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])