import importlib.util
import sys
import types
import unittest
from pathlib import Path

ROOT = Path(__file__).resolve().parents[2]
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))


class _DummyLogger:
    def info(self, *_args, **_kwargs):
        return None


class _DummyStateGraph:
    def __init__(self, *args, **kwargs):
        pass

    def add_node(self, *args, **kwargs):
        return None

    def add_conditional_edges(self, *args, **kwargs):
        return None

    def add_edge(self, *args, **kwargs):
        return None

    def set_entry_point(self, *args, **kwargs):
        return None

    def compile(self):
        return self


class DummyMessage:
    def __init__(self, message_type, content):
        self.type = message_type
        self.content = content


def _load_graph_module():
    langgraph = types.ModuleType("langgraph")
    graph_module = types.ModuleType("langgraph.graph")
    graph_module.StateGraph = _DummyStateGraph
    graph_module.END = "END"
    langgraph.graph = graph_module

    prebuilt_module = types.ModuleType("langgraph.prebuilt")
    prebuilt_module.ToolNode = lambda tools: tools

    langchain_core = types.ModuleType("langchain_core")
    messages_module = types.ModuleType("langchain_core.messages")

    class AIMessage:
        pass

    class ToolMessage:
        pass

    messages_module.AIMessage = AIMessage
    messages_module.ToolMessage = ToolMessage

    runnables_module = types.ModuleType("langchain_core.runnables")
    config_module = types.ModuleType("langchain_core.runnables.config")
    config_module.RunnableConfig = dict
    runnables_module.config = config_module
    langchain_core.messages = messages_module
    langchain_core.runnables = runnables_module

    sys.modules.setdefault("langgraph", langgraph)
    sys.modules.setdefault("langgraph.graph", graph_module)
    sys.modules.setdefault("langgraph.prebuilt", prebuilt_module)
    sys.modules.setdefault("langchain_core", langchain_core)
    sys.modules.setdefault("langchain_core.messages", messages_module)
    sys.modules.setdefault("langchain_core.runnables", runnables_module)
    sys.modules.setdefault("langchain_core.runnables.config", config_module)

    dummy_tools_module = types.ModuleType("src.tools.web_tools")
    dummy_tools_module.web_search_tool = object()

    captured = {}

    class DummySaveFHIR:
        def invoke(self, payload):
            captured.update(payload)
            return "saved"

    dummy_fhir_module = types.ModuleType("src.tools.fhir_memory")
    dummy_fhir_module.save_chat_as_fhir = DummySaveFHIR()

    logger_module = types.ModuleType("src.utils.logger")
    logger_module.setup_logger = lambda _name: _DummyLogger()

    dietary_module = types.ModuleType("src.tools.dietary_tools")
    dietary_module.page_indexed_retrieval = object()
    dietary_module.search_guidelines = object()
    dietary_module.get_nutritional_data = object()

    agent_instances_module = types.ModuleType("src.agents.agent_instances")
    agent_instances_module.role_classifier = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)
    agent_instances_module.patient_llm = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)
    agent_instances_module.caregiver_llm = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)
    agent_instances_module.validator = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)
    agent_instances_module.safety_check = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)
    agent_instances_module.intent_classifier = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)
    agent_instances_module.diagnosis_assist = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)
    agent_instances_module.treatment_assist = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)
    agent_instances_module.monitoring_assist = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)
    agent_instances_module.general_assist = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)
    agent_instances_module.output_merger = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)
    agent_instances_module.research_agent = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)
    agent_instances_module.dietary_assist = types.SimpleNamespace(run=lambda *_args, **_kwargs: None)

    sys.modules.setdefault("src.tools.web_tools", dummy_tools_module)
    sys.modules.setdefault("src.tools.fhir_memory", dummy_fhir_module)
    sys.modules.setdefault("src.utils.logger", logger_module)
    sys.modules.setdefault("src.tools.dietary_tools", dietary_module)
    sys.modules.setdefault("src.agents.agent_instances", agent_instances_module)

    spec = importlib.util.spec_from_file_location("graph_under_test", ROOT / "backend" / "src" / "core" / "graph.py")
    module = importlib.util.module_from_spec(spec)
    sys.modules[spec.name] = module
    spec.loader.exec_module(module)
    return module, captured


class TestSessionPersistence(unittest.IsolatedAsyncioTestCase):
    async def test_persistence_node_passes_session_id_to_fhir(self):
        graph, captured = _load_graph_module()

        state = {
            "messages": [
                DummyMessage("human", "What is my glucose trend?"),
                DummyMessage("ai", "Your glucose trend is stable."),
            ],
            "user_role": "patient",
            "patient_id": "patient-123",
            "session_id": "session-456",
        }

        result = await graph.persistence_node(state)

        self.assertEqual(captured["patient_id"], "patient-123")
        self.assertEqual(captured["session_id"], "session-456")
        self.assertEqual(captured["messages"][0]["role"], "user")
        self.assertEqual(captured["messages"][1]["role"], "assistant")
        self.assertEqual(result["metrics"][0]["agent"], "PersistenceNode")


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