import json
import os
import shutil
import subprocess
import threading
import time
import uuid
import venv
from pathlib import Path

import pytest
from dotenv import load_dotenv
from letta_client import Letta
from letta_client.types import MessageCreateParam, Tool, ToolReturnMessage
from letta_client.types.agents import ToolCallMessage

from letta.functions.mcp_client.types import SSEServerConfig, StdioServerConfig, StreamableHTTPServerConfig
from letta.schemas.embedding_config import EmbeddingConfig
from letta.schemas.llm_config import LLMConfig
from tests.utils import wait_for_server


def create_virtualenv_and_install_requirements(requirements_path: Path, name="venv", force_recreate=True) -> Path:
    requirements_path = requirements_path.resolve()

    if not requirements_path.exists():
        raise FileNotFoundError(f"Requirements file not found: {requirements_path}")
    if requirements_path.name != "requirements.txt":
        raise ValueError(f"Expected file named 'requirements.txt', got: {requirements_path.name}")

    venv_dir = requirements_path.parent / name

    # Always clean up existing venv if force_recreate is True (default)
    # This prevents corruption issues
    if venv_dir.exists() and force_recreate:
        try:
            shutil.rmtree(venv_dir)
            print(f"Cleaned up existing venv at {venv_dir}")
        except Exception as e:
            print(f"Warning: Failed to remove existing venv: {e}")
            # Continue anyway, might still work

    # Create fresh venv
    if not venv_dir.exists():
        venv.EnvBuilder(with_pip=True, clear=True).create(venv_dir)

    pip_path = venv_dir / ("Scripts" if os.name == "nt" else "bin") / "pip"

    # Wait a moment for venv creation to complete
    for _ in range(10):
        if pip_path.exists():
            break
        time.sleep(0.1)

    if not pip_path.exists():
        raise FileNotFoundError(f"pip executable not found at: {pip_path}")

    try:
        # Upgrade pip first to avoid potential issues
        subprocess.check_call([str(pip_path), "install", "--upgrade", "pip"], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
        # Install requirements
        subprocess.check_call([str(pip_path), "install", "-r", str(requirements_path)])
    except subprocess.CalledProcessError as exc:
        # On failure, try to clean up and recreate once more
        if not force_recreate:  # Avoid infinite recursion
            print("Initial pip install failed, attempting clean recreation...")
            return create_virtualenv_and_install_requirements(requirements_path, name, force_recreate=False)
        raise RuntimeError(f"pip install failed with exit code {exc.returncode}")

    return venv_dir


# --- Server Management --- #


def _run_server():
    """Starts the Letta server in a background thread."""
    load_dotenv()
    from letta.server.rest_api.app import start_server

    start_server(debug=True)


@pytest.fixture
def empty_mcp_config():
    path = Path(__file__).parent / "mcp_config.json"
    path.write_text(json.dumps({}))  # writes "{}"

    return path


@pytest.fixture(autouse=True)
def cleanup_test_venvs():
    """Fixture to clean up test virtual environments before and after tests."""
    venv_path = Path(__file__).parent / "weather" / "venv"

    # Clean before test (in case of previous failure)
    if venv_path.exists():
        try:
            shutil.rmtree(venv_path)
        except Exception:
            pass  # Ignore errors during cleanup

    yield  # Run the test

    # Note: We don't clean after test to allow debugging if needed
    # The next test run will clean it anyway


@pytest.fixture()
def server_url(empty_mcp_config):
    """Ensures a server is running and returns its base URL."""
    url = os.getenv("LETTA_SERVER_URL", "http://localhost:8283")

    if not os.getenv("LETTA_SERVER_URL"):
        thread = threading.Thread(target=_run_server, daemon=True)
        thread.start()
        wait_for_server(url)

    return url


@pytest.fixture()
def client(server_url):
    """Creates a REST client for testing."""
    client = Letta(base_url=server_url)
    return client


@pytest.fixture()
def agent_state(client):
    """Creates an agent and ensures cleanup after tests."""
    agent_state = client.agents.create(
        name=f"test_compl_{str(uuid.uuid4())[5:]}",
        include_base_tools=True,
        memory_blocks=[
            {
                "label": "human",
                "value": "Name: Matt",
            },
            {
                "label": "persona",
                "value": "Friendly agent",
            },
        ],
        llm_config=LLMConfig.default_config(model_name="gpt-4o-mini"),
        embedding_config=EmbeddingConfig.default_config(provider="openai"),
    )
    yield agent_state
    client.agents.delete(agent_state.id)


@pytest.mark.asyncio
async def test_sse_mcp_server(client, agent_state):
    mcp_server_name = "deepwiki"
    server_url = "https://mcp.deepwiki.com/sse"
    sse_mcp_config = SSEServerConfig(server_name=mcp_server_name, server_url=server_url)

    # Create MCP server using new API - convert 'type' to 'mcp_server_type' for 1.0 API
    config_dict = sse_mcp_config.model_dump()
    config_dict["mcp_server_type"] = config_dict.pop("type")
    config_dict.pop("server_name")  # server_name is passed separately
    server = client.mcp_servers.create(server_name=mcp_server_name, config=config_dict)

    try:
        # Check that it's in the server list
        servers = client.mcp_servers.list()
        server_names = [s.server_name for s in servers]
        assert mcp_server_name in server_names

        # Check tools - now tools are automatically registered
        tools = client.mcp_servers.tools.list(mcp_server_id=server.id)
        assert len(tools) > 0
        assert isinstance(tools[0], Tool)

        # Test with the ask_question tool which is one of the available deepwiki tools
        ask_question_tool = next((t for t in tools if t.name == "ask_question"), None)
        assert ask_question_tool is not None, f"ask_question tool not found. Available tools: {[t.name for t in tools]}"

        tool_args = {"repoName": "facebook/react", "question": "What is React?"}

        # Add to agent - tool is already registered, just attach it
        client.agents.tools.attach(agent_id=agent_state.id, tool_id=ask_question_tool.id)

        # Create message using MessageCreateParam
        response = client.agents.messages.create(
            agent_id=agent_state.id,
            messages=[
                MessageCreateParam(role="user", content=f"Use the `{ask_question_tool.name}` tool with these arguments: {tool_args}.")
            ],
        )
        seq = response.messages
        calls = [m for m in seq if isinstance(m, ToolCallMessage)]
        assert calls, "Expected a ToolCallMessage"
        assert calls[0].tool_call.name == "ask_question"

        returns = [m for m in seq if isinstance(m, ToolReturnMessage)]
        assert returns, "Expected a ToolReturnMessage"
        tr = returns[0]
        # status field
        assert tr.status == "success", f"Bad status: {tr.status}"
        # Check that we got some content back
        assert len(tr.tool_return.strip()) > 0, f"Expected non-empty tool return, got: {tr.tool_return}"
    finally:
        client.mcp_servers.delete(mcp_server_id=server.id)
        servers = client.mcp_servers.list()
        server_names = [s.server_name for s in servers]
        assert mcp_server_name not in server_names


def test_stdio_mcp_server(client, agent_state, server_url):
    req_file = Path(__file__).parent / "weather" / "requirements.txt"
    create_virtualenv_and_install_requirements(req_file, name="venv")

    mcp_server_name = "weather"
    command = str(Path(__file__).parent / "weather" / "venv" / "bin" / "python3")
    args = [str(Path(__file__).parent / "weather" / "weather.py")]

    stdio_config = StdioServerConfig(
        server_name=mcp_server_name,
        command=command,
        args=args,
    )

    # Create MCP server using new API - convert 'type' to 'mcp_server_type' for 1.0 API
    config_dict = stdio_config.model_dump()
    config_dict["mcp_server_type"] = config_dict.pop("type")
    config_dict.pop("server_name")  # server_name is passed separately
    server = client.mcp_servers.create(server_name=mcp_server_name, config=config_dict)

    try:
        servers = client.mcp_servers.list()
        server_names = [s.server_name for s in servers]
        assert mcp_server_name in server_names

        # Get tools - now automatically registered
        tools = client.mcp_servers.tools.list(mcp_server_id=server.id)
        assert tools, "Expected at least one tool from the weather MCP server"
        assert any(t.name == "get_alerts" for t in tools), f"Got: {[t.name for t in tools]}"

        get_alerts = next(t for t in tools if t.name == "get_alerts")

        # Tool is already registered, just attach it
        client.agents.tools.attach(agent_id=agent_state.id, tool_id=get_alerts.id)

        # Create message using MessageCreateParam
        response = client.agents.messages.create(
            agent_id=agent_state.id,
            messages=[
                MessageCreateParam(role="user", content=f"Use the `{get_alerts.name}` tool with these arguments: {{'state': 'CA'}}.")
            ],
        )

        calls = [m for m in response.messages if isinstance(m, ToolCallMessage) and m.tool_call.name == "get_alerts"]
        assert calls, "Expected a get_alerts ToolCallMessage"

        returns = [m for m in response.messages if isinstance(m, ToolReturnMessage) and m.tool_call_id == calls[0].tool_call.tool_call_id]
        assert returns, "Expected a ToolReturnMessage for get_alerts"
        ret = returns[0]

        assert ret.status == "success", f"Unexpected status: {ret.status}"
        # make sure there's at least some payload
        assert len(ret.tool_return.strip()) >= 10, f"Expected at least 10 characters in tool_return, got {len(ret.tool_return.strip())}"
    finally:
        client.mcp_servers.delete(mcp_server_id=server.id)
        servers = client.mcp_servers.list()
        server_names = [s.server_name for s in servers]
        assert mcp_server_name not in server_names


# Optional OpenAI validation test for MCP-normalized schema
# Skips unless OPENAI_API_KEY is set to avoid network flakiness in CI
EXAMPLE_BAD_SCHEMA = {
    "type": "object",
    "properties": {
        "conversation_type": {
            "type": "string",
            "const": "Group",
            "description": "Specifies the type of conversation to be created. Must be 'Group' for this action.",
        },
        "message": {
            "type": "object",
            "additionalProperties": {},  # invalid for OpenAI: missing "type"
            "description": "Initial message payload",
        },
        "participant_ids": {
            "type": "array",
            "items": {"type": "string"},
            "description": "Participant IDs",
        },
    },
    "required": ["conversation_type", "message", "participant_ids"],
    "additionalProperties": False,
    "$schema": "http://json-schema.org/draft-07/schema#",
}


@pytest.mark.skipif(
    not os.getenv("OPENAI_API_KEY"),
    reason="Requires OPENAI_API_KEY to call OpenAI for schema validation",
)
def test_openai_rejects_untyped_additional_properties_and_accepts_normalized_schema():
    """Test written to check if our extra schema validation works.

    Some MCP servers will return faulty schemas that require correction, or they will brick the LLM client calls.
    """
    import copy

    try:
        from openai import OpenAI
    except Exception as e:  # pragma: no cover
        pytest.skip(f"openai package not available: {e}")

    client = OpenAI()

    def run_request_with_schema(schema: dict):
        tools = [
            {
                "type": "function",
                "function": {
                    "name": "TWITTER_CREATE_A_NEW_DM_CONVERSATION",
                    "description": "Create a DM conversation",
                    "parameters": schema,
                    "strict": True,
                },
            }
        ]

        return client.chat.completions.create(
            model="gpt-4o-mini",
            messages=[{"role": "user", "content": "hello"}],
            tools=tools,
        )

    # Bad schema should raise
    with pytest.raises(Exception):
        run_request_with_schema(EXAMPLE_BAD_SCHEMA)

    # Normalized should succeed
    normalized = copy.deepcopy(EXAMPLE_BAD_SCHEMA)
    normalized["properties"]["message"]["additionalProperties"] = False
    normalized["properties"]["message"]["properties"] = {"text": {"type": "string"}}
    normalized["properties"]["message"]["required"] = ["text"]
    resp = run_request_with_schema(normalized)
    assert getattr(resp, "id", None)


@pytest.mark.asyncio
async def test_streamable_http_mcp_server_update_schema_no_docstring_required(client, agent_state, server_url):
    """
    Repro for schema-derivation-on-update error with MCP tools.

    Without the fix, calling add_mcp_tool a second time for the same MCP tool
    triggers a docstring-based schema derivation on a generated wrapper that has
    no docstring, causing a 500. With the fix in place, updates should succeed.

    With 1.0 API, tools are automatically registered when server is created,
    so this test verifies that tools can be retrieved multiple times without issues.
    """
    mcp_server_name = f"deepwiki_http_{uuid.uuid4().hex[:6]}"
    mcp_url = "https://mcp.deepwiki.com/mcp"

    http_mcp_config = StreamableHTTPServerConfig(server_name=mcp_server_name, server_url=mcp_url)

    # Create MCP server using new API - convert 'type' to 'mcp_server_type' for 1.0 API
    config_dict = http_mcp_config.model_dump()
    config_dict["mcp_server_type"] = config_dict.pop("type")
    config_dict.pop("server_name")  # server_name is passed separately
    server = client.mcp_servers.create(server_name=mcp_server_name, config=config_dict)

    try:
        # Ensure server is registered
        servers = client.mcp_servers.list()
        server_names = [s.server_name for s in servers]
        assert mcp_server_name in server_names

        # Fetch available tools from server - tools are automatically registered
        tools = client.mcp_servers.tools.list(mcp_server_id=server.id)
        assert tools, "Expected at least one tool from deepwiki streamable-http MCP server"
        ask_question_tool = next((t for t in tools if t.name == "ask_question"), None)
        assert ask_question_tool is not None, f"ask_question tool not found. Available: {[t.name for t in tools]}"

        # Verify tool is accessible
        letta_tool_1 = client.mcp_servers.tools.retrieve(mcp_server_id=server.id, tool_id=ask_question_tool.id)
        assert letta_tool_1 is not None

        # Retrieve again - should work without issues
        letta_tool_2 = client.mcp_servers.tools.retrieve(mcp_server_id=server.id, tool_id=ask_question_tool.id)
        assert letta_tool_2 is not None
    finally:
        client.mcp_servers.delete(mcp_server_id=server.id)
        servers = client.mcp_servers.list()
        server_names = [s.server_name for s in servers]
        assert mcp_server_name not in server_names
