"""Tests for the `_should_think` classifier.

`_should_think` decides whether qwen3-class models should engage chain-of-
thought for a given chat turn. It is the single source of truth: frontend
callers pass `think_requested=False` by default and defer to this function,
while explicit `think_requested=True` acts as an override for curated
analytical entry points.

These tests lock in the content-based behavior so future tweaks don't
silently regress the short / long / keyword boundaries.
"""

import pytest

from fabledassistant.services.generation_task import (
    _LONG_MESSAGE_CHARS,
    _SHORT_MESSAGE_CHARS,
    _should_think,
)


class TestExplicitOverride:
    def test_override_forces_on_for_empty(self):
        assert _should_think("", think_requested=True) is True

    def test_override_forces_on_for_short_greeting(self):
        assert _should_think("hi", think_requested=True) is True

    def test_override_forces_on_for_medium_no_keyword(self):
        text = "just checking in on the status of things for the week"
        assert _should_think(text, think_requested=True) is True


class TestEmptyAndWhitespace:
    def test_empty_string_off(self):
        assert _should_think("", think_requested=False) is False

    def test_none_content_off(self):
        # _should_think defensively handles None content from upstream callers
        assert _should_think(None, think_requested=False) is False  # type: ignore[arg-type]

    def test_whitespace_only_off(self):
        assert _should_think("   \n\t  ", think_requested=False) is False


class TestShortMessages:
    def test_short_greeting_off(self):
        assert _should_think("hi", think_requested=False) is False

    def test_short_thanks_off(self):
        assert _should_think("thanks!", think_requested=False) is False

    def test_short_acknowledgement_off(self):
        assert _should_think("ok sounds good", think_requested=False) is False

    def test_just_below_short_threshold_off(self):
        text = "a" * (_SHORT_MESSAGE_CHARS - 1)
        assert _should_think(text, think_requested=False) is False


class TestLongMessages:
    def test_at_long_threshold_on(self):
        text = "a" * _LONG_MESSAGE_CHARS
        assert _should_think(text, think_requested=False) is True

    def test_well_above_long_threshold_on(self):
        text = "x" * (_LONG_MESSAGE_CHARS * 3)
        assert _should_think(text, think_requested=False) is True


class TestMediumMessages:
    def test_medium_no_keyword_off(self):
        # Between the short and long thresholds with no reasoning cue.
        text = "a" * ((_SHORT_MESSAGE_CHARS + _LONG_MESSAGE_CHARS) // 2)
        assert _should_think(text, think_requested=False) is False


class TestKeywordTriggers:
    @pytest.mark.parametrize(
        "text",
        [
            "why is this failing",
            "how does caching work here",
            "how do i configure this",
            "explain the retry logic",
            "analyze the latency breakdown",
            "compare gemma3 vs qwen3 for tool use",
            "please design the schema for X",
            "debug this error",
            "troubleshoot the connection issue",
            "root cause the outage",
            "review this PR",
            "critique my approach",
            "walk me through the flow",
            "step by step instructions please",
            "pros and cons of each option",
            "help me figure out what's wrong",
            "discuss this article",  # covers briefing /discuss entry points
        ],
    )
    def test_keyword_forces_on(self, text):
        assert _should_think(text, think_requested=False) is True

    def test_keyword_case_insensitive(self):
        assert _should_think("WHY does this break?", think_requested=False) is True

    def test_keyword_in_longer_sentence(self):
        text = "hey quick one — can you explain what caching does for qwen3"
        assert _should_think(text, think_requested=False) is True


class TestNonTriggers:
    """Messages that look chatty and should NOT trigger thinking."""

    @pytest.mark.parametrize(
        "text",
        [
            "hey",
            "yep",
            "no worries",
            "got it, thanks",
            "good morning",
            "remind me later",  # no reasoning keyword, short
        ],
    )
    def test_chatty_messages_off(self, text):
        assert _should_think(text, think_requested=False) is False