UPDATE

config/proxy.py

@@ -0,0 +1,68 @@
+from __future__ import annotations
+
+import os
+from typing import Any
+from urllib.parse import urlsplit
+
+
+def _is_truthy(value: str | None) -> bool:
+    return (value or "").strip().lower() in {"1", "true", "yes", "on"}
+
+
+def _normalize_proxy_scheme(scheme: str) -> str:
+    normalized = (scheme or "").strip().lower()
+    if normalized == "socks4":
+        return "socks4a"
+    if normalized == "socks5":
+        return "socks5h"
+    return normalized
+
+
+def build_proxy_url_from_proxychains_env(*, require_enabled: bool = True) -> str | None:
+    if require_enabled and not _is_truthy(os.environ.get("ENABLE_PROXYCHAINS")):
+        return None
+
+    scheme = _normalize_proxy_scheme(os.environ.get("PROXYCHAINS_PROXY_TYPE", "socks4"))
+    host = (os.environ.get("PROXYCHAINS_PROXY_HOST") or "").strip()
+    port = (os.environ.get("PROXYCHAINS_PROXY_PORT") or "").strip()
+    if not host or not port:
+        return None
+    return f"{scheme}://{host}:{port}"
+
+
+def _same_proxy_endpoint(left: str, right: str) -> bool:
+    left_parts = urlsplit(left)
+    right_parts = urlsplit(right)
+    return (
+        left_parts.hostname == right_parts.hostname
+        and left_parts.port == right_parts.port
+    )
+
+
+def resolve_requests_proxy_url(proxy_url: str | None) -> str:
+    value = (proxy_url or "").strip()
+    if not value:
+        return ""
+
+    proxychains_url = build_proxy_url_from_proxychains_env()
+    if proxychains_url and _same_proxy_endpoint(value, proxychains_url):
+        # Avoid double-proxying requests when the whole process is already wrapped by proxychains.
+        return ""
+
+    return value
+
+
+def build_requests_proxies(proxy_url: str | None) -> dict[str, str] | None:
+    value = resolve_requests_proxy_url(proxy_url)
+    if not value:
+        return None
+    return {"http": value, "https": value}
+
+
+def apply_requests_proxy(session: Any, proxy_url: str | None) -> Any:
+    proxies = build_requests_proxies(proxy_url)
+    if not proxies:
+        return session
+    session.proxies.update(proxies)
+    session.trust_env = False
+    return session