"""VLM 适配器单元测试。"""

from __future__ import annotations

from typing import TYPE_CHECKING

from adapters.vlm import GovernedVLMClient

if TYPE_CHECKING:
    from pathlib import Path


class TestGovernedVLMClientProtocol:
    def test_has_chat_with_images(self):
        assert hasattr(GovernedVLMClient, "chat_with_images")

    def test_satisfies_vlm_protocol(self):
        """GovernedVLMClient 应满足 VLMProvider Protocol。"""
        assert hasattr(GovernedVLMClient, "chat_with_images")


class TestImageEncoding:
    def test_encode_jpeg(self, tmp_path: Path):
        img = tmp_path / "test.jpg"
        img.write_bytes(b"\xff\xd8\xff\xe0fake_jpeg_data")
        result = GovernedVLMClient._encode_image(img)
        assert result.startswith("data:image/jpeg;base64,")

    def test_encode_png(self, tmp_path: Path):
        img = tmp_path / "test.png"
        img.write_bytes(b"\x89PNG\r\n\x1a\nfake_png_data")
        result = GovernedVLMClient._encode_image(img)
        assert result.startswith("data:image/png;base64,")


class TestInjectImages:
    def test_inject_single_image(self, tmp_path: Path):
        img = tmp_path / "frame.jpg"
        img.write_bytes(b"\xff\xd8\xff\xe0data")
        messages = [{"role": "user", "content": "描述这帧画面"}]
        result = GovernedVLMClient._inject_images(messages, [img])

        assert len(result) == 1
        content = result[0]["content"]
        assert isinstance(content, list)
        assert len(content) == 2  # 1 image + 1 text
        assert content[0]["type"] == "image_url"
        assert content[1]["type"] == "text"
        assert content[1]["text"] == "描述这帧画面"

    def test_inject_does_not_mutate_original(self, tmp_path: Path):
        img = tmp_path / "frame.jpg"
        img.write_bytes(b"\xff\xd8\xff\xe0data")
        messages = [{"role": "user", "content": "text"}]
        original_content = messages[0]["content"]
        GovernedVLMClient._inject_images(messages, [img])
        assert messages[0]["content"] == original_content  # 原列表未变

    def test_no_images_passthrough(self):
        messages = [{"role": "user", "content": "hello"}]
        result = GovernedVLMClient._inject_images(messages, [])
        assert result[0]["content"] == "hello"

    def test_multiple_images(self, tmp_path: Path):
        imgs = []
        for i in range(3):
            img = tmp_path / f"frame_{i}.jpg"
            img.write_bytes(b"\xff\xd8\xff\xe0data")
            imgs.append(img)
        messages = [{"role": "user", "content": "描述"}]
        result = GovernedVLMClient._inject_images(messages, imgs)
        content = result[0]["content"]
        assert len(content) == 4  # 3 images + 1 text