# Task 1 Report: Source Metadata Schema And Identity Helpers

## Outcome
- Implemented Task 1 in `go/vehicle-gateway/internal/stats`.
- Added source metadata schema, identity helpers, and focused tests.

## RED Evidence
Initial focused test run failed as expected because the new helpers did not exist yet:

```bash
cd /Users/lingniu/project/ai-coding/lingniu-vehicle-ingest/go/vehicle-gateway
go test ./internal/stats -run 'TestNormalizeSourceIP|TestNewSourceIdentity|TestUpsertDataSource' -count=1
```

Result:
- `undefined: NormalizeSourceIP`
- `undefined: NewSourceIdentity`
- `undefined: SourceIdentity`
- `undefined: UpsertDataSource`

## GREEN Evidence
After implementation, the focused tests passed:

```bash
cd /Users/lingniu/project/ai-coding/lingniu-vehicle-ingest/go/vehicle-gateway
go test ./internal/stats -run 'TestNormalizeSourceIP|TestNewSourceIdentity|TestUpsertDataSource' -count=1
```

Result:
- `ok  	lingniu-vehicle-ingest/go/vehicle-gateway/internal/stats	0.927s`

Full package verification also passed:

```bash
cd /Users/lingniu/project/ai-coding/lingniu-vehicle-ingest/go/vehicle-gateway
go test ./internal/stats -count=1
```

Result:
- `ok  	lingniu-vehicle-ingest/go/vehicle-gateway/internal/stats	0.355s`

## Files Changed
- `go/vehicle-gateway/internal/stats/schema.go`
- `go/vehicle-gateway/internal/stats/source.go`
- `go/vehicle-gateway/internal/stats/source_test.go`

## Notes
- `DataSourceTableSQL` was added verbatim to `schema.go` for the future schema wiring step.
- `UpsertDataSource` follows the brief exactly, including the nil exec panic, empty-source short circuit, and SQL shape.

## Self-Review
- The implementation is tightly scoped to Task 1.
- The new tests cover IP normalization, identity construction, and the SQL shape for the upsert helper.
- No additional concerns at this stage.