enh: resolve schema changes

lib/Service/StructureService.php

@@ -0,0 +1,124 @@
+<?php
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Tables\Service;
+
+use OCA\Tables\Errors\InternalError;
+use OCA\Tables\Errors\NotFoundError;
+use OCA\Tables\Errors\PermissionError;
+
+class StructureService {
+
+	public function __construct(
+		private readonly TableService $tableService,
+	) {
+	}
+
+	protected array $addedColumns = [];
+	protected array $removedColumns = [];
+	protected array $modifiedColumns = [];
+
+	/**
+	 * Calling this method expects having manage permissions against the
+	 * specified table and does not check them any further.
+	 *
+	 * @throws PermissionError
+	 * @throws NotFoundError
+	 * @throws InternalError
+	 */
+	public function resolveChangesForTable(int $tableId, array $updateSchema): void {
+		$currentSchema = $this->tableService->getScheme($tableId);
+		$this->resolveChanges($currentSchema->jsonSerialize(), $updateSchema);
+	}
+
+	public function resolveChanges(array $currentSchema, array $updateSchema): void {
+		$this->resolveColumnChanges($currentSchema, $updateSchema);
+	}
+
+	public function addedColumns(): array {
+		return $this->addedColumns;
+	}
+
+	public function removedColumns(): array {
+		return $this->removedColumns;
+	}
+
+	public function modifiedColumn(): array {
+		return $this->modifiedColumns;
+	}
+
+	protected function resolveColumnChanges(array $currentSchema, array $updateSchema): void {
+		$existingColumnMap = $this->getColumnMap($currentSchema['columns']);
+		$updatedColumnMap = $this->getColumnMap($updateSchema['columns']);
+
+		$this->determineAddedColumns($existingColumnMap, $updatedColumnMap, $updateSchema);
+		$this->determineRemovedColumns($existingColumnMap, $updatedColumnMap, $currentSchema);
+		$this->determineModifiedColumns($existingColumnMap, $updatedColumnMap, $currentSchema, $updateSchema);
+	}
+
+	protected function determineAddedColumns(array $existingColumnMap, array $updatedColumnMap, array $updateSchema): void {
+		$columnUuids = array_diff_key($updatedColumnMap, $existingColumnMap);
+		foreach ($columnUuids as $uuid) {
+			$this->addedColumns[$uuid] = $updateSchema['columns'][$updatedColumnMap[$uuid]['arrayIndex']];
+		}
+	}
+
+	protected function determineRemovedColumns(array $existingColumnMap, array $updatedColumnMap, array $currentSchema): void {
+		$columnUuids = array_diff_key($existingColumnMap, $updatedColumnMap);
+		foreach ($columnUuids as $uuid) {
+			$this->removedColumns[$uuid] = $currentSchema['columns'][$existingColumnMap[$uuid]['arrayIndex']];
+		}
+	}
+
+	protected function determineModifiedColumns(array $existingColumnMap, array $updatedColumnMap, array $currentSchema, array $updateSchema): void {
+		$updatedColumnUuids = array_keys(array_intersect_key($existingColumnMap, $updatedColumnMap));
+
+		$updatedColumnUuids = array_filter(
+			$updatedColumnUuids,
+			function (string $uuid) use ($currentSchema, $updateSchema, $existingColumnMap, $updatedColumnMap): bool {
+				$columnCurrent = $currentSchema['columns'][$existingColumnMap[$uuid]['arrayIndex']];
+				$columnNew = $updateSchema['columns'][$updatedColumnMap[$uuid]['arrayIndex']];
+				return $this->isColumnModified($columnNew, $columnCurrent);
+			}
+		);
+
+		foreach ($updatedColumnUuids as $uuid) {
+			$this->modifiedColumns[$uuid] = [
+				'from' => $currentSchema['columns'][$existingColumnMap[$uuid]['arrayIndex']],
+				'to' => $updateSchema['columns'][$updatedColumnMap[$uuid]['arrayIndex']],
+			];
+		}
+	}
+
+	protected function isColumnModified($columnA, $columnB): bool {
+		unset(
+			$columnA['id'], $columnB['id'],
+			$columnA['createdBy'], $columnB['createdBy'],
+			$columnA['createdByDisplayName'], $columnB['createdByDisplayName'],
+			$columnA['createdAt'], $columnB['createdAt'],
+			$columnA['lastEditBy'], $columnB['lastEditBy'],
+			$columnA['lastEditByDisplayName'], $columnB['lastEditByDisplayName'],
+			$columnA['lastEditAt'], $columnB['lastEditAt'],
+			$columnA['tableId'], $columnB['tableId'],
+		);
+		$jsonColumnA = json_encode($columnA);
+		$jsonColumnB = json_encode($columnB);
+		// cannot use array_diff_assoc() is it does not deal with nested arrays
+		return $jsonColumnA !== $jsonColumnB;
+	}
+
+	protected function getColumnMap(array $currentSchemaColumns): array {
+		$map = [];
+		foreach ($currentSchemaColumns as $i => $column) {
+			$map[$column['uuid']] = [
+				'arrayIndex' => $i,
+				'id' => $column['id'],
+			];
+		}
+		return $map;
+	}
+}

tests/unit/Service/StructureServiceTest.php

@@ -0,0 +1,34 @@
+<?php
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Tables\Tests\Unit\Service;
+
+use OCA\Tables\Service\StructureService;
+use OCA\Tables\Service\TableService;
+use PHPUnit\Framework\MockObject\MockObject;
+use PHPUnit\Framework\TestCase;
+
+class StructureServiceTest extends TestCase {
+	private readonly StructureService $service;
+	private readonly array $originalSchema;
+	private readonly TableService|MockObject $tableService;
+
+	public function setUp(): void {
+		$this->tableService = $this->createMock(TableService::class);
+
+		$this->originalSchema = json_decode(file_get_contents(__DIR__ . '/../res/feature-list-schema.json'), true);
+
+		$this->service = new StructureService($this->tableService);
+	}
+
+	public function testNoChanges() {
+		$this->service->resolveChanges($this->originalSchema, $this->originalSchema);
+		$this->assertSame([], $this->service->addedColumns());
+		$this->assertSame([], $this->service->removedColumns());
+		$this->assertSame([], $this->service->modifiedColumn());
+	}
+}