#!/usr/bin/env python3
"""
[Agent 入口] Python 独立进程 — JSON-RPC over HTTP
改监听地址：HOST / PORT
改业务方法：handle_rpc 内的 method 分支
协议字段必须与 Go internal/protocol 对齐（protocolVersion=1.0）
"""

from __future__ import annotations

import json
import uuid
from http.server import BaseHTTPRequestHandler, HTTPServer
from typing import Any

HOST = "127.0.0.1"
PORT = 17890
PROTOCOL_VERSION = "1.0"


def handle_rpc(body: dict[str, Any]) -> dict[str, Any]:
    # ---------- [关键] 所有 Agent method 分发在这里 ----------
    req_id = body.get("id") or str(uuid.uuid4())
    version = body.get("protocolVersion", "")
    method = body.get("method", "")
    params = body.get("params") or {}

    if version != PROTOCOL_VERSION:
        return {
            "protocolVersion": PROTOCOL_VERSION,
            "id": req_id,
            "error": {
                "code": -32000,
                "message": f"protocol mismatch: got {version}, want {PROTOCOL_VERSION}",
            },
        }

    if method == "agent.health":
        return {
            "protocolVersion": PROTOCOL_VERSION,
            "id": req_id,
            "result": {"ok": True, "engine": "python-stub"},
        }

    if method == "agent.chat":
        # TODO[云端 API]: 在此接入 OpenAI / Claude 等
        message = ""
        if isinstance(params, dict):
            message = str(params.get("message") or params.get("userMessage") or "")
        return {
            "protocolVersion": PROTOCOL_VERSION,
            "id": req_id,
            "result": {
                "role": "assistant",
                "content": f"（Python stub）收到：{message}",
            },
        }

    if method == "agent.plan_next":
        # TODO[多模态]: 解析 frameBase64 + userMessage → actions
        return {
            "protocolVersion": PROTOCOL_VERSION,
            "id": req_id,
            "result": {
                "thought": "骨架：尚未接入视觉模型",
                "actions": [],
            },
        }

    return {
        "protocolVersion": PROTOCOL_VERSION,
        "id": req_id,
        "error": {"code": -32601, "message": f"method not found: {method}"},
    }


class RPCHandler(BaseHTTPRequestHandler):
    def log_message(self, fmt: str, *args: Any) -> None:
        print(f"[agent] {self.address_string()} - {fmt % args}")

    def do_POST(self) -> None:
        # [关键] 唯一 RPC 入口路径
        if self.path != "/rpc":
            self.send_error(404)
            return
        length = int(self.headers.get("Content-Length", "0"))
        raw = self.rfile.read(length)
        try:
            body = json.loads(raw.decode("utf-8"))
        except json.JSONDecodeError:
            self._write(400, {"error": {"code": -32700, "message": "parse error"}})
            return
        self._write(200, handle_rpc(body))

    def _write(self, status: int, payload: dict[str, Any]) -> None:
        data = json.dumps(payload, ensure_ascii=False).encode("utf-8")
        self.send_response(status)
        self.send_header("Content-Type", "application/json; charset=utf-8")
        self.send_header("Content-Length", str(len(data)))
        self.end_headers()
        self.wfile.write(data)


def main() -> None:
    server = HTTPServer((HOST, PORT), RPCHandler)
    print(f"[agent] listening on http://{HOST}:{PORT}/rpc  protocol={PROTOCOL_VERSION}")
    server.serve_forever()


if __name__ == "__main__":
    main()