app.py

"""Application entry point for the Router Agent.

Run with::

    python app.py
"""

from __future__ import annotations

import argparse
import os
import sys
from pathlib import Path
from typing import Any

ROOT = Path(__file__).resolve().parent
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

from config.logging_config import configure_logging, get_logger  # noqa: E402
from config.settings import ConfigurationError, get_settings, reset_settings_cache  # noqa: E402
from graph.llm_factory import build_llm, configure_langsmith  # noqa: E402
from graph.workflow import RouterWorkflow  # noqa: E402

logger = get_logger(__name__)


def _parse_args(argv: list[str] | None = None) -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Run the Router Agent.")
    parser.add_argument(
        "query",
        nargs="*",
        help="Optional query to process. If omitted, an interactive prompt is shown.",
    )
    parser.add_argument(
        "--config",
        default=os.getenv("APP_CONFIG_PATH", "config/config.yaml"),
        help="Path to the YAML configuration file.",
    )
    return parser.parse_args(argv)


def _build_workflow() -> RouterWorkflow:
    reset_settings_cache()
    try:
        settings = get_settings()
    except ConfigurationError as exc:
        logger.error("config.error", extra={"error": str(exc)})
        raise SystemExit(f"Configuration error: {exc}") from exc
    configure_logging(settings)
    configure_langsmith(settings)
    llm = build_llm(settings)
    return RouterWorkflow(settings=settings, llm=llm)


def _format_result(result: dict[str, Any]) -> str:
    parts = [
        f"Route: {result.get('route', 'unknown')}",
        f"Confidence: {result.get('confidence', 0.0):.2f}",
        f"Reasoning: {result.get('reasoning', '')}",
        "",
        f"Answer: {result.get('response', '')}",
    ]
    path = result.get("execution_path") or []
    if path:
        parts.append("")
        parts.append(f"Execution path: {' -> '.join(path)}")
    return "\n".join(parts)


def main(argv: list[str] | None = None) -> int:
    args = _parse_args(argv)
    if args.config:
        os.environ["APP_CONFIG_PATH"] = args.config

    workflow = _build_workflow()

    if args.query:
        query = " ".join(args.query).strip()
        if not query:
            print("No query provided.", file=sys.stderr)
            return 2
        result = workflow.run(query)
        print(_format_result(result))
        return 0

    print("Router Agent interactive shell. Type 'exit' or Ctrl-C to quit.")
    while True:
        try:
            user_input = input("> ").strip()
        except (EOFError, KeyboardInterrupt):
            print()
            break
        if not user_input:
            continue
        if user_input.lower() in {"exit", "quit"}:
            break
        result = workflow.run(user_input)
        print(_format_result(result))
        print()
    return 0


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