"""Client library for LSP tool scripts. Connects to the bridge daemon, starting it if needed."""

import json
import os
import socket
import subprocess
import sys
import time

SOCK_PATH = os.path.join(os.environ.get("XDG_RUNTIME_DIR", "/tmp"), "ollie-lsp.sock")
PID_PATH = SOCK_PATH + ".pid"


def _bridge_running() -> bool:
    if not os.path.exists(PID_PATH):
        return False
    try:
        pid = int(open(PID_PATH).read().strip())
        os.kill(pid, 0)
        return True
    except (OSError, ValueError):
        return False


def _start_bridge():
    """Start the bridge daemon as a background process."""
    lib_dir = os.path.dirname(os.path.abspath(__file__))
    bridge_script = os.path.join(lib_dir, "bridge.py")
    subprocess.Popen(
        [sys.executable, bridge_script],
        stdin=subprocess.DEVNULL,
        stdout=subprocess.DEVNULL,
        stderr=subprocess.DEVNULL,
        start_new_session=True,
    )
    # Wait for socket to appear
    for _ in range(50):
        if os.path.exists(SOCK_PATH):
            return
        time.sleep(0.1)
    print("error: bridge daemon failed to start", file=sys.stderr)
    sys.exit(1)


def request(method: str, **kwargs) -> dict:
    """Send a request to the bridge and return the response."""
    if not _bridge_running():
        _start_bridge()

    payload = {"method": method, **kwargs}
    data = json.dumps(payload).encode()

    sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
    try:
        sock.connect(SOCK_PATH)
        sock.sendall(data)
        sock.shutdown(socket.SHUT_WR)
        chunks = []
        while True:
            chunk = sock.recv(4096)
            if not chunk:
                break
            chunks.append(chunk)
        response = json.loads(b"".join(chunks))
    except ConnectionRefusedError:
        # Stale socket, restart
        if os.path.exists(SOCK_PATH):
            os.unlink(SOCK_PATH)
        _start_bridge()
        return request(method, **kwargs)
    finally:
        sock.close()

    if "error" in response:
        print(f"error: {response['error']}", file=sys.stderr)
        sys.exit(1)
    return response.get("result")