"""LangGraph Platform client - run/stream agent graphs, thread state."""
import os
import requests

BASE = os.getenv("LANGGRAPH_API_URL", "http://localhost:8123")
TOKEN = os.getenv("LANGGRAPH_AUTH_TOKEN")


def _h():
    headers = {"Content-Type": "application/json"}
    if TOKEN:
        headers["Authorization"] = f"Bearer {TOKEN}"
    return headers


def invoke(graph_id, input, thread_id=None, config=None):
    body = {"input": input, "config": config or {}}
    if thread_id:
        body["config"] = {"configurable": {"thread_id": thread_id}}
    return requests.post(f"{BASE}/{graph_id}/invoke", headers=_h(), json=body, timeout=120).json()


def stream(graph_id, input, thread_id=None):
    body = {"input": input, "config": {"configurable": {"thread_id": thread_id}} if thread_id else {}}
    r = requests.post(f"{BASE}/{graph_id}/stream", headers=_h(), json=body, timeout=300, stream=True)
    r.raise_for_status()
    for line in r.iter_lines(decode_unicode=True):
        if line:
            yield line


def get_state(graph_id, thread_id):
    return requests.get(f"{BASE}/{graph_id}/state", headers=_h(), params={"thread_id": thread_id}, timeout=60).json()


def list_threads(graph_id, **params):
    return requests.get(f"{BASE}/{graph_id}/threads", headers=_h(), params=params, timeout=60).json()