Align apartment document upload validation (#51)

backend/src/main/java/fr/nessar/lmnporganizer/rental/adapter/in/web/apartment/ApartmentDocumentApi.java

@@ -1,12 +1,76 @@
 package fr.nessar.lmnporganizer.rental.adapter.in.web.apartment;
 
 import fr.nessar.lmnporganizer.rental.domain.apartment.ApartmentDocument;
+import fr.nessar.lmnporganizer.rental.domain.apartment.ApartmentDocumentType;
 import java.time.Instant;
 import java.time.LocalDate;
+import java.time.format.DateTimeParseException;
+import java.util.ArrayList;
+import java.util.List;
 
 final class ApartmentDocumentApi {
 private ApartmentDocumentApi() {}
 
+record UploadRequest(String type, String establishedOn, String expiresOn) {
+	List<FieldValidationError> validationErrors() {
+	List<FieldValidationError> errors = new ArrayList<>();
+	if (blank(type)) {
+		errors.add(new FieldValidationError("type", "required"));
+	} else if (documentType() == null) {
+		errors.add(new FieldValidationError("type", "invalid"));
+	}
+	if (blank(establishedOn)) {
+		errors.add(new FieldValidationError("establishedOn", "required"));
+	} else if (establishmentDate() == null) {
+		errors.add(new FieldValidationError("establishedOn", "invalid"));
+	}
+	if (expiresOn != null && expiryDate() == null) {
+		errors.add(new FieldValidationError("expiresOn", "invalid"));
+	}
+	if (establishmentDate() != null
+		&& expiryDate() != null
+		&& expiryDate().isBefore(establishmentDate())) {
+		errors.add(new FieldValidationError("expiresOn", "before_establishment"));
+	}
+	return errors;
+	}
+
+	private static boolean blank(String value) {
+	return value == null || value.isBlank();
+	}
+
+	ApartmentDocumentType documentType() {
+	try {
+		return ApartmentDocumentType.fromCode(type);
+	} catch (IllegalArgumentException exception) {
+		return null;
+	}
+	}
+
+	LocalDate establishmentDate() {
+	return date(establishedOn);
+	}
+
+	LocalDate expiryDate() {
+	return expiresOn == null || expiresOn.isBlank() ? null : date(expiresOn);
+	}
+
+	private static LocalDate date(String value) {
+	if (value == null || value.isBlank()) {
+		return null;
+	}
+	try {
+		return LocalDate.parse(value);
+	} catch (DateTimeParseException exception) {
+		return null;
+	}
+	}
+}
+
+record ValidationErrorResponse(String code, List<FieldValidationError> errors) {}
+
+record FieldValidationError(String field, String code) {}
+
 record Response(
 	String id,
 	String type,

backend/src/main/java/fr/nessar/lmnporganizer/rental/adapter/in/web/apartment/ApartmentDocumentController.java

@@ -3,10 +3,9 @@ package fr.nessar.lmnporganizer.rental.adapter.in.web.apartment;
 import fr.nessar.lmnporganizer.rental.adapter.in.web.common.AuthenticatedLandlord;
 import fr.nessar.lmnporganizer.rental.application.apartment.ApartmentDocumentService;
 import fr.nessar.lmnporganizer.rental.application.shared.AttachmentStorageFailure;
-import fr.nessar.lmnporganizer.rental.domain.apartment.ApartmentDocumentType;
 import fr.nessar.lmnporganizer.rental.domain.apartment.ApartmentId;
 import java.io.IOException;
-import java.time.LocalDate;
+import java.util.ArrayList;
 import java.util.List;
 import org.springframework.http.ContentDisposition;
 import org.springframework.http.HttpHeaders;
@@ -16,6 +15,7 @@ import org.springframework.http.ResponseEntity;
 import org.springframework.security.core.annotation.AuthenticationPrincipal;
 import org.springframework.security.oauth2.core.oidc.user.OidcUser;
 import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
@@ -51,17 +51,27 @@ List<ApartmentDocumentApi.Response> list(
 ResponseEntity<ApartmentDocumentApi.Response> upload(
 	@AuthenticationPrincipal OidcUser principal,
 	@PathVariable String apartmentId,
-	@RequestParam String type,
-	@RequestParam LocalDate establishedOn,
-	@RequestParam(required = false) LocalDate expiresOn,
-	@RequestPart("file") MultipartFile file) {
+	@RequestParam(required = false) String type,
+	@RequestParam(required = false) String establishedOn,
+	@RequestParam(required = false) String expiresOn,
+	@RequestPart(value = "file", required = false) MultipartFile file) {
+	ApartmentDocumentApi.UploadRequest request =
+		new ApartmentDocumentApi.UploadRequest(type, establishedOn, expiresOn);
+	List<ApartmentDocumentApi.FieldValidationError> errors =
+		new ArrayList<>(request.validationErrors());
+	if (file == null || file.isEmpty()) {
+	errors.add(new ApartmentDocumentApi.FieldValidationError("file", "required"));
+	}
+	if (!errors.isEmpty()) {
+	throw new UploadValidationFailure(errors);
+	}
 	var stored =
 		documents.upload(
 			authenticatedLandlord.id(principal),
 			new ApartmentId(apartmentId),
-			ApartmentDocumentType.fromCode(type),
-			establishedOn,
-			expiresOn,
+			request.documentType(),
+			request.establishmentDate(),
+			request.expiryDate(),
 			upload(file),
 			principal.getSubject());
 	return ResponseEntity.status(HttpStatus.CREATED)
@@ -98,6 +108,15 @@ ResponseEntity<Void> delete(
 	return ResponseEntity.noContent().build();
 }
 
+@ExceptionHandler(UploadValidationFailure.class)
+ResponseEntity<ApartmentDocumentApi.ValidationErrorResponse> invalidUpload(
+	UploadValidationFailure failure) {
+	return ResponseEntity.badRequest()
+		.body(
+			new ApartmentDocumentApi.ValidationErrorResponse(
+				"validation_failed", failure.errors()));
+}
+
 private static ApartmentDocumentService.PdfUpload upload(MultipartFile file) {
 	try {
 	return new ApartmentDocumentService.PdfUpload(
@@ -106,4 +125,16 @@ private static ApartmentDocumentService.PdfUpload upload(MultipartFile file) {
 	throw new AttachmentStorageFailure("Apartment document could not be opened.", failure);
 	}
 }
+
+private static final class UploadValidationFailure extends RuntimeException {
+	private final List<ApartmentDocumentApi.FieldValidationError> errors;
+
+	private UploadValidationFailure(List<ApartmentDocumentApi.FieldValidationError> errors) {
+	this.errors = List.copyOf(errors);
+	}
+
+	private List<ApartmentDocumentApi.FieldValidationError> errors() {
+	return errors;
+	}
+}
 }

backend/src/test/java/fr/nessar/lmnporganizer/rental/adapter/in/web/apartment/ApartmentDocumentWebTest.java

@@ -112,6 +112,43 @@ void uploadUsesTheAuthenticatedScopeAndNativeMultipartFields() throws Exception
 			org.mockito.ArgumentMatchers.eq("subject-1"));
 }
 
+@Test
+void uploadReturnsStableFieldErrorsForInvalidMetadata() throws Exception {
+	MockMultipartFile file =
+		new MockMultipartFile("file", "dpe.pdf", MediaType.APPLICATION_PDF_VALUE, PDF);
+
+	mockMvc
+		.perform(
+			multipart("/api/apartments/apartment-1/documents")
+				.file(file)
+				.param("type", "UNKNOWN")
+				.param("establishedOn", "2026-07-02")
+				.param("expiresOn", "2026-07-01")
+				.with(owner())
+				.with(csrf()))
+		.andExpect(status().isBadRequest())
+		.andExpect(jsonPath("$.code").value("validation_failed"))
+		.andExpect(jsonPath("$.errors[0].field").value("type"))
+		.andExpect(jsonPath("$.errors[0].code").value("invalid"))
+		.andExpect(jsonPath("$.errors[1].field").value("expiresOn"))
+		.andExpect(jsonPath("$.errors[1].code").value("before_establishment"));
+}
+
+@Test
+void uploadReportsAMissingMultipartFileAsAFieldError() throws Exception {
+	mockMvc
+		.perform(
+			multipart("/api/apartments/apartment-1/documents")
+				.param("type", "DPE")
+				.param("establishedOn", "2026-07-01")
+				.with(owner())
+				.with(csrf()))
+		.andExpect(status().isBadRequest())
+		.andExpect(jsonPath("$.code").value("validation_failed"))
+		.andExpect(jsonPath("$.errors[0].field").value("file"))
+		.andExpect(jsonPath("$.errors[0].code").value("required"));
+}
+
 @Test
 void downloadReturnsPdfBytesWithASafeAttachmentHeader() throws Exception {
 	when(documents.download(LANDLORD_ID, APARTMENT_ID, "document-1"))

backend/src/test/java/fr/nessar/lmnporganizer/rental/application/apartment/ApartmentDocumentServiceTest.java

@@ -113,6 +113,26 @@ void uploadReplacesTheCurrentDocumentOfTheSameTypeWithAStagedDeletion() {
 	verify(storage, never()).restore(deletion);
 }
 
+@Test
+void uploadAcceptsPdfMimeAndSignatureWithoutAPdfFileExtension() {
+	when(identifiers.next()).thenReturn("document-1");
+	when(storage.store(PDF)).thenReturn("storage-1");
+	when(apartments.save(apartment)).thenReturn(apartment);
+
+	ApartmentDocument document =
+		service(10_000)
+			.upload(
+				LANDLORD_ID,
+				APARTMENT_ID,
+				ApartmentDocumentType.ENERGY_PERFORMANCE_DIAGNOSIS,
+				LocalDate.of(2026, 7, 19),
+				null,
+				upload("dpe", "application/pdf", PDF),
+				"subject-1");
+
+	assertEquals("dpe.pdf", document.fileName());
+}
+
 @Test
 void uploadRestoresTheReplacedFileAndDiscardsTheNewFileWhenSavingMetadataFails() {
 	ApartmentDocument previous =

frontend/src/app/components/apartment-document-manager/apartment-document-manager.html

@@ -93,18 +93,28 @@
 		<fieldset [disabled]="uploading()">
 			<mat-form-field appearance="outline">
 				<mat-label>Type de document</mat-label>
-				<mat-select [formField]="uploadForm.type">
+				<mat-select
+					[formField]="uploadForm.type"
+					(selectionChange)="clearUploadFieldError('type')"
+				>
 					<mat-option value="">Choisissez un type</mat-option>
 					@for (type of documentTypes; track type.value) {
 						<mat-option [value]="type.value">{{ type.label }}</mat-option>
 					}
 				</mat-select>
 			</mat-form-field>
+			@if (fieldError('type'); as error) {
+				<p class="form-error" role="alert">{{ error }}</p>
+			}
 			<label class="file-picker">
 				<span>Fichier PDF</span>
-				<input type="file" accept=".pdf,application/pdf" (change)="selectFile($event)" />
+				<input type="file" accept="application/pdf" (change)="selectFile($event)" />
 				<small>{{ selectedFile()?.name ?? 'Aucun fichier sélectionné' }}</small>
+				<small>Le type et le contenu PDF sont vérifiés avant l’envoi.</small>
 			</label>
+			@if (fieldError('file'); as error) {
+				<p class="form-error" role="alert">{{ error }}</p>
+			}
 			<div class="date-fields">
 				<mat-form-field appearance="outline">
 					<mat-label>Date d’établissement</mat-label>
@@ -112,16 +122,29 @@
 						matInput
 						id="establishedOn"
 						type="date"
+						(input)="clearUploadFieldError('establishedOn')"
 						[formField]="uploadForm.establishedOn"
 					/>
 				</mat-form-field>
+				@if (fieldError('establishedOn'); as error) {
+					<p class="form-error" role="alert">{{ error }}</p>
+				}
 				<mat-form-field appearance="outline">
 					<mat-label>Date d’expiration (facultative)</mat-label>
-					<input matInput id="expiresOn" type="date" [formField]="uploadForm.expiresOn" />
+					<input
+						matInput
+						id="expiresOn"
+						type="date"
+						(input)="clearUploadFieldError('expiresOn')"
+						[formField]="uploadForm.expiresOn"
+					/>
 				</mat-form-field>
+				@if (fieldError('expiresOn'); as error) {
+					<p class="form-error" role="alert">{{ error }}</p>
+				}
 			</div>
-			@if (validationError() || uploadError()) {
-				<p class="form-error" role="alert">{{ validationError() || uploadError() }}</p>
+			@if (uploadError()) {
+				<p class="form-error" role="alert">{{ uploadError() }}</p>
 			}
 			<button
 				mat-flat-button

frontend/src/app/components/apartment-document-manager/apartment-document-manager.spec.ts

@@ -83,6 +83,25 @@ describe('ApartmentDocumentManager', () => {
 		http.expectNone((request) => request.method === 'POST');
 	});
 
+	it('shows every local upload error and focuses the first invalid control', () => {
+		const fixture = TestBed.createComponent(ApartmentDocumentManager);
+		fixture.componentRef.setInput('apartmentId', 'apartment-1');
+		fixture.detectChanges();
+		http.expectOne('/api/apartments/apartment-1/documents').flush([]);
+		fixture.detectChanges();
+
+		fixture.nativeElement.querySelector('.upload-submit').click();
+		fixture.detectChanges();
+
+		expect(fixture.nativeElement.textContent).toContain('Choisissez un type de document.');
+		expect(fixture.nativeElement.textContent).toContain('Sélectionnez un fichier PDF.');
+		expect(fixture.nativeElement.textContent).toContain(
+			'Renseignez une date d’établissement valide.',
+		);
+		expect(document.activeElement).toBe(fixture.nativeElement.querySelector('mat-select'));
+		http.expectNone((request) => request.method === 'POST');
+	});
+
 	it('requires a PDF after the document type is selected', async () => {
 		const fixture = TestBed.createComponent(ApartmentDocumentManager);
 		fixture.componentRef.setInput('apartmentId', 'apartment-1');
@@ -120,7 +139,7 @@ describe('ApartmentDocumentManager', () => {
 		);
 		if (!dpeOption) throw new Error('Option DPE introuvable.');
 		(dpeOption as HTMLElement).click();
-		const file = new File(['pdf'], 'dpe.pdf', { type: 'application/pdf' });
+		const file = new File(['%PDF-document'], 'dpe.pdf', { type: 'application/pdf' });
 		const fileInput: HTMLInputElement = fixture.nativeElement.querySelector('input[type=file]');
 		Object.defineProperty(fileInput, 'files', {
 			configurable: true,
@@ -133,7 +152,7 @@ describe('ApartmentDocumentManager', () => {
 		fixture.detectChanges();
 
 		expect(fixture.nativeElement.textContent).toContain(
-			'Renseignez la date d’établissement du document.',
+			'Renseignez une date d’établissement valide.',
 		);
 		http.expectNone((request) => request.method === 'POST');
 	});
@@ -152,7 +171,7 @@ describe('ApartmentDocumentManager', () => {
 		);
 		if (!dpeOption) throw new Error('Option DPE introuvable.');
 		(dpeOption as HTMLElement).click();
-		const file = new File(['pdf'], 'dpe.pdf', { type: 'application/pdf' });
+		const file = new File(['%PDF-document'], 'dpe.pdf', { type: 'application/pdf' });
 		const fileInput: HTMLInputElement = fixture.nativeElement.querySelector('input[type=file]');
 		Object.defineProperty(fileInput, 'files', {
 			configurable: true,
@@ -192,7 +211,7 @@ describe('ApartmentDocumentManager', () => {
 		);
 		if (!dpeOption) throw new Error('Option DPE introuvable.');
 		(dpeOption as HTMLElement).click();
-		const file = new File(['pdf'], 'dpe-2026.pdf', { type: 'application/pdf' });
+		const file = new File(['%PDF-document'], 'dpe-2026', { type: 'application/pdf' });
 		const fileInput: HTMLInputElement = fixture.nativeElement.querySelector('input[type=file]');
 		Object.defineProperty(fileInput, 'files', {
 			configurable: true,
@@ -234,6 +253,116 @@ describe('ApartmentDocumentManager', () => {
 		expect(submit.disabled).toBe(false);
 	});
 
+	it('accepts a PDF MIME type and signature without relying on the file name', async () => {
+		const fixture = TestBed.createComponent(ApartmentDocumentManager);
+		fixture.componentRef.setInput('apartmentId', 'apartment-1');
+		fixture.detectChanges();
+		http.expectOne('/api/apartments/apartment-1/documents').flush([]);
+		fixture.detectChanges();
+
+		const file = new File(['%PDF-document'], 'dpe', { type: 'application/pdf' });
+		const fileInput: HTMLInputElement = fixture.nativeElement.querySelector('input[type=file]');
+		Object.defineProperty(fileInput, 'files', {
+			configurable: true,
+			value: { item: () => file },
+		});
+		fileInput.dispatchEvent(new Event('change'));
+		await fixture.whenStable();
+
+		expect(fixture.componentInstance.selectedFile()).toBe(file);
+	});
+
+	it('rejects a filename-only PDF before upload', async () => {
+		const fixture = TestBed.createComponent(ApartmentDocumentManager);
+		fixture.componentRef.setInput('apartmentId', 'apartment-1');
+		fixture.detectChanges();
+		http.expectOne('/api/apartments/apartment-1/documents').flush([]);
+		fixture.detectChanges();
+
+		const file = new File(['%PDF-document'], 'dpe.pdf', { type: '' });
+		const fileInput: HTMLInputElement = fixture.nativeElement.querySelector('input[type=file]');
+		Object.defineProperty(fileInput, 'files', {
+			configurable: true,
+			value: { item: () => file },
+		});
+		fileInput.dispatchEvent(new Event('change'));
+		await fixture.whenStable();
+		fixture.detectChanges();
+
+		expect(fixture.componentInstance.selectedFile()).toBeNull();
+		expect(fixture.nativeElement.textContent).toContain('Sélectionnez un fichier PDF valide.');
+	});
+
+	it('keeps the replacement form and existing document after a failed upload', () => {
+		const fixture = TestBed.createComponent(ApartmentDocumentManager);
+		fixture.componentRef.setInput('apartmentId', 'apartment-1');
+		fixture.detectChanges();
+		http.expectOne('/api/apartments/apartment-1/documents').flush([
+			{
+				id: 'document-1',
+				type: 'DPE',
+				establishedOn: '2026-07-19',
+				expiresOn: null,
+				fileName: 'dpe-existant.pdf',
+				sha256: 'a'.repeat(64),
+				authorId: 'owner-1',
+				uploadedAt: '2026-07-19T10:00:00Z',
+			},
+		]);
+		const file = new File(['%PDF-document'], 'dpe-2026', { type: 'application/pdf' });
+		fixture.componentInstance.uploadModel.set({
+			type: 'DPE',
+			establishedOn: '2026-07-20',
+			expiresOn: '',
+		});
+		fixture.componentInstance.selectedFile.set(file);
+		fixture.componentInstance.submitUpload();
+
+		const upload = http.expectOne('/api/apartments/apartment-1/documents');
+		upload.flush(
+			{
+				code: 'validation_failed',
+				errors: [{ field: 'establishedOn', code: 'invalid' }],
+			},
+			{ status: 400, statusText: 'Bad Request' },
+		);
+		fixture.detectChanges();
+
+		expect(fixture.nativeElement.textContent).toContain('dpe-existant.pdf');
+		expect(fixture.componentInstance.uploadModel()).toEqual({
+			type: 'DPE',
+			establishedOn: '2026-07-20',
+			expiresOn: '',
+		});
+		expect(fixture.componentInstance.selectedFile()).toBe(file);
+		expect(fixture.nativeElement.textContent).toContain(
+			'Renseignez une date d’établissement valide.',
+		);
+		expect(fixture.nativeElement.textContent).not.toContain(
+			'Veuillez corriger les champs signalés.',
+		);
+		expect(document.activeElement).toBe(fixture.nativeElement.querySelector('#establishedOn'));
+	});
+
+	it('clears only the corrected upload field error', () => {
+		const fixture = TestBed.createComponent(ApartmentDocumentManager);
+		fixture.componentRef.setInput('apartmentId', 'apartment-1');
+		fixture.detectChanges();
+		http.expectOne('/api/apartments/apartment-1/documents').flush([]);
+		fixture.componentInstance.uploadFieldErrors.set([
+			{ field: 'type', code: 'invalid' },
+			{ field: 'establishedOn', code: 'invalid' },
+			{ field: 'expiresOn', code: 'before_establishment' },
+		]);
+
+		fixture.componentInstance.clearUploadFieldError('establishedOn');
+
+		expect(fixture.componentInstance.uploadFieldErrors()).toEqual([
+			{ field: 'type', code: 'invalid' },
+			{ field: 'expiresOn', code: 'before_establishment' },
+		]);
+	});
+
 	it('shows a load failure and retries without presenting an empty result', () => {
 		const fixture = TestBed.createComponent(ApartmentDocumentManager);
 		fixture.componentRef.setInput('apartmentId', 'apartment-1');
@@ -334,4 +463,38 @@ describe('ApartmentDocumentManager', () => {
 		expect(fixture.nativeElement.textContent).not.toContain('dpe.pdf');
 		expect(fixture.nativeElement.textContent).toContain('Aucun document enregistré.');
 	});
+
+	it('keeps a document visible when its deletion fails', async () => {
+		const fixture = TestBed.createComponent(ApartmentDocumentManager);
+		fixture.componentRef.setInput('apartmentId', 'apartment-1');
+		fixture.detectChanges();
+		http.expectOne('/api/apartments/apartment-1/documents').flush([
+			{
+				id: 'document-1',
+				type: 'DPE',
+				establishedOn: '2026-07-19',
+				expiresOn: null,
+				fileName: 'dpe.pdf',
+				sha256: 'a'.repeat(64),
+				authorId: 'owner-1',
+				uploadedAt: '2026-07-19T10:00:00Z',
+			},
+		]);
+		fixture.detectChanges();
+		vi.useFakeTimers();
+
+		fixture.nativeElement.querySelector('.delete-document').click();
+		fixture.detectChanges();
+		const confirm: HTMLButtonElement | null = document.querySelector('.confirm-action');
+		if (!confirm) throw new Error('Confirmation de suppression introuvable.');
+		confirm.click();
+		await vi.runAllTimersAsync();
+
+		const request = http.expectOne('/api/apartments/apartment-1/documents/document-1');
+		request.flush({}, { status: 500, statusText: 'Server Error' });
+		fixture.detectChanges();
+
+		expect(fixture.nativeElement.textContent).toContain('dpe.pdf');
+		expect(fixture.nativeElement.textContent).toContain('Impossible de supprimer ce document.');
+	});
 });

frontend/src/app/components/apartment-document-manager/apartment-document-manager.ts

@@ -1,4 +1,4 @@
-import { Component, DestroyRef, effect, inject, input, signal } from '@angular/core';
+import { Component, DestroyRef, effect, ElementRef, inject, input, signal } from '@angular/core';
 import { takeUntilDestroyed } from '@angular/core/rxjs-interop';
 import { FormsModule } from '@angular/forms';
 import { FormField, FormRoot, form, required, validate } from '@angular/forms/signals';
@@ -13,7 +13,7 @@ import {
 	ApartmentDocumentType,
 	ApartmentService,
 } from '../../services/apartment.service';
-import { httpErrorMessage } from '../../services/http-error-message';
+import { FieldValidationError, saveFailure } from '../../services/http-error-message';
 import { ApartmentDocumentActions } from './apartment-document-actions.service';
 import {
 	apartmentDocumentTypeLabel,
@@ -27,6 +27,15 @@ const frenchDate = new Intl.DateTimeFormat('fr-FR', {
 	timeZone: 'UTC',
 });
 
+type UploadField = 'type' | 'file' | 'establishedOn' | 'expiresOn';
+type UploadFieldError = FieldValidationError & { field: UploadField };
+
+function isUploadField(field: string): field is UploadField {
+	return (
+		field === 'type' || field === 'file' || field === 'establishedOn' || field === 'expiresOn'
+	);
+}
+
 @Component({
 	selector: 'app-apartment-document-manager',
 	imports: [
@@ -46,6 +55,8 @@ const frenchDate = new Intl.DateTimeFormat('fr-FR', {
 export class ApartmentDocumentManager {
 	private readonly apartments = inject(ApartmentService);
 	private readonly destroyRef = inject(DestroyRef);
+	private readonly host = inject(ElementRef<HTMLElement>);
+	private fileSelectionId = 0;
 	private requestId = 0;
 
 	readonly actions = inject(ApartmentDocumentActions);
@@ -74,8 +85,8 @@ export class ApartmentDocumentManager {
 	});
 	readonly selectedFile = signal<File | null>(null);
 	readonly uploading = signal(false);
-	readonly validationError = signal('');
 	readonly uploadError = signal('');
+	readonly uploadFieldErrors = signal<FieldValidationError[]>([]);
 
 	constructor() {
 		effect(() => this.load(this.apartmentId()));
@@ -111,73 +122,133 @@ export class ApartmentDocumentManager {
 		this.uploadForm().markAsTouched();
 		const model = this.uploadModel();
 		const file = this.selectedFile();
-		if (!model.type) {
-			this.validationError.set('Choisissez un type de document.');
-		} else if (!file) {
-			this.validationError.set('Sélectionnez un fichier PDF.');
-		} else if (!model.establishedOn) {
-			this.validationError.set('Renseignez la date d’établissement du document.');
-		} else if (model.expiresOn && model.expiresOn < model.establishedOn) {
-			this.validationError.set(
-				'La date d’expiration doit être postérieure ou égale à la date d’établissement.',
-			);
-		} else {
-			this.validationError.set('');
+		const fieldErrors = this.validationErrors(model, file);
+		if (fieldErrors.length) {
 			this.uploadError.set('');
-			this.uploading.set(true);
-			this.apartments
-				.uploadDocument(this.apartmentId(), {
-					file,
-					type: model.type,
-					establishedOn: model.establishedOn,
-					expiresOn: model.expiresOn || null,
-				})
-				.pipe(
-					takeUntilDestroyed(this.destroyRef),
-					finalize(() => this.uploading.set(false)),
-				)
-				.subscribe({
-					next: (uploaded) => {
-						this.documents.update((documents) =>
-							[
-								...documents.filter((document) => document.type !== uploaded.type),
-								uploaded,
-							].sort(
-								(left, right) =>
-									apartmentDocumentTypes.findIndex(
-										(type) => type.value === left.type,
-									) -
-									apartmentDocumentTypes.findIndex(
-										(type) => type.value === right.type,
-									),
-							),
-						);
-						this.uploadModel.set({ type: '', establishedOn: '', expiresOn: '' });
-						this.selectedFile.set(null);
-					},
-					error: (error: unknown) =>
-						this.uploadError.set(
-							httpErrorMessage(error, 'Impossible de téléverser ce document.'),
+			this.uploadFieldErrors.set(fieldErrors);
+			this.focus(fieldErrors[0].field);
+			return;
+		}
+		if (!file || !model.type) return;
+		this.uploadError.set('');
+		this.uploadFieldErrors.set([]);
+		this.uploading.set(true);
+		this.apartments
+			.uploadDocument(this.apartmentId(), {
+				file,
+				type: model.type,
+				establishedOn: model.establishedOn,
+				expiresOn: model.expiresOn || null,
+			})
+			.pipe(
+				takeUntilDestroyed(this.destroyRef),
+				finalize(() => this.uploading.set(false)),
+			)
+			.subscribe({
+				next: (uploaded) => {
+					this.documents.update((documents) =>
+						[
+							...documents.filter((document) => document.type !== uploaded.type),
+							uploaded,
+						].sort(
+							(left, right) =>
+								apartmentDocumentTypes.findIndex(
+									(type) => type.value === left.type,
+								) -
+								apartmentDocumentTypes.findIndex(
+									(type) => type.value === right.type,
+								),
 						),
-				});
+					);
+					this.uploadModel.set({ type: '', establishedOn: '', expiresOn: '' });
+					this.selectedFile.set(null);
+				},
+				error: (error: unknown) => {
+					const failure = saveFailure(
+						error,
+						'Impossible de téléverser ce document. Vérifiez que le PDF est valide et respecte la taille maximale du serveur.',
+					);
+					const inlineErrors = failure.fieldErrors.filter(
+						(error): error is UploadFieldError => isUploadField(error.field),
+					);
+					this.uploadFieldErrors.set(inlineErrors);
+					if (inlineErrors.length) this.focus(inlineErrors[0].field);
+					this.uploadError.set(
+						inlineErrors.length > 0 &&
+							inlineErrors.length === failure.fieldErrors.length
+							? ''
+							: failure.message,
+					);
+				},
+			});
+	}
+
+	async selectFile(event: Event): Promise<void> {
+		const input = event.target;
+		const file = input instanceof HTMLInputElement ? (input.files?.item(0) ?? null) : null;
+		const selectionId = ++this.fileSelectionId;
+		if (input instanceof HTMLInputElement) input.value = '';
+		this.clearUploadFieldError('file');
+		if (!file) {
+			this.selectedFile.set(null);
+			return;
+		}
+		if (
+			file.type.toLowerCase() === 'application/pdf' &&
+			(await file.slice(0, 5).text()) === '%PDF-'
+		) {
+			if (selectionId !== this.fileSelectionId) return;
+			this.selectedFile.set(file);
+		} else {
+			if (selectionId !== this.fileSelectionId) return;
+			this.selectedFile.set(null);
+			this.uploadFieldErrors.update((errors) => [
+				...errors,
+				{ field: 'file', code: 'invalid' },
+			]);
 		}
 	}
 
-	selectFile(event: Event): void {
-		const input = event.target;
-		const file = input instanceof HTMLInputElement ? (input.files?.item(0) ?? null) : null;
-		if (
-			file &&
-			file.name.toLowerCase().endsWith('.pdf') &&
-			(file.type === 'application/pdf' || file.type === '')
-		) {
-			this.selectedFile.set(file);
-			this.validationError.set('');
-		} else {
-			this.selectedFile.set(null);
-			if (file) this.validationError.set('Sélectionnez un fichier PDF.');
-		}
-		if (input instanceof HTMLInputElement) input.value = '';
+	clearUploadFieldError(field: UploadField): void {
+		this.uploadFieldErrors.update((errors) => errors.filter((error) => error.field !== field));
+	}
+
+	fieldError(field: UploadField): string {
+		const code = this.uploadFieldErrors().find((error) => error.field === field)?.code;
+		if (!code) return '';
+		if (field === 'type') return 'Choisissez un type de document.';
+		if (field === 'establishedOn') return 'Renseignez une date d’établissement valide.';
+		if (field === 'expiresOn')
+			return code === 'before_establishment'
+				? 'La date d’expiration doit être postérieure ou égale à la date d’établissement.'
+				: 'Renseignez une date d’expiration valide.';
+		return code === 'invalid'
+			? 'Sélectionnez un fichier PDF valide.'
+			: 'Sélectionnez un fichier PDF.';
+	}
+
+	private validationErrors(
+		model: { type: ApartmentDocumentType | ''; establishedOn: string; expiresOn: string },
+		file: File | null,
+	): UploadFieldError[] {
+		const errors: UploadFieldError[] = [];
+		if (!model.type) errors.push({ field: 'type', code: 'required' });
+		if (!file) errors.push({ field: 'file', code: 'required' });
+		if (!model.establishedOn) errors.push({ field: 'establishedOn', code: 'required' });
+		if (model.expiresOn && model.establishedOn && model.expiresOn < model.establishedOn)
+			errors.push({ field: 'expiresOn', code: 'before_establishment' });
+		return errors;
+	}
+
+	private focus(field: UploadField): void {
+		const selector = {
+			type: 'mat-select',
+			file: 'input[type=file]',
+			establishedOn: '#establishedOn',
+			expiresOn: '#expiresOn',
+		}[field];
+		const control = this.host.nativeElement.querySelector(selector);
+		if (control instanceof HTMLElement) control.focus();
 	}
 
 	private load(apartmentId: string): void {