import logging
import os
from hashlib import sha256
from typing import List, Tuple

import grpc
from google.protobuf import empty_pb2 as google_dot_protobuf_dot_empty__pb2

from protos import container_pb2, container_pb2_grpc


class Container(object):
    _channel: grpc.Channel = None
    _stub: container_pb2_grpc.ContainerServiceStub = None

    def __new__(cls, *args, **kwargs):
        if cls._channel is None:
            cls._channel = grpc.insecure_channel(
                target=f'{os.getenv("CONTAINER_GRPC_HOST")}:{os.getenv("CONTAINER_GRPC_PORT")}',
                options=[
                    ('grpc.keepalive_time_ms', 10000),
                    ('grpc.keepalive_timeout_ms', 5000),
                    ('grpc.keepalive_permit_without_calls', True),
                    ('grpc.http2.max_pings_without_data', 0),
                ],
            )
        cls._stub = container_pb2_grpc.ContainerServiceStub(channel=cls._channel)
        return super().__new__(cls, *args, **kwargs)

    def __init__(self):
        self.container_id = None

    # def close_channel(self):
    #     """关闭通道"""
    #     if self._channel is not None:
    #         self._channel.close()

    def start_container(self):
        """启动一个容器，其最大运行时间为1小时，到期自动停止销毁"""
        response = self._stub.StartContainer(request=google_dot_protobuf_dot_empty__pb2.Empty())
        container_id = response.container_id
        if not container_id:
            raise RuntimeError('创建容器失败')
        self.container_id = container_id

    def stop_container(self) -> bool:
        """关闭一个容器"""
        if self.container_id:
            request = container_pb2.StopContainerRequest(container_id=self.container_id)
            response = self._stub.StopContainer(request=request)
            return response.success
        return True

    def run_command(self, command: List[str], show_log: bool = False) -> Tuple[int, str, List[str]]:
        """在容器内执行一条命令，可用的命令为: ffprobe | ffmpeg"""
        exit_code, msg = -999, ''
        request = container_pb2.RunCommandRequest(container_id=self.container_id, command=command)
        for response in self._stub.RunCommand(request=request):
            if show_log:
                logging.info(response.msg)
            msg += response.msg
            if response.exit_code != -999:
                exit_code = response.exit_code
        return exit_code, msg, command

    def file_exists(self, file_path: str) -> bool:
        """判断容器内指定路径的文件是否存在"""
        request = container_pb2.FileExistsRequest(container_id=self.container_id, path=file_path)
        response = self._stub.FileExists(request=request)
        return response.exists

    def get_file(self, container_file_path: str, host_file_path: str) -> bool:
        """从容器内获取文件"""
        hasher, tmp, sha256sum, length = sha256(), dict(), None, 0
        request = container_pb2.GetFileRequest(container_id=self.container_id, path=container_file_path)
        with open(host_file_path, 'wb') as f:
            for response in self._stub.GetFile(request=request):
                if response.sha256sum:
                    sha256sum = response.sha256sum
                    continue
                if response.payload:
                    hasher.update(response.payload)
                    f.seek(response.offset)
                    f.write(response.payload)
                    length += len(response.payload)
        return hasher.hexdigest() == sha256sum

    def put_file(self, host_file_path: str, container_file_path: str) -> bool:
        """将宿主机上的文件复制到容器内"""
        total_size = os.path.getsize(host_file_path)
        hasher, chunk_size, offset = sha256(), 1024 * 1024, 0
        with open(host_file_path, 'rb') as f:
            while offset < total_size:
                f.seek(offset)
                chunk = f.read(min(chunk_size, total_size - offset))
                if not chunk:
                    break
                hasher.update(chunk)
                offset += len(chunk)
        sha256sum = hasher.hexdigest()

        def chunk_generator():
            yield container_pb2.ReusableChunk(container_id=self.container_id, path=container_file_path, sha256sum=sha256sum)

            _offset = 0
            with open(host_file_path, 'rb') as _f:
                while _offset < total_size:
                    _f.seek(_offset)
                    _chunk = _f.read(min(chunk_size, total_size - _offset))
                    if not _chunk:
                        break
                    yield container_pb2.ReusableChunk(container_id=self.container_id, offset=_offset, payload=_chunk)
                    _offset += len(_chunk)

        response = self._stub.PutFile(chunk_generator())
        return response.success

    def download_oss(self, bucket_name: str, object_key: str) -> str:
        """将OSS文件下载到容器"""
        request = container_pb2.DownloadOssRequest(container_id=self.container_id, bucket_name=bucket_name, object_key=object_key)
        response = self._stub.DownloadOss(request=request)
        return response.save_path

    def upload_oss(self, bucket_name: str, object_key: str, container_file_path: str, media_type: str):
        """将容器内文件上传到OSS"""
        request = container_pb2.UploadOssRequest(container_id=self.container_id,
                                                 bucket_name=bucket_name,
                                                 object_key=object_key,
                                                 file_path=container_file_path,
                                                 media_type=media_type)
        response = self._stub.UploadOss(request=request)
        return response.object_key