"""The Novox Mesh SDK for Python — the skeleton (novox/hq ADR 0187).

A tools bundle is a process the node's runtime launches and speaks MCP over stdio to: `initialize`,
`tools/list` once, `tools/call` per call, newline-framed JSON-RPC on stdin and stdout. This module is
the loop, so a bundle writes its tools and nothing else. A tool named `<seat>.<verb>` is the
module's implementation of that seat's verb; any other name is the module's own.

No transport here: the bus, the subjects and the memberships are the runtime's (ADR 0039, 0175).
stdout is the protocol; log to stderr.
"""
import json
import sys
from dataclasses import dataclass, field
from typing import Any, Callable, Dict, List

PROTOCOL = "2025-03-26"


@dataclass
class Tool:
    name: str
    description: str
    run: Callable[[Dict[str, Any]], Any]
    # The JSON schema of the arguments, or the bare property map the catalogue's modules write.
    input: Dict[str, Any] = field(default_factory=dict)


def as_schema(given: Dict[str, Any]) -> Dict[str, Any]:
    if not given:
        return {"type": "object", "properties": {}}
    if given.get("type") == "object" or "properties" in given:
        return given
    return {"type": "object", "properties": given}


def serve(name: str, tools: List[Tool]) -> None:
    """Serve these tools to the runtime over stdio until stdin closes."""
    by_name = {t.name: t for t in tools}
    out = sys.stdout

    def say(message: Dict[str, Any]) -> None:
        out.write(json.dumps(message) + "\n")
        out.flush()

    for line in sys.stdin:
        line = line.strip()
        if not line:
            continue
        try:
            request = json.loads(line)
        except ValueError:
            continue
        rid = request.get("id")
        method = request.get("method")
        params = request.get("params") or {}
        if method == "initialize":
            say({"jsonrpc": "2.0", "id": rid, "result": {"protocolVersion": PROTOCOL, "capabilities": {"tools": {}}, "serverInfo": {"name": name, "version": "1"}}})
        elif method == "notifications/initialized":
            pass
        elif method == "ping":
            if rid is not None:
                say({"jsonrpc": "2.0", "id": rid, "result": {}})
        elif method == "tools/list":
            say({"jsonrpc": "2.0", "id": rid, "result": {"tools": [
                {"name": t.name, "description": t.description, "inputSchema": as_schema(t.input)} for t in tools]}})
        elif method == "tools/call":
            tool = by_name.get(str(params.get("name", "")))
            if tool is None:
                say({"jsonrpc": "2.0", "id": rid, "error": {"code": -32602, "message": f"{name} has no tool {params.get('name')}"}})
                continue
            try:
                result = tool.run(params.get("arguments") or {})
                say({"jsonrpc": "2.0", "id": rid, "result": {"content": [{"type": "text", "text": json.dumps(result)}]}})
            except Exception as err:  # the tool failed: a tool error, not a protocol one
                say({"jsonrpc": "2.0", "id": rid, "result": {"content": [{"type": "text", "text": str(err)}], "isError": True}})
        elif rid is not None:
            say({"jsonrpc": "2.0", "id": rid, "error": {"code": -32601, "message": f"no {method}"}})