# requires: langgraph, pydantic, pytest
from langgraph.checkpoint.memory import InMemorySaver
from langgraph.types import Command

from ticket_flow import FakeLLM, Mailer, build


def run(text, llm=None, mailer=None, tid="t"):
    llm, mailer = llm or FakeLLM(), mailer or Mailer()
    app = build(llm, mailer, InMemorySaver())
    cfg = {"configurable": {"thread_id": tid}}
    out = app.invoke({"ticket_id": tid, "text": text, "status": "new", "events": []}, cfg)
    return app, cfg, out, llm, mailer


def test_small_refund_sent_without_approval():
    _, _, out, _, mailer = run("申请退款 30 元")
    assert out["status"] == "sent" and "t" in mailer.sent


def test_large_refund_waits_then_rejected():
    app, cfg, _, _, mailer = run("申请退款 900 元")
    assert app.get_state(cfg).next == ("approve",)
    out = app.invoke(Command(resume={"ok": False, "note": "超过权限"}), cfg)
    assert out["status"] == "rejected" and not mailer.sent


def test_transient_error_retried():
    _, _, out, llm, _ = run("系统报错 500", llm=FakeLLM(fail_times=2))
    assert out["status"] == "sent" and llm.calls == 3


def test_retry_exhausted_raises_and_can_resume():
    llm = FakeLLM(fail_times=3)
    app = build(llm, Mailer(), InMemorySaver())
    cfg = {"configurable": {"thread_id": "x"}}
    try:
        app.invoke({"ticket_id": "x", "text": "怎么开发票", "status": "new", "events": []}, cfg)
        raise AssertionError("应该抛出异常")
    except Exception as e:
        assert "超时" in str(e)
    assert app.get_state(cfg).next == ("draft",)     # 停在失败的节点，分类结果保留
    out = app.invoke(None, cfg)                       # 故障恢复后续跑
    assert out["status"] == "sent" and out["events"].count("classified:question") == 1


def test_send_is_idempotent():
    mailer = Mailer()
    mailer.send("a", "x")
    mailer.send("a", "y")
    assert mailer.sent == {"a": "x"}