"""Design-token checks for src/javis/gui/theme.py (WCAG 2.2 AA contrast)."""
from __future__ import annotations

import re

import pytest

from javis.gui import theme

# (foreground, background) pairs rendered as text: need 4.5:1 (SC 1.4.3).
TEXT_PAIRS = [
    ("text", "bg"), ("text", "surface"), ("text", "surface2"), ("text", "input"),
    ("muted", "bg"), ("muted", "surface"), ("muted", "surface2"),
    ("accent", "bg"), ("accent", "surface"),
    ("on_accent", "primary"), ("on_accent", "primary_hover"),
    ("success", "bg"), ("error", "bg"), ("error", "error_bg"), ("warn_fg", "bg"),
    ("tool_fg", "tool_bg"), ("tool_muted", "tool_bg"), ("code_fg", "code_bg"),
    ("link", "bg"),
]
# Control boundaries and focus indicators: need 3:1 (SC 1.4.11).
UI_PAIRS = [
    ("stroke_strong", "bg"), ("stroke_strong", "surface"),
    ("focus", "bg"), ("focus", "surface"), ("primary", "bg"), ("on_accent", "primary"),
]


@pytest.mark.parametrize("name", sorted(theme.THEMES))
@pytest.mark.parametrize("fg,bg", TEXT_PAIRS)
def test_text_contrast(name, fg, bg):
    t = theme.THEMES[name]
    assert theme.contrast_ratio(t[fg], t[bg]) >= 4.5, f"{name}: {fg} on {bg}"


@pytest.mark.parametrize("name", sorted(theme.THEMES))
@pytest.mark.parametrize("fg,bg", UI_PAIRS)
def test_ui_contrast(name, fg, bg):
    t = theme.THEMES[name]
    assert theme.contrast_ratio(t[fg], t[bg]) >= 3.0, f"{name}: {fg} vs {bg}"


def test_palettes_share_keys():
    assert set(theme.PAL_DARK) == set(theme.PAL_LIGHT)


def test_accent_hue_kept():
    # The redesign must keep the brand colours of the dark theme.
    assert theme.PAL_DARK["accent"].lower() == "#da7756"
    assert theme.PAL_DARK["bg"] == "#1e1e1e"


def test_contrast_math():
    assert theme.contrast_ratio("#000000", "#ffffff") == pytest.approx(21.0)
    assert theme.readable_on("#DA7756") == "#1e1e1e"
    assert theme.readable_on("#3c3c3c") == "#ffffff"


@pytest.mark.parametrize("name", sorted(theme.THEMES))
def test_qss_is_well_formed(name):
    qss = theme.build_qss(theme.THEMES[name], "Segoe UI")
    assert qss.count("{") == qss.count("}")
    # every palette value used in the sheet is a full hex colour
    for hex_color in re.findall(r"#[0-9a-fA-F]+\b", qss):
        assert len(hex_color) in (4, 7), hex_color
    assert "variant=\"primary\"" in qss