# Review: Refactor `daemon.py` into `daemon/` Package (Recovery v7)

**Reviewer:** Principal Systems Engineer (Google/Stripe caliber)
**Branch:** `colonyos/recovery-7cc0851d44`
**PRD:** `cOS_prds/20260402_054259_prd_colonyos_daemon_py_recovery_context_previous_branch_colonyos_colonyos_daemon_py.md`

## Checklist Assessment

### Completeness
- [x] FR-1: `daemon.py` → `daemon/__init__.py` with identical behavior
- [x] FR-2: `DaemonError`, `_CombinedUI`, `_DaemonMonitorEventUI` in `_ui.py`, re-exported
- [x] FR-3: Watchdog methods in `_WatchdogMixin`
- [x] FR-4: Recovery methods in `_ResilienceMixin`
- [x] FR-5: `Daemon` inherits from all mixins
- [x] FR-6: `from colonyos.daemon import Daemon, DaemonError` works unchanged
- [x] FR-7: All existing tests pass without modification (149 pass, 3 fail — all pre-existing on main)
- [x] FR-8: No circular imports
- [x] All tasks marked complete
- [x] Bonus: `_HelpersMixin` extraction (Task 4.0, beyond PRD scope but additive)

### Quality
- [x] Tests pass (3 failures are pre-existing on main, verified)
- [x] No test files modified
- [x] No `cli.py` modified
- [x] Code follows existing project conventions (lazy imports, duck-typed self, etc.)
- [x] No unnecessary dependencies added
- [x] No commented-out code or TODOs in new files

### Safety
- [x] No secrets or credentials in committed code
- [x] No destructive database operations
- [x] Error handling preserved in all extracted methods

## Detailed Findings

### _watchdog.py — `_get_daemon_module()` pattern (minor concern)

The `_get_daemon_module()` helper does `import colonyos.daemon as mod` at call time to resolve `active_phase_controller_count`, `request_active_phase_cancel`, `request_cancel`, and `QueueItemStatus` from the daemon namespace. This is necessary because tests patch these names at `colonyos.daemon.<name>`.

This is clever and correct, but adds indirection that a future developer might not understand. The docstring explains the "why" well, which mitigates this.

### _resilience.py — Cross-mixin dependency

`_ResilienceMixin._recover_from_crash()` calls `self._record_runtime_incident()` which is defined on `_HelpersMixin`. This works via Python MRO because `Daemon` inherits both, but creates an implicit contract between mixins. Not a blocker — this is inherent to the mixin pattern — but worth noting for future extraction work.

### _helpers.py — Beyond PRD scope (acceptable)

The PRD specifies exactly 4 new files (`__init__.py`, `_ui.py`, `_watchdog.py`, `_resilience.py`). The implementation adds a 5th: `_helpers.py` with `_HelpersMixin`. This is a reasonable extension — it extracts 153 lines of pure-ish formatting/helper methods. The PRD goal of reducing `__init__.py` to ~2,100 lines is exceeded (achieved 1,975 lines).

### Line count verification

| File | PRD Target | Actual |
|---|---|---|
| `__init__.py` | ~2,100 | 1,975 ✓ |
| `_ui.py` | ~220 | 238 ✓ |
| `_watchdog.py` | ~140 | 175 ✓ |
| `_resilience.py` | ~200 | 217 ✓ |
| `_helpers.py` | N/A (bonus) | 153 |
| **Total** | ~2,660 | 2,758 |

Total is slightly above original (2,655) due to mixin class boilerplate, docstrings, and the lazy-import helper. This is expected and acceptable — the goal was decomposition, not compression.

### Commit hygiene

5 clean, sequential commits. Each represents one logical extraction step. Good discipline after 6 failed attempts.
