"""Unit tests for the bridge sentence splitter that drives streaming TTS.

The splitter is the only new logic on the bridge's streaming path: it chops a
reply into sentence-sized chunks so the first sentence can be synthesised and
played while the rest are still being spoken. It must be language-agnostic
(punctuation only, no hardcoded words) per the project rule.
"""

import pytest

from bridge.text_utils import split_sentences


@pytest.mark.unit
def test_empty_text_yields_no_chunks():
    assert split_sentences("") == []
    assert split_sentences("   ") == []
    assert split_sentences(None) == []  # type: ignore[arg-type]


@pytest.mark.unit
def test_text_without_terminal_punctuation_is_one_chunk():
    assert split_sentences("오늘 날씨 맑음") == ["오늘 날씨 맑음"]


@pytest.mark.unit
def test_splits_on_sentence_ending_punctuation():
    chunks = split_sentences("안녕하세요. 반갑습니다!")
    assert chunks == ["안녕하세요.", "반갑습니다!"]


@pytest.mark.unit
def test_splits_on_fullwidth_cjk_punctuation():
    chunks = split_sentences("これはペンです。あれは何ですか？")
    assert chunks == ["これはペンです。", "あれは何ですか？"]


@pytest.mark.unit
def test_splits_english_sentences():
    chunks = split_sentences("Hello there. How are you? I am fine!")
    assert chunks == ["Hello there.", "How are you?", "I am fine!"]


@pytest.mark.unit
def test_short_leading_fragment_merges_forward():
    # "네." is below the min length, so it should ride along with the next
    # sentence rather than become its own micro-clip.
    chunks = split_sentences("네. 지금 바로 처리하겠습니다.")
    assert chunks == ["네. 지금 바로 처리하겠습니다."]


@pytest.mark.unit
def test_short_trailing_fragment_merges_backward():
    chunks = split_sentences("지금 바로 처리하겠습니다. 응")
    assert chunks == ["지금 바로 처리하겠습니다. 응"]


@pytest.mark.unit
def test_newline_is_a_boundary():
    chunks = split_sentences("첫 번째 줄입니다\n두 번째 줄입니다")
    assert chunks == ["첫 번째 줄입니다", "두 번째 줄입니다"]


@pytest.mark.unit
def test_chunks_preserve_all_visible_content_in_order():
    text = "안녕하세요. 오늘 일정 알려드릴게요. 회의가 세 개 있습니다!"
    chunks = split_sentences(text)
    assert len(chunks) >= 2
    # No content lost: stripping spaces, the concatenation matches the source.
    joined = "".join(chunks)
    assert joined.replace(" ", "") == text.replace(" ", "")


@pytest.mark.unit
def test_collapses_repeated_terminators_into_one_chunk():
    chunks = split_sentences("정말요?! 네 맞습니다.")
    assert chunks == ["정말요?!", "네 맞습니다."]


@pytest.mark.unit
def test_decimal_point_is_not_a_sentence_boundary():
    # Regression: "17.5" / "1.8" used to split as "17." / "5" and "1." / "8",
    # making the TTS read numbers digit-by-digit. The decimal dot is followed by
    # a digit (no space), so it must stay inside one chunk.
    assert split_sentences("현재 기온은 17.5도입니다.") == ["현재 기온은 17.5도입니다."]
    assert split_sentences("바람은 1.8 km/h입니다.") == ["바람은 1.8 km/h입니다."]


@pytest.mark.unit
def test_decimals_across_two_sentences_split_only_at_the_real_end():
    chunks = split_sentences("기온은 17.5도입니다. 바람은 1.8 km/h입니다.")
    assert chunks == ["기온은 17.5도입니다.", "바람은 1.8 km/h입니다."]


@pytest.mark.unit
def test_english_decimal_and_version_numbers_stay_whole():
    assert split_sentences("Pi is about 3.14 today.") == ["Pi is about 3.14 today."]
    assert split_sentences("Upgrade to v2.0 now.") == ["Upgrade to v2.0 now."]


@pytest.mark.unit
def test_url_dots_are_not_boundaries():
    # Dots inside a host/path are followed by letters, not whitespace, so the
    # link is spoken in one piece; only the trailing sentence dot splits.
    chunks = split_sentences("Visit example.com for details. Thanks!")
    assert chunks == ["Visit example.com for details.", "Thanks!"]


@pytest.mark.unit
def test_integer_at_sentence_end_still_splits():
    # A dot after a number that genuinely ends a sentence (followed by a space)
    # is still a boundary - only the *internal* decimal dot is protected.
    chunks = split_sentences("I scored 5. Next round now.")
    assert chunks == ["I scored 5.", "Next round now."]