#!/usr/bin/env python3

from urllib.error import HTTPError
from urllib.request import urlopen, Request
import logging

# from requests_oauthlib import OAuth1Session
from datetime import datetime
import sys
import json

bearer = None


def _format_date(dt):
    """convert a datetime into an RFC 822 formatted date
    Input date must be in GMT.
    Stolen from PyRSS2Gen.
    """
    # Looks like:
    #   Sat, 07 Sep 2002 00:00:01 GMT
    # Can't use strftime because that's locale dependent
    #
    # Isn't there a standard way to do this for Python?  The
    # rfc822 and email.Utils modules assume a timestamp.  The
    # following is based on the rfc822 module.
    return "%s, %02d %s %04d %02d:%02d:%02d GMT" % (
        ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"][dt.weekday()],
        dt.day,
        [
            "Jan",
            "Feb",
            "Mar",
            "Apr",
            "May",
            "Jun",
            "Jul",
            "Aug",
            "Sep",
            "Oct",
            "Nov",
            "Dec",
        ][dt.month - 1],
        dt.year,
        dt.hour,
        dt.minute,
        dt.second,
    )


def getBearer():
    global bearer
    if bearer:
        return bearer
    headers = {
        "Authorization": "Basic Zzl1MXI2SFpYTXg0SXU5UGs5VlNvTzFUdzpmeTIyQjN2QVRRNUI2eGthb1BFdFFRUmtuUGQ1WGZBbnBKVG5hc0ZRa3NyUm5qaVNsaw==",
        "Content-Type": "application/x-www-form-urlencoded;charset=UTF-8",
    }
    data = b"grant_type=client_credentials"
    url = "https://api.twitter.com/oauth2/token"

    res = urlopen(Request(url, headers=headers, data=data, method="POST"))
    response = json.loads(res.read().decode("UTF-8"))
    bearer = response["access_token"]

    return bearer


def unshorten_urls(title, description, urls):
    for url in urls:
        shorted_url = url["url"]
        long_url = url["expanded_url"]

        if "images" in url:
            img = url["images"][0]["url"]
            long_url_html = '<a href="' + long_url + '"><img src="' + img + '"/></a>'
        else:
            long_url_html = '<a href="' + long_url + '">' + long_url + "</a>"

        description = description.replace(shorted_url, long_url_html)
        title = title.replace(shorted_url, long_url)
    return title, description


def twitter(user):
    # 500.000 Tweets per month
    # API KEY = g9u1r6HZXMx4Iu9Pk9VSoO1Tw
    # API SECRET KEY = fy22B3vATQ5B6xkaoPEtQQRknPd5XfAnpJTnasFQksrRnjiSlk

    headers = {"authorization": "Bearer " + getBearer()}

    # Recent = last 7 days
    url = (
        "https://api.twitter.com/2/tweets/search/recent?query=from:"
        + user
        + "&tweet.fields=created_at,author_id,lang,source,public_metrics,entities&expansions=referenced_tweets.id,attachments.media_keys&media.fields=url"
    )

    try:
        res = urlopen(Request(url, headers=headers))
        response = json.loads(res.read().decode("UTF-8"))
    except Exception as exc:
        logging.error('Request to twitter failed.', exc_info=exc)
        return None

    if not response["meta"]["result_count"]:
        return []

    for tweet in response["data"]:
        title = tweet["text"]
        description = tweet["text"]
        link = "https://twitter.com/" + user + "/status/" + str(tweet["id"])

        # Check included tweets
        if (
            "referenced_tweets" in tweet
            and len(tweet["referenced_tweets"]) == 1
            and tweet["referenced_tweets"][0]["type"] == "retweeted"
        ):
            rt_info = title[: title.index(":") + 2]
            ref_id = tweet["referenced_tweets"][0]["id"]
            ref_tweet = next(
                t for t in response["includes"]["tweets"] if t["id"] == ref_id
            )
            title = rt_info + ref_tweet["text"]
            description = rt_info + ref_tweet["text"]
            title, description = unshorten_urls(
                title, description, ref_tweet.get("entities", {}).get("urls", [])
            )

        title, description = unshorten_urls(
            title, description, tweet.get("entities", {}).get("urls", [])
        )

        # Attach media
        enclosures = []
        medias = tweet.get('attachments', {}).get('media_keys', [])
        for media in medias:
            ref_media = next(
                t for t in response["includes"]["media"] if t["media_key"] == media
            )
            if 'url' not in ref_media: continue
            if ref_media.get('type', '') == 'photo':
                description += "<br/><img src=\"" + ref_media['url'] + "\" />"
            else:
                enclosures.append(ref_media['url'])

        # Append Retweets etc
        description += "<br/><br/>"
        description += str(tweet["public_metrics"]["retweet_count"]) + " Retweets, "
        description += str(tweet["public_metrics"]["like_count"]) + " Likes, "
        description += str(tweet["public_metrics"]["reply_count"]) + " Replies, "
        description += str(tweet["public_metrics"]["quote_count"]) + " Quotes"
        description += "<br/>"
        description += "Source: " + tweet["source"]

        date = datetime.strptime(tweet["created_at"], "%Y-%m-%dT%H:%M:%S.%fZ")


        yield title, description, link, date, enclosures


def main(channel):
    print(
        """<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <title>Twitter: """
        + channel
        + """</title>
    <link>https://twitter.com/"""
        + channel
        + """</link>
    <description>The latest entries of the twitter account of """
        + channel
        + """</description>
    <lastBuildDate>"""
        + _format_date(datetime.now())
        + """</lastBuildDate>"""
    )

    for title, description, link, date, enclosures in twitter(channel):
        print("    <item>")
        print("      <title><![CDATA[" + title + "]]></title>")
        print("      <link>" + link + "</link>")
        print("      <description><![CDATA[" + description + "]]></description>")
        print("      <pubDate>" + _format_date(date) + "</pubDate>")
        for enclosure in enclosures:
            print('      <media:content url="' + enclosure + '" />')
        print("    </item>")

    print("  </channel>")
    print("</rss>")


if __name__ == "__main__":
    if len(sys.argv) != 2:
        print("Usage:", sys.argv[0], "<twitter channel>")
        sys.exit(1)
    main(sys.argv[1])
    # twitter('rheinbahn_intim')
    # twitter('realDonaldTrump')