"""Collector for instagram metrics."""

import requests

from social_analytics import config
from social_analytics.constants import collectors


def collect_instagram_metrics(profile_id, instagram_auth_token):
    """
    Collect instagram metrics for a given profile id.

    Args:
        profile_id (str): the id by which to query the instagram API.
        instagram_auth_token (str): the instagram auth token.
    Returns:
        dict: instagram API's json response dict.
    """
    if not profile_id.strip():
        return

    url = construct_instagram_url(profile_id, instagram_auth_token)
    result = requests.get(url)

    return result.json()


def construct_instagram_url(profile_id, instagram_auth_token):
    """
    Generate a instagram api url based on a profile id.

    Args:
        profile_id (str): the id for which to generate a instagram API url.
        instagram_auth_token (str): the instagram access token.
    Returns:
        url (str): a instagram API url for the given id.
    """
    url = '{base_url}{profile_id}?access_token={access_token}'.format(
        base_url=collectors.INSTAGRAM_BASE_URL,
        profile_id=profile_id,
        access_token=instagram_auth_token)

    return url


def refresh_token():
    """Refresh instagram access token.

    Returns:
        dict: Until the refresh token functionality is implemented,
         the token stored in config.
    """
    # TODO implement instagram token refresh.
    return config.INSTAGRAM_ACCESS_TOKEN


def recommend_instagram_profile(profile_name, instagram_auth_token):
    """Recommend instagram profile.

    Args:
        profile_name (str): The profile name of the artist.
        instagram_auth_token (str): The instagram access token.
    Returns:
        Dict or None: A dictionary with the suggested profile or None when
        no profile matches the given name.
    """
    # Get users list limited to a count of 1.
    # Sometimes the result has more than one items.
    url = (
        '{base_url}search?q={profile_name}&count=1&access_token={access_token}'
        .format(
            base_url=collectors.INSTAGRAM_BASE_URL,
            profile_name=profile_name,
            access_token=instagram_auth_token))

    result = requests.get(url)
    result_json = result.json()

    if 'data' not in result_json or not result_json['data']:
        return None

    profiles = result_json['data']
    profile_with_most_likes = None

    # In the case of more than one result iterate over them.
    for profile in profiles:
        # Fetch info for profile.
        user_search_response = collect_instagram_metrics(
            profile['id'], instagram_auth_token)

        # In case of error, usually it's a private profile.
        if 'data' not in user_search_response:
            continue

        user_info = user_search_response['data']

        if profile_with_most_likes is None:
            profile_with_most_likes = user_info
            continue

        if (user_info['counts']['followed_by'] >
                profile_with_most_likes['counts']['followed_by']):
            profile_with_most_likes = user_info

    if profile_with_most_likes:
        return {
            'platform': 'instagram',
            'platform_id': profile_with_most_likes['id'],
            'platform_name': profile_with_most_likes['username'],
            'metric_value': profile_with_most_likes['counts']['followed_by']
        }


def verify_instagram_profile(platform_id, instagram_auth_token):
    """Verify instagram profile.

    Args:
        platform_id (str): The profile id of the artist e.g. 123444453
    Returns:
        Dict or None: A dictionary with the verified profile or None when
        there is not any profile for the given profile name.
    """
    url = construct_instagram_url(platform_id, instagram_auth_token)

    result = requests.get(url)
    result_json = result.json()

    if 'error_message' in result_json['meta']:
        return None

    data = result_json['data']

    return {
            'platform': 'instagram',
            'platform_id': data['id'],
            'platform_name': data['username'],
            'metric_value': data['counts']['followed_by']
        }