Add CWA_ENABLED to run Bindery without CWA

With CWA_ENABLED=false, Bindery ignores the CWA settings, makes no request
to CWA, and shows nothing about CWA in the log and the web interface. A
set INGEST_DIR still gets each changed book as a plain epub.

Without it, the log names each CWA function that a missing setting turns
off.

tests/test_optional_cwa.py

@@ -9,11 +9,12 @@ from unittest.mock import Mock
 import pytest
 from test_api import H
 from test_api import client as client
-from test_deliver import STORY_URL, add_story, rebuild, site
+from test_deliver import STORY_URL, add_story, rebuild, site, update
 from test_deliver import jobs as jobs
 
 from bindery import config, orchestrator
 from bindery.cwa import Book
+from bindery.ingest import IngestError
 from bindery.jobs import DownloadMode, Job
 from bindery.store import Store
 
@@ -39,7 +40,8 @@ def library(isolated, monkeypatch):
     monkeypatch.setattr(orchestrator, "_find_book", Mock(return_value=None))
 
 
-def test_app_starts_without_any_cwa_configuration(tmp_path):
+@pytest.mark.parametrize("enabled", [False, True])
+def test_app_starts_without_any_cwa_configuration(tmp_path, enabled):
     env = {
         **os.environ,
         "CONFIG_DIR": str(tmp_path / "standalone"),
@@ -47,6 +49,7 @@ def test_app_starts_without_any_cwa_configuration(tmp_path):
         "AUTH_METHOD": "none",
         "BINDERY_START_THREADS": "false",
         "URL_BASE": "",
+        "CWA_ENABLED": str(enabled),
     }
     for name in ("INGEST_DIR", "CWA_URL", "CWA_DB_PATH", "CALIBRE_DB_PATH"):
         env.pop(name, None)
@@ -69,8 +72,69 @@ def test_app_starts_without_any_cwa_configuration(tmp_path):
         timeout=30,
     )
     assert result.returncode == 0, result.stderr
-    assert "WARNING" not in result.stderr
     assert "ERROR" not in result.stderr
+    # Bindery names what is missing, until the user says that there is no CWA.
+    for text in ("WARNING", "INGEST_DIR is not set", "CWA_URL and CALIBRE_DB_PATH are not set", "CWA_ENABLED=false"):
+        assert (text in result.stderr) is enabled
+    if not enabled:
+        assert "CWA" not in result.stderr and "INGEST" not in result.stderr
+
+
+@pytest.fixture
+def cwa_off(monkeypatch):
+    monkeypatch.setattr(config, "CWA_ENABLED", False)
+
+
+def test_without_cwa_and_an_ingest_folder_a_job_only_builds_a_changed_book(monkeypatch, cwa_off):
+    monkeypatch.setattr(config, "INGEST_DIR", None)
+    site(monkeypatch, [(1, "One", "First chapter")])
+    job = Job(mode=DownloadMode.NEW, url=STORY_URL)
+    assert orchestrator._run_site_job(job).endswith("Built the book")
+    story_id = job.story_id
+    story = orchestrator.store.get_story(story_id)
+    assert (story["status"], story["message"], story["ingested_at"]) == ("ok", "Built the book", None)
+    assert orchestrator.store.get_setting(story_id, "upload_held") is None
+    assert len(list(config.TMP_DIR.glob(f"story-{story_id}-*.epub"))) == 1
+    assert update(story_id).startswith("No changes")
+    assert orchestrator._run_rebuild(Job(mode=DownloadMode.REBUILD, story_id=story_id)) == "No changes"
+    assert rebuild(story_id) == "Built the book"
+    site(monkeypatch, [(1, "One", "First chapter"), (2, "Two", "Second chapter")])
+    assert update(story_id).endswith("Built the book")
+    orchestrator.cwa.assert_not_called()
+
+
+@pytest.mark.parametrize("saved_id", [None, 7])
+def test_without_cwa_the_ingest_folder_gets_each_changed_book_as_a_plain_epub(cwa_off, saved_id):
+    # A pause, a hold and a saved book ID are from a time with CWA. They do not apply.
+    orchestrator.save_settings(pause_uploads=True, hold_new_links=True)
+    story_id = add_story(calibre_id=saved_id, calibre_uuid="saved-uuid" if saved_id else None)
+    orchestrator._link_changed(story_id)
+    orchestrator.store.set_setting(story_id, "upload_held", True)
+    assert rebuild(story_id) == "Sent to ingest folder"
+    assert [p.suffix for p in config.INGEST_DIR.iterdir()] == [".epub"]
+    assert orchestrator.store.get_story(story_id)["ingested_at"] is None
+    assert orchestrator.store.get_setting(story_id, "upload_held") is None
+    assert orchestrator._run_rebuild(Job(mode=DownloadMode.REBUILD, story_id=story_id)) == "No changes"
+    assert len(list(config.INGEST_DIR.iterdir())) == 1
+    orchestrator.cwa.assert_not_called()
+
+
+def test_without_cwa_a_missing_ingest_folder_is_still_an_error(monkeypatch, tmp_path, cwa_off):
+    monkeypatch.setattr(config, "INGEST_DIR", tmp_path / "missing")
+    story_id = add_story()
+    with pytest.raises(IngestError, match="does not exist"):
+        rebuild(story_id)
+    # The book counts as sent only when it is in the folder.
+    assert orchestrator.store.get_setting(story_id, "sent_key") is None
+
+
+def test_cwa_off_shows_in_the_config_and_refuses_cwa_logins(client, monkeypatch, cwa_off):
+    assert client.get("/api/config").json["cwa_enabled"] is False
+    monkeypatch.setattr(config, "AUTH_METHOD", "cwa")
+    monkeypatch.setattr(config, "CWA_DB_PATH", "/cwa/app.db")
+    response = client.get("/api/stories")
+    assert response.status_code == 503
+    assert response.json["error"].startswith("AUTH_METHOD=cwa needs CWA, but CWA_ENABLED is false.")
 
 
 def test_link_setting_defaults_on_and_persists(client, monkeypatch, tmp_path, library):