"""A half-block wordmark font for the header hero.

Every shipped catalogue draws its brand the same way: four-column capitals,
six pixels tall, emitted as three rows of half blocks (``▀``/``▄``/``█``) — the
same shape as the original SomaFM logo.  The header paints every wordmark with
the app's active palette gradient, so catalogues differ only in the word they
spell; the font lives here and each provider's ``hero.py`` is one line of data.

Glyphs are 6x4 bitmaps (``M`` is 6x5).  Two pixel rows become one text row, so
a wordmark is always three rows tall and the header keeps a fixed height.
"""

from __future__ import annotations

#: 6-row bitmap per capital; all rows of one glyph are the same width.
GLYPHS: dict[str, tuple[str, ...]] = {
    "A": (".##.", "#..#", "####", "#..#", "#..#", "#..#"),
    "B": ("###.", "#..#", "###.", "#..#", "#..#", "###."),
    "C": (".##.", "#..#", "#...", "#...", "#..#", ".##."),
    "D": ("###.", "#..#", "#..#", "#..#", "#..#", "###."),
    "E": ("####", "#...", "###.", "#...", "#...", "####"),
    "F": ("####", "#...", "###.", "#...", "#...", "#..."),
    "G": (".##.", "#..#", "#...", "#.##", "#..#", ".##."),
    "H": ("#..#", "#..#", "####", "#..#", "#..#", "#..#"),
    "I": ("###", ".#.", ".#.", ".#.", ".#.", "###"),
    "K": ("#..#", "#.#.", "##..", "##..", "#.#.", "#..#"),
    "L": ("#...", "#...", "#...", "#...", "#...", "####"),
    # 5 wide on purpose: the M is the odd one out in the original wordmark.
    "M": ("#...#", "##.##", "#.#.#", "#.#.#", "#...#", "#...#"),
    "N": ("#..#", "##.#", "##.#", "#.##", "#..#", "#..#"),
    "O": (".##.", "#..#", "#..#", "#..#", "#..#", ".##."),
    "P": ("###.", "#..#", "###.", "#...", "#...", "#..."),
    "R": ("###.", "#..#", "###.", "#.#.", "#..#", "#..#"),
    "S": (".###", "#...", "###.", "...#", "...#", "###."),
    "T": ("###", ".#.", ".#.", ".#.", ".#.", ".#."),
    "U": ("#..#", "#..#", "#..#", "#..#", "#..#", ".##."),
    "V": ("#..#", "#..#", "#..#", "#..#", ".##.", ".##."),
    "W": ("#...#", "#...#", "#.#.#", "#.#.#", "##.##", "#...#"),
    "Y": ("#..#", "#..#", ".##.", "..#.", "..#.", "..#."),
}

ROWS = 3
_GAP = " "


def _cell(top: str, bottom: str) -> str:
    if top == "#" and bottom == "#":
        return "█"
    if top == "#":
        return "▀"
    if bottom == "#":
        return "▄"
    return " "


def _glyph_rows(char: str) -> tuple[str, ...]:
    bitmap = GLYPHS.get(char)
    if bitmap is None:
        raise KeyError(f"no wordmark glyph for {char!r}")
    return tuple(
        "".join(_cell(bitmap[row * 2][col], bitmap[row * 2 + 1][col]) for col in range(len(bitmap[0])))
        for row in range(ROWS)
    )


def render(text: str) -> tuple[str, ...]:
    """Spell ``text`` as three rows of half blocks."""
    glyphs = [_glyph_rows(char.upper()) for char in text]
    rows: list[str] = []
    for row in range(ROWS):
        rows.append(_GAP.join(glyph[row] for glyph in glyphs).rstrip())
    return tuple(rows)