"""Subtitle styling correctness: vertical offset sign, fontsize clamp, hex
validation, and preset-honouring uppercase.

Pure / file-only tests for ``clippyme.domain.subtitles`` — no ffmpeg, no model
load, host-runnable. These guard the customization flow fixes:

- ``_offset_margin``: a POSITIVE offset_y moves the caption DOWN regardless of
  anchor (shared convention between the ASS karaoke and the SRT classic path).
- ``_clamp_fontsize``: out-of-range / garbage sizes never reach ffmpeg.
- ``generate_ass_karaoke``: invalid colours raise instead of silently going
  white; ``uppercase=None`` honours the preset's own casing.
"""
import pytest

from clippyme.domain.subtitles import (
    _clamp_fontsize,
    _offset_margin,
    _SUB_FONTSIZE_MAX,
    _SUB_FONTSIZE_MIN,
    generate_ass_karaoke,
)


def _transcript(*words):
    segs_words = []
    t = 0.0
    for w in words:
        segs_words.append({"word": w, "start": t, "end": t + 0.4})
        t += 0.4
    return {"segments": [{"words": segs_words}]}


# --- _offset_margin: positive = DOWN, both anchors -------------------------

def test_offset_zero_is_identity():
    assert _offset_margin("bottom", 350, 0) == 350
    assert _offset_margin("top", 260, 0) == 260


def test_offset_positive_moves_down_bottom_anchor():
    # bottom anchor: MarginV is gap from bottom → smaller = lower → subtract
    assert _offset_margin("bottom", 350, 10) == 350 - int(1920 * 10 / 100)


def test_offset_positive_moves_down_top_anchor():
    # top anchor: MarginV is gap from top → larger = lower → add
    assert _offset_margin("top", 260, 10) == 260 + int(1920 * 10 / 100)


def test_offset_negative_moves_up_bottom_anchor():
    assert _offset_margin("bottom", 350, -10) == 350 + int(1920 * 10 / 100)


def test_offset_never_negative_margin():
    assert _offset_margin("bottom", 100, 50) == 0


def test_offset_garbage_is_zero():
    assert _offset_margin("bottom", 350, None) == 350
    assert _offset_margin("bottom", 350, "abc") == 350


# --- _clamp_fontsize -------------------------------------------------------

def test_clamp_in_range_passthrough():
    assert _clamp_fontsize(40, 38) == 40


def test_clamp_too_big():
    assert _clamp_fontsize(100000, 38) == _SUB_FONTSIZE_MAX


def test_clamp_too_small():
    assert _clamp_fontsize(1, 38) == _SUB_FONTSIZE_MIN


def test_clamp_garbage_returns_default():
    assert _clamp_fontsize(None, 38) == 38
    assert _clamp_fontsize("xx", 38) == 38


# --- generate_ass_karaoke validation + casing ------------------------------

def test_invalid_font_color_raises(tmp_path):
    out = tmp_path / "x.ass"
    with pytest.raises(ValueError):
        generate_ass_karaoke(
            _transcript("hello", "world"), 0, 10, str(out),
            preset="classic_white", font_color="red; rm -rf",
        )


def test_invalid_highlight_color_raises(tmp_path):
    out = tmp_path / "x.ass"
    with pytest.raises(ValueError):
        generate_ass_karaoke(
            _transcript("hello", "world"), 0, 10, str(out),
            preset="classic_white", highlight_color="notahex",
        )


def test_uppercase_none_honours_preset_lowercase(tmp_path):
    # mrbeast_box preset has uppercase=False → with uppercase=None the words
    # must keep their original casing.
    out = tmp_path / "x.ass"
    ok = generate_ass_karaoke(
        _transcript("hello", "world"), 0, 10, str(out),
        preset="mrbeast_box", uppercase=None,
    )
    assert ok
    text = out.read_text(encoding="utf-8")
    assert "hello" in text and "HELLO" not in text


def test_uppercase_none_honours_preset_uppercase(tmp_path):
    # classic_white preset has uppercase=True → uppercase=None still uppercases.
    out = tmp_path / "x.ass"
    ok = generate_ass_karaoke(
        _transcript("hello", "world"), 0, 10, str(out),
        preset="classic_white", uppercase=None,
    )
    assert ok
    text = out.read_text(encoding="utf-8")
    assert "HELLO" in text


def test_uppercase_explicit_overrides_preset(tmp_path):
    out = tmp_path / "x.ass"
    generate_ass_karaoke(
        _transcript("hello", "world"), 0, 10, str(out),
        preset="mrbeast_box", uppercase=True,
    )
    assert "HELLO" in out.read_text(encoding="utf-8")


def _style_fields(ass_text):
    # "Style: Viral,<font>,<size>,...,<align>,<L>,<R>,<marginV>,1"
    for line in ass_text.splitlines():
        if line.startswith("Style: Viral,"):
            return line.split(",")
    raise AssertionError("no Viral style line")


def test_center_no_offset_uses_centered_anchor(tmp_path):
    out = tmp_path / "x.ass"
    generate_ass_karaoke(
        _transcript("hi"), 0, 10, str(out), preset="classic_white",
        position="center", offset_y=0,
    )
    f = _style_fields(out.read_text(encoding="utf-8"))
    align, margin_v = f[-5], f[-2]
    assert align == "5" and margin_v == "0"


def test_center_with_offset_reanchors_so_nudge_works(tmp_path):
    # A non-zero nudge at center must NOT silently no-op: re-anchor to top (8)
    # with an absolute margin measured from frame centre, positive = down.
    out = tmp_path / "x.ass"
    generate_ass_karaoke(
        _transcript("hi"), 0, 10, str(out), preset="classic_white",
        position="center", offset_y=10,
    )
    f = _style_fields(out.read_text(encoding="utf-8"))
    align, margin_v = f[-5], f[-2]
    assert align == "8"
    assert int(margin_v) == 960 + int(1920 * 10 / 100)


def test_extreme_fontsize_clamped_in_output(tmp_path):
    out = tmp_path / "x.ass"
    generate_ass_karaoke(
        _transcript("hello"), 0, 10, str(out),
        preset="classic_white", font_size=100000,
    )
    # the Style line carries the clamped size, never the raw 100000
    text = out.read_text(encoding="utf-8")
    assert "100000" not in text
    assert f"Viral,Montserrat-Black,{_SUB_FONTSIZE_MAX}," in text