---
phase: 04-analysis-orchestration
plan: 01
subsystem: pipeline-architecture
tags: [processor, abstract-class, url-parsing, tdd, pydantic]

requires:
  - phase: 01-foundation
    provides: WorkflowStateManager, StepInput/StepOutput schemas
  - phase: 02-platform-skills
    provides: LinkParser for URL parsing
provides:
  - BaseProcessor abstract class for unified processor interface
  - ParseProcessor implementation wrapping LinkParser
  - ParseInput/ParseOutput schemas for parse step
affects: [04-02, 04-03, 04-04, 04-05]

tech-stack:
  added: []
  patterns:
    - "ABC (Abstract Base Class) pattern for processor interface"
    - "TDD workflow: RED (failing tests) -> GREEN (implementation) -> commit"

key-files:
  created:
    - kb_pipeline/processors/base.py
    - kb_pipeline/processors/parse.py
    - tests/test_processors/test_base.py
    - tests/test_processors/test_parse.py
  modified:
    - kb_pipeline/schemas.py
    - kb_pipeline/processors/__init__.py

key-decisions:
  - "BaseProcessor uses ABC with @abstractmethod for process()"
  - "STEP_NAME as class attribute (not instance) for consistency with ASRProcessor pattern"
  - "ParseInput content_id and platform default to empty string (populated after parse)"
  - "ParseProcessor wraps LinkParser directly without retry logic (retry belongs in concrete implementations)"

patterns-established:
  - "All processors inherit from BaseProcessor with STEP_NAME and async process() method"
  - "State recording only when state_manager is provided (optional dependency)"

requirements-completed: [MNT-01]

duration: 5min
completed: 2026-03-13
---

# Phase 04 Plan 01: BaseProcessor and ParseProcessor Summary

**Unified BaseProcessor abstract class and ParseProcessor implementation establishing the foundation for pipeline architecture**

## Performance

- **Duration:** 5 min
- **Started:** 2026-03-13T15:09:46Z
- **Completed:** 2026-03-13T15:14:40Z
- **Tasks:** 3
- **Files modified:** 6

## Accomplishments
- BaseProcessor abstract class defining unified interface for all processors
- ParseProcessor correctly wrapping LinkParser for Bilibili/Zhihu URL parsing
- ParseInput/ParseOutput schemas with proper validation
- All processors exportable from kb_pipeline.processors module

## Task Commits

Each task was committed atomically:

1. **Task 1: Define BaseProcessor abstract class** - `3ad2576` (test/feat)
2. **Task 2: Add ParseInput and ParseOutput schemas** - `efddef9` (feat)
3. **Task 3: Implement ParseProcessor with __init__.py export** - `06d36fc` (feat)

**Plan metadata:** pending (docs: complete plan)

_Note: TDD tasks may have multiple commits (test -> feat -> refactor)_

## Files Created/Modified
- `kb_pipeline/processors/base.py` - Abstract base class with STEP_NAME and process() method
- `kb_pipeline/processors/parse.py` - ParseProcessor wrapping LinkParser
- `kb_pipeline/processors/__init__.py` - Module exports (BaseProcessor, ParseProcessor, ASRProcessor)
- `kb_pipeline/schemas.py` - Added ParseInput and ParseOutput schemas
- `tests/test_processors/test_base.py` - Tests for BaseProcessor abstract behavior
- `tests/test_processors/test_parse.py` - Tests for ParseProcessor URL parsing

## Decisions Made
- BaseProcessor uses ABC with @abstractmethod to enforce process() implementation
- STEP_NAME as class attribute (matches existing ASRProcessor pattern)
- ParseInput content_id/platform default to empty (populated after parsing)
- No retry logic in BaseProcessor (belongs in concrete implementations)
- State recording optional (only when state_manager provided)

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered
- Test mock path needed adjustment: mock `kb_pipeline.processors.base.get_settings` instead of `kb_pipeline.processors.parse.get_settings` because BaseProcessor.__init__ calls get_settings()

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness
- Processor interface established, ready for additional processor implementations
- ParseProcessor provides URL parsing for downstream download/ASR steps
- State management integration tested and working

---
*Phase: 04-analysis-orchestration*
*Completed: 2026-03-13*

## Self-Check: PASSED

All files verified:
- kb_pipeline/processors/base.py
- kb_pipeline/processors/parse.py
- tests/test_processors/test_base.py
- tests/test_processors/test_parse.py
- .planning/phases/04-analysis-orchestration/04-01-SUMMARY.md

All commits verified:
- 3ad2576: test(04-01): add failing tests for BaseProcessor abstract class
- efddef9: feat(04-01): add ParseInput and ParseOutput schemas
- 06d36fc: feat(04-01): implement ParseProcessor and update module exports