#!/usr/bin/env python3
# vim: ai ts=4 sts=4 sw=4
"""PostgreSQL Planet Aggregator

This file contains a base class for twitter integration
scripts.

Copyright (C) 2009-2019 PostgreSQL Global Development Group
"""
import requests_oauthlib


class TwitterClient(object):
    """
    Base class representing a twitter client, implementing all those twitter
    API calls that are in use.
    Does not attempt to be a complete twitter client, just to fill the needs
    for the planet software.
    """

    def __init__(self, cfg):
        """
        Initialize the instance. The parameter cfg is a ConfigParser object
        that has loaded the planet.ini file.
        """
        self.twittername = cfg.get('twitter', 'account')
        self.twitterlist = cfg.get('twitter', 'listname')

        self.tw = requests_oauthlib.OAuth1Session(cfg.get('twitter', 'consumer'),
                                                  cfg.get('twitter', 'consumersecret'),
                                                  cfg.get('twitter', 'token'),
                                                  cfg.get('twitter', 'secret'))

        self.twitter_api = 'https://api.twitter.com/1.1/'

    def list_subscribers(self):
        # Eek. It seems subscribers are paged even if we don't ask for it
        # Thus, we need to loop with multiple requests
        cursor = -1
        handles = []
        while cursor != 0:
            response = self.tw.get('{0}lists/members.json'.format(self.twitter_api), params={
                'owner_screen_name': self.twittername,
                'slug': self.twitterlist,
                'cursor': cursor,
                })
            if response.status_code != 200:
                print(response.json())
                raise Exception("Received status {0} when listing users".format(response.status_code))
            j = response.json()
            handles.extend([x['screen_name'].lower() for x in j['users']])
            cursor = j['next_cursor']

        return handles

    def remove_subscriber(self, name):
        print("Removing twitter user %s from list." % name)
        r = self.tw.post('{0}lists/members/destroy.json'.format(self.twitter_api), data={
            'owner_screen_name': self.twittername,
            'slug': self.twitterlist,
            'screen_name': name,
        })
        if r.status_code != 200:
            try:
                err = r.json()['errors'][0]['message']
            except Exception:
                err = 'Response does not contain error messages with json'
            print("Failed to remove subscriber {0}: {1}".format(name, err))
            return False
        return True

    def add_subscriber(self, name):
        print("Adding twitter user %s to list." % name)
        r = self.tw.post('{0}lists/members/create.json'.format(self.twitter_api), data={
            'owner_screen_name': self.twittername,
            'slug': self.twitterlist,
            'screen_name': name,
        })
        if r.status_code != 200:
            try:
                err = r.json()['errors'][0]['message']
            except Exception:
                err = 'Response does not contain error messages with json'
            print("Failed to add subscriber {0}: {1}".format(name, err))
            return False
        return True