import json

from api.run_journal import (
    RunJournalWriter,
    append_run_event,
    find_run_summary,
    latest_run_summary,
    read_run_events,
    stale_interrupted_event,
)


def test_run_journal_appends_monotonic_seq_and_reads_after_cursor(tmp_path):
    writer = RunJournalWriter("session_1", "run_1", session_dir=tmp_path)

    first = writer.append_sse_event("token", {"text": "hello"})
    second = writer.append_sse_event("done", {"session": {"session_id": "session_1"}})

    assert first["seq"] == 1
    assert first["event_id"] == "run_1:1"
    assert first["terminal"] is False
    assert second["seq"] == 2
    assert second["terminal"] is True
    assert second["terminal_state"] == "completed"

    journal = read_run_events("session_1", "run_1", after_seq=1, session_dir=tmp_path)
    assert [event["event"] for event in journal["events"]] == ["done"]


def test_run_journal_reads_bounded_replay_window(tmp_path):
    writer = RunJournalWriter("session_1", "run_1", session_dir=tmp_path)

    writer.append_sse_event("token", {"text": "one"})
    writer.append_sse_event("token", {"text": "two"})
    writer.append_sse_event("token", {"text": "three"})
    writer.append_sse_event("token", {"text": "four"})

    journal = read_run_events(
        "session_1",
        "run_1",
        after_seq=1,
        max_seq=3,
        session_dir=tmp_path,
    )

    assert [event["seq"] for event in journal["events"]] == [2, 3]
    assert [event["payload"]["text"] for event in journal["events"]] == ["two", "three"]


def test_run_journal_default_fsyncs_terminal_events_only(tmp_path, monkeypatch):
    path = tmp_path / "_run_journal" / "session_1" / "run_1.jsonl"
    path.parent.mkdir(parents=True)
    path.touch()
    fsync_calls = []
    monkeypatch.delenv("HERMES_WEBUI_RUN_JOURNAL_FSYNC", raising=False)
    monkeypatch.setattr("api.run_journal.os.fsync", lambda fd: fsync_calls.append(fd))

    append_run_event("session_1", "run_1", "token", {"text": "ok"}, session_dir=tmp_path)

    assert fsync_calls == []

    append_run_event("session_1", "run_1", "done", {"session": {}}, session_dir=tmp_path)

    assert len(fsync_calls) == 1


def test_run_journal_eager_fsync_mode_fsyncs_non_terminal_events(tmp_path, monkeypatch):
    path = tmp_path / "_run_journal" / "session_1" / "run_1.jsonl"
    path.parent.mkdir(parents=True)
    path.touch()
    fsync_calls = []
    monkeypatch.setenv("HERMES_WEBUI_RUN_JOURNAL_FSYNC", "eager")
    monkeypatch.setattr("api.run_journal.os.fsync", lambda fd: fsync_calls.append(fd))

    append_run_event("session_1", "run_1", "token", {"text": "ok"}, session_dir=tmp_path)

    assert len(fsync_calls) == 1


def test_run_journal_tolerates_malformed_lines(tmp_path):
    append_run_event("session_1", "run_1", "token", {"text": "ok"}, session_dir=tmp_path)
    path = tmp_path / "_run_journal" / "session_1" / "run_1.jsonl"
    with path.open("a", encoding="utf-8") as fh:
        fh.write("{not json}\n")
        fh.write(json.dumps(["wrong-shape"]) + "\n")

    journal = read_run_events("session_1", "run_1", session_dir=tmp_path)

    assert len(journal["events"]) == 1
    assert len(journal["malformed"]) == 2


def test_latest_summary_and_find_run_summary_classify_terminal_state(tmp_path):
    append_run_event("session_1", "run_1", "token", {"text": "ok"}, session_dir=tmp_path)
    append_run_event("session_1", "run_1", "cancel", {"message": "Cancelled by user"}, session_dir=tmp_path)

    summary = latest_run_summary("session_1", "run_1", session_dir=tmp_path)
    found = find_run_summary("run_1", session_dir=tmp_path)

    assert summary["terminal"] is True
    assert summary["terminal_state"] == "interrupted-by-user"
    assert summary["last_seq"] == 2
    assert found["session_id"] == "session_1"
    assert found["terminal_state"] == "interrupted-by-user"


def test_terminal_state_classification_distinguishes_crash_from_user_cancel(tmp_path):
    append_run_event("session_1", "run_cancelled", "cancel", {"message": "Cancelled by user"}, session_dir=tmp_path)
    append_run_event("session_1", "run_crashed", "apperror", {"type": "interrupted"}, session_dir=tmp_path)
    append_run_event("session_1", "run_failed", "apperror", {"type": "auth_mismatch"}, session_dir=tmp_path)
    append_run_event("session_1", "run_tool_limit", "apperror", {"type": "tool_limit_reached"}, session_dir=tmp_path)
    append_run_event("session_1", "run_tool_limit_done", "done", {"terminal_state": "tool_limit_reached"}, session_dir=tmp_path)
    append_run_event("session_1", "run_unknown_done", "done", {"terminal_state": "future_unknown_state"}, session_dir=tmp_path)
    append_run_event("session_1", "run_done", "done", {"session": {}}, session_dir=tmp_path)

    assert latest_run_summary("session_1", "run_cancelled", session_dir=tmp_path)["terminal_state"] == "interrupted-by-user"
    assert latest_run_summary("session_1", "run_crashed", session_dir=tmp_path)["terminal_state"] == "interrupted-by-crash"
    assert latest_run_summary("session_1", "run_failed", session_dir=tmp_path)["terminal_state"] == "errored"
    assert latest_run_summary("session_1", "run_tool_limit", session_dir=tmp_path)["terminal_state"] == "tool_limit_reached"
    assert latest_run_summary("session_1", "run_tool_limit_done", session_dir=tmp_path)["terminal_state"] == "tool_limit_reached"
    assert latest_run_summary("session_1", "run_unknown_done", session_dir=tmp_path)["terminal_state"] == "completed"
    assert latest_run_summary("session_1", "run_done", session_dir=tmp_path)["terminal_state"] == "completed"


def test_summary_keeps_logical_terminal_state_when_stream_end_follows(tmp_path):
    append_run_event("session_1", "run_1", "apperror", {"type": "auth_mismatch"}, session_dir=tmp_path)
    append_run_event("session_1", "run_1", "stream_end", {"session_id": "session_1"}, session_dir=tmp_path)

    summary = latest_run_summary("session_1", "run_1", session_dir=tmp_path)

    assert summary["terminal"] is True
    assert summary["last_event"] == "stream_end"
    assert summary["terminal_state"] == "errored"


def test_stale_interrupted_event_reports_non_terminal_journal(tmp_path, monkeypatch):
    append_run_event("session_1", "run_1", "token", {"text": "partial"}, session_dir=tmp_path)

    monkeypatch.setattr("api.run_journal._default_session_dir", lambda: tmp_path)
    event = stale_interrupted_event("session_1", "run_1")
    assert event is not None

    assert event["event"] == "apperror"
    assert event["seq"] == 2
    assert event["terminal_state"] == "lost-worker-bookkeeping"
    assert event["payload"]["type"] == "interrupted"
    assert "last journaled event" in event["payload"]["hint"]
    assert "process restarted" not in event["payload"]["message"]
    assert "lost the live worker" not in event["payload"]["message"]
    assert "live worker stopped" in event["payload"]["message"]


def test_stale_interrupted_event_skips_terminal_journal(tmp_path, monkeypatch):
    append_run_event("session_1", "run_1", "done", {"session": {}}, session_dir=tmp_path)

    monkeypatch.setattr("api.run_journal._default_session_dir", lambda: tmp_path)

    assert stale_interrupted_event("session_1", "run_1") is None