---

description: "Task list for Migration Process and UI Redesign implementation"
---

# Tasks: Migration Process and UI Redesign

**Input**: Design documents from `specs/001-migration-ui-redesign/`
**Prerequisites**: plan.md (required), spec.md (required for user stories), research.md, data-model.md, quickstart.md

**Tests**: Tests are NOT explicitly requested in the feature specification, so they are omitted from this task list.

**Organization**: Tasks are grouped by user story to enable independent implementation and testing of each story.

## Format: `[ID] [P?] [Story] Description`

- **[P]**: Can run in parallel (different files, no dependencies)
- **[Story]**: Which user story this task belongs to (e.g., US1, US2, US3)
- Include exact file paths in descriptions

## Path Conventions

- **Web app**: `backend/src/`, `frontend/src/`

---

## Phase 1: Setup (Shared Infrastructure)

**Purpose**: Project initialization and basic structure

- [ ] T001 Create project structure per implementation plan in `backend/src/` and `frontend/src/`
- [ ] T002 [P] Install backend dependencies (rapidfuzz, sqlalchemy) in `backend/requirements.txt`
- [ ] T003 [P] Install frontend dependencies (if any new) in `frontend/package.json`

---

## Phase 2: Foundational (Blocking Prerequisites)

**Purpose**: Core infrastructure that MUST be complete before ANY user story can be implemented

**⚠️ CRITICAL**: No user story work can begin until this phase is complete

- [ ] T004 Setup SQLite database schema and SQLAlchemy models in `backend/src/models/mapping.py`
- [ ] T005 [P] Implement fuzzy matching utility using RapidFuzz in `backend/src/core/utils/matching.py`
- [ ] T006 [P] Extend SupersetClient to support database listing and metadata fetching in `backend/src/core/superset_client.py`
- [ ] T007 Configure database mapping persistence layer in `backend/src/core/database.py`

**Checkpoint**: Foundation ready - user story implementation can now begin in parallel

---

## Phase 3: User Story 1 - Environment-Based Migration Setup (Priority: P1) 🎯 MVP

**Goal**: Enable selection of source and target environments and toggle database replacement.

**Independent Test**: Open the migration page and verify that the "Source" and "Target" dropdowns are populated with configured environments and can be selected.

### Implementation for User Story 1

- [ ] T008 [P] [US1] Implement environment selection API endpoints in `backend/src/api/routes/environments.py`
- [ ] T009 [P] [US1] Create `EnvSelector.svelte` component for source/target selection in `frontend/src/components/EnvSelector.svelte`
- [ ] T010 [US1] Integrate `EnvSelector` and "Replace Database" toggle into migration dashboard in `frontend/src/routes/migration/+page.svelte`
- [ ] T011 [US1] Add validation to ensure source and target environments are different in `frontend/src/routes/migration/+page.svelte`

**Checkpoint**: At this point, User Story 1 should be fully functional and testable independently.

---

## Phase 4: User Story 2 - Database Mapping Management (Priority: P1)

**Goal**: Fetch databases from environments, suggest mappings using fuzzy matching, and allow manual overrides/persistence.

**Independent Test**: Navigate to the "Database Mapping" tab, fetch databases, and verify that mappings can be created, saved, and edited.

### Implementation for User Story 2

- [ ] T012 [P] [US2] Implement database mapping CRUD API endpoints in `backend/src/api/routes/mappings.py`
- [ ] T013 [US2] Implement mapping service with fuzzy matching logic in `backend/src/services/mapping_service.py`
- [ ] T014 [P] [US2] Create `MappingTable.svelte` component for displaying and editing pairs in `frontend/src/components/MappingTable.svelte`
- [ ] T015 [US2] Create database mapping management view in `frontend/src/routes/migration/mappings/+page.svelte`
- [ ] T016 [US2] Implement "Fetch Databases" action and suggestion highlighting in `frontend/src/routes/migration/mappings/+page.svelte`

**Checkpoint**: At this point, User Stories 1 AND 2 should both work independently.

---

## Phase 5: User Story 3 - Migration with Automated DB Replacement (Priority: P2)

**Goal**: Intercept assets during migration, apply database mappings, and prompt for missing ones.

**Independent Test**: Run a migration with "Replace Database" enabled and verify that the resulting assets in the target environment point to the mapped databases.

### Implementation for User Story 3

- [ ] T017 [US3] Implement ZIP-based asset interception and YAML transformation logic in `backend/src/core/migration_engine.py`
- [ ] T018 [US3] Integrate database mapping application into the migration job execution flow in `backend/src/core/task_manager.py`
- [ ] T019 [P] [US3] Create `MissingMappingModal.svelte` for on-the-fly mapping prompts in `frontend/src/components/MissingMappingModal.svelte`
- [ ] T020 [US3] Implement backend pause and frontend modal trigger for missing mappings in `backend/src/api/routes/tasks.py` and `frontend/src/components/TaskRunner.svelte`

**Checkpoint**: All user stories should now be independently functional.

---

## Phase 6: Polish & Cross-Cutting Concerns

**Purpose**: Improvements that affect multiple user stories

- [ ] T021 [P] Update documentation in `docs/` to include database mapping instructions
- [ ] T022 Code cleanup and refactoring of migration logic
- [ ] T023 [P] Performance optimization for fuzzy matching and ZIP processing
- [ ] T024 Run `quickstart.md` validation to ensure end-to-end flow works as documented

---

## Dependencies & Execution Order

### Phase Dependencies

- **Setup (Phase 1)**: No dependencies - can start immediately
- **Foundational (Phase 2)**: Depends on Setup completion - BLOCKS all user stories
- **User Stories (Phase 3+)**: All depend on Foundational phase completion
  - User stories can then proceed in parallel (if staffed)
  - Or sequentially in priority order (P1 → P2 → P3)
- **Polish (Final Phase)**: Depends on all desired user stories being complete

### User Story Dependencies

- **User Story 1 (P1)**: Can start after Foundational (Phase 2) - No dependencies on other stories
- **User Story 2 (P1)**: Can start after Foundational (Phase 2) - No dependencies on other stories
- **User Story 3 (P2)**: Can start after Foundational (Phase 2) - Depends on US1/US2 for mapping data and configuration

### Within Each User Story

- Models before services
- Services before endpoints
- Core implementation before integration
- Story complete before moving to next priority

### Parallel Opportunities

- All Setup tasks marked [P] can run in parallel
- All Foundational tasks marked [P] can run in parallel (within Phase 2)
- Once Foundational phase completes, US1 and US2 can start in parallel
- Models and UI components within a story marked [P] can run in parallel

---

## Parallel Example: User Story 2

```bash
# Launch backend and frontend components for User Story 2 together:
Task: "Implement database mapping CRUD API endpoints in backend/src/api/routes/mappings.py"
Task: "Create MappingTable.svelte component for displaying and editing pairs in frontend/src/components/MappingTable.svelte"
```

---

## Implementation Strategy

### MVP First (User Story 1 & 2)

1. Complete Phase 1: Setup
2. Complete Phase 2: Foundational (CRITICAL - blocks all stories)
3. Complete Phase 3: User Story 1
4. Complete Phase 4: User Story 2
5. **STOP and VALIDATE**: Test environment selection and mapping management independently
6. Deploy/demo if ready

### Incremental Delivery

1. Complete Setup + Foundational → Foundation ready
2. Add User Story 1 → Test independently → Deploy/Demo
3. Add User Story 2 → Test independently → Deploy/Demo (MVP!)
4. Add User Story 3 → Test independently → Deploy/Demo
5. Each story adds value without breaking previous stories

---

## Notes

- [P] tasks = different files, no dependencies
- [Story] label maps task to specific user story for traceability
- Each user story should be independently completable and testable
- Commit after each task or logical group
- Stop at any checkpoint to validate story independently
- Avoid: vague tasks, same file conflicts, cross-story dependencies that break independence
