# Standard Imports
import sys
import json
from pprint import pprint

# Package Imports
import requests
import peertube

# Local Imports
from peertube.rest import ApiException
from pathlib import Path


def peertube_request(endpoint: str, verb: str, **kwargs):
    """
    A helper function that facilitates basic requests to PeerTube and decodes.

    Args:
      endpoint (str): A URL to act against.
      verb (str): either "GET" or "POST".
      **kwargs: Passed through to underlying request call (for e.g. POSTs).

    Returns:
      dict: The JSON-decoded response from the request, or None if there was an error.
    """

    data = kwargs.get('data', None)
    try:
        if verb == 'GET':
            response = requests.get(endpoint)
        elif verb == 'POST':
            response = requests.post(endpoint, data=data)
        else:
            return None
        status_code = response.status_code
        data = response.json()
        if status_code != 200:
            print(
                f'Received a {status_code} response from PeerTube: {response}', file=sys.stderr)
            return None
    except json.JSONDecodeError as e:
        print(
            f'Unable to parse response JSON from PeerTube: {e}: {response}', file=sys.stderr)
        return None
    except requests.exceptions.RequestException as e:
        print(
            f'An error occurred while communicating with PeerTube: {e}', file=sys.stderr)
        return None
    else:
        return data


def authenticate_to_peertube(api_base: str, username: str, password: str):
    """
    Collects an access token from PeerTube via password authentication

    Args:
      api_base (str): The API base url for the given PeerTube instance, e.g. https://video.site/api/v1
      username (str): The username of the PeerTube account to be used in authentication
      password (str): The password of the PeerTube account to be used in authentication

    Returns:
      str: A string containing the access_token following authentication, or None if unable to auth.
    """

    if (data := peertube_request(api_base + '/oauth-clients/local', 'GET')) is None:
        print('Error initializing OAuth flow with PeerTube.', file=sys.stderr)
        return None
    client_id = data['client_id']
    client_secret = data['client_secret']
    data = {
        'client_id': client_id,
        'client_secret': client_secret,
        'grant_type': 'password',
        'response_type': 'code',
        'username': username,
        'password': password
    }
    if (data := peertube_request(api_base + '/users/token', 'POST', data=data)) is None:
        print('Error authenticating with PeerTube via OAuth.', file=sys.stderr)
        return None
    return data['access_token']


def upload_to_peertube(api_base: str, api_token: str, file: Path, channel_id: int, title: str, **kwargs):
    """
    Uploads a file from the local filesystem to PeerTube and returns a ready-to-consume URL to the video.

    Args:
      api_base (str): The API base url for the given PeerTube instance, e.g. https://video.site/api/v1
      api_token (str): A valid OAuth access token obtained from previous authentication.
      file (Path): An absolute path to the video file to be uploaded.
      channel_id (int): The internal ID number of the PeerTube channel to be uploaded to.
      title (str): The public-facing name of the video on PeerTube
      **kwargs: Any other values to pass to the PeerTube Video Upload API: https://framagit.org/framasoft/peertube/clients/python/-/blob/master/docs/VideoApi.md#videos_upload_post

    Returns:
      str: A string containing the URL to the video on PeerTube, or None if unable to publish.
    """
    configuration = peertube.Configuration(
        host=api_base
    )
    configuration.access_token = api_token

    with peertube.ApiClient(configuration) as api_client:
        api_instance = peertube.VideoApi(api_client)
        try:
            options = {
                **kwargs,
                'privacy': 1,
                'wait_transcoding': True
            }
            api_response = api_instance.videos_upload_post(
                file, channel_id, title, **options)
        except ApiException as e:
            print(
                f'Exception while uploading to PeerTube: {e}', file=sys.stderr)
            return None

        try:
            video_id = api_response.video.uuid
            api_response = api_instance.videos_id_get(video_id)
        except ApiException as e:
            print(
                f'Exception while getting Clip URL from PeerTube: {e}', file=sys.stderr)
            return None
        except KeyError as e:
            print(
                f'Could not find Video ID in response from PeerTube: {e}', file=sys.stderr)
            return None
    return api_response.embed_path