"""
提供 MCP 工具发现、调用以及流式会话的 HTTP 接入。
"""

from typing import Annotated, Any, Dict, List, Union

from fastapi import Depends, HTTPException, Request
from fastapi.responses import JSONResponse, Response

from app.adapters.web.security.access import verify_apikey
from app.agent.tools.manager import ToolDefinition, moviepilot_tool_manager
from app.agent.tools.projection import project_tool_schema
from app.api.response import (
    RAW_RESPONSE_OPENAPI_KEY,
    CompatibleCountParam,
    CompatiblePageParam,
    ResponseAPIRouter,
)
from app.runtime.log import logger
from app.runtime.version import get_app_version
from app.schemas.mcp import MCP_JSONRPC_REQUEST_SCHEMA as _SchemaMCP_JSONRPC_REQUEST_SCHEMA
from app.schemas.mcp import McpJsonRpcError as _SchemaMcpJsonRpcError
from app.schemas.mcp import McpJsonRpcResponse as _SchemaMcpJsonRpcResponse
from app.schemas.mcp import McpJsonSchema as _SchemaMcpJsonSchema
from app.schemas.mcp import McpToolInfo as _SchemaMcpToolInfo
from app.schemas.mcp import ToolCallData as _SchemaToolCallData
from app.schemas.mcp import ToolCallRequest as _SchemaToolCallRequest
from app.schemas.response import Response as _SchemaResponse

router = ResponseAPIRouter()

# MCP 协议版本
MCP_PROTOCOL_VERSIONS = ["2025-11-25", "2025-06-18", "2024-11-05"]
# 默认使用最新版本
MCP_PROTOCOL_VERSION = MCP_PROTOCOL_VERSIONS[0]
# MCP 经 API_TOKEN / X-API-KEY 认证后是管理员级集成入口；隐藏工具只收敛暴露面，不构成权限边界。
MCP_HIDDEN_TOOLS = {
    "execute_command",
    "search_web",
    "edit_file",
    "apply_patch",
    "write_file",
    "read_file",
    "read_skill",
    "view_image",
}

# 客户端 schema 模式：默认 full 保持完整 oneOf 合同；compact 为显式 opt-in，
# 把序列化后超出客户端压缩阈值的工具 schema 投影为顶层对象合同（见 projection 模块）。
MCP_SCHEMA_MODE_FULL = "full"
MCP_SCHEMA_MODE_COMPACT = "compact"
MCP_SCHEMA_MODES = (MCP_SCHEMA_MODE_FULL, MCP_SCHEMA_MODE_COMPACT)
MCP_SCHEMA_MODE_HEADER = "X-MCP-Schema-Mode"

MCP_JSONRPC_ERROR_RESPONSES: dict[int | str, dict[str, object]] = {
    400: {"model": _SchemaMcpJsonRpcError, "description": "JSON-RPC 请求错误"},
    401: {"model": _SchemaMcpJsonRpcError, "description": "JSON-RPC 认证失败"},
    403: {"model": _SchemaMcpJsonRpcError, "description": "JSON-RPC 访问被拒绝"},
    404: {"model": _SchemaMcpJsonRpcError, "description": "JSON-RPC 方法不存在"},
    409: {"model": _SchemaMcpJsonRpcError, "description": "JSON-RPC 请求冲突"},
    422: {"model": _SchemaMcpJsonRpcError, "description": "JSON-RPC 参数校验失败"},
    500: {"model": _SchemaMcpJsonRpcError, "description": "JSON-RPC 内部错误"},
}


def list_exposed_tools() -> List[ToolDefinition]:
    """
    获取 MCP 可见工具列表
    """
    tools: List[ToolDefinition] = list(moviepilot_tool_manager.list_tools())
    return [tool for tool in tools if tool.name not in MCP_HIDDEN_TOOLS]


def resolve_schema_mode(request: Request) -> str:
    """
    读取客户端的 schema 模式；未声明或取值不支持时保持默认 full。
    """
    raw = request.headers.get(MCP_SCHEMA_MODE_HEADER) or ""
    mode = raw.strip().lower()
    return mode if mode in MCP_SCHEMA_MODES else MCP_SCHEMA_MODE_FULL


def list_client_tools(schema_mode: str = MCP_SCHEMA_MODE_FULL) -> List[ToolDefinition]:
    """
    按客户端 schema 模式返回工具；compact 模式下投影超出客户端阈值的 schema。
    """
    tools = list_exposed_tools()
    if schema_mode != MCP_SCHEMA_MODE_COMPACT:
        return tools

    client_tools: List[ToolDefinition] = []
    projected_names: List[str] = []
    for tool in tools:
        schema, projected = project_tool_schema(tool.input_schema)
        if not projected:
            client_tools.append(tool)
            continue
        projected_names.append(tool.name)
        client_tools.append(
            ToolDefinition(name=tool.name, description=tool.description, input_schema=schema)
        )
    if projected_names:
        logger.debug(f"MCP schema compact 投影：{', '.join(projected_names)}")
    return client_tools


def create_jsonrpc_response(request_id: Union[str, int, None], result: Any) -> Dict[str, Any]:
    """
    创建 JSON-RPC 成功响应
    """
    response = {"jsonrpc": "2.0", "id": request_id, "result": result}
    return response


def create_jsonrpc_error(
    request_id: Union[str, int, None], code: int, message: str, data: Any = None
) -> Dict[str, Any]:
    """
    创建 JSON-RPC 错误响应
    """
    error_detail: Dict[str, object] = {"code": code, "message": message}
    error = {
        "jsonrpc": "2.0",
        "id": request_id,
        "error": error_detail,
    }
    if data is not None:
        error_detail["data"] = data
    return error


async def _dispatch_jsonrpc_method(
    method: Any,
    params: Dict[str, Any],
    request_id: Union[str, int, None],
    schema_mode: str = MCP_SCHEMA_MODE_FULL,
) -> Union[JSONResponse, Response]:
    """
    分派一个已经通过基础格式校验的 MCP JSON-RPC 方法。
    """
    if method == "initialize":
        result = await handle_initialize(params)
        return JSONResponse(content=create_jsonrpc_response(request_id, result))
    if method == "notifications/initialized":
        if request_id is None:
            return Response(status_code=204)
        return JSONResponse(
            status_code=400,
            content=create_jsonrpc_error(request_id, -32600, "initialized must be a notification"),
        )
    if method == "tools/list":
        result = await handle_tools_list(schema_mode)
        return JSONResponse(content=create_jsonrpc_response(request_id, result))
    if method == "tools/call":
        result = await handle_tools_call(params)
        return JSONResponse(content=create_jsonrpc_response(request_id, result))
    if method == "ping":
        return JSONResponse(content=create_jsonrpc_response(request_id, {}))
    return JSONResponse(content=create_jsonrpc_error(request_id, -32601, f"Method not found: {method}"))


@router.post(
    "",
    summary="MCP JSON-RPC 端点",
    response_model=_SchemaMcpJsonRpcResponse,
    openapi_extra={
        RAW_RESPONSE_OPENAPI_KEY: True,
        "requestBody": {
            "required": True,
            "content": {"application/json": {"schema": _SchemaMCP_JSONRPC_REQUEST_SCHEMA}},
        },
    },
    responses={
        **MCP_JSONRPC_ERROR_RESPONSES,
        204: {"description": "JSON-RPC 通知已接收"},
    },
)
async def mcp_jsonrpc(
    request: Request, _: Annotated[Union[str, None], Depends(verify_apikey)] = None
) -> Union[JSONResponse, Response]:
    """
    MCP 标准 JSON-RPC 2.0 端点

    处理所有 MCP 协议消息（初始化、工具列表、工具调用等）
    """
    try:
        body = await request.json()
    except Exception as e:
        logger.error(f"解析请求体失败: {e}")
        return JSONResponse(
            status_code=400,
            content=create_jsonrpc_error(None, -32700, "Parse error", str(e)),
        )

    # 验证 JSON-RPC 格式
    if not isinstance(body, dict) or body.get("jsonrpc") != "2.0":
        return JSONResponse(
            status_code=400,
            content=create_jsonrpc_error(
                body.get("id") if isinstance(body, dict) else None, -32600, "Invalid Request"
            ),
        )

    method = body.get("method")
    params = body.get("params", {})
    request_id = body.get("id")

    try:
        return await _dispatch_jsonrpc_method(method, params, request_id, schema_mode=resolve_schema_mode(request))

    except ValueError as e:
        logger.warning(f"MCP 请求参数错误: {e}")
        return JSONResponse(
            status_code=400,
            content=create_jsonrpc_error(request_id, -32602, "Invalid params", str(e)),
        )
    except Exception as e:
        logger.error(f"处理 MCP 请求失败: {e}", exc_info=True)
        return JSONResponse(
            status_code=500,
            content=create_jsonrpc_error(request_id, -32603, "Internal error", str(e)),
        )


async def handle_initialize(params: Dict[str, Any]) -> Dict[str, Any]:
    """
    处理初始化请求
    """
    protocol_version = params.get("protocolVersion")
    client_info = params.get("clientInfo", {})

    logger.info(f"MCP 初始化请求: 客户端={client_info.get('name')}, 协议版本={protocol_version}")

    # 版本协商：选择客户端和服务器都支持的版本
    negotiated_version = MCP_PROTOCOL_VERSION
    if protocol_version in MCP_PROTOCOL_VERSIONS:
        # 客户端版本在支持列表中，使用客户端版本
        negotiated_version = protocol_version
        logger.info(f"使用客户端协议版本: {negotiated_version}")
    else:
        # 客户端版本不支持，使用服务器默认版本
        logger.warning(f"协议版本不匹配: 客户端={protocol_version}, 使用服务器版本={negotiated_version}")

    return {
        "protocolVersion": negotiated_version,
        "capabilities": {
            "tools": {
                # 暂不支持工具列表变更通知
                "listChanged": False
            },
            "logging": {},
        },
        "serverInfo": {
            "name": "MoviePilot",
            "version": get_app_version(),
            "description": "MoviePilot MCP Server - 电影自动化管理工具",
        },
        "instructions": "MoviePilot MCP 服务器，提供媒体管理、订阅、下载等工具。",
    }


async def handle_tools_list(schema_mode: str = MCP_SCHEMA_MODE_FULL) -> Dict[str, Any]:
    """
    处理工具列表请求（默认完整合同；compact 模式按客户端预算投影）
    """
    tools = list_client_tools(schema_mode)

    # 转换为 MCP 工具格式
    mcp_tools = []
    for tool in tools:
        mcp_tool = {
            "name": tool.name,
            "description": tool.description,
            "inputSchema": tool.input_schema,
        }
        mcp_tools.append(mcp_tool)

    return {"tools": mcp_tools}


async def handle_tools_call(params: Dict[str, Any]) -> Dict[str, Any]:
    """
    处理工具调用请求
    """
    tool_name = params.get("name")
    arguments = params.get("arguments", {})

    if not tool_name:
        raise ValueError("Missing tool name")

    try:
        if tool_name in MCP_HIDDEN_TOOLS:
            raise ValueError(f"工具 '{tool_name}' 未找到")

        result_text = await moviepilot_tool_manager.call_tool(tool_name, arguments)

        return {"content": [{"type": "text", "text": result_text}]}
    except Exception as e:
        logger.error(f"工具调用失败: {tool_name}, 错误: {e}", exc_info=True)
        return {
            "content": [{"type": "text", "text": f"错误: {str(e)}"}],
            "isError": True,
        }


@router.delete(
    "",
    summary="终止 MCP 会话",
    status_code=204,
    response_class=Response,
    response_model=None,
    responses={
        **MCP_JSONRPC_ERROR_RESPONSES,
        204: {"description": "MCP 会话已终止"},
    },
)
async def delete_mcp_session(
    _: Annotated[Union[str, None], Depends(verify_apikey)] = None,
) -> Union[JSONResponse, Response]:
    """
    终止 MCP 会话（无状态模式下仅返回成功）
    """
    return Response(status_code=204)


# HTTP 工具管理端点
@router.get(
    "/tools",
    summary="列出所有可用工具",
    response_model=List[_SchemaMcpToolInfo],
)
async def list_tools(_: Annotated[str, Depends(verify_apikey)], page: CompatiblePageParam = None, count: CompatibleCountParam = None) -> Any:
    """
    获取所有可用的工具列表

    返回每个工具的名称、描述和参数定义
    """
    try:
        # 获取所有工具定义
        tools = list_exposed_tools()

        # 转换为字典格式
        tools_list = []
        for tool in tools:
            tool_dict = {
                "name": tool.name,
                "description": tool.description,
                "inputSchema": tool.input_schema,
            }
            tools_list.append(tool_dict)

        return tools_list
    except Exception as e:
        logger.error(f"获取工具列表失败: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail=f"获取工具列表失败: {str(e)}")


@router.post(
    "/tools/call",
    summary="调用工具",
    response_model=_SchemaResponse[_SchemaToolCallData],
)
async def call_tool(request: _SchemaToolCallRequest, _: Annotated[Union[str, None], Depends(verify_apikey)] = None) -> Any:
    """
    调用对外开放的指定工具。

    :param request: 工具名称和对应参数
    :param _: 已通过 API Key 校验的依赖结果
    :return: 工具执行结果；工具不可见、不存在或执行异常时返回失败响应
    """
    try:
        if request.tool_name in MCP_HIDDEN_TOOLS:
            raise ValueError(f"工具 '{request.tool_name}' 未找到")

        result_text = await moviepilot_tool_manager.call_tool(request.tool_name, request.arguments)

        return _SchemaResponse(
            success=True,
            data=_SchemaToolCallData(result=result_text),
        )
    except Exception as e:
        logger.error(f"调用工具 {request.tool_name} 失败: {e}", exc_info=True)
        return _SchemaResponse(success=False, message="调用工具失败")


@router.get(
    "/tools/{tool_name}",
    summary="获取工具详情",
    response_model=_SchemaMcpToolInfo,
)
async def get_tool_info(tool_name: str, _: Annotated[str, Depends(verify_apikey)]) -> Any:
    """
    获取对外开放工具的详细信息。

    :param tool_name: 工具登记名称
    :param _: 已验证的 API Key
    :return: 工具名称、中文描述和输入 Schema
    :raises HTTPException: 工具不存在时为 404，读取失败时为 500
    """
    try:
        # 获取所有工具
        tools = list_exposed_tools()

        # 查找指定工具
        for tool in tools:
            if tool.name == tool_name:
                return {
                    "name": tool.name,
                    "description": tool.description,
                    "inputSchema": tool.input_schema,
                }

        raise HTTPException(status_code=404, detail=f"工具 '{tool_name}' 未找到")
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"获取工具信息失败: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail=f"获取工具信息失败: {str(e)}")


@router.get(
    "/tools/{tool_name}/schema",
    summary="获取工具参数Schema",
    response_model=_SchemaMcpJsonSchema,
)
async def get_tool_schema(tool_name: str, _: Annotated[str, Depends(verify_apikey)]) -> Any:
    """
    读取对外开放工具的输入 JSON Schema。

    :param tool_name: 工具登记名称
    :param _: 已验证的 API Key
    :return: 工具输入 Schema
    :raises HTTPException: 工具不存在时为 404，读取失败时为 500
    """
    try:
        # 获取所有工具
        tools = list_exposed_tools()

        # 查找指定工具
        for tool in tools:
            if tool.name == tool_name:
                return tool.input_schema

        raise HTTPException(status_code=404, detail=f"工具 '{tool_name}' 未找到")
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"获取工具Schema失败: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail=f"获取工具Schema失败: {str(e)}")