Merge pull request #50208 from nextcloud/feat/conversion-adjusting

fix(files): conversion api simplification and conflict check

18 files changed, 358 insertions, 126 deletions

diff --git a/.github/workflows/integration-sqlite.yml b/.github/workflows/integration-sqlite.yml
index b16e64b21da..d19e45600ae 100644
--- a/.github/workflows/integration-sqlite.yml
+++ b/.github/workflows/integration-sqlite.yml
@@ -61,6 +61,7 @@ jobs:
           - 'federation_features'
           - '--tags ~@large files_features'
           - 'filesdrop_features'
+          - 'file_conversions'
           - 'openldap_features'
           - 'openldap_numerical_features'
           - 'ldap_features'
diff --git a/apps/files/lib/Capabilities.php b/apps/files/lib/Capabilities.php
index 88efb4fcaf0..6b50e5807a5 100644
--- a/apps/files/lib/Capabilities.php
+++ b/apps/files/lib/Capabilities.php
@@ -10,7 +10,7 @@ namespace OCA\Files;
 use OC\Files\FilenameValidator;
 use OCA\Files\Service\ChunkedUploadConfig;
 use OCP\Capabilities\ICapability;
-use OCP\Files\Conversion\ConversionMimeTuple;
+use OCP\Files\Conversion\ConversionMimeProvider;
 use OCP\Files\Conversion\IConversionManager;
 
 class Capabilities implements ICapability {
@@ -24,7 +24,7 @@ class Capabilities implements ICapability {
 	/**
 	 * Return this classes capabilities
 	 *
-	 * @return array{files: array{'$comment': ?string, bigfilechunking: bool, blacklisted_files: list<mixed>, forbidden_filenames: list<string>, forbidden_filename_basenames: list<string>, forbidden_filename_characters: list<string>, forbidden_filename_extensions: list<string>, chunked_upload: array{max_size: int, max_parallel_count: int}, file_conversions: list<array{from: string, to: list<array{mime: string, name: string}>}>}}
+	 * @return array{files: array{'$comment': ?string, bigfilechunking: bool, blacklisted_files: list<mixed>, forbidden_filenames: list<string>, forbidden_filename_basenames: list<string>, forbidden_filename_characters: list<string>, forbidden_filename_extensions: list<string>, chunked_upload: array{max_size: int, max_parallel_count: int}, file_conversions: list<array{from: string, to: string, extension: string, displayName: string}>}}
 	 */
 	public function getCapabilities(): array {
 		return [
@@ -42,9 +42,9 @@ class Capabilities implements ICapability {
 					'max_parallel_count' => ChunkedUploadConfig::getMaxParallelCount(),
 				],
 
-				'file_conversions' => array_map(function (ConversionMimeTuple $mimeTuple) {
-					return $mimeTuple->jsonSerialize();
-				}, $this->fileConversionManager->getMimeTypes()),
+				'file_conversions' => array_map(function (ConversionMimeProvider $mimeProvider) {
+					return $mimeProvider->jsonSerialize();
+				}, $this->fileConversionManager->getProviders()),
 			],
 		];
 	}
diff --git a/apps/files/openapi.json b/apps/files/openapi.json
index 015d4f42648..ddf3535c55f 100644
--- a/apps/files/openapi.json
+++ b/apps/files/openapi.json
@@ -101,29 +101,22 @@
                                     "type": "object",
                                     "required": [
                                         "from",
-                                        "to"
+                                        "to",
+                                        "extension",
+                                        "displayName"
                                     ],
                                     "properties": {
                                         "from": {
                                             "type": "string"
                                         },
                                         "to": {
-                                            "type": "array",
-                                            "items": {
-                                                "type": "object",
-                                                "required": [
-                                                    "mime",
-                                                    "name"
-                                                ],
-                                                "properties": {
-                                                    "mime": {
-                                                        "type": "string"
-                                                    },
-                                                    "name": {
-                                                        "type": "string"
-                                                    }
-                                                }
-                                            }
+                                            "type": "string"
+                                        },
+                                        "extension": {
+                                            "type": "string"
+                                        },
+                                        "displayName": {
+                                            "type": "string"
                                         }
                                     }
                                 }
diff --git a/apps/testing/lib/Conversion/ConversionProvider.php b/apps/testing/lib/Conversion/ConversionProvider.php
index 15e468b0756..b8d93428694 100644
--- a/apps/testing/lib/Conversion/ConversionProvider.php
+++ b/apps/testing/lib/Conversion/ConversionProvider.php
@@ -9,7 +9,7 @@ declare(strict_types=1);
 
 namespace OCA\Testing\Conversion;
 
-use OCP\Files\Conversion\ConversionMimeTuple;
+use OCP\Files\Conversion\ConversionMimeProvider;
 use OCP\Files\Conversion\IConversionProvider;
 use OCP\Files\File;
 use OCP\IL10N;
@@ -22,19 +22,26 @@ class ConversionProvider implements IConversionProvider {
 
 	public function getSupportedMimeTypes(): array {
 		return [
-			new ConversionMimeTuple('image/jpeg', [
-				['mime' => 'image/png', 'name' => $this->l10n->t('Image (.png)')],
-			])
+			new ConversionMimeProvider('image/jpeg', 'image/png', 'png', $this->l10n->t('Image (.png)')),
+			new ConversionMimeProvider('image/jpeg', 'image/gif', 'gif', $this->l10n->t('Image (.gif)')),
 		];
 	}
 
 	public function convertFile(File $file, string $targetMimeType): mixed {
 		$image = imagecreatefromstring($file->getContent());
-
 		imagepalettetotruecolor($image);
 
+		// Start output buffering
 		ob_start();
-		imagepng($image);
+
+		// Convert the image to the target format
+		if ($targetMimeType === 'image/gif') {
+			imagegif($image);
+		} else {
+			imagepng($image);
+		}
+
+		// End and return the output buffer
 		return ob_get_clean();
 	}
 }
diff --git a/build/integration/config/behat.yml b/build/integration/config/behat.yml
index 21e0cdb3309..47f8f3c827c 100644
--- a/build/integration/config/behat.yml
+++ b/build/integration/config/behat.yml
@@ -16,7 +16,7 @@ default:
         - "%paths.base%/../features"
       contexts:
         - FeatureContext:
-            baseUrl:  http://localhost:8080/ocs/
+            baseUrl: http://localhost:8080/ocs/
             admin:
               - admin
               - admin
@@ -39,7 +39,7 @@ default:
         - "%paths.base%/../comments_features"
       contexts:
         - FeatureContext:
-            baseUrl:  http://localhost:8080/ocs/
+            baseUrl: http://localhost:8080/ocs/
             admin:
               - admin
               - admin
@@ -62,7 +62,7 @@ default:
         - "%paths.base%/../dav_features"
       contexts:
         - DavFeatureContext:
-            baseUrl:  http://localhost:8080/ocs/
+            baseUrl: http://localhost:8080/ocs/
             admin:
               - admin
               - admin
@@ -85,7 +85,7 @@ default:
         - "%paths.base%/../federation_features"
       contexts:
         - FederationContext:
-            baseUrl:  http://localhost:8080/ocs/
+            baseUrl: http://localhost:8080/ocs/
             admin:
               - admin
               - admin
@@ -95,7 +95,7 @@ default:
         - "%paths.base%/../files_features"
       contexts:
         - FeatureContext:
-            baseUrl:  http://localhost:8080/ocs/
+            baseUrl: http://localhost:8080/ocs/
             admin:
               - admin
               - admin
@@ -113,12 +113,22 @@ default:
         - CommandLineContext:
             baseUrl: http://localhost:8080
             ocPath: ../../
+    files_conversion:
+      paths:
+        - "%paths.base%/../file_conversions"
+      contexts:
+        - ConversionsContext:
+            baseUrl: http://localhost:8080
+            admin:
+              - admin
+              - admin
+            regular_user_password: 123456
     capabilities:
       paths:
         - "%paths.base%/../capabilities_features"
       contexts:
         - CapabilitiesContext:
-            baseUrl:  http://localhost:8080/ocs/
+            baseUrl: http://localhost:8080/ocs/
             admin:
               - admin
               - admin
@@ -128,7 +138,7 @@ default:
         - "%paths.base%/../collaboration_features"
       contexts:
         - CollaborationContext:
-            baseUrl:  http://localhost:8080/ocs/
+            baseUrl: http://localhost:8080/ocs/
             admin:
               - admin
               - admin
@@ -138,7 +148,7 @@ default:
         - "%paths.base%/../sharees_features"
       contexts:
         - ShareesContext:
-            baseUrl:  http://localhost:8080/ocs/
+            baseUrl: http://localhost:8080/ocs/
             admin:
               - admin
               - admin
@@ -148,7 +158,7 @@ default:
         - "%paths.base%/../sharing_features"
       contexts:
         - SharingContext:
-            baseUrl:  http://localhost:8080/ocs/
+            baseUrl: http://localhost:8080/ocs/
             admin:
               - admin
               - admin
@@ -159,7 +169,7 @@ default:
         - "%paths.base%/../videoverification_features"
       contexts:
         - SharingContext:
-            baseUrl:  http://localhost:8080/ocs/
+            baseUrl: http://localhost:8080/ocs/
             admin:
               - admin
               - admin
@@ -170,7 +180,7 @@ default:
         - "%paths.base%/../setup_features"
       contexts:
         - SetupContext:
-            baseUrl:  http://localhost:8080/ocs/
+            baseUrl: http://localhost:8080/ocs/
             admin:
               - admin
               - admin
@@ -220,10 +230,10 @@ default:
         - "%paths.base%/../remoteapi_features"
       contexts:
         - FeatureContext:
-            baseUrl:  http://localhost:8080/ocs/
+            baseUrl: http://localhost:8080/ocs/
             admin:
               - admin
               - admin
             regular_user_password: 123456
         - RemoteContext:
-            remote:  http://localhost:8080
+            remote: http://localhost:8080
diff --git a/build/integration/data/clouds.jpg b/build/integration/data/clouds.jpg
new file mode 100644
index 00000000000..2433b140766
--- /dev/null
+++ b/build/integration/data/clouds.jpg
diff --git a/build/integration/data/clouds.jpg.license b/build/integration/data/clouds.jpg.license
new file mode 100644
index 00000000000..d7c54c39d02
--- /dev/null
+++ b/build/integration/data/clouds.jpg.license
@@ -0,0 +1,2 @@
+SPDX-FileCopyrightText: 2019 CHUTTERSNAP <https://unsplash.com/@chuttersnap> <https://unsplash.com/photos/blue-clouds-under-white-sky-9AqIdzEc9pY>"
+SPDX-License-Identifier: LicenseRef-Unsplash
diff --git a/build/integration/features/bootstrap/BasicStructure.php b/build/integration/features/bootstrap/BasicStructure.php
index b51c0a6a34c..60926e65f5c 100644
--- a/build/integration/features/bootstrap/BasicStructure.php
+++ b/build/integration/features/bootstrap/BasicStructure.php
@@ -8,6 +8,7 @@ use Behat\Gherkin\Node\TableNode;
 use GuzzleHttp\Client;
 use GuzzleHttp\Cookie\CookieJar;
 use GuzzleHttp\Exception\ClientException;
+use GuzzleHttp\Exception\ServerException;
 use PHPUnit\Framework\Assert;
 use Psr\Http\Message\ResponseInterface;
 
@@ -170,6 +171,8 @@ trait BasicStructure {
 			$this->response = $client->request($verb, $fullUrl, $options);
 		} catch (ClientException $ex) {
 			$this->response = $ex->getResponse();
+		} catch (ServerException $ex) {
+			$this->response = $ex->getResponse();
 		}
 	}
 
diff --git a/build/integration/features/bootstrap/ConversionsContext.php b/build/integration/features/bootstrap/ConversionsContext.php
new file mode 100644
index 00000000000..099a2263630
--- /dev/null
+++ b/build/integration/features/bootstrap/ConversionsContext.php
@@ -0,0 +1,59 @@
+<?php
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+require __DIR__ . '/../../vendor/autoload.php';
+
+use Behat\Behat\Context\Context;
+use Behat\Behat\Context\SnippetAcceptingContext;
+use Behat\Gherkin\Node\TableNode;
+
+class ConversionsContext implements Context, SnippetAcceptingContext {
+	use AppConfiguration;
+	use BasicStructure;
+	use WebDav;
+
+	/** @BeforeScenario */
+	public function setUpScenario() {
+		$this->asAn('admin');
+		$this->setStatusTestingApp(true);
+	}
+
+	/** @AfterScenario */
+	public function tearDownScenario() {
+		$this->asAn('admin');
+		$this->setStatusTestingApp(false);
+	}
+
+	protected function resetAppConfigs() {
+	}
+
+	/**
+	 * @When /^user "([^"]*)" converts file "([^"]*)" to "([^"]*)"$/
+	 */
+	public function userConvertsTheSavedFileId(string $user, string $path, string $mime) {
+		$this->userConvertsTheSavedFileIdTo($user, $path, $mime, null);
+	}
+
+	/**
+	 * @When /^user "([^"]*)" converts file "([^"]*)" to "([^"]*)" and saves it to "([^"]*)"$/
+	 */
+	public function userConvertsTheSavedFileIdTo(string $user, string $path, string $mime, ?string $destination) {
+		try {
+			$fileId = $this->getFileIdForPath($user, $path);
+		} catch (Exception $e) {
+			// return a fake value to keep going and be able to test the error
+			$fileId = 0;
+		}
+
+		$data = [['fileId', $fileId], ['targetMimeType', $mime]];
+		if ($destination !== null) {
+			$data[] = ['destination', $destination];
+		}
+
+		$this->asAn($user);
+		$this->sendingToWith('post', '/apps/files/api/v1/convert', new TableNode($data));
+	}
+}
diff --git a/build/integration/file_conversions/file_conversions.feature b/build/integration/file_conversions/file_conversions.feature
new file mode 100644
index 00000000000..f56dca0ebb4
--- /dev/null
+++ b/build/integration/file_conversions/file_conversions.feature
@@ -0,0 +1,101 @@
+# SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+# SPDX-License-Identifier: AGPL-3.0-only
+
+Feature: conversions
+	Background:
+		Given using api version "2"
+    Given using new dav path
+    Given user "user0" exists
+
+  Scenario: Converting a file works
+    Given user "user0" uploads file "data/clouds.jpg" to "/image.jpg"
+    Then as "user0" the file "/image.jpg" exists
+    When user "user0" converts file "/image.jpg" to "image/png"
+    Then the HTTP status code should be "201"
+    Then the OCS status code should be "201"
+    Then as "user0" the file "/image.png" exists
+
+  Scenario: Converting a file to a given path works
+    Given user "user0" uploads file "data/clouds.jpg" to "/image.jpg"
+    And User "user0" created a folder "/folder"
+    Then as "user0" the file "/image.jpg" exists
+    Then as "user0" the folder "/folder" exists
+    When user "user0" converts file "/image.jpg" to "image/png" and saves it to "/folder/image.png"
+    Then the HTTP status code should be "201"
+    Then the OCS status code should be "201"
+    Then as "user0" the file "/folder/image.png" exists
+    Then as "user0" the file "/image.png" does not exist
+
+  Scenario: Converting a file path with overwrite
+    Given user "user0" uploads file "data/clouds.jpg" to "/image.jpg"
+    And user "user0" uploads file "data/green-square-256.png" to "/image.png"
+    Then as "user0" the file "/image.jpg" exists
+    Then as "user0" the file "/image.png" exists
+    When user "user0" converts file "/image.jpg" to "image/png"
+    Then the HTTP status code should be "201"
+    Then the OCS status code should be "201"
+    Then as "user0" the file "/image.jpg" exists
+    Then as "user0" the file "/image.png" exists
+    Then as "user0" the file "/image (2).png" exists
+
+  Scenario: Converting a file path with overwrite to a given path
+    Given user "user0" uploads file "data/clouds.jpg" to "/image.jpg"
+    And User "user0" created a folder "/folder"
+    And user "user0" uploads file "data/green-square-256.png" to "/folder/image.png"
+    Then as "user0" the file "/image.jpg" exists
+    Then as "user0" the folder "/folder" exists
+    Then as "user0" the file "/folder/image.png" exists
+    When user "user0" converts file "/image.jpg" to "image/png" and saves it to "/folder/image.png"
+    Then the HTTP status code should be "201"
+    Then the OCS status code should be "201"
+    Then as "user0" the file "/folder/image.png" exists
+    Then as "user0" the file "/folder/image (2).png" exists
+    Then as "user0" the file "/image.png" does not exist
+    Then as "user0" the file "/image.jpg" exists
+
+  Scenario: Converting a file which does not exist fails
+    When user "user0" converts file "/image.jpg" to "image/png"
+    Then the HTTP status code should be "404"
+    Then the OCS status code should be "404"
+    Then as "user0" the file "/image.jpg" does not exist
+    Then as "user0" the file "/image.png" does not exist
+
+  Scenario: Converting a file to an invalid destination path fails
+    Given user "user0" uploads file "data/clouds.jpg" to "/image.jpg"
+    When user "user0" converts file "/image.jpg" to "image/png" and saves it to "/folder/image.png"
+    Then the HTTP status code should be "404"
+    Then the OCS status code should be "404"
+    Then as "user0" the file "/image.jpg" exists
+    Then as "user0" the file "/folder/image.png" does not exist
+
+  Scenario: Converting a file to an invalid format fails
+    Given user "user0" uploads file "data/clouds.jpg" to "/image.jpg"
+    When user "user0" converts file "/image.jpg" to "image/invalid"
+    Then the HTTP status code should be "500"
+    Then the OCS status code should be "999"
+    Then as "user0" the file "/image.jpg" exists
+    Then as "user0" the file "/image.png" does not exist
+
+  Scenario: Forbid conversion to a destination without create permission
+    Given user "user1" exists
+    # Share the folder with user1
+    Given User "user0" created a folder "/folder"
+    Then As an "user0"
+    When creating a share with
+      | path | folder |
+      | shareWith | user1 |
+      | shareType | 0 |
+      | permissions | 1 |
+    Then the OCS status code should be "200"
+    And the HTTP status code should be "200"
+    # Create the folder, upload the image
+    Then As an "user1"
+    Given user "user1" accepts last share
+    Given as "user1" the folder "/folder" exists
+    Given user "user1" uploads file "data/clouds.jpg" to "/image.jpg"
+    Then as "user1" the file "/image.jpg" exists
+    # Try to convert the image to a folder where user1 has no create permission
+    When user "user1" converts file "/image.jpg" to "image/png" and saves it to "/folder/folder.png"
+    Then the OCS status code should be "403" 
+    And the HTTP status code should be "403"
+    Then as "user1" the file "/folder/folder.png" does not exist
diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index dab71032ccc..d20e3f9f501 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -377,7 +377,7 @@ return array(
     'OCP\\Files\\Config\\IRootMountProvider' => $baseDir . '/lib/public/Files/Config/IRootMountProvider.php',
     'OCP\\Files\\Config\\IUserMountCache' => $baseDir . '/lib/public/Files/Config/IUserMountCache.php',
     'OCP\\Files\\ConnectionLostException' => $baseDir . '/lib/public/Files/ConnectionLostException.php',
-    'OCP\\Files\\Conversion\\ConversionMimeTuple' => $baseDir . '/lib/public/Files/Conversion/ConversionMimeTuple.php',
+    'OCP\\Files\\Conversion\\ConversionMimeProvider' => $baseDir . '/lib/public/Files/Conversion/ConversionMimeProvider.php',
     'OCP\\Files\\Conversion\\IConversionManager' => $baseDir . '/lib/public/Files/Conversion/IConversionManager.php',
     'OCP\\Files\\Conversion\\IConversionProvider' => $baseDir . '/lib/public/Files/Conversion/IConversionProvider.php',
     'OCP\\Files\\DavUtil' => $baseDir . '/lib/public/Files/DavUtil.php',
diff --git a/lib/composer/composer/autoload_psr4.php b/lib/composer/composer/autoload_psr4.php
index b07b2c0074b..09892528d3a 100644
--- a/lib/composer/composer/autoload_psr4.php
+++ b/lib/composer/composer/autoload_psr4.php
@@ -10,5 +10,6 @@ return array(
     'OC\\' => array($baseDir . '/lib/private'),
     'OCP\\' => array($baseDir . '/lib/public'),
     'NCU\\' => array($baseDir . '/lib/unstable'),
+    'Bamarni\\Composer\\Bin\\' => array($vendorDir . '/bamarni/composer-bin-plugin/src'),
     '' => array($baseDir . '/lib/private/legacy'),
 );
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index 00d3b2c2b5a..ead08210def 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -21,6 +21,10 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         array (
             'NCU\\' => 4,
         ),
+        'B' => 
+        array (
+            'Bamarni\\Composer\\Bin\\' => 21,
+        ),
     );
 
     public static $prefixDirsPsr4 = array (
@@ -40,6 +44,10 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         array (
             0 => __DIR__ . '/../../..' . '/lib/unstable',
         ),
+        'Bamarni\\Composer\\Bin\\' => 
+        array (
+            0 => __DIR__ . '/..' . '/bamarni/composer-bin-plugin/src',
+        ),
     );
 
     public static $fallbackDirsPsr4 = array (
@@ -418,7 +426,7 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         'OCP\\Files\\Config\\IRootMountProvider' => __DIR__ . '/../../..' . '/lib/public/Files/Config/IRootMountProvider.php',
         'OCP\\Files\\Config\\IUserMountCache' => __DIR__ . '/../../..' . '/lib/public/Files/Config/IUserMountCache.php',
         'OCP\\Files\\ConnectionLostException' => __DIR__ . '/../../..' . '/lib/public/Files/ConnectionLostException.php',
-        'OCP\\Files\\Conversion\\ConversionMimeTuple' => __DIR__ . '/../../..' . '/lib/public/Files/Conversion/ConversionMimeTuple.php',
+        'OCP\\Files\\Conversion\\ConversionMimeProvider' => __DIR__ . '/../../..' . '/lib/public/Files/Conversion/ConversionMimeProvider.php',
         'OCP\\Files\\Conversion\\IConversionManager' => __DIR__ . '/../../..' . '/lib/public/Files/Conversion/IConversionManager.php',
         'OCP\\Files\\Conversion\\IConversionProvider' => __DIR__ . '/../../..' . '/lib/public/Files/Conversion/IConversionProvider.php',
         'OCP\\Files\\DavUtil' => __DIR__ . '/../../..' . '/lib/public/Files/DavUtil.php',
diff --git a/lib/private/Files/Conversion/ConversionManager.php b/lib/private/Files/Conversion/ConversionManager.php
index 37fc9a6c754..db49f7afed9 100644
--- a/lib/private/Files/Conversion/ConversionManager.php
+++ b/lib/private/Files/Conversion/ConversionManager.php
@@ -11,7 +11,7 @@ namespace OC\Files\Conversion;
 
 use OC\AppFramework\Bootstrap\Coordinator;
 use OC\SystemConfig;
-use OCP\Files\Conversion\ConversionMimeTuple;
+use OCP\Files\Conversion\ConversionMimeProvider;
 use OCP\Files\Conversion\IConversionManager;
 use OCP\Files\Conversion\IConversionProvider;
 use OCP\Files\File;
@@ -32,10 +32,10 @@ class ConversionManager implements IConversionManager {
 		'richdocuments',
 	];
 
-	/** @var IConversionProvider[] */
+	/** @var list<IConversionProvider> */
 	private array $preferredProviders = [];
 
-	/** @var IConversionProvider[] */
+	/** @var list<IConversionProvider> */
 	private array $providers = [];
 
 	public function __construct(
@@ -53,16 +53,28 @@ class ConversionManager implements IConversionManager {
 		return !empty($context->getFileConversionProviders());
 	}
 
-	public function getMimeTypes(): array {
-		$mimeTypes = [];
-
-		foreach ($this->getProviders() as $provider) {
-			$mimeTypes[] = $provider->getSupportedMimetypes();
+	public function getProviders(): array {
+		$providers = [];
+		foreach ($this->getRegisteredProviders() as $provider) {
+			$providers = array_merge($providers, $provider->getSupportedMimeTypes());
 		}
+		return $providers;
+	}
+
+	/**
+	 * @param string $mime
+	 * @return list<ConversionMimeProvider>
+	 */
+	private function getProvidersForMime(string $mime): array {
+		$mimeTypes = $this->getProviders();
+		$filtered = array_filter(
+			$mimeTypes,
+			function (ConversionMimeProvider $mimeProvider) use ($mime) {
+				return $mimeProvider->getFrom() === $mime;
+			}
+		);
 
-		/** @var list<ConversionMimeTuple> */
-		$mimeTypes = array_merge(...$mimeTypes);
-		return $mimeTypes;
+		return array_values($filtered);
 	}
 
 	public function convert(File $file, string $targetMimeType, ?string $destination = null): string {
@@ -80,24 +92,36 @@ class ConversionManager implements IConversionManager {
 		$fileMimeType = $file->getMimetype();
 		$validProvider = $this->getValidProvider($fileMimeType, $targetMimeType);
 
+		$targetExtension = '';
+		foreach ($this->getProvidersForMime($fileMimeType) as $mimeProvider) {
+			if ($mimeProvider->getTo() === $targetMimeType) {
+				$targetExtension = $mimeProvider->getExtension();
+				break;
+			}
+		}
+
 		if ($validProvider !== null) {
 			$convertedFile = $validProvider->convertFile($file, $targetMimeType);
 
-			if ($destination !== null) {
-				$convertedFile = $this->writeToDestination($destination, $convertedFile);
-				return $convertedFile->getPath();
+			// If destination not provided, we use the same path
+			// as the original file, but with the new extension
+			if ($destination === null) {
+				$basename = pathinfo($file->getPath(), PATHINFO_FILENAME);
+				$parent = $file->getParent();
+				$destination = $parent->getFullPath($basename . '.' . $targetExtension);
 			}
 
-			$tmp = $this->tempManager->getTemporaryFile();
-			file_put_contents($tmp, $convertedFile);
-
-			return $tmp;
+			$convertedFile = $this->writeToDestination($destination, $convertedFile);
+			return $convertedFile->getPath();
 		}
 
 		throw new RuntimeException('Could not convert file');
 	}
 
-	public function getProviders(): array {
+	/**
+	 * @return list<IConversionProvider>
+	 */
+	private function getRegisteredProviders(): array {
 		if (count($this->providers) > 0) {
 			return $this->providers;
 		}
@@ -121,32 +145,33 @@ class ConversionManager implements IConversionManager {
 			}
 		}
 
-		return array_merge([], $this->preferredProviders, $this->providers);
+		return array_values(array_merge([], $this->preferredProviders, $this->providers));
 	}
 
 	private function writeToDestination(string $destination, mixed $content): File {
+		if ($this->rootFolder->nodeExists($destination)) {
+			$file = $this->rootFolder->get($destination);
+			$parent = $file->getParent();
+			if (!$parent->isCreatable()) {
+				throw new GenericFileException('Destination is not creatable');
+			}
+
+			$newName = $parent->getNonExistingName(basename($destination));
+			$destination = $parent->getFullPath($newName);
+		}
+
 		return $this->rootFolder->newFile($destination, $content);
 	}
 
 	private function getValidProvider(string $fileMimeType, string $targetMimeType): ?IConversionProvider {
-		$validProvider = null;
-		foreach ($this->getProviders() as $provider) {
-			$suitableMimeTypes = array_filter(
-				$provider->getSupportedMimeTypes(),
-				function (ConversionMimeTuple $mimeTuple) use ($fileMimeType, $targetMimeType) {
-					['from' => $from, 'to' => $to] = $mimeTuple->jsonSerialize();
-					
-					$supportsTargetMimeType = in_array($targetMimeType, array_column($to, 'mime'));
-					return ($from === $fileMimeType) && $supportsTargetMimeType;
+		foreach ($this->getRegisteredProviders() as $provider) {
+			foreach ($provider->getSupportedMimeTypes() as $mimeProvider) {
+				if ($mimeProvider->getFrom() === $fileMimeType && $mimeProvider->getTo() === $targetMimeType) {
+					return $provider;
 				}
-			);
-
-			if (!empty($suitableMimeTypes)) {
-				$validProvider = $provider;
-				break;
 			}
 		}
-
-		return $validProvider;
+		
+		return null;
 	}
 }
diff --git a/lib/public/Files/Conversion/ConversionMimeProvider.php b/lib/public/Files/Conversion/ConversionMimeProvider.php
new file mode 100644
index 00000000000..0daf4a10648
--- /dev/null
+++ b/lib/public/Files/Conversion/ConversionMimeProvider.php
@@ -0,0 +1,66 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCP\Files\Conversion;
+
+use JsonSerializable;
+
+/**
+ * A tuple-like object representing both an original and target
+ * MIME type for a file conversion
+ *
+ * @since 31.0.0
+ */
+class ConversionMimeProvider implements JsonSerializable {
+	/**
+	 * @param string $from The source MIME type of a file
+	 * @param string $to The target MIME type for the file
+	 * @param string $extension The file extension for the target MIME type (e.g. 'png')
+	 * @param string $displayName The human-readable name of the target MIME type (e.g. 'Image (.png)')
+	 *
+	 * @since 31.0.0
+	 */
+	public function __construct(
+		private string $from,
+		private string $to,
+		private string $extension,
+		private string $displayName,
+	) {
+	}
+
+	public function getFrom(): string {
+		return $this->from;
+	}
+
+	public function getTo(): string {
+		return $this->to;
+	}
+
+	public function getExtension(): string {
+		return $this->extension;
+	}
+
+	public function getDisplayName(): string {
+		return $this->displayName;
+	}
+
+	/**
+	 * @return array{from: string, to: string, extension: string, displayName: string}
+	 *
+	 * @since 31.0.0
+	 */
+	public function jsonSerialize(): array {
+		return [
+			'from' => $this->from,
+			'to' => $this->to,
+			'extension' => $this->extension,
+			'displayName' => $this->displayName,
+		];
+	}
+}
diff --git a/lib/public/Files/Conversion/ConversionMimeTuple.php b/lib/public/Files/Conversion/ConversionMimeTuple.php
deleted file mode 100644
index 0180f3311f3..00000000000
--- a/lib/public/Files/Conversion/ConversionMimeTuple.php
+++ /dev/null
@@ -1,44 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-/**
- * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
- * SPDX-License-Identifier: AGPL-3.0-or-later
- */
-
-namespace OCP\Files\Conversion;
-
-use JsonSerializable;
-
-/**
- * A tuple-like object representing both an original and target
- * MIME type for a file conversion
- *
- * @since 31.0.0
- */
-class ConversionMimeTuple implements JsonSerializable {
-	/**
-	 * @param string $from The original MIME type of a file
-	 * @param list<array{mime: string, name: string}> $to The desired MIME type for the file mapped to its translated name
-	 *
-	 * @since 31.0.0
-	 */
-	public function __construct(
-		private string $from,
-		private array $to,
-	) {
-	}
-
-	/**
-	 * @return array{from: string, to: list<array{mime: string, name: string}>}
-	 *
-	 * @since 31.0.0
-	 */
-	public function jsonSerialize(): array {
-		return [
-			'from' => $this->from,
-			'to' => $this->to,
-		];
-	}
-}
diff --git a/lib/public/Files/Conversion/IConversionManager.php b/lib/public/Files/Conversion/IConversionManager.php
index 59ff580fdf1..ed418129d3b 100644
--- a/lib/public/Files/Conversion/IConversionManager.php
+++ b/lib/public/Files/Conversion/IConversionManager.php
@@ -25,11 +25,11 @@ interface IConversionManager {
 	/**
 	 * Gets all supported MIME type conversions
 	 *
-	 * @return list<ConversionMimeTuple>
+	 * @return list<ConversionMimeProvider>
 	 *
 	 * @since 31.0.0
 	 */
-	public function getMimeTypes(): array;
+	public function getProviders(): array;
 
 	/**
 	 * Convert a file to a given MIME type
diff --git a/lib/public/Files/Conversion/IConversionProvider.php b/lib/public/Files/Conversion/IConversionProvider.php
index b0a09fc93a4..3b5c5945c99 100644
--- a/lib/public/Files/Conversion/IConversionProvider.php
+++ b/lib/public/Files/Conversion/IConversionProvider.php
@@ -21,7 +21,7 @@ interface IConversionProvider {
 	/**
 	 * Get an array of MIME type tuples this conversion provider supports
 	 *
-	 * @return list<ConversionMimeTuple>
+	 * @return list<ConversionMimeProvider>
 	 *
 	 * @since 31.0.0
 	 */