"""Models for smart downloader."""

import dataclasses
import datetime
import json
from typing import List
from typing import Optional


class Status:
    """Status of download request."""

    NEW = 'NEW'
    PROCESSING = 'PROCESSING'
    DONE = 'DONE'
    ERROR = 'ERROR'


class BaseDataClassMixin:
    """Mixin for dataclasses."""

    def to_dict(self, **kwargs):
        """Convert self to dict."""
        return dataclasses.asdict(self)

    def to_json(self, **json_kwargs):
        """Convert self to json string."""
        return json.dumps(self.to_dict(), **json_kwargs)


@dataclasses.dataclass
class DownloadTask:
    """Represents single download task."""

    source_url: str
    destination_url: str


@dataclasses.dataclass
class DownloadRequest(BaseDataClassMixin):
    """Represents one request for smart downloader."""

    tasks: List[DownloadTask]
    tasksMessageId: str
    status: Status = Status.NEW
    n_threads: Optional[int] = None


@dataclasses.dataclass
class DownloadResponse(BaseDataClassMixin):
    """Represents response for smart downloader."""

    return_code: Optional[int] = None
    duration: Optional[float] = None
    n_threads: Optional[int] = None
    n_tasks: Optional[int] = None
    processing_started_at: Optional[datetime.datetime] = None
    processing_finished_at: Optional[datetime.datetime] = None