"""Verify generate_image over the Streamable HTTP transport with the real GPU backend.

This script connects to a running ``generate-image-sd15-mcp`` server that was started with
``transport = "streamable-http"`` and calls ``generate_image`` through the HTTP
endpoint.  It exercises the full request path: HTTP connect → MCP initialize →
tools/call → PNG response.
"""

from __future__ import annotations

import argparse
import asyncio
import base64
from pathlib import Path

from mcp import Client
from mcp.types import ImageContent


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser()
    parser.add_argument("--url", default="http://127.0.0.1:8123/mcp")
    parser.add_argument("--output", type=Path, required=True)
    parser.add_argument(
        "--prompt",
        default="a small red cube on a white table, studio photograph, detailed",
    )
    parser.add_argument("--negative-prompt", default="blurry, low quality")
    parser.add_argument("--size", default="square_512")
    return parser.parse_args()


async def run(args: argparse.Namespace) -> None:
    async with Client(args.url, raise_exceptions=True) as client:
        tools = (await client.list_tools()).tools
        tool_names = {tool.name for tool in tools}
        if tool_names != {"generate_image", "generate_guided_image", "inpaint_image"}:
            raise RuntimeError(f"unexpected tools: {tool_names}")

        result = await client.call_tool(
            "generate_image",
            {
                "positive_prompt": args.prompt,
                "negative_prompt": args.negative_prompt,
                "size": args.size,
            },
        )

    if result.is_error or len(result.content) != 1:
        raise RuntimeError(f"generate_image failed: {result}")
    content = result.content[0]
    if not isinstance(content, ImageContent) or content.mime_type != "image/png":
        raise RuntimeError(f"generate_image returned unexpected content: {content}")
    args.output.parent.mkdir(parents=True, exist_ok=True)
    args.output.write_bytes(base64.b64decode(content.data, validate=True))
    print(f"generated={args.output.resolve()}")


def main() -> None:
    asyncio.run(run(parse_args()))


if __name__ == "__main__":
    raise SystemExit(main())