"""Stdio MCP framing: Cursor expects NDJSON responses (pi-subagents style)."""
from __future__ import annotations

import json
import subprocess
import unittest
from pathlib import Path

REPO = Path(__file__).resolve().parents[2]
MCP = REPO / "scripts" / "mcp"


class McpNdjsonFramingTest(unittest.TestCase):
    def _handshake(self, script: Path) -> dict:
        """Send NDJSON initialize; expect a single NDJSON JSON-RPC response line."""
        req = {
            "jsonrpc": "2.0",
            "id": 1,
            "method": "initialize",
            "params": {
                "protocolVersion": "2024-11-05",
                "capabilities": {},
                "clientInfo": {"name": "unittest", "version": "0"},
            },
        }
        r = subprocess.run(
            ["node", str(script)],
            input=json.dumps(req) + "\n",
            capture_output=True,
            text=True,
            cwd=str(REPO),
            timeout=10,
            check=False,
        )
        out = (r.stdout or "").strip()
        # Must not use Content-Length response framing for Cursor IDE.
        self.assertFalse(
            out.lower().startswith("content-length:"),
            f"{script.name} still uses Content-Length response: {out[:120]!r}",
        )
        lines = [ln for ln in out.splitlines() if ln.strip()]
        self.assertTrue(lines, f"{script.name} produced no stdout: stderr={r.stderr!r}")
        msg = json.loads(lines[0])
        self.assertEqual(msg.get("jsonrpc"), "2.0")
        self.assertEqual(msg.get("id"), 1)
        self.assertIn("result", msg)
        return msg

    def test_agentctl_initialize_ndjson(self):
        msg = self._handshake(MCP / "agentctl-mcp.mjs")
        self.assertEqual(msg["result"]["serverInfo"]["name"], "agentctl")

    def test_jev_initialize_ndjson(self):
        msg = self._handshake(MCP / "jev-mcp.mjs")
        self.assertEqual(msg["result"]["serverInfo"]["name"], "jev")

    def test_pi_subagents_initialize_ndjson(self):
        msg = self._handshake(MCP / "pi-subagents-mcp.mjs")
        self.assertEqual(msg["result"]["serverInfo"]["name"], "pi-subagents")

    def test_mcp_json_stdio_type_for_all_node_servers(self):
        cfg = json.loads((REPO / ".cursor" / "mcp.json").read_text(encoding="utf-8"))
        for name in ("agentctl", "jev", "pi-subagents"):
            entry = cfg["mcpServers"][name]
            self.assertEqual(entry.get("type"), "stdio", name)
            self.assertTrue(any(a.startswith("scripts/") for a in entry["args"]), name)


if __name__ == "__main__":
    unittest.main()