import http.client
import tempfile
import threading
import unittest
from pathlib import Path

from server import MAX_FILE_BYTES, detect_image_type, make_server


PNG = b"\x89PNG\r\n\x1a\n" + b"test-image"


def multipart(filename: str, payload: bytes, boundary: str = "test-boundary") -> tuple[bytes, str]:
    body = (
        f"--{boundary}\r\n"
        f'Content-Disposition: form-data; name="image"; filename="{filename}"\r\n'
        "Content-Type: application/octet-stream\r\n\r\n"
    ).encode() + payload + f"\r\n--{boundary}--\r\n".encode()
    return body, f"multipart/form-data; boundary={boundary}"


class ServerTests(unittest.TestCase):
    def setUp(self):
        self.temp = tempfile.TemporaryDirectory()
        self.upload_dir = Path(self.temp.name) / "private"
        self.server = make_server("127.0.0.1", 0, self.upload_dir)
        self.thread = threading.Thread(target=self.server.serve_forever, daemon=True)
        self.thread.start()
        self.port = self.server.server_address[1]

    def tearDown(self):
        self.server.shutdown()
        self.server.server_close()
        self.thread.join()
        self.temp.cleanup()

    def request(self, method, path, body=None, headers=None):
        connection = http.client.HTTPConnection("127.0.0.1", self.port, timeout=3)
        connection.request(method, path, body=body, headers=headers or {})
        response = connection.getresponse()
        data = response.read()
        connection.close()
        return response, data

    def test_accepts_png_and_stores_it_under_target(self):
        body, content_type = multipart("photo.png", PNG)
        response, data = self.request(
            "POST", "/logo-contest", body, {"Content-Type": content_type, "Content-Length": str(len(body))}
        )
        self.assertEqual(response.status, 201, data)
        target_dir = self.upload_dir / "logo-contest"
        files = list(target_dir.iterdir())
        self.assertEqual(len(files), 1)
        self.assertEqual(files[0].read_bytes(), PNG)
        self.assertNotIn("photo", files[0].name)
        self.assertEqual(files[0].stat().st_mode & 0o777, 0o600)
        self.assertEqual(target_dir.stat().st_mode & 0o777, 0o700)

        hidden_response, _ = self.request("GET", f"/logo-contest/{files[0].name}")
        self.assertEqual(hidden_response.status, 404)

    def test_root_is_rejected_but_target_page_is_available(self):
        root_response, _ = self.request("GET", "/")
        target_response, page = self.request("GET", "/911u19jasdl")
        self.assertEqual(root_response.status, 418)
        self.assertEqual(target_response.status, 200)
        self.assertIn(b"Private Drop", page)

    def test_upload_to_root_is_rejected_as_teapot(self):
        body, content_type = multipart("photo.png", PNG)
        response, _ = self.request(
            "POST", "/", body, {"Content-Type": content_type, "Content-Length": str(len(body))}
        )
        self.assertEqual(response.status, 418)

    def test_targets_are_stored_in_separate_directories(self):
        for target in ("logo-contest", "911u19jasdl"):
            body, content_type = multipart("photo.png", PNG)
            response, _ = self.request(
                "POST", f"/{target}", body, {"Content-Type": content_type, "Content-Length": str(len(body))}
            )
            self.assertEqual(response.status, 201)
            self.assertEqual(len(list((self.upload_dir / target).iterdir())), 1)

    def test_invalid_or_nested_targets_are_rejected(self):
        for path in ("/bad.target", "/nested/target", "/%2e%2e", "/healthz"):
            body, content_type = multipart("photo.png", PNG)
            response, _ = self.request(
                "POST", path, body, {"Content-Type": content_type, "Content-Length": str(len(body))}
            )
            self.assertEqual(response.status, 404)

    def test_rejects_non_image_content(self):
        body, content_type = multipart("fake.jpg", b"not really an image")
        response, _ = self.request(
            "POST", "/logo-contest", body, {"Content-Type": content_type, "Content-Length": str(len(body))}
        )
        self.assertEqual(response.status, 400)
        self.assertFalse((self.upload_dir / "logo-contest").exists())

    def test_rejects_oversized_request_before_reading_body(self):
        response, _ = self.request(
            "POST", "/logo-contest", b"", {"Content-Type": "multipart/form-data; boundary=x", "Content-Length": str(MAX_FILE_BYTES + 1024 * 1024 + 1)}
        )
        self.assertEqual(response.status, 413)

    def test_unknown_paths_are_not_served(self):
        response, _ = self.request("GET", "/server.py")
        self.assertEqual(response.status, 404)

    def test_detects_supported_signatures(self):
        self.assertEqual(detect_image_type(b"\xff\xd8\xffrest"), (".jpg", "image/jpeg"))
        self.assertEqual(detect_image_type(PNG), (".png", "image/png"))
        self.assertEqual(detect_image_type(b"\x00\x00\x00\x18ftypheic\x00\x00\x00\x00heic"), (".heic", "image/heic"))


if __name__ == "__main__":
    unittest.main()