Add support for bookmark thumbnails (#721)

* Preview Image

* fix tests

* add test

* download preview image

* relative path

* gst

* details view

* fix tests

* Improve preview image styles

* Remove preview image URL from model

* Revert form changes

* update tests

* make it work in uwsgi

---------

Co-authored-by: Sascha Ißbrücker <sascha.issbruecker@gmail.com>

bookmarks/tests/test_preview_image_loader.py

@@ -0,0 +1,108 @@
+import io
+import os
+import tempfile
+from pathlib import Path
+from unittest import mock
+
+from django.conf import settings
+from django.test import TestCase
+
+from bookmarks.services import preview_image_loader
+
+mock_image_data = b"mock_image"
+
+
+class MockStreamingResponse:
+    def __init__(self, data=mock_image_data, content_type="image/png"):
+        self.chunks = [data]
+        self.headers = {"Content-Type": content_type}
+
+    def iter_content(self, **kwargs):
+        return self.chunks
+
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        pass
+
+
+class PreviewImageLoaderTestCase(TestCase):
+    def setUp(self) -> None:
+        self.temp_folder = tempfile.TemporaryDirectory()
+        self.settings_override = self.settings(LD_PREVIEW_FOLDER=self.temp_folder.name)
+        self.settings_override.enable()
+        self.mock_load_website_metadata_patcher = mock.patch(
+            "bookmarks.services.website_loader.load_website_metadata"
+        )
+        self.mock_load_website_metadata = (
+            self.mock_load_website_metadata_patcher.start()
+        )
+        self.mock_load_website_metadata.return_value = mock.Mock(
+            preview_image="https://example.com/image.png"
+        )
+
+    def tearDown(self) -> None:
+        self.temp_folder.cleanup()
+        self.settings_override.disable()
+        self.mock_load_website_metadata_patcher.stop()
+
+    def create_mock_response(self, icon_data=mock_image_data, content_type="image/png"):
+        mock_response = mock.Mock()
+        mock_response.raw = io.BytesIO(icon_data)
+        return MockStreamingResponse(icon_data, content_type)
+
+    def get_image_path(self, filename):
+        return Path(os.path.join(settings.LD_PREVIEW_FOLDER, filename))
+
+    def image_exists(self, filename):
+        return self.get_image_path(filename).exists()
+
+    def get_image_data(self, filename):
+        return self.get_image_path(filename).read_bytes()
+
+    def test_load_preview_image(self):
+        with mock.patch("requests.get") as mock_get:
+            mock_get.return_value = self.create_mock_response()
+
+            file = preview_image_loader.load_preview_image("https://example.com")
+
+            self.assertTrue(self.image_exists(file))
+            self.assertEqual(mock_image_data, self.get_image_data(file))
+
+    def test_load_preview_image_returns_none_if_no_preview_image_detected(self):
+        with mock.patch("requests.get") as mock_get:
+            mock_get.return_value = self.create_mock_response()
+            self.mock_load_website_metadata.return_value = mock.Mock(preview_image=None)
+
+            file = preview_image_loader.load_preview_image("https://example.com")
+
+            self.assertIsNone(file)
+
+    def test_load_preview_image_creates_folder_if_not_exists(self):
+        with mock.patch("requests.get") as mock_get:
+            mock_get.return_value = self.create_mock_response()
+
+            folder = Path(settings.LD_PREVIEW_FOLDER)
+            folder.rmdir()
+
+            self.assertFalse(folder.exists())
+
+            preview_image_loader.load_preview_image("https://example.com")
+
+            self.assertTrue(folder.exists())
+
+    def test_guess_file_extension(self):
+        with mock.patch("requests.get") as mock_get:
+            mock_get.return_value = self.create_mock_response(content_type="image/png")
+            file = preview_image_loader.load_preview_image("https://example.com")
+
+            self.assertTrue(self.image_exists(file))
+            self.assertEqual("png", file.split(".")[-1])
+
+        with mock.patch("requests.get") as mock_get:
+            mock_get.return_value = self.create_mock_response(content_type="image/jpeg")
+            file = preview_image_loader.load_preview_image("https://example.com")
+
+            self.assertTrue(self.image_exists(file))
+            self.assertEqual("jpg", file.split(".")[-1])