#!/usr/bin/env python3
"""stdio bridge to the Mark VIII MCP server.

Agents that only support stdio transport can run:

    MCP_URL=http://172.16.52.1:8080/mcp \
    MCP_TOKEN=<device session token> \
    python3 scripts/harness_stdio.py

JSON-RPC messages are read line-by-line from stdin (one JSON object per
line, no embedded newlines) and forwarded to the Mark VIII Streamable-HTTP
MCP endpoint. Responses are printed back on stdout as single-line JSON.

Get a token from the Mark VIII Harness page, or fetch one:

    curl -s -X POST http://172.16.52.1:8080/api/login \
      -H 'Content-Type: application/json' \
      -d '{"username":"root","password":"<device password>"}' \
      -c cookies.txt
"""
import json
import os
import sys
import urllib.request

URL = os.environ.get('MCP_URL', 'http://172.16.52.1:8080/mcp')
TOKEN = os.environ.get('MCP_TOKEN', '')


def forward(msg):
    data = json.dumps(msg).encode()
    req = urllib.request.Request(URL, data=data, method='POST')
    req.add_header('Content-Type', 'application/json')
    req.add_header('Accept', 'application/json, text/event-stream')
    if TOKEN:
        req.add_header('Authorization', 'Bearer ' + TOKEN)
    try:
        with urllib.request.urlopen(req, timeout=120) as resp:
            return resp.read().decode()
    except urllib.error.HTTPError as exc:
        return json.dumps({'jsonrpc': '2.0', 'id': msg.get('id'),
                           'error': {'code': exc.code, 'message': exc.read().decode()[:300]}})
    except Exception as exc:  # noqa: BLE001
        return json.dumps({'jsonrpc': '2.0', 'id': msg.get('id'),
                           'error': {'code': -32000, 'message': str(exc)}})


def main():
    if not TOKEN:
        print('warning: MCP_TOKEN not set; server will reject calls', file=sys.stderr)
    for line in sys.stdin:
        line = line.strip()
        if not line:
            continue
        try:
            msg = json.loads(line)
        except ValueError:
            print(json.dumps({'jsonrpc': '2.0', 'id': None,
                              'error': {'code': -32700, 'message': 'parse error'}}))
            continue
        print(forward(msg), flush=True)


if __name__ == '__main__':
    main()