"""Youtube feeds specific util functions."""

import datetime
import gzip
import os
import re

from googleapiclient.discovery import build
from googleapiclient.http import MediaIoBaseDownload
import httplib2
from oauth2client.file import Storage

from feed_ingestion.util import os_tools


def get_days(date):
    """Get download, start and end dates of ingestion.

    Args:
        date (str): Reporting date (YYYY-MM-DD).
    Returns:
        tuple(datetime, datetime, datetime): Download day, start day, end day.
    """
    date_obj = datetime.datetime.strptime(date, '%Y-%m-%d').date()
    start_date = date_obj
    end_date = date_obj + datetime.timedelta(days=6)
    return date_obj, start_date, end_date


def get_authenticated_services(
        credentials_path, api_service_name, api_version):
    """Get YouTube API authenticated service.

    Args:
        credentials_path (str): Path to credentials file.
        api_service_name (str): YouTube API service name.
        api_version (str): YouTube API version.

    Returns:
        Resource: A Resource object with methods for
        interacting with the service.
    """
    storage = Storage(credentials_path)
    credentials = storage.get()

    if credentials is None:
        raise Exception('Valid YouTube API credentials file required.')

    http = credentials.authorize(httplib2.Http())

    return build(api_service_name, api_version, http=http)


def get_url(content_owner, job_id, start_date, youtube_reports):
    """Make an HTTP API call to the YT API.

    Checks if an report exists upstream, and returns a DL url.

    Args:
        content_owner (str): Content owner id.
        job_id (str): Report id.
        start_date (str): Report date.
        youtube_reports (Resource): YouTube API object.

    Returns:
        str: Report url.
    """
    date_obj = datetime.datetime.strptime(start_date, '%Y-%m-%d')
    start_time = date_obj.strftime('%Y-%m-%dT%H:%M:%S.%fZ')
    end_time = (
            date_obj + datetime.timedelta(days=1)).strftime(
        '%Y-%m-%dT%H:%M:%S.%fZ')

    target_report = youtube_reports.jobs().reports().list(
        onBehalfOfContentOwner=content_owner,
        jobId=job_id,
        startTimeAtOrAfter=start_time,
        startTimeBefore=end_time).execute()

    if not target_report:
        raise ValueError(
            'Report not available. Job id: {}. Date: {}'.format(
                job_id, start_time))

    return target_report['reports'][0]['downloadUrl']


def get_job(content_owner, jobs, report_name):
    """Get job description from jobs list.

    Args:
        content_owner (str): Content owner id.
        jobs (list): List of available jobs from jobs file.
            Generated by YouTube.
        report_name (str): Name of the report to ingest.
    """
    pattern = re.compile(
        r'^{report_name}.*'.format(report_name=report_name))

    jobs_list = [j for j in jobs
                 if j['content_owner'] == content_owner
                 and re.match(pattern, j['job_name'])]

    if not jobs_list:
        raise Exception('Invalid report name {}.'.format(report_name))

    return jobs_list[0]


def grab_reports_files_for_content_owner(
        content_owner, content_owner_id, job, date,
        youtube_reports, report_name, feed_name, gz=True):
    """Download reports files and archive on S3 for a single content owner.

    Args:
        content_owner (str): Content owner name.
        content_owner_id (str): Content owner id.
        job (dict): Job description.
        date (str): Reporting date (YYYY-MM).
        youtube_reports (Resource): YouTube API object.
        report_name (str): Name of the report to ingest.
        feed_name (str): flow Feed name.
    """
    # 100mb chunks to aviod HttpError 429 when requesting
    # https://youtubereporting.googleapis.com/[...]?alt=media returned
    # "Quota exceeded for quota metric 'Free requests' and limit
    # 'Free requests per minute' of service 'youtubereporting.googleapis.com'
    CHUNK_SIZE = 200 * 1024 * 1024

    url = get_url(
        content_owner_id, job['job_id'], date, youtube_reports)

    report_filename_out = '{}.{}.csv.gz'.format(
        report_name, content_owner)

    local_dir = os_tools.create_temp_dir(feed_name=feed_name, date=date)
    local_file_path = os.path.join(local_dir, report_filename_out)

    request = youtube_reports.media().download(resourceName=' ')
    request.uri = url

    if gz is True:
        with gzip.open(local_file_path, 'wb') as f_out:
            downloader = MediaIoBaseDownload(
                f_out, request, chunksize=CHUNK_SIZE)
            done = False
            while not done:
                _, done = downloader.next_chunk()
    else:
        with open(local_file_path, 'wb') as f_out:
            downloader = MediaIoBaseDownload(
                f_out, request, chunksize=CHUNK_SIZE)
            done = False
            while not done:
                _, done = downloader.next_chunk()

    return local_dir, local_file_path