feat(#119): GenerateProofOfApplicationUseCase 추가

- GenerateProofOfApplicationUseCase를 추가했어요.

src/main/java/com/bamdoliro/maru/application/form/GenerateProofOfApplicationUseCase.java

@@ -0,0 +1,52 @@
+package com.bamdoliro.maru.application.form;
+
+import com.bamdoliro.maru.domain.form.domain.Form;
+import com.bamdoliro.maru.domain.form.exception.InvalidFormStatusException;
+import com.bamdoliro.maru.domain.form.service.FormFacade;
+import com.bamdoliro.maru.domain.user.domain.User;
+import com.bamdoliro.maru.infrastructure.pdf.GeneratePdfService;
+import com.bamdoliro.maru.infrastructure.s3.FileService;
+import com.bamdoliro.maru.infrastructure.s3.constants.FolderConstant;
+import com.bamdoliro.maru.infrastructure.thymeleaf.ProcessTemplateService;
+import com.bamdoliro.maru.infrastructure.thymeleaf.Templates;
+import com.bamdoliro.maru.shared.annotation.UseCase;
+import com.bamdoliro.maru.shared.constants.Schedule;
+import lombok.RequiredArgsConstructor;
+import org.springframework.core.io.ByteArrayResource;
+
+import java.io.ByteArrayOutputStream;
+import java.util.Map;
+
+import static com.bamdoliro.maru.shared.constants.Schedule.ANNOUNCEMENT_OF_FIRST_PASS;
+
+@RequiredArgsConstructor
+@UseCase
+public class GenerateProofOfApplicationUseCase {
+
+    private final FormFacade formFacade;
+    private final ProcessTemplateService processTemplateService;
+    private final GeneratePdfService generatePdfService;
+    private final FileService fileService;
+
+    public ByteArrayResource execute(User user) {
+        Form form = formFacade.getForm(user);
+        validateFormStatus(form);
+
+        Map<String, Object> formMap = Map.of(
+                "form", form,
+                "year", Schedule.getAdmissionYear(),
+                "announcement_of_first_pass", Schedule.toLocaleString(ANNOUNCEMENT_OF_FIRST_PASS),
+                "identificationPictureUri", fileService.getPresignedUrl(FolderConstant.IDENTIFICATION_PICTURE, user.getUuid().toString()).getDownloadUrl()
+        );
+        String html = processTemplateService.execute(Templates.PROOF_OF_APPLICATION, formMap);
+        ByteArrayOutputStream outputStream = generatePdfService.execute(html);
+
+        return new ByteArrayResource(outputStream.toByteArray());
+    }
+
+    private void validateFormStatus(Form form) {
+        if (form.isSubmitted()) {
+            throw new InvalidFormStatusException();
+        }
+    }
+}