"""Tests for mcgibs.colormaps -- XML parsing and natural-language explanations."""

import pytest

from mcgibs.colormaps import (
    _describe_rgb,
    _parse_interval_value,
    explain_colormap,
    parse_colormap,
)

# ---------------------------------------------------------------------------
# parse_colormap
# ---------------------------------------------------------------------------


def test_parse_colormap_map_count(colormap_xml: str):
    """Sample XML contains exactly 2 ColorMap elements."""
    result = parse_colormap(colormap_xml)
    assert len(result.maps) == 2


def test_parse_colormap_data_entries(colormap_xml: str):
    """First ColorMap has 14 data entries, correct title and units."""
    result = parse_colormap(colormap_xml)
    first = result.maps[0]

    assert len(first.entries) == 14
    assert first.title == "Surface Air Temperature"
    assert first.units == "K"


def test_parse_colormap_nodata_entry(colormap_xml: str):
    """Second ColorMap has a nodata entry labelled 'Missing Data'."""
    result = parse_colormap(colormap_xml)
    second = result.maps[1]

    nodata = [e for e in second.entries if e.nodata]
    assert len(nodata) == 1
    assert nodata[0].label == "Missing Data"


def test_parse_colormap_rgb_values(colormap_xml: str):
    """First entry of the first ColorMap has rgb (227, 245, 255)."""
    result = parse_colormap(colormap_xml)
    first_entry = result.maps[0].entries[0]
    assert first_entry.rgb == (227, 245, 255)


def test_parse_colormap_value_intervals(colormap_xml: str):
    """First entry value is '[-INF,200.0)', last entry is '[320.0,+INF)'."""
    result = parse_colormap(colormap_xml)
    entries = result.maps[0].entries

    assert entries[0].value == "[-INF,200.0)"
    assert entries[-1].value == "[320.0,+INF)"


def test_parse_colormap_legend(colormap_xml: str):
    """First ColorMap has legend entries with expected tooltips."""
    result = parse_colormap(colormap_xml)
    legend = result.maps[0].legend

    assert len(legend) == 5
    tooltips = [le.tooltip for le in legend]
    assert "< 200 K" in tooltips
    assert "200 - 210 K" in tooltips
    assert "> 320 K" in tooltips


# ---------------------------------------------------------------------------
# _parse_interval_value
# ---------------------------------------------------------------------------


def test_parse_interval_value_bounded():
    """Bounded interval '[200.0,200.5)' parses to (200.0, 200.5)."""
    assert _parse_interval_value("[200.0,200.5)") == (200.0, 200.5)


def test_parse_interval_value_neg_inf():
    """Negative infinity '[-INF,200.0)' parses to (None, 200.0)."""
    assert _parse_interval_value("[-INF,200.0)") == (None, 200.0)


def test_parse_interval_value_pos_inf():
    """Positive infinity '[320.0,+INF)' parses to (320.0, None)."""
    assert _parse_interval_value("[320.0,+INF)") == (320.0, None)


def test_parse_interval_value_single():
    """Single value '[42]' parses to (42.0, 42.0)."""
    assert _parse_interval_value("[42]") == (42.0, 42.0)


# ---------------------------------------------------------------------------
# explain_colormap
# ---------------------------------------------------------------------------


def test_explain_colormap_includes_title(colormap_xml: str):
    """Explanation text contains the layer title."""
    cms = parse_colormap(colormap_xml)
    text = explain_colormap(cms)
    assert "Surface Air Temperature" in text


def test_explain_colormap_includes_units(colormap_xml: str):
    """Explanation mentions the native unit and Celsius conversion."""
    cms = parse_colormap(colormap_xml)
    text = explain_colormap(cms)

    assert "(K)" in text
    assert "C)" in text  # Celsius conversion appears as e.g. "(-73 C)"


def test_explain_colormap_nodata_mention(colormap_xml: str):
    """Explanation mentions 'Missing Data' from the nodata entry."""
    cms = parse_colormap(colormap_xml)
    text = explain_colormap(cms)
    assert "Missing Data" in text


# ---------------------------------------------------------------------------
# _describe_rgb
# ---------------------------------------------------------------------------


@pytest.mark.parametrize(
    ("rgb", "expected_substring"),
    [
        ((255, 0, 0), "red"),
        ((0, 128, 0), "green"),
        ((0, 0, 255), "blue"),
        ((255, 255, 255), "white"),
        ((0, 0, 0), "black"),
        ((255, 255, 0), "yellow"),
    ],
)
def test_describe_rgb_basic(rgb: tuple[int, int, int], expected_substring: str):
    """Known RGB triples produce color names containing the expected word."""
    result = _describe_rgb(rgb)
    assert expected_substring in result.lower()