"""Tests for translate.py auto_translate and main.py title_case."""
import pytest
from backend.translate import auto_translate


# ---------------------------------------------------------------------------
# title_case (inlined here since it's a trivial helper in main.py)
# ---------------------------------------------------------------------------
def title_case(s: str) -> str:
    return s.strip().title() if s else s


class TestTitleCase:
    def test_basic(self):
        assert title_case("pain relief") == "Pain Relief"

    def test_single_word(self):
        assert title_case("sleep") == "Sleep"

    def test_preserves_already_cased(self):
        assert title_case("Pain Relief") == "Pain Relief"

    def test_empty_string(self):
        assert title_case("") == ""

    def test_none(self):
        assert title_case(None) is None

    def test_strips_whitespace(self):
        assert title_case("  hello world  ") == "Hello World"


# ---------------------------------------------------------------------------
# auto_translate
# ---------------------------------------------------------------------------
class TestAutoTranslate:
    def test_empty_string(self):
        assert auto_translate("") == ""

    def test_single_keyword(self):
        assert auto_translate("失眠") == "Insomnia"

    def test_compound_name(self):
        result = auto_translate("助眠配方")
        assert "Sleep" in result
        assert "Blend" in result

    def test_head_pain(self):
        result = auto_translate("头痛")
        # 头痛 is a single keyword → Headache
        assert "Headache" in result

    def test_shoulder_neck_massage(self):
        result = auto_translate("肩颈按摩")
        assert "Neck" in result or "Shoulder" in result
        assert "Massage" in result

    def test_no_duplicate_words(self):
        # 肩颈 → "Neck & Shoulder", but should not duplicate if sub-keys match
        result = auto_translate("肩颈护理")
        words = result.split()
        # No exact duplicate consecutive words
        for i in range(len(words) - 1):
            if words[i] == words[i + 1]:
                pytest.fail(f"Duplicate word '{words[i]}' in '{result}'")

    def test_skincare_blend(self):
        result = auto_translate("皮肤修复")
        assert "Skin" in result
        assert "Repair" in result

    def test_foot_soak(self):
        result = auto_translate("泡脚配方")
        assert "Foot Soak" in result or "Foot" in result

    def test_ascii_passthrough(self):
        # Embedded ASCII letters are preserved
        result = auto_translate("DIY面膜")
        assert "DIY" in result or "Diy" in result
        assert "Face Mask" in result or "Mask" in result

    def test_pure_chinese_returns_english(self):
        result = auto_translate("薰衣草精华")
        # Should not return original Chinese; should have English words
        assert any(c.isascii() and c.isalpha() for c in result)

    def test_fallback_for_unknown(self):
        # Completely unknown chars get skipped; if nothing matches, returns original
        result = auto_translate("㊗㊗㊗")
        assert result == "㊗㊗㊗"

    def test_children_sleep(self):
        result = auto_translate("儿童助眠")
        assert "Children" in result
        assert "Sleep" in result

    def test_menstrual_pain(self):
        result = auto_translate("痛经调理")
        assert "Menstrual Pain" in result or "Menstrual" in result
        assert "Therapy" in result

    def test_result_is_title_cased(self):
        result = auto_translate("排毒按摩")
        # Each word should start with uppercase
        for word in result.split():
            if word == "&":
                continue
            assert word[0].isupper(), f"'{word}' in '{result}' is not title-cased"