Добавить основную функциональность загрузки YouTube Shorts с использованием файла сессии и обработкой ошибок

src/yt_shorts_downloader/session.py

@@ -0,0 +1,185 @@
+from __future__ import annotations
+
+import time
+from pathlib import Path
+
+from .models import SessionCookie, SessionValidation
+
+_SESSION_DOMAIN_SUFFIXES = ("youtube.com", "google.com")
+_AUTH_COOKIE_NAMES = {
+    "SID",
+    "HSID",
+    "SSID",
+    "APISID",
+    "SAPISID",
+    "__Secure-1PSID",
+    "__Secure-3PSID",
+    "LOGIN_INFO",
+}
+_AUTH_COOKIE_ANCHORS = {
+    "SID",
+    "SAPISID",
+    "__Secure-1PSID",
+    "__Secure-3PSID",
+    "LOGIN_INFO",
+}
+
+
+def validate_session_file(path: Path) -> SessionValidation:
+    normalized_path = path.expanduser().resolve()
+    if not normalized_path.exists():
+        return SessionValidation(
+            exists=False,
+            structurally_valid=False,
+            fresh=False,
+            is_usable=False,
+            message=f"Файл сессии не найден: {normalized_path}",
+        )
+
+    try:
+        cookies = _parse_session_file(normalized_path)
+    except ValueError as exc:
+        return SessionValidation(
+            exists=True,
+            structurally_valid=False,
+            fresh=False,
+            is_usable=False,
+            message=f"Файл сессии не прошёл проверку формата: {exc}",
+        )
+
+    if not cookies:
+        return SessionValidation(
+            exists=True,
+            structurally_valid=False,
+            fresh=False,
+            is_usable=False,
+            message="Файл сессии пустой",
+        )
+
+    relevant_cookies = [
+        cookie
+        for cookie in cookies
+        if _matches_domain(cookie.domain, _SESSION_DOMAIN_SUFFIXES)
+    ]
+    if not relevant_cookies:
+        return SessionValidation(
+            exists=True,
+            structurally_valid=False,
+            fresh=False,
+            is_usable=False,
+            message="В файле сессии нет записей для YouTube или Google",
+        )
+
+    now = int(time.time())
+    fresh_auth_names: set[str] = set()
+    soonest_expiry: int | None = None
+
+    for cookie in relevant_cookies:
+        if cookie.name not in _AUTH_COOKIE_NAMES:
+            continue
+        if cookie.expires != 0 and cookie.expires <= now:
+            continue
+
+        fresh_auth_names.add(cookie.name)
+        if cookie.expires > 0 and (
+            soonest_expiry is None or cookie.expires < soonest_expiry
+        ):
+            soonest_expiry = cookie.expires
+
+    anchor_count = len(fresh_auth_names & _AUTH_COOKIE_ANCHORS)
+    fresh = len(fresh_auth_names) >= 3 and anchor_count >= 1
+    if not fresh:
+        return SessionValidation(
+            exists=True,
+            structurally_valid=True,
+            fresh=False,
+            is_usable=False,
+            message=(
+                "Файл сессии в корректном формате, но в нём нет достаточного набора "
+                "актуальных YouTube auth-cookie"
+            ),
+        )
+
+    message = (
+        "Файл сессии валиден и выглядит актуальным для YouTube: "
+        f"найдено {len(fresh_auth_names)} свежих auth-cookie"
+    )
+    if soonest_expiry is not None:
+        hours_left = max((soonest_expiry - now) // 3600, 0)
+        message += f", ближайшее истечение примерно через {hours_left} ч"
+
+    return SessionValidation(
+        exists=True,
+        structurally_valid=True,
+        fresh=True,
+        is_usable=True,
+        message=message,
+    )
+
+
+def _parse_session_file(path: Path) -> list[SessionCookie]:
+    cookies: list[SessionCookie] = []
+
+    with path.open("r", encoding="utf-8") as handle:
+        for line_number, raw_line in enumerate(handle, start=1):
+            stripped = raw_line.strip()
+            if not stripped:
+                continue
+
+            is_httponly_cookie = stripped.startswith("#HttpOnly_")
+            if stripped.startswith("#") and not is_httponly_cookie:
+                continue
+
+            if is_httponly_cookie:
+                stripped = stripped.removeprefix("#HttpOnly_")
+
+            parts = stripped.split("\t")
+            if len(parts) != 7:
+                raise ValueError(
+                    "Строка "
+                    f"{line_number}: ожидалось 7 колонок Netscape cookie file, "
+                    f"получено {len(parts)}"
+                )
+
+            (
+                domain,
+                include_subdomains,
+                cookie_path,
+                secure,
+                expires,
+                name,
+                value,
+            ) = parts
+
+            try:
+                expires_at = int(expires)
+            except ValueError as exc:
+                raise ValueError(
+                    f"Строка {line_number}: expires должен быть UNIX timestamp"
+                ) from exc
+
+            cookies.append(
+                SessionCookie(
+                    domain=domain,
+                    include_subdomains=include_subdomains.upper() == "TRUE",
+                    path=cookie_path,
+                    secure=secure.upper() == "TRUE",
+                    expires=expires_at,
+                    name=name,
+                    value=value,
+                )
+            )
+
+    return cookies
+
+
+def _matches_domain(domain: str, suffixes: tuple[str, ...]) -> bool:
+    normalized_domain = _normalize_domain(domain)
+    return any(
+        normalized_domain == suffix or normalized_domain.endswith(f".{suffix}")
+        for suffix in suffixes
+    )
+
+
+def _normalize_domain(domain: str) -> str:
+    return domain.removeprefix("#HttpOnly_").lstrip(".").lower()