_bytes == 0:
            if self.download_manager is None:
                return 0
            else:
                self._calculated_total_bytes = self.download_manager.calculate_total_bytes()
        return self._calculated_total_bytes

    def get_bytes_left_to_output(self):
        if self.download_manager is not None:
            return self.download_manager.calculate_bytes_left_to_output()
        else:
            return 0

    def get_bytes_left_to_download(self):
        if self.download_manager is not None:
            return self.download_manager.calculate_bytes_left_to_download()
        else:
            return 0

    def _get_metadata_handler(self, download_manager):
        return LBRYFileMetadataHandler(self.stream_hash, self.stream_info_manager, download_manager)


class LBRYFileDownloaderFactory(object):
    implements(IStreamDownloaderFactory)

    def __init__(self, peer_finder, rate_limiter, blob_manager, stream_info_manager,
                 wallet):
        self.peer_finder = peer_finder
        self.rate_limiter = rate_limiter
        self.blob_manager = blob_manager
        self.stream_info_manager = stream_info_manager
        self.wallet = wallet

    def can_download(self, sd_validator):
        return True

    def make_downloader(self, sd_validator, options, payment_rate_manager, **kwargs):
        payment_rate_manager.min_blob_data_payment_rate = options[0]
        upload_allowed = options[1]

        def create_downloader(stream_hash):
            downloader = self._make_downloader(stream_hash, payment_rate_manager, sd_validator.raw_info,
                                               upload_allowed)
            d = downloader.set_stream_info()
            d.addCallback(lambda _: downloader)
            return d

        d = save_sd_info(self.stream_info_manager, sd_validator.raw_info)

        d.addCallback(create_downloader)
        return d

    def _make_downloader(self, stream_hash, payment_rate_manager, stream_info, upload_allowed):
        pass


class LBRYFileSaver(LBRYFileDownloader):
    def __init__(self, stream_hash, peer_finder, rate_limiter, blob_manager, stream_info_manager,
                 payment_rate_manager, wallet, download_directory, upload_allowed, file_name=None):
        LBRYFileDownloader.__init__(self, stream_hash, peer_finder, rate_limiter, blob_manager,
                                    stream_info_manager, payment_rate_manager, wallet, upload_allowed)
        self.download_directory = download_directory
        self.file_name = file_name
        self.file_handle = None

    def set_stream_info(self):
        d = LBRYFileDownloader.set_stream_info(self)

        def set_file_name():
            if self.file_name is None:
                if self.suggested_file_name:
                    self.file_name = os.path.basename(self.suggested_file_name)
                else:
                    self.file_name = os.path.basename(self.stream_name)

        d.addCallback(lambda _: set_file_name())
        return d

    def stop(self, err=None):
        d = LBRYFileDownloader.stop(self, err=err)
        d.addCallback(lambda _: self._delete_from_info_manager())
        return d

    def _get_progress_manager(self, download_manager):
        return FullStreamProgressManager(self._finished_downloading, self.blob_manager, download_manager,
                                         delete_blob_after_finished=not self.upload_allowed)

    def _setup_output(self):
        def open_file():
            if self.file_handle is None:
                file_name = self.file_name
                if not file_name:
                    file_name = "_"
                if os.path.exists(os.path.join(self.download_directory, file_name)):
                    ext_num = 1
                    while os.path.exists(os.path.join(self.download_directory,
                                                      file_name + "_" + str(ext_num))):
                        ext_num += 1
                    file_name = file_name + "_" + str(ext_num)
                self.file_handle = open(os.path.join(self.download_directory, file_name), 'wb')
        return threads.deferToThread(open_file)

    def _close_output(self):
        self.file_handle, file_handle = None, self.file_handle

        def close_file():
            if file_handle is not None:
                name = file_handle.name
                file_handle.close()
                if self.completed is False:
                    os.remove(name)

        return threads.deferToThread(close_file)

    def _get_write_func(self):
        def write_func(data):
            if self.stopped is False and self.file_handle is not None:
                self.file_handle.write(data)
        return write_func

    def _delete_from_info_manager(self):
        return self.stream_info_manager.delete_stream(self.stream_hash)


class LBRYFileSaverFactory(LBRYFileDownloaderFactory):
    def __init__(self, peer_finder, rate_limiter, blob_manager, stream_info_manager,
                 wallet, download_directory):
        LBRYFileDownloaderFactory.__init__(self, peer_finder, rate_limiter, blob_manager,
                                           stream_info_manager, wallet)
        self.download_directory = download_directory

    def _make_downloader(self, stream_hash, payment_rate_manager, stream_info, upload_allowed):
        return LBRYFileSaver(stream_hash, self.peer_finder, self.rate_limiter, self.blob_manager,
                             self.stream_info_manager, payment_rate_manager, self.wallet,
                             self.download_directory, upload_allowed)

    def get_description(self):
        return "Save"


class LBRYFileOpener(LBRYFileDownloader):
    def __init__(self, stream_hash, peer_finder, rate_limiter, blob_manager, stream_info_manager,
                 payment_rate_manager, wallet, upload_allowed):
        LBRYFileDownloader.__init__(self, stream_hash, peer_finder, rate_limiter, blob_manager,
                                    stream_info_manager, payment_rate_manager, wallet, upload_allowed)
        self.process = None
        self.process_log = None

    def stop(self, err=None):
        d = LBRYFileDownloader.stop(self, err=err)
        d.addCallback(lambda _: self._delete_from_info_manager())
        return d

    def _get_progress_manager(self, download_manager):
        return FullStreamProgressManager(self._finished_downloading, self.blob_manager, download_manager,
                                         delete_blob_after_finished=not self.upload_allowed)

    def _setup_output(self):
        def start_process():
            if os.name == "nt":
                paths = [r'C:\Program Files\VideoLAN\VLC\vlc.exe',
                         r'C:\Program Files (x86)\VideoLAN\VLC\vlc.exe']
                for p in paths:
                    if os.path.exists(p):
                        vlc_path = p
                        break
                else:
                    raise ValueError("You must install VLC media player to stream files")
            else:
                vlc_path = 'vlc'
            self.process_log = open("vlc.out", 'a')
            try:
                self.process = subprocess.Popen([vlc_path, '-'], stdin=subprocess.PIPE,
                                                stdout=self.process_log, stderr=self.process_log)
            except OSError:
                raise ValueError("VLC media player could not be opened")

        d = threads.deferToThread(start_process)
        return d

    def _close_output(self):
        if self.process is not None:
            self.process.stdin.close()
        self.process = None
        return defer.succeed(True)

    def _get_write_func(self):
        def write_func(data):
            if self.stopped is False and self.process is not None:
                try:
                    self.process.stdin.write(data)
                except IOError:
                    reactor.callLater(0, self.stop)
        return write_func

    def _delete_from_info_manager(self):
        return self.stream_info_manager.delete_stream(self.stream_hash)


class LBRYFileOpenerFactory(LBRYFileDownloaderFactory):
    def can_download(self, sd_validator):
        if which('vlc'):
            return True
        elif os.name == "nt":
            paths = [r'C:\Program Files\VideoLAN\VLC\vlc.exe',
                     r'C:\Program Files (x86)\VideoLAN\VLC\vlc.exe']
            for p in paths:
                if os.path.exists(p):
                    return True
        return False

    def _make_downloader(self, stream_hash, payment_rate_manager, stream_info, upload_allowed):
        return LBRYFileOpener(stream_hash, self.peer_finder, self.rate_limiter, self.blob_manager,
                              self.stream_info_manager, payment_rate_manager, self.wallet, upload_allowed)

    def get_description(self):
        return "Stream"