"""MCP 客户端 — Streamable HTTP 与 stdio 均用的 JSON-RPC 解析工具。

两种传输层的具体实现在 ``transports/`` 子包中。
"""

from __future__ import annotations

from typing import Any

import httpx

from app.core.config import settings
from app.modules.tool_runtime.definition import ToolResult


def _auth_headers(auth_token: str | None) -> dict[str, str]:
    return {"Authorization": f"Bearer {auth_token}"} if auth_token else {}


def _parse_call_result(data: dict) -> ToolResult:
    """解析 JSON-RPC tools/call 响应为 ToolResult。

    供 StreamableHttpTransport 和 StdioTransport 共用。
    """
    if data.get("error"):
        return ToolResult(
            ok=False,
            stdout="",
            stderr=data["error"].get("message", "MCP 错误"),
            duration_ms=0,
            exit_code=1,
            timeout=False,
            truncated=False,
            trace_id="",
        )
    result = data.get("result") if isinstance(data, dict) else None
    if not isinstance(result, dict):
        return ToolResult(
            ok=False,
            stdout=str(result) if result else "",
            stderr="无效响应格式",
            duration_ms=0,
            exit_code=1,
            timeout=False,
            truncated=False,
            trace_id="",
        )
    content = result.get("content", [])
    stdout_parts = []
    for item in content:
        if item.get("type") in ("text", "json"):
            stdout_parts.append(item.get("text", ""))
    truncated = bool((result.get("meta") or {}).get("truncated", False))
    return ToolResult(
        ok=not result.get("isError", False),
        stdout="".join(stdout_parts),
        stderr="",
        duration_ms=0,
        exit_code=0 if not result.get("isError", False) else 1,
        timeout=False,
        truncated=truncated,
        trace_id="",
    )


async def call_tool(
    http_client: httpx.AsyncClient,
    endpoint_url: str,
    tool_name: str,
    arguments: dict,
    auth_token: str | None = None,
    meta: dict | None = None,
) -> ToolResult:
    """通过 Streamable HTTP 调用 MCP 工具（供 _make_mcp_executor 使用）。"""
    body: dict[str, Any] = {
        "jsonrpc": "2.0",
        "id": 1,
        "method": "tools/call",
        "params": {
            "name": tool_name,
            "arguments": arguments,
        },
    }
    if meta:
        body["meta"] = meta
    try:
        resp = await http_client.post(
            endpoint_url,
            json=body,
            headers=_auth_headers(auth_token),
            timeout=settings.mcp_call_timeout_seconds,
        )
        resp.raise_for_status()
        data = resp.json()
    except (httpx.HTTPError, ValueError, TypeError) as exc:
        return ToolResult(
            ok=False,
            stdout="",
            stderr=str(exc),
            duration_ms=0,
            exit_code=None,
            timeout=False,
            truncated=False,
            trace_id="",
        )
    return _parse_call_result(data)