# Acceptance Criteria

## Tile Download

| # | Criterion | Measurable Value | Source |
|---|----------|-----------------|--------|
| T1 | Tiles are cached and not re-downloaded | 0 duplicate downloads for same (lat, lon, zoom, version) | Unique index idx_tiles_unique_location |
| T2 | Concurrent download limit is enforced | Max 4 simultaneous HTTP requests to Google Maps | ProcessingConfig.MaxConcurrentDownloads |
| T3 | Tile stored on disk with correct path | File exists at `./tiles/{zoom}/{x}/{y}.jpg` | TileService storage logic |
| T4 | Tile metadata persisted in database | TileEntity row created with all fields populated | TileRepository.InsertAsync |

## Region Processing

| # | Criterion | Measurable Value | Source |
|---|----------|-----------------|--------|
| R1 | Region transitions through correct states | pending → processing → completed (or failed) | RegionProcessingService state updates |
| R2 | CSV manifest generated on completion | File exists at `./ready/region_{id}_ready.csv` | RegionService.ProcessRegionAsync |
| R3 | Summary file generated on completion | File exists at `./ready/region_{id}_summary.txt` | RegionService.GenerateSummaryFileAsync |
| R4 | Stitched image generated when requested | File exists at `./ready/region_{id}_stitched.jpg` when stitch_tiles=true | RegionService.StitchTilesAsync |
| R5 | Stitched image has valid content | File size > 1024 bytes | Integration test assertion |
| R6 | Region processing is bounded | Max 20 concurrent regions | ProcessingConfig.MaxConcurrentRegions |

## Route Management

| # | Criterion | Measurable Value | Source |
|---|----------|-----------------|--------|
| RT1 | Points interpolated at correct interval | Intermediate points every ~200m along path | RouteService (InterpolatePoints) |
| RT2 | Point types correctly assigned | "original" for input waypoints, "intermediate" for generated | RoutePointEntity.PointType |
| RT3 | Total distance calculated | Haversine sum matches within acceptable precision | RouteService.CreateRoute |
| RT4 | Geofence filtering applied | Only points inside geofence rectangles generate regions | RouteService (point-in-rectangle check) |
| RT5 | ZIP archive within size limit | ≤ 50 MB | RouteProcessingService ZIP generation |
| RT6 | Route map stitched when maps requested | Stitched image > 1024 bytes when request_maps=true | Integration test assertion |

## API Behavior

| # | Criterion | Measurable Value | Source |
|---|----------|-----------------|--------|
| A1 | Region request returns immediately | HTTP 200 with region_id (async processing) | POST /api/satellite/request |
| A2 | Status endpoint reflects real state | Returns current status and file paths | GET /api/satellite/region/{id} |
| A3 | Route creation returns computed metadata | Response includes total_points, total_distance_meters | POST /api/satellite/route |

## System Reliability

| # | Criterion | Measurable Value | Source |
|---|----------|-----------------|--------|
| S1 | Database migrations run on startup | All numbered scripts executed in order | DatabaseMigrator.Migrate() |
| S2 | Queue rejects when full | Channel capacity = 1000, bounded wait | RegionRequestQueue (BoundedChannelOptions) |
| S3 | Failed regions marked as failed | Status = "failed" on unrecoverable error | RegionProcessingService error handling |