import urllib.parse
import os
import requests
import redis
import xml.etree.ElementTree as ET
import re
from flask import request, Response

PROXY_URL = os.getenv("PROXY_URL")
REDIS_URL = os.getenv("REDIS_URL", "redis://localhost:6379/0")
CACHE_TTL = int(os.getenv("CACHE_TTL", 3600))

rdb = redis.from_url(REDIS_URL)


def extract_viewtopic_link(description):
    """Search viewtopic.php in description"""
    match = re.search(r'href="(http://tapochek\.net/viewtopic\.php\?t=\d+)"', description)
    return match.group(1) if match else None


def init_proxy(app):
    @app.route("/proxy")
    def proxy():
        """Proxy RSS feed with per-item caching and GUID replacement."""
        raw_query = request.query_string.decode()
        if raw_query.startswith("url="):
            url = urllib.parse.unquote(raw_query[4:])
        else:
            return "Missing URL", 400

        try:
            proxies = {"http": PROXY_URL, "https": PROXY_URL} if PROXY_URL else None
            r = requests.get(url, timeout=10, proxies=proxies)
            _encode = r.apparent_encoding.lower()
            r.encoding = _encode
            xml_data = r.text.replace(f'<?xml version="1.0" encoding="{_encode}"?>',
                                      '<?xml version="1.0" encoding="UTF-8"?>')

            root = ET.fromstring(xml_data)
            items = root.findall(".//item")

            cached_items = []
            new_items = []

            for item in items:
                guid = item.find("guid")
                if guid is None or guid.get("isPermaLink") == "true":
                    continue

                cache_key = f"rss:item:{guid.text}"
                cached_item = rdb.get(cache_key)

                if cached_item:
                    cached_items.append(cached_item.decode())
                else:
                    description = item.find("description")
                    if description is not None:
                        new_guid = extract_viewtopic_link(description.text)
                        if new_guid:
                            guid.text = new_guid

                    item_str = ET.tostring(item, encoding="unicode")
                    rdb.setex(cache_key, CACHE_TTL, item_str)
                    new_items.append(item_str)

            final_items = cached_items + new_items
            response_xml = f'<?xml version="1.0" encoding="UTF-8"?><rss><channel>{"".join(final_items)}</channel></rss>'

            return Response(response_xml, content_type="application/xml; charset=utf-8")

        except Exception as e:
            return f"Error: {e}", 500