feat(fc3c): PatreonResolver — vanity → campaign_id via requests

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/app/services/patreon_resolver.py

@@ -0,0 +1,102 @@
+"""Patreon vanity → campaign ID resolver.
+
+When gallery-dl fails with "Failed to extract campaign ID" on a Patreon
+source URL, call resolve_campaign_id(vanity, cookies_path) to look up
+the campaign ID via Patreon's public campaigns API. Caller then retries
+with `patreon.com/id:<campaign_id>` to bypass the broken vanity path.
+
+Uses the stdlib `requests` (already a transitive dep via gallery-dl) so
+we don't add `aiohttp`. The sync call is wrapped in run_in_executor so
+the calling async code stays non-blocking.
+
+Never raises. Returns None on any error (network, auth, parse, missing
+match).
+"""
+
+from __future__ import annotations
+
+import asyncio
+import http.cookiejar
+import logging
+import os
+
+import requests
+
+log = logging.getLogger(__name__)
+
+_CAMPAIGNS_URL = "https://www.patreon.com/api/campaigns"
+_USER_AGENT = (
+    "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 "
+    "(KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36"
+)
+_TIMEOUT_SECONDS = 10.0
+
+
+def _load_cookie_jar(cookies_path: str | None) -> http.cookiejar.MozillaCookieJar | None:
+    if not cookies_path or not os.path.isfile(cookies_path):
+        return None
+    try:
+        jar = http.cookiejar.MozillaCookieJar(cookies_path)
+        jar.load(ignore_discard=True, ignore_expires=True)
+        return jar
+    except (OSError, http.cookiejar.LoadError) as exc:
+        log.debug("Could not load cookies from %s: %s", cookies_path, exc)
+        return None
+
+
+def _sync_lookup(vanity: str, cookies_path: str | None) -> str | None:
+    jar = _load_cookie_jar(cookies_path)
+    headers = {
+        "User-Agent": _USER_AGENT,
+        "Accept": "application/vnd.api+json",
+    }
+    params = {
+        "filter[vanity]": vanity,
+        "fields[campaign]": "name",
+    }
+    try:
+        resp = requests.get(
+            _CAMPAIGNS_URL,
+            params=params,
+            headers=headers,
+            cookies=jar,
+            timeout=_TIMEOUT_SECONDS,
+        )
+    except requests.RequestException as exc:
+        log.warning("Patreon campaigns API request failed for vanity=%s: %s", vanity, exc)
+        return None
+
+    if resp.status_code != 200:
+        log.warning(
+            "Patreon campaigns API returned HTTP %d for vanity=%s",
+            resp.status_code, vanity,
+        )
+        return None
+
+    try:
+        payload = resp.json()
+    except ValueError as exc:
+        log.warning("Patreon campaigns API returned non-JSON for vanity=%s: %s", vanity, exc)
+        return None
+
+    if not isinstance(payload, dict):
+        return None
+    data = payload.get("data")
+    if not isinstance(data, list) or not data:
+        return None
+    first = data[0] if isinstance(data[0], dict) else None
+    campaign_id = first.get("id") if first else None
+    if not isinstance(campaign_id, str) or not campaign_id:
+        return None
+    log.info("Resolved Patreon vanity=%s → campaign_id=%s", vanity, campaign_id)
+    return campaign_id
+
+
+async def resolve_campaign_id(
+    vanity: str,
+    cookies_path: str | None,
+) -> str | None:
+    """Async wrapper. Returns the campaign id string or None on any failure.
+    Never raises."""
+    loop = asyncio.get_running_loop()
+    return await loop.run_in_executor(None, _sync_lookup, vanity, cookies_path)

tests/test_patreon_resolver.py

@@ -0,0 +1,88 @@
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from backend.app.services.patreon_resolver import resolve_campaign_id
+
+
+@pytest.mark.asyncio
+async def test_resolves_on_happy_path():
+    fake_response = MagicMock()
+    fake_response.status_code = 200
+    fake_response.json.return_value = {"data": [{"id": "12345678", "type": "campaign"}]}
+    with patch("backend.app.services.patreon_resolver.requests.get", return_value=fake_response):
+        result = await resolve_campaign_id("alice", cookies_path=None)
+    assert result == "12345678"
+
+
+@pytest.mark.asyncio
+async def test_returns_none_on_401():
+    fake_response = MagicMock()
+    fake_response.status_code = 401
+    fake_response.json.return_value = {}
+    with patch("backend.app.services.patreon_resolver.requests.get", return_value=fake_response):
+        result = await resolve_campaign_id("alice", cookies_path=None)
+    assert result is None
+
+
+@pytest.mark.asyncio
+async def test_returns_none_on_network_error():
+    import requests
+    with patch(
+        "backend.app.services.patreon_resolver.requests.get",
+        side_effect=requests.ConnectionError("nope"),
+    ):
+        result = await resolve_campaign_id("alice", cookies_path=None)
+    assert result is None
+
+
+@pytest.mark.asyncio
+async def test_returns_none_on_empty_data():
+    fake_response = MagicMock()
+    fake_response.status_code = 200
+    fake_response.json.return_value = {"data": []}
+    with patch("backend.app.services.patreon_resolver.requests.get", return_value=fake_response):
+        result = await resolve_campaign_id("alice", cookies_path=None)
+    assert result is None
+
+
+@pytest.mark.asyncio
+async def test_returns_none_on_malformed_json():
+    fake_response = MagicMock()
+    fake_response.status_code = 200
+    fake_response.json.side_effect = ValueError("not json")
+    with patch("backend.app.services.patreon_resolver.requests.get", return_value=fake_response):
+        result = await resolve_campaign_id("alice", cookies_path=None)
+    assert result is None
+
+
+@pytest.mark.asyncio
+async def test_missing_cookies_file_does_not_raise(tmp_path):
+    fake_response = MagicMock()
+    fake_response.status_code = 200
+    fake_response.json.return_value = {"data": [{"id": "1", "type": "campaign"}]}
+    with patch("backend.app.services.patreon_resolver.requests.get", return_value=fake_response):
+        result = await resolve_campaign_id(
+            "alice", cookies_path=str(tmp_path / "does-not-exist.txt")
+        )
+    assert result == "1"
+
+
+@pytest.mark.asyncio
+async def test_loads_cookies_file_when_present(tmp_path):
+    cookies = tmp_path / "cookies.txt"
+    cookies.write_text(
+        "# Netscape HTTP Cookie File\n"
+        ".patreon.com\tTRUE\t/\tTRUE\t1700000000\tsession_id\tabc\n"
+    )
+    fake_response = MagicMock()
+    fake_response.status_code = 200
+    fake_response.json.return_value = {"data": [{"id": "9", "type": "campaign"}]}
+    with patch(
+        "backend.app.services.patreon_resolver.requests.get",
+        return_value=fake_response,
+    ) as mock_get:
+        result = await resolve_campaign_id("alice", cookies_path=str(cookies))
+    assert result == "9"
+    _, kwargs = mock_get.call_args
+    assert kwargs.get("cookies") is not None