import json

import httpx

from nisse_core.models.probe import interpret, probe


def test_a_cut_at_the_declared_window_matches() -> None:
    result = interpret(declared=4096, sent=6144, reported=4096, error=None)
    assert result.verdict == "matches"
    assert result.server_window == 4096


def test_a_cut_below_the_declaration_says_what_to_set() -> None:
    # The dangerous case: prompts between the two would be silently cut.
    result = interpret(declared=8192, sent=12288, reported=4096, error=None)
    assert result.verdict == "declared_too_high"
    assert "set max_input_tokens to 4096" in result.message


def test_a_cut_above_the_declaration_is_conservative() -> None:
    result = interpret(declared=4096, sent=6144, reported=5000, error=None)
    assert result.verdict == "declared_conservative"


def test_an_uncut_prompt_means_the_server_allows_more() -> None:
    result = interpret(declared=4096, sent=6144, reported=6100, error=None)
    assert result.verdict == "declared_conservative"
    assert result.server_window is None


def test_a_refusal_is_the_safe_behaviour() -> None:
    result = interpret(declared=4096, sent=6144, reported=None, error="400: too long")
    assert result.verdict == "refuses"


def test_probe_calibrates_then_sends_half_again_the_window() -> None:
    """Against a fake Ollama: 2 tokens a word, silently cut at 4096."""
    sizes: list[int] = []

    def handler(request: httpx.Request) -> httpx.Response:
        words = len(json.loads(request.content)["messages"][0]["content"].split())
        sizes.append(words * 2)
        reported = min(words * 2, 4096)
        return httpx.Response(
            200, json={"model": "llama3.2", "usage": {"prompt_tokens": reported}}
        )

    with httpx.Client(
        base_url="http://litellm", transport=httpx.MockTransport(handler)
    ) as http:
        result = probe(http, "llama3.2", declared=4096)

    assert result.verdict == "matches"
    assert sizes[1] >= 4096 * 1.4  # the probe really exceeded the window


def test_a_fallback_answer_is_never_credited_to_the_model() -> None:
    """Measured: LiteLLM answered an oversized prompt to local-coder with
    claude-sonnet-5, and the probe called the refusing server roomy."""

    def handler(request: httpx.Request) -> httpx.Response:
        words = len(json.loads(request.content)["messages"][0]["content"].split())
        model = "local-coder" if words < 1000 else "claude-sonnet-5"
        return httpx.Response(
            200, json={"model": model, "usage": {"prompt_tokens": words * 2}}
        )

    with httpx.Client(
        base_url="http://litellm", transport=httpx.MockTransport(handler)
    ) as http:
        result = probe(http, "local-coder", declared=32768, backing="openai/qwen3-14b")

    assert result.verdict == "fallback"
    assert "claude-sonnet-5 answered instead of local-coder" in result.message


def test_a_provider_reporting_its_own_model_name_is_not_a_fallback() -> None:
    def handler(request: httpx.Request) -> httpx.Response:
        return httpx.Response(
            200, json={"model": "qwen3-14b", "usage": {"prompt_tokens": 400}}
        )

    with httpx.Client(
        base_url="http://litellm", transport=httpx.MockTransport(handler)
    ) as http:
        result = probe(http, "local-coder", declared=32768, backing="openai/qwen3-14b")

    assert result.verdict != "fallback"