Spring Boot Integration

documentstack:
  api-key: ${DS_API_KEY}
  base-url: https://api.documentstack.dev/api/v1

@Configuration
@ConfigurationProperties(prefix = "documentstack")
public class DocumentStackConfig {
    private String apiKey;
    private String baseUrl;

    // getters and setters

    @Bean
    public RestClient documentStackClient() {
        return RestClient.builder()
            .baseUrl(baseUrl)
            .defaultHeader("Authorization", "Bearer " + apiKey)
            .defaultHeader("Content-Type", "application/json")
            .build();
    }
}

@Service
public class DocumentStackService {

    private final RestClient client;

    public DocumentStackService(RestClient documentStackClient) {
        this.client = documentStackClient;
    }

    public GenerateResponse generate(String templateId, Map<String, Object> data) {
        var request = Map.of(
            "templateId", templateId,
            "data", data
        );

        return client.post()
            .uri("/generate")
            .body(request)
            .retrieve()
            .body(GenerateResponse.class);
    }

    public byte[] downloadPdf(String templateId, Map<String, Object> data) {
        var result = generate(templateId, data);
        return client.get()
            .uri(result.getData().getUrl())
            .retrieve()
            .body(byte[].class);
    }
}

public record GenerateResponse(
    boolean success,
    GenerateData data
) {
    public record GenerateData(
        String url,
        String id
    ) {}
}

@RestController
@RequestMapping("/api/pdf")
public class PdfController {

    private final DocumentStackService dsService;

    public PdfController(DocumentStackService dsService) {
        this.dsService = dsService;
    }

    @PostMapping("/generate")
    public ResponseEntity<?> generate(@RequestBody GenerateRequest request) {
        var result = dsService.generate(
            request.templateId(),
            request.data()
        );
        return ResponseEntity.ok(result);
    }

    @GetMapping("/download/{templateId}")
    public ResponseEntity<byte[]> download(@PathVariable String templateId) {
        byte[] pdf = dsService.downloadPdf(templateId, Map.of());

        return ResponseEntity.ok()
            .header("Content-Type", "application/pdf")
            .header("Content-Disposition",
                "attachment; filename=\"document.pdf\"")
            .body(pdf);
    }
}

record GenerateRequest(String templateId, Map<String, Object> data) {}

@RestControllerAdvice
public class DocumentStackErrorHandler {

    @ExceptionHandler(RestClientResponseException.class)
    public ResponseEntity<?> handleDsError(RestClientResponseException ex) {
        return ResponseEntity
            .status(ex.getStatusCode())
            .body(Map.of(
                "success", false,
                "error", "PDF generation failed: " + ex.getMessage()
            ));
    }
}