"""Tool calling via a stdio MCP server.

`BackendOptions.mcp_servers` materializes into a temp `--mcp-config` JSON
file under the hood. The model decides when to invoke the tool, claude's
TUI runs the round-trip, and the events stream surfaces a `ToolUseBlock`
plus its `ToolResultBlock`.

This example wires the bundled echo server at `scripts/echo_mcp_server.py`
— same one the smoke test uses.

Run:
  python examples/mcp_tool.py
"""

from __future__ import annotations

import asyncio
import os
import sys
from pathlib import Path

from claude_code_api import (
    AssistantMessage,
    BackendOptions,
    ClaudeCodeBackend,
    ResultMessage,
    TextBlock,
    ToolResultBlock,
    ToolUseBlock,
    UserMessage,
)

REPO_ROOT = Path(__file__).resolve().parent.parent
ECHO_SCRIPT = REPO_ROOT / "scripts" / "echo_mcp_server.py"
CWD = Path(os.environ.get("CLAUDE_CODE_CWD", Path.cwd())).resolve()


async def main() -> None:
    opts = BackendOptions(
        cwd=str(CWD),
        dangerously_skip_permissions=True,
        mcp_servers={
            "echo": {"command": sys.executable, "args": [str(ECHO_SCRIPT)]},
        },
    )
    async with ClaudeCodeBackend(opts) as backend:
        prompt = (
            "Call the `mcp__echo__echo` tool with text='ping' and then "
            "tell me what it returned. Reply with one short sentence."
        )
        async for event in backend.complete([{"role": "user", "content": prompt}]):
            if isinstance(event, AssistantMessage):
                for block in event.content:
                    if isinstance(block, TextBlock) and block.text.strip():
                        print(f"[assistant] {block.text.strip()}")
                    elif isinstance(block, ToolUseBlock):
                        print(f"[tool_use]  {block.name}({block.input})")
            elif isinstance(event, UserMessage) and isinstance(event.content, list):
                for block in event.content:
                    if isinstance(block, ToolResultBlock):
                        print(f"[tool_res]  {block.content!r}")
            elif isinstance(event, ResultMessage):
                print(f"[result]    stop_reason={event.stop_reason}")


if __name__ == "__main__":
    asyncio.run(main())