import asyncio
import hashlib
import logging
import os
import tempfile
from Utils import calcDownloadPath
from Config import Config

LOG = logging.getLogger('segments')


class Segments:
    duration: int
    index: int
    vconvert: bool
    aconvert: bool
    vcodec: str
    acodec: str

    def __init__(self, index: int, duration: float, vconvert: bool, aconvert: bool):
        config = Config.get_instance()
        self.index = int(index)
        self.duration = float(duration)
        self.vconvert = bool(vconvert)
        self.aconvert = bool(aconvert)
        self.vcodec = config.streamer_vcodec
        self.acodec = config.streamer_acodec
        self.vconvert = True

    async def stream(self, path: str, file: str) -> bytes:
        realFile: str = calcDownloadPath(basePath=path, folder=file, createPath=False)

        if not os.path.exists(realFile):
            raise Exception(f"File {realFile} does not exist.")

        tmpDir: str = tempfile.gettempdir()
        tmpFile = os.path.join(tmpDir, f'ytptube_stream.{hashlib.md5(realFile.encode("utf-8")).hexdigest()}')

        if not os.path.exists(tmpFile):
            os.symlink(realFile, tmpFile)

        if self.index == 0:
            startTime: float = '{:.6f}'.format(0)
        else:
            startTime: float = '{:.6f}'.format((self.duration * self.index))

        fargs = []
        fargs.append('-xerror')
        fargs.append('-hide_banner')
        fargs.append('-loglevel')
        fargs.append('error')

        fargs.append('-ss')
        fargs.append(str(startTime if startTime else '0.00000'))
        fargs.append('-t')
        fargs.append(str('{:.6f}'.format(self.duration)))

        fargs.append('-copyts')

        fargs.append('-i')
        fargs.append(f'file:{tmpFile}')
        fargs.append('-map_metadata')
        fargs.append('-1')

        fargs.append('-pix_fmt')
        fargs.append('yuv420p')
        fargs.append('-g')
        fargs.append('52')

        fargs.append('-map')
        fargs.append('0:v:0')
        fargs.append('-strict')
        fargs.append('-2')

        fargs.append('-codec:v')
        fargs.append(self.vcodec if self.vconvert else 'copy')

        # audio section.
        fargs.append('-map')
        fargs.append('0:a:0')
        fargs.append('-codec:a')
        fargs.append(self.acodec if self.aconvert else 'copy')

        fargs.append('-sn')

        fargs.append('-muxdelay')
        fargs.append('0')
        fargs.append('-f')
        fargs.append('mpegts')
        fargs.append('pipe:1')

        LOG.debug(f"Streaming '{realFile}' segment '{self.index}'. " + " ".join(fargs))

        proc = await asyncio.subprocess.create_subprocess_exec(
            'ffmpeg', *fargs,
            stdin=asyncio.subprocess.DEVNULL,
            stdout=asyncio.subprocess.PIPE,
            stderr=asyncio.subprocess.PIPE
        )

        data, err = await proc.communicate()

        if 0 != proc.returncode:
            LOG.error(f'Failed to stream {realFile} segment {self.index}. {err.decode("utf-8")}.')
            raise Exception(f'Failed to stream {realFile} segment {self.index}.')

        return data