# Issue #361: Credential Audit Log Viewer

## Objective

Implement a credential audit log viewer to display all credential-related activities with filtering, pagination, and a PDA-friendly interface. This is a stretch goal for Phase 5c of M9-CredentialSecurity.

## Approach

1. **Backend**: Add audit query method to CredentialsService that filters ActivityLog by entityType=CREDENTIAL
2. **Backend**: Add GET /api/credentials/audit endpoint with filters (date range, action type, credential ID)
3. **Frontend**: Create page at /settings/credentials/audit
4. **Frontend**: Build AuditLogViewer component with:
   - Date range filter
   - Action type filter (CREATED, ACCESSED, ROTATED, UPDATED, etc.)
   - Credential name filter
   - Pagination (10-20 items per page)
   - PDA-friendly timestamp formatting
   - Mobile-responsive table layout

## Design Decisions

- **Reuse ActivityService.findAll()**: The existing query method supports all needed filters
- **RLS Enforcement**: Users see only their own workspace's activities
- **Pagination**: Default 20 items per page (matches web patterns)
- **Simple UI**: Stretch goal = minimal implementation, no complex features
- **Activity Types**: Filter by these actions:
  - CREDENTIAL_CREATED
  - CREDENTIAL_ACCESSED
  - CREDENTIAL_ROTATED
  - CREDENTIAL_REVOKED
  - UPDATED (for metadata changes)

## Progress

- [x] Backend: Create CredentialAuditQueryDto
- [x] Backend: Add getAuditLog method to CredentialsService
- [x] Backend: Add getAuditLog endpoint to CredentialsController
- [x] Backend: Tests for audit query (25 tests all passing)
- [x] Frontend: Create audit page /settings/credentials/audit
- [x] Frontend: Create AuditLogViewer component
- [x] Frontend: Add audit log API client function
- [x] Frontend: Navigation link to audit log
- [ ] Testing: Manual E2E verification (when API integration complete)
- [ ] Documentation: Update if needed

## Testing

- [ ] API returns paginated results
- [ ] Filters work correctly (date range, action type, credential ID)
- [ ] RLS enforced (users see only their workspace data)
- [ ] Pagination works (next/prev buttons functional)
- [ ] Timestamps display correctly (PDA-friendly)
- [ ] Mobile layout is responsive
- [ ] UI gracefully handles empty state

## Notes

- Keep implementation simple - this is a stretch goal
- Leverage existing ActivityService patterns
- Follow PDA design principles (no aggressive language, clear status)
- No complex analytics needed

## Implementation Status

- Started: 2026-02-07
- Completed: 2026-02-07

## Files Created/Modified

### Backend

1. **apps/api/src/credentials/dto/query-credential-audit.dto.ts** (NEW)
   - QueryCredentialAuditDto with filters: credentialId, action, startDate, endDate, page, limit
   - Validation with class-validator decorators
   - Default page=1, limit=20, max limit=100

2. **apps/api/src/credentials/dto/index.ts** (MODIFIED)
   - Exported QueryCredentialAuditDto

3. **apps/api/src/credentials/credentials.service.ts** (MODIFIED)
   - Added getAuditLog() method
   - Filters by workspaceId and entityType=CREDENTIAL
   - Returns paginated audit logs with user info
   - Supports filtering by credentialId, action, and date range
   - Returns metadata: total, page, limit, totalPages

4. **apps/api/src/credentials/credentials.controller.ts** (MODIFIED)
   - Added GET /api/credentials/audit endpoint
   - Placed before parameterized routes to avoid path conflicts
   - Requires WORKSPACE_ANY permission (all members can view)
   - Uses existing WorkspaceGuard for RLS enforcement

5. **apps/api/src/credentials/credentials.service.spec.ts** (MODIFIED)
   - Added 8 comprehensive tests for getAuditLog():
     - Returns paginated results
     - Filters by credentialId
     - Filters by action type
     - Filters by date range
     - Handles pagination correctly
     - Orders by createdAt descending
     - Always filters by CREDENTIAL entityType

### Frontend

1. **apps/web/src/lib/api/credentials.ts** (MODIFIED)
   - Added AuditLogEntry interface
   - Added QueryAuditLogDto interface
   - Added fetchCredentialAuditLog() function
   - Builds query string with optional parameters

2. **apps/web/src/app/(authenticated)/settings/credentials/audit/page.tsx** (NEW)
   - Full audit log viewer page component
   - Features:
     - Filter by action type (dropdown with 5 options)
     - Filter by date range (start and end date inputs)
     - Pagination (20 items per page)
     - Desktop table layout with responsive mobile cards
     - PDA-friendly timestamp formatting
     - Action badges with color coding
     - User information display (name + email)
     - Details display (credential name, provider)
     - Empty state handling
     - Error state handling

3. **apps/web/src/app/(authenticated)/settings/credentials/page.tsx** (MODIFIED)
   - Added History icon import
   - Added Link import for next/link
   - Added "Audit Log" button linking to /settings/credentials/audit
   - Button positioned in header next to "Add Credential"

## Design Decisions

1. **Activity Type Filtering**: Shows 5 main action types (CREATED, ACCESSED, ROTATED, REVOKED, UPDATED)
2. **Pagination**: Default 20 items per page (good balance for both mobile and desktop)
3. **PDA-Friendly Design**:
   - No aggressive language
   - Clear status indicators with colors
   - Responsive layout for all screen sizes
   - Timestamps in readable format
4. **Mobile Support**: Separate desktop table and mobile card layouts
5. **Reused Patterns**: Activity service already handles entity filtering

## Test Coverage

- Backend: 25 tests all passing
- Unit tests cover all major scenarios
- Tests use mocked PrismaService and ActivityService
- Async/parallel query testing included

## Notes

- Stretch goal kept simple and pragmatic
- Reused existing ActivityLog and ActivityService patterns
- RLS enforcement via existing WorkspaceGuard
- No complex analytics or exports needed
- All timestamps handled via browser Intl API for localization

## Build Status

- ✅ API builds successfully (`pnpm build` in apps/api)
- ✅ Web builds successfully (`pnpm build` in apps/web)
- ✅ All backend unit tests passing (25/25)
- ✅ TypeScript compilation successful for both apps

## Endpoints Implemented

- **GET /api/credentials/audit** - Fetch audit logs with filters
  - Query params: credentialId, action, startDate, endDate, page, limit
  - Response: Paginated audit logs with user info
  - Authentication: Required (WORKSPACE_ANY permission)

## Frontend Routes Implemented

- **GET /settings/credentials** - Credentials management page (updated with audit log link)
- **GET /settings/credentials/audit** - Credential audit log viewer page

## API Client Functions

- `fetchCredentialAuditLog(workspaceId, query?)` - Get paginated audit logs with optional filters
