---
phase: 05-cloud-storage-backends
plan: 12
type: execute
wave: 1
depends_on: []
files_modified:
  - backend/api/cloud.py
  - backend/api/documents.py
  - docker-compose.yml
  - frontend/src/views/CloudStorageView.vue
  - backend/tests/test_cloud_api.py
autonomous: true
requirements: [CLOUD-01, CLOUD-02, CLOUD-07]
gap_closure: true

must_haves:
  truths:
    - "OneDrive OAuth initiate returns HTTP 400 with a descriptive message when ONEDRIVE_CLIENT_ID or ONEDRIVE_CLIENT_SECRET is not configured — not a 500 from MSAL"
    - "Google Drive OAuth initiate returns HTTP 400 with a descriptive message when GOOGLE_CLIENT_ID or GOOGLE_CLIENT_SECRET is not configured"
    - "stream_document_content returns 502 (not 500) when a cloud backend raises an unexpected exception"
    - "celery-worker in docker-compose.yml has a volume mount so code changes are picked up by docker compose restart (no rebuild required)"
    - "CloudStorageView shows an upload hint directing users to navigate into a cloud folder to upload files"
  artifacts:
    - path: "backend/api/cloud.py"
      provides: "Pre-flight config check in oauth_initiate for both onedrive and google_drive providers"
    - path: "backend/api/documents.py"
      provides: "Broad except-clause in stream_document_content catches non-CloudConnectionError exceptions and returns 502"
    - path: "docker-compose.yml"
      provides: "celery-worker service has volumes: - ./backend:/app matching the backend service"
    - path: "frontend/src/views/CloudStorageView.vue"
      provides: "Upload hint paragraph shown when connections exist, directing users to navigate into a folder"
  key_links:
    - from: "frontend Settings → Cloud Storage → Connect OneDrive"
      to: "GET /api/cloud/oauth/initiate/onedrive"
      via: "Returns 400 with readable error when env vars missing"
    - from: "frontend document preview"
      to: "GET /api/documents/{id}/content"
      via: "Returns 502 instead of 500 on cloud backend failure"
---

<objective>
Close 3 UAT gaps from Phase 5 testing:

1. **OneDrive OAuth 500** (major): When ONEDRIVE_CLIENT_ID/SECRET env vars are not set, MSAL raises an exception that surfaces as a 500 error. Users cannot distinguish misconfiguration from a code bug. Add a pre-flight check that returns 400 with a human-readable message before touching MSAL. Same check for Google Drive.

2. **Cloud document stream opaque 500** (blocker): `stream_document_content` catches `CloudConnectionError` → 503, but any other exception from the cloud backend becomes a raw 500. Add a broad `except Exception` → 502 with a user-friendly message. Also add `volumes: ./backend:/app` to celery-worker in docker-compose.yml so code changes are reflected by `docker compose restart` without a full rebuild.

3. **Upload hint in CloudStorageView** (blocker): The sidebar "Cloud Storage" link now navigates to `/cloud` (CloudStorageView) which shows provider connections but has no DropZone. Users expect to be able to upload there. Adding a DropZone would require knowing which cloud folder to target (not available at this level). Instead, add a clear inline hint: "To upload files, navigate into a cloud folder first."
</objective>

<execution_context>
@$HOME/.claude/get-shit-done/workflows/execute-plan.md
@$HOME/.claude/get-shit-done/templates/summary.md
</execution_context>

<context>
@.planning/PROJECT.md
@.planning/ROADMAP.md
@.planning/STATE.md
@.planning/phases/05-cloud-storage-backends/05-UAT.md
</context>

<interfaces>
<!-- Key contracts the executor needs. -->

From backend/api/cloud.py — oauth_initiate (lines ~314–384):
- Route: GET /api/cloud/oauth/initiate/{provider}
- Provider validation at line ~336: `if provider not in VALID_OAUTH_PROVIDERS: raise HTTPException(400, ...)`
- google_drive block starts at line ~348 with `if provider == "google_drive":`
- onedrive block starts at line ~370 with `elif provider == "onedrive":`
- settings fields: `settings.google_client_id`, `settings.google_client_secret` (config.py line ~62); `settings.onedrive_client_id`, `settings.onedrive_client_secret`, `settings.onedrive_tenant_id` (config.py line ~64)
- All three onedrive fields default to empty string — no startup validation

From backend/api/documents.py — stream_document_content (lines ~708–780):
- CloudConnectionError catch at line ~754 returns 503
- No broad except-clause after it — any other cloud exception becomes unhandled 500
- `from storage import get_storage_backend, get_storage_backend_for_document` at line 40

From docker-compose.yml — celery-worker service (lines ~81–100):
- Has no `volumes:` block — backend code changes require `docker compose up --build celery-worker`
- `backend` service at line ~53 has `volumes: - ./backend:/app` — same pattern needed for celery-worker

From frontend/src/views/CloudStorageView.vue:
- Content section starts at line ~12: `<div class="flex-1 overflow-y-auto px-6 py-5">`
- Empty state div at line ~23: `<div v-else-if="connections.length === 0" ...>`
- Connections list at line ~30: `<div v-else class="flex flex-col divide-y ...">` (rows listing providers)
- No DropZone imported or rendered anywhere in the component
- Upload hint must appear AFTER the connections list (inside the `v-else` branch) — not in the empty state

From backend/tests/test_cloud_api.py:
- Read the file to understand existing test fixtures before adding new tests
- Add tests for the 400 response when env vars are missing (mock settings)
</interfaces>

<tasks>

<task type="auto" tdd="true">
  <name>Task 1: Backend — pre-flight config validation in oauth_initiate</name>
  <files>backend/api/cloud.py, backend/tests/test_cloud_api.py</files>
  <read_first>
    - backend/api/cloud.py (lines 310–390: oauth_initiate function)
    - backend/config.py (lines 60–70: onedrive_client_id, google_client_id fields)
    - backend/tests/test_cloud_api.py (full file: existing fixtures and test patterns)
  </read_first>
  <behavior>
    - GET /api/cloud/oauth/initiate/google_drive with google_client_id="" → 400 {"detail": "Google Drive OAuth is not configured on this server. Set GOOGLE_CLIENT_ID and GOOGLE_CLIENT_SECRET in your environment."}
    - GET /api/cloud/oauth/initiate/onedrive with onedrive_client_id="" → 400 {"detail": "OneDrive OAuth is not configured on this server. Set ONEDRIVE_CLIENT_ID, ONEDRIVE_CLIENT_SECRET, and ONEDRIVE_TENANT_ID in your environment."}
    - GET /api/cloud/oauth/initiate/onedrive with all onedrive env vars set → still attempts MSAL (existing behavior, not broken)
    - GET /api/cloud/oauth/initiate/unknown_provider → still 400 "Unsupported OAuth provider" (existing behavior unchanged)
  </behavior>
  <action>
    In backend/api/cloud.py, inside the `oauth_initiate` function, AFTER the existing `VALID_OAUTH_PROVIDERS` check and BEFORE the `if provider == "google_drive":` block, insert two pre-flight checks:

    1. For google_drive: immediately before `if provider == "google_drive":`, add:
       ```
       if provider == "google_drive" and (not settings.google_client_id or not settings.google_client_secret):
           raise HTTPException(
               status_code=status.HTTP_400_BAD_REQUEST,
               detail="Google Drive OAuth is not configured on this server. Set GOOGLE_CLIENT_ID and GOOGLE_CLIENT_SECRET in your environment.",
           )
       ```

    2. For onedrive: immediately before `elif provider == "onedrive":`, add:
       ```
       if provider == "onedrive" and (not settings.onedrive_client_id or not settings.onedrive_client_secret):
           raise HTTPException(
               status_code=status.HTTP_400_BAD_REQUEST,
               detail="OneDrive OAuth is not configured on this server. Set ONEDRIVE_CLIENT_ID, ONEDRIVE_CLIENT_SECRET, and ONEDRIVE_TENANT_ID in your environment.",
           )
       ```

    These checks must fire before the `if provider == "google_drive":` / `elif provider == "onedrive":` blocks — do NOT restructure the if/elif chain.

    In backend/tests/test_cloud_api.py, add two tests using `monkeypatch` (pytest) to override settings fields:
    1. `test_oauth_initiate_google_drive_not_configured` — monkeypatch `settings.google_client_id = ""` and `settings.google_client_secret = ""`, call GET /api/cloud/oauth/initiate/google_drive as an authenticated regular user, assert 400, assert "GOOGLE_CLIENT_ID" in detail.
    2. `test_oauth_initiate_onedrive_not_configured` — monkeypatch `settings.onedrive_client_id = ""`, call GET /api/cloud/oauth/initiate/onedrive, assert 400, assert "ONEDRIVE_CLIENT_ID" in detail.

    Use the existing authenticated client fixture from the test file — read the file to find its name before writing tests.
  </action>
  <acceptance_criteria>
    - backend/api/cloud.py oauth_initiate contains `if provider == "google_drive" and (not settings.google_client_id or not settings.google_client_secret)` before the `if provider == "google_drive":` block
    - backend/api/cloud.py oauth_initiate contains `if provider == "onedrive" and (not settings.onedrive_client_id or not settings.onedrive_client_secret)` before the `elif provider == "onedrive":` block
    - `pytest backend/tests/test_cloud_api.py::test_oauth_initiate_google_drive_not_configured backend/tests/test_cloud_api.py::test_oauth_initiate_onedrive_not_configured -v` exits 0
    - Both tests assert HTTP 400 and the relevant env var name in the detail string
  </acceptance_criteria>
  <verify>
    <automated>cd /Users/nik/Documents/Progamming/document_scanner/backend && python -m pytest tests/test_cloud_api.py::test_oauth_initiate_google_drive_not_configured tests/test_cloud_api.py::test_oauth_initiate_onedrive_not_configured -v</automated>
  </verify>
  <done>Two new tests pass. oauth_initiate returns 400 with descriptive message when provider credentials are empty. Existing tests unchanged.</done>
</task>

<task type="auto">
  <name>Task 2: Backend — 502 fallback in stream_document_content + celery-worker volume mount</name>
  <files>backend/api/documents.py, docker-compose.yml, backend/tests/test_documents_api.py</files>
  <read_first>
    - backend/api/documents.py (lines 708–780: stream_document_content function)
    - docker-compose.yml (lines 53–100: backend and celery-worker service definitions)
    - backend/tests/test_documents_api.py (read to find fixtures for mocking get_storage_backend_for_document)
  </read_first>
  <behavior>
    - GET /api/documents/{id}/content when cloud backend raises CloudConnectionError → 503 "Cloud connection requires re-authentication" (EXISTING, unchanged)
    - GET /api/documents/{id}/content when cloud backend raises any other Exception (e.g., aiohttp.ClientError, timeout, generic RuntimeError) → 502 "Cloud backend unreachable. Please try again or reconnect in Settings."
    - GET /api/documents/{id}/content for a MinIO document → 200 with file bytes (unchanged, MinIO errors are not affected by the new clause)
  </behavior>
  <action>
    ### 1. backend/api/documents.py — add broad except-clause

    In the `stream_document_content` function, find the `except CloudConnectionError as exc:` block (lines ~754–758). IMMEDIATELY AFTER its closing line (`from exc`), add a second except clause:

    ```python
    except Exception as exc:
        raise HTTPException(
            status_code=502,
            detail="Cloud backend unreachable. Please try again or reconnect in Settings.",
        ) from exc
    ```

    The final try/except structure must be:
    ```
    try:
        storage_backend = await get_storage_backend_for_document(...)
        file_bytes = await storage_backend.get_object(doc.object_key)
    except CloudConnectionError as exc:
        raise HTTPException(503, ...) from exc
    except Exception as exc:
        raise HTTPException(502, ...) from exc
    ```

    Do NOT catch Exception before CloudConnectionError — order matters (specific before broad).

    ### 2. docker-compose.yml — add volume mount to celery-worker

    In the `celery-worker` service block, add a `volumes:` key with the same bind mount as the `backend` service:
    ```yaml
    volumes:
      - ./backend:/app
    ```

    Place it after `environment:` and before `extra_hosts:` (or after `extra_hosts:` if that reads more cleanly). Match the indentation of surrounding keys (2 spaces).

    Also add `PYTHONDONTWRITEBYTECODE=1` to the celery-worker environment if it is not already there (prevents .pyc files from cluttering the bind-mounted source).

    ### 3. backend/tests/test_documents_api.py — add test for 502 path

    Add `test_stream_document_content_cloud_backend_error`: 
    - Create a document with `storage_backend = "google_drive"` (or any non-minio value)
    - Mock `get_storage_backend_for_document` to raise `RuntimeError("connection timeout")`
    - Call GET /api/documents/{doc.id}/content as the document owner
    - Assert 502 and "Cloud backend unreachable" in the response detail
    
    Read existing document stream tests to find the right fixture pattern before writing.
  </action>
  <acceptance_criteria>
    - backend/api/documents.py stream_document_content has `except Exception as exc:` AFTER `except CloudConnectionError as exc:` block, raising HTTPException(502)
    - docker-compose.yml celery-worker service has `volumes: - ./backend:/app`
    - `pytest backend/tests/test_documents_api.py::test_stream_document_content_cloud_backend_error -v` exits 0
    - `pytest backend/tests/ -v -k "stream_document_content"` — all stream tests pass (no regression)
  </acceptance_criteria>
  <verify>
    <automated>cd /Users/nik/Documents/Progamming/document_scanner/backend && python -m pytest tests/test_documents_api.py -v -k "stream" 2>&1 | tail -20</automated>
  </verify>
  <done>502 except-clause added. Volume mount added to docker-compose.yml. New test passes. Existing stream tests pass.</done>
</task>

<task type="auto">
  <name>Task 3: Frontend — upload hint in CloudStorageView</name>
  <files>frontend/src/views/CloudStorageView.vue</files>
  <read_first>
    - frontend/src/views/CloudStorageView.vue (full file — understand existing template structure)
    - frontend/src/views/CloudFolderView.vue (for reference — how upload works inside a folder)
  </read_first>
  <behavior>
    - When at /cloud with at least one active connection, a hint paragraph is visible below the connections list: "To upload files, navigate into a cloud folder first."
    - The hint does not appear on the empty state (no connections) — that state already directs to Settings.
    - Clicking a connection row still navigates to /cloud/{provider}/root (existing behavior unchanged).
    - No DropZone component is added to this view (no cloud folder context is available at this level).
  </behavior>
  <action>
    In frontend/src/views/CloudStorageView.vue, inside the `v-else` block (the div that renders the connections list, starting at `<div v-else class="flex flex-col divide-y ...`), add a hint paragraph immediately AFTER the closing `</div>` of the connections list (after the `</div>` that closes `v-for`), still inside the `v-else` wrapper:

    ```html
    <p class="mt-4 text-xs text-gray-400 text-center">
      To upload files, navigate into a cloud folder first.
    </p>
    ```

    The hint must be a sibling of the connections list `<div>`, not nested inside it. Keep both inside the single `v-else` block so the hint is only visible when connections exist.
  </action>
  <acceptance_criteria>
    - CloudStorageView.vue contains `To upload files, navigate into a cloud folder first.` in a `<p>` element inside the `v-else` block
    - The `<p>` is NOT inside the `v-else-if="connections.length === 0"` empty state block
    - `cd frontend && npm run build` exits 0 with no errors
    - No DropZone or UploadProgress imported or rendered in CloudStorageView.vue
  </acceptance_criteria>
  <verify>
    <automated>cd /Users/nik/Documents/Progamming/document_scanner/frontend && npm run build 2>&1 | tail -5</automated>
  </verify>
  <done>Upload hint added below connections list. Build passes. No DropZone added. Existing connection click behavior unchanged.</done>
</task>

</tasks>

<threat_model>
## Trust Boundaries

| Boundary | Description |
|----------|-------------|
| oauth_initiate preflight | User-supplied provider string already validated; new checks only inspect server-side settings values — no user input involved |
| 502 error message | Static string, no user data reflected in the error detail |
| volume mount | Read-only to container — same bind mount pattern as backend service |

## STRIDE Threat Register

| Threat ID | Category | Component | Disposition | Mitigation Plan |
|-----------|----------|-----------|-------------|-----------------|
| T-05-12-01 | Information Disclosure | 400 error message for missing creds | mitigate | Message names env vars (server config), not any user data or secret values — safe to expose |
| T-05-12-02 | Information Disclosure | 502 error message | mitigate | Static string "Cloud backend unreachable" — no stack trace, no exception detail leaked to client |
| T-05-12-03 | Tampering | celery-worker volume mount | accept | Bind mount is same as backend service; only developer-controlled source files are mounted; production deployments use image builds, not bind mounts |
| T-05-12-SC | Tampering | npm/pip installs | mitigate | No new packages installed in this plan |
</threat_model>

<verification>
After all tasks complete:
- `cd backend && python -m pytest tests/test_cloud_api.py::test_oauth_initiate_google_drive_not_configured tests/test_cloud_api.py::test_oauth_initiate_onedrive_not_configured -v` — 2 tests pass
- `cd backend && python -m pytest tests/test_documents_api.py::test_stream_document_content_cloud_backend_error -v` — 1 test passes
- `cd backend && python -m pytest -v` — zero new failures
- `cd frontend && npm run build` — zero errors
- Manual: docker-compose.yml celery-worker service has `volumes: - ./backend:/app`
- Manual: open CloudStorageView at /cloud — upload hint visible below connections list
- Manual: curl -H "Authorization: Bearer <token>" http://localhost:8000/api/cloud/oauth/initiate/onedrive (with empty OneDrive creds) → 400 with "ONEDRIVE_CLIENT_ID" in detail
</verification>

<success_criteria>
- oauth_initiate returns 400 with descriptive env-var hint for unconfigured google_drive and onedrive
- stream_document_content returns 502 (not 500) for non-CloudConnectionError cloud exceptions
- celery-worker has volume mount so `docker compose restart celery-worker` picks up code changes
- CloudStorageView shows upload hint directing users to navigate into a folder
- 3 new backend tests pass; full pytest suite has zero new failures; frontend build clean
</success_criteria>

<output>
Create `.planning/phases/05-cloud-storage-backends/05-12-SUMMARY.md` when done
</output>