"""The per-call log line carries what a cost or cache investigation needs: the cache write count, the
provider's response id, and the serving upstream when the route reports one. Existing parsers read a
prefix of the line, so the fields are appended and optional."""
import logging
from types import SimpleNamespace


def _agent(tmp_path, monkeypatch):
    monkeypatch.setenv("HERMES_HOME", str(tmp_path))
    from run_agent import AIAgent
    return AIAgent(api_key="k", base_url="https://inference-api.nousresearch.com/v1", provider="nous",
                   api_mode="chat_completions", model="anthropic/claude-fable-5.1", session_id="t", platform="cli",
                   quiet_mode=True, skip_context_files=True, skip_memory=True, save_trajectories=False, enabled_toolsets=["file"])


def _usage(read, write, prompt):
    return SimpleNamespace(prompt_tokens=prompt, completion_tokens=7, total_tokens=prompt + 7,
                           prompt_tokens_details=SimpleNamespace(cached_tokens=read, cache_write_tokens=write),
                           completion_tokens_details=None)


def _line(agent, caplog, resp):
    from agent import turn_usage
    caplog.clear()
    with caplog.at_level(logging.INFO, logger="agent.turn_usage"):
        turn_usage.record_response_usage(agent, resp, messages=[{"role": "user", "content": "hi"}], api_call_count=1,
                                         api_duration=0.2, compression_attempts=0, max_compression_attempts=3)
    return next(r.getMessage() for r in caplog.records if r.getMessage().startswith("API call #"))


def test_write_id_and_upstream_are_on_the_line(tmp_path, monkeypatch, caplog):
    a = _agent(tmp_path, monkeypatch)
    try:
        line = _line(a, caplog, SimpleNamespace(usage=_usage(34_283, 28_604, 62_889), id="gen-1788636728-qMa1SbYZcwjrvUzJuF1g",
                                                provider="Anthropic", model="anthropic/claude-fable-5.1"))
    finally:
        a.close()
    assert " cache=34283/62889 (55%)" in line
    assert " write=28604" in line
    assert " id=gen-1788636728-qMa1SbYZcwjrvUzJuF1g" in line
    assert " upstream=Anthropic" in line
    # the pre-existing prefix is unchanged, so older parsers keep matching
    assert line.startswith("API call #1: model=anthropic/claude-fable-5.1 provider=nous in=62889 out=7 total=62896 latency=0.2s")


def test_fields_are_omitted_when_absent(tmp_path, monkeypatch, caplog):
    a = _agent(tmp_path, monkeypatch)
    try:
        line = _line(a, caplog, SimpleNamespace(usage=_usage(0, 0, 100), id=None, model="anthropic/claude-fable-5.1"))
    finally:
        a.close()
    assert "write=" not in line and "id=" not in line and "upstream=" not in line


def test_forensics_parser_reads_the_new_fields(tmp_path):
    from evals.postmortem.forensics.logcalls import parse_logs
    log = tmp_path / "agent.log"
    log.write_text(
        "2026-09-06 19:32:08,549 INFO [s1] agent.conversation_loop: API call #3: model=anthropic/claude-fable-5.1 provider=nous "
        "in=62889 out=7 total=62896 latency=0.2s cache=34283/62889 (55%) write=28604 id=gen-1788636728-qMa1 upstream=Claude Platform on AWS\n"
        "2026-09-06 19:32:09,549 INFO [s1] agent.conversation_loop: API call #4: model=anthropic/claude-fable-5.1 provider=nous "
        "in=91079 out=7 total=91086 latency=0.2s cache=62887/91079 (69%)\n", encoding="utf-8")
    calls = parse_logs([str(log)], {"s1"})
    assert [c["n"] for c in calls] == [3, 4]
    assert calls[0]["write"] == 28604 and calls[0]["id"] == "gen-1788636728-qMa1" and calls[0]["upstream"] == "Claude Platform on AWS"
    assert "write" not in calls[1] and "id" not in calls[1]


def test_long_decode_context_buckets_use_the_first_hop(tmp_path, monkeypatch, caplog):
    """A multi-hop Gemini long decode sums every hop's re-sent prefix for billing; the context engine's
    prompt AND canonical input/cache buckets carry hop 1, so cache_read never exceeds prompt there."""
    a = _agent(tmp_path, monkeypatch)
    usage = _usage(32_840, 0, 32_968)
    usage.initial_prompt_tokens, usage.initial_cached_tokens = 100, 40
    seen = {}
    monkeypatch.setattr(a.context_compressor, "update_from_response", lambda u: seen.update(u))
    try:
        line = _line(a, caplog, SimpleNamespace(usage=usage, id=None, model="anthropic/claude-fable-5.1"))
    finally:
        a.close()
    assert " in=32968 " in line  # the log line keeps the billed sum
    assert (seen["prompt_tokens"], seen["input_tokens"], seen["cache_read_tokens"]) == (100, 60, 40)