"""sxyprn.com — direct stream extractor.

Page → `data-vnfo` JSON → URL transform algorytmem boo/ssut51/preda → .vid mp4.

Sxyprn URL'e w `data-vnfo` mają format `/cdn/c8/<seg3>/<seg4>/<ts>/<seg6>/<seg7>.vid`
który wymaga rebuildu zanim CDN zaserwuje video bytes (bez tego endpoint zwraca tylko
pojedynczy timestamp 10B jako placeholder/probe response). Algorytm z `main2.js`:

    tmp[1] += "8/" + base64url("<ssut51(tmp[6])>-sxyprn.com-<ssut51(tmp[7])>")
    tmp[5] -= ssut51(tmp[6]) + ssut51(tmp[7])    # preda

gdzie ssut51 sumuje cyfry w stringu. Po tym joinujemy → finalny URL serwujący mp4.

Każdy fetch strony zwraca FRESH signed URL (różne tokeny i timestamp).
"""
from __future__ import annotations

import base64
import json
import logging
import re

from app.extractors._fetch import fetch_tube_html
from app.extractors._models import StreamSource

log = logging.getLogger(__name__)


_VNFO_RE = re.compile(r"data-vnfo='([^']+)'")


def _ssut51(s: str) -> int:
    """Sumuje wszystkie cyfry w stringu."""
    return sum(int(c) for c in s if c.isdigit())


def _boo(ss: int, es: int) -> str:
    """base64url-safe `<ss>-sxyprn.com-<es>` z `=`→`.`."""
    raw = f"{ss}-sxyprn.com-{es}".encode()
    return (
        base64.b64encode(raw)
        .decode()
        .replace("+", "-")
        .replace("/", "_")
        .replace("=", ".")
    )


def extract(page_url: str, *, timeout: float = 60.0) -> list[StreamSource] | None:
    html = fetch_tube_html(page_url, timeout=timeout)
    m = _VNFO_RE.search(html)
    if not m:
        log.warning("sxyprn: no data-vnfo in %s", page_url)
        return None
    try:
        vnfo = json.loads(m.group(1))
    except json.JSONDecodeError:
        log.warning("sxyprn: bad vnfo JSON in %s", page_url)
        return None
    if not isinstance(vnfo, dict) or not vnfo:
        return None

    sources: list[StreamSource] = []
    for _pid, src in vnfo.items():
        if not isinstance(src, str) or not src.startswith("/cdn/"):
            continue
        tmp = src.split("/")
        if len(tmp) < 8:
            log.warning("sxyprn: short path (%d segs) %s", len(tmp), src)
            continue
        try:
            s6 = _ssut51(tmp[6])
            s7 = _ssut51(tmp[7])
            tmp[1] += "8" + "/" + _boo(s6, s7)
            tmp[5] = str(int(tmp[5]) - s6 - s7)
        except (ValueError, IndexError) as e:
            log.warning("sxyprn: transform failed for %s: %s", src, e)
            continue
        final_path = "/".join(tmp)
        full = "https://sxyprn.com" + final_path
        sources.append(StreamSource(link=full, type="mp4"))

    if not sources:
        return None
    return sources