@Component
@RequiredArgsConstructor
public class HotspotDownloader {
    private final WebClient client;

    @Scheduled(fixedDelayString = "${app.pull-interval}")
    public void pullLatestCsv() {
        client.get()
              .uri("")
              .retrieve()
              .bodyToFlux(String.class)
              .flatMap(HotspotParser::parse)
              .subscribe(HotspotService::handle);
    }
}

public class HotspotParser {
    private static final ColumnPositionMappingStrategy<HotspotEvent> strat =
        new ColumnPositionMappingStrategy<>();
    static {
        strat.setType(HotspotEvent.class);
        strat.setColumnMapping("satTs","lat","lon","confidence");
    }
    public static Flux<HotspotEvent> parse(String csv) {
        return Flux.using(
            () -> new CSVReader(new StringReader(csv)),
            r -> Flux.fromIterable(new CsvToBeanBuilder<HotspotEvent>(r)
                    .withMappingStrategy(strat)
                    .build().parse()),
            CSVReader::close);
    }
}

@Service
public class HotspotService {
    private final List<PreparedGeometry> farms;
    private final AlertService alertService;

    public HotspotService(@Value("classpath:geo/farm.geojson") Resource r) throws IOException {
        GeometryJSON gjson = new GeometryJSON();
        try (Reader rd = new InputStreamReader(r.getInputStream())) {
            Geometry farm = gjson.read(rd);
            this.farms = List.of(new PreparedGeometryFactory().create(farm));
        }
    }
    public void handle(HotspotEvent e) {
        farms.stream()
             .filter(pg -> pg.contains(e.toPoint()))
             .findFirst()
             .ifPresent(pg -> alertService.createAlert(e));
    }
}

@Entity @Table(name = "alerts")
@Data @NoArgsConstructor @AllArgsConstructor
public class Alert {
    @Id @GeneratedValue private UUID id;
    private double lat;
    private double lon;
    private LocalDateTime timestamp;
}

@Repository
public interface AlertRepository extends CrudRepository<Alert, UUID> {
    List<Alert> findTop100ByOrderByTimestampDesc();
}

@RestController
@RequiredArgsConstructor
@RequestMapping("/alerts")
public class AlertController {
    private final AlertRepository repo;

    @GetMapping
    public List<Alert> latest() {
        return repo.findTop100ByOrderByTimestampDesc();
    }
}

@Controller
@RequiredArgsConstructor
public class UiController {
    private final AlertRepository repo;

    @GetMapping("/")
    public String home(Model m) {
        m.addAttribute("alerts", repo.findTop100ByOrderByTimestampDesc());
        return "alerts";
    }
}

@Service
@RequiredArgsConstructor
public class EmailService {
    private final JavaMailSender mail;
    public void notify(Alert a) {
        SimpleMailMessage msg = new SimpleMailMessage();
        msg.setTo("manager@mill.com");
        msg.setSubject("🔥 Sugar‑cane fire detected");
        msg.setText(String.format(
            "Hotspot at %.4f, %.4f on %s%nMap: https://maps.google.com/?q=%f,%f",
            a.getLat(), a.getLon(), a.getTimestamp(), a.getLat(), a.getLon()));
        mail.send(msg);
    }
}