"""Client script that connects to the MCP server via stdio and demonstrates tool usage.

Run this script after starting the server: ``python server.py``.
In another terminal, execute ``python client.py``.
"""

import subprocess
import json

# Helper to send a request via stdin and read the JSON response

def invoke_tool(tool_name, **kwargs):
    # Build the JSON request payload
    payload = {
        "name": tool_name,
        "arguments": kwargs,
    }
    # Start a subprocess that runs the server in stdio mode
    proc = subprocess.Popen(
        ["python", "server.py"],
        stdin=subprocess.PIPE,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE,
        text=True,
    )
    # Send the payload and close stdin to signal end of input
    stdout, stderr = proc.communicate(json.dumps(payload))
    if stderr:
        raise RuntimeError(f"Server error: {stderr.strip()}")
    # Parse the server's response
    return json.loads(stdout.strip())

# Demonstrate each tool
if __name__ == "__main__":
    print("--- Saving key 'foo' with value 'bar' ---")
    print(invoke_tool("save", key="foo", value="bar"))

    print("\n--- Getting key 'foo' ---")
    print(invoke_tool("get", key="foo"))

    print("\n--- Listing keys ---")
    print(invoke_tool("list_keys"))

    print("\n--- Saving namespaced key 'test:count' with value '1' ---")
    print(invoke_tool("save_with_namespace", namespace="test", key="count", value="1"))

    print("\n--- Getting namespaced key 'test:count' ---")
    print(invoke_tool("get_by_namespace", namespace="test", key="count"))

    print("\n--- Deleting key 'foo' ---")
    print(invoke_tool("delete", key="foo"))

    print("\n--- Listing keys after deletion ---")
    print(invoke_tool("list_keys"))