import json
from unittest.mock import MagicMock, patch

import pytest

from photools3.lm_studio import LMStudioError, LMStudioModelManager


def _http_response(payload: dict):
    response = MagicMock()
    response.__enter__.return_value = response
    response.read.return_value = json.dumps(payload).encode("utf-8")
    return response


def test_reload_model_unloads_and_reloads_preserving_context_config():
    model_response = {
        "models": [
            {
                "key": "qwen/qwen3-vl-4b",
                "loaded_instances": [
                    {
                        "id": "qwen/qwen3-vl-4b-instance",
                        "config": {
                            "context_length": 16384,
                            "eval_batch_size": 256,
                            "flash_attention": True,
                            "offload_kv_cache_to_gpu": False,
                            "parallel": 2,
                        },
                    }
                ],
            }
        ]
    }
    with patch(
        "photools3.lm_studio.urlopen",
        side_effect=[
            _http_response(model_response),
            _http_response({"instance_id": "qwen/qwen3-vl-4b-instance"}),
            _http_response({"instance_id": "qwen/qwen3-vl-4b-instance"}),
        ],
    ) as mocked_urlopen:
        manager = LMStudioModelManager(
            "http://localhost:1234/v1", "test-token", timeout=12
        )
        manager.reload_model("qwen/qwen3-vl-4b")

    requests = [call.args[0] for call in mocked_urlopen.call_args_list]
    assert requests[0].full_url == "http://localhost:1234/api/v1/models"
    assert requests[0].get_method() == "GET"
    assert requests[0].get_header("Authorization") == "Bearer test-token"

    assert requests[1].full_url.endswith("/models/unload")
    assert json.loads(requests[1].data) == {"instance_id": "qwen/qwen3-vl-4b-instance"}

    assert requests[2].full_url.endswith("/models/load")
    assert json.loads(requests[2].data) == {
        "model": "qwen/qwen3-vl-4b",
        "context_length": 16384,
        "eval_batch_size": 256,
        "flash_attention": True,
        "offload_kv_cache_to_gpu": False,
    }


def test_reload_model_loads_by_key_if_no_instance_is_loaded():
    model_response = {"models": [{"key": "qwen/model", "loaded_instances": []}]}
    with patch(
        "photools3.lm_studio.urlopen",
        side_effect=[
            _http_response(model_response),
            _http_response({"status": "loaded"}),
        ],
    ) as mocked_urlopen:
        manager = LMStudioModelManager("http://localhost:1234/v1", "token")
        manager.reload_model("qwen/model")

    assert mocked_urlopen.call_count == 2
    load_request = mocked_urlopen.call_args.args[0]
    assert load_request.full_url.endswith("/models/load")
    assert json.loads(load_request.data) == {"model": "qwen/model"}


def test_reload_model_rejects_ambiguous_model_selection():
    model_response = {
        "models": [
            {
                "key": "qwen/model",
                "loaded_instances": [
                    {"id": "instance-1", "config": {}},
                    {"id": "instance-2", "config": {}},
                ],
            }
        ]
    }
    with patch(
        "photools3.lm_studio.urlopen", return_value=_http_response(model_response)
    ):
        manager = LMStudioModelManager("http://localhost:1234/v1", "token")
        with pytest.raises(LMStudioError, match="Multiple loaded instances"):
            manager.reload_model("qwen/model")