# Story 1.7: Legacy Schema Compatibility Validation Gate

Status: ready-for-dev

## Story

As a an administrator,
I want to run a compatibility check that confirms legacy table schemas are unchanged against the approved baseline,
so that every release can be gated on legacy integrity before deployment.

## Acceptance Criteria

1. **Given** the compatibility check is triggered **When** it runs against the live database **Then** it compares all legacy table structures (column names, types, constraints) against the approved schema baseline stored at initialization
2. **Given** a structural change is detected on any legacy table **When** the check completes **Then** it returns a failure status with a detailed report identifying the affected table, column, and change type (NFR12)
3. **Given** no schema drift is detected **When** the check completes **Then** it returns a pass confirmation with timestamp, number of tables verified, and zero drift count
4. **Given** the check is integrated into the release pipeline **When** it fails **Then** the release is blocked automatically and a failure report is surfaced to the administrator
5. **Given** an administrator is logged in **When** they navigate to the compatibility check feature **Then** they can trigger the check manually and view the most recent check history with timestamps

## Tasks / Subtasks

- [ ] Implement story behavior in aligned backend/frontend modules (AC: #1)
  - [ ] Add or update API/service/UI components required by the story scope
  - [ ] Keep legacy Access entities read-only and route writes to extension-layer structures
- [ ] Cover acceptance criteria #2 in implementation and tests (AC: #2)
  - [ ] Add validation/error handling and UX state updates as needed
- [ ] Cover acceptance criteria #3 in implementation and tests (AC: #3)
  - [ ] Add validation/error handling and UX state updates as needed
- [ ] Cover acceptance criteria #4 in implementation and tests (AC: #4)
  - [ ] Add validation/error handling and UX state updates as needed
- [ ] Validate and document completion evidence
  - [ ] Verify build/tests for touched modules
  - [ ] Capture changed files and any migration/config implications

## Dev Notes

- Follow Epic 1 architecture constraints: ASP.NET Core + React separation, RBAC-aware patterns, and immutable legacy tables.
- Reuse shared component and workflow patterns defined in UX and architecture docs; avoid parallel custom implementations.
- Keep changes scoped to this story; do not pull forward Epic 2+ features.

### Project Structure Notes

- Backend: `BriansClientRouteReports.Server/`
- Frontend: `brians-client-route-reports-client/`
- Story artifacts: `_bmad-output/implementation-artifacts/`

### References

- Story source: `_bmad-output/planning-artifacts/epics.md` (Epic 1 / Story 1.7)
- Architecture constraints: `_bmad-output/planning-artifacts/architecture.md`
- UX patterns: `_bmad-output/planning-artifacts/ux-design-specification.md`

## Dev Agent Record

### Agent Model Used

GPT-5 Codex

### Debug Log References

- Story generated from epic source and architecture/UX planning artifacts.

### Completion Notes List

- Story context created and marked ready-for-dev.

### File List

- `_bmad-output/implementation-artifacts/1-7-legacy-schema-compatibility-validation-gate.md`