"""LangGraph example: one node calls precheck before checkout.

No model call. If langgraph is not installed, the same node still runs so CI
can call a mock. Keep this file next to precheck_tool.py.
"""

from __future__ import annotations

import json
import os
import sys
from pathlib import Path
from typing import TypedDict

sys.path.insert(0, str(Path(__file__).resolve().parent))
from precheck_tool import precheck


class PrecheckState(TypedDict, total=False):
    url: str
    reading: dict


def precheck_node(state: PrecheckState) -> dict:
    raw = precheck.invoke({"url": state["url"]}) if hasattr(precheck, "invoke") else precheck(state["url"])
    return {"reading": json.loads(raw)}


def run(url: str) -> dict:
    os.environ.setdefault("ARC_CLIENT_REF", "int-langgraph-py")
    try:
        from langgraph.graph import END, START, StateGraph
    except ImportError:
        return precheck_node({"url": url})
    graph = StateGraph(PrecheckState)
    graph.add_node("precheck", precheck_node)
    graph.add_edge(START, "precheck")
    graph.add_edge("precheck", END)
    return graph.compile().invoke({"url": url})


def main() -> None:
    url = os.environ.get("PRECHECK_EXAMPLE_URL", "https://allbirds.com/products/shoe")
    print(json.dumps(run(url)))


if __name__ == "__main__":
    main()