#!/usr/bin/env python3
"""Disegna il Regolino, pixel per pixel, senza immagini sorgenti.

    python3 tools/favicon.py

Scrive assets/favicon/ e /tmp/regolo-shots/favicon-anteprima.png.
La matrice 16×16 è il disegno originale: ogni simbolo è un pixel.
Tutti gli ingrandimenti sono interi e usano NEAREST, anche nell'ICO.
Colori e carattere riprendono regolo() in src/engine/briscola-render.js.
"""

from pathlib import Path

from PIL import Image, ImageDraw, ImageFont


ROOT = Path(__file__).resolve().parent.parent
OUTPUT = ROOT / "assets" / "favicon"
PREVIEW = Path("/tmp/regolo-shots/favicon-anteprima.png")
BACKGROUND = "#1b1420"
PALETTE = {
    ".": (0, 0, 0, 0),
    "#": "#38271f",  # contorno del dorso
    "G": "#dba32b",  # oro
    "H": "#ffe396",  # luce sulla corona
    "R": "#aa4034",  # rubino
    "L": "#94b365",  # testa verde salvia
    "S": "#487348",  # ombra / spira
    "V": "#a3bc72",  # luce sulla spira
    "B": "#d0cd83",  # ventre
    "W": "#fff0cd",  # occhi crema
}

# Corona a tre punte, grande testa sorridente, collo e coda arrotolata.
# Nessun tratto viene interpolato: anche gli occhi sono singoli pixel.
PIXELS = (
    "....#..##..#....",
    "...#H##HH##H#...",
    "...#HGGGGGGH#...",
    "....#GGRGGG#....",
    "...##########...",
    "..#LLLLLLLLLL#..",
    ".#LLWWLLWWLLLL#.",
    ".#LLW#LL#WLLLS#.",
    ".#LLLLLLLLLLLS#.",
    "..#L#LLLLL#LS#..",
    "...#L#####LS#...",
    "....###BS###....",
    "..###SSBSLSS##..",
    ".#SVV##BS##SSS#.",
    ".#SVVVVVVVVSS#..",
    "..###########...",
)


def sprite():
    """Interpreta la matrice letterale, mantenendo solo alpha 0 o 255."""
    if len(PIXELS) != 16 or any(len(row) != 16 for row in PIXELS):
        raise ValueError("Il disegno deve contenere esattamente 16×16 pixel")
    result = Image.new("RGBA", (16, 16))
    for y, row in enumerate(PIXELS):
        for x, symbol in enumerate(row):
            color = PALETTE[symbol]
            if isinstance(color, str):
                color = tuple(bytes.fromhex(color[1:])) + (255,)
            result.putpixel((x, y), color)
    return result


def enlarge(source, factor):
    return source.resize(
        (source.width * factor, source.height * factor), Image.Resampling.NEAREST
    )


def preview(icons):
    """Mostra ogni PNG a 1× e 8×, sia su chiaro sia su scuro.

    Le sei righe includono anche le icone grandi: il foglio è volutamente
    ampio, così la scala dichiarata resta esatta per tutti i file.
    """
    margin, gap, label_height = 24, 24, 32
    largest = max(icon.width for _, icon in icons)
    panel_width = margin * 2 + largest + gap + largest * 8
    height = margin + sum(label_height + icon.height * 8 + gap for _, icon in icons)
    sheet = Image.new("RGB", (panel_width * 2, height))
    draw = ImageDraw.Draw(sheet)
    font = ImageFont.load_default(size=16)
    for panel, (background, foreground) in enumerate(
        (("#f5f1e9", "#38271f"), (BACKGROUND, "#fff0cd"))
    ):
        left = panel * panel_width
        draw.rectangle((left, 0, left + panel_width - 1, height - 1), fill=background)
        y = margin
        for name, icon in icons:
            draw.text(
                (left + margin, y),
                f"{name}  |  {icon.width} x {icon.height}  |  1x e 8x",
                fill=foreground,
                font=font,
            )
            y += label_height
            sheet.paste(icon, (left + margin, y), icon)
            magnified = enlarge(icon, 8)
            sheet.paste(magnified, (left + margin + icon.width + gap, y), magnified)
            y += icon.height * 8 + gap
    PREVIEW.parent.mkdir(parents=True, exist_ok=True)
    sheet.save(PREVIEW, optimize=True)


def main():
    OUTPUT.mkdir(parents=True, exist_ok=True)
    base = sprite()
    icons = []
    for size in (16, 32, 48):
        icon = enlarge(base, size // 16)
        name = f"favicon-{size}.png"
        icon.save(OUTPUT / name, optimize=True)
        icons.append((name, icon))

    # 16×9 = 144: margini di 18 px, centratura esatta sul fondo opaco.
    apple = Image.new("RGBA", (180, 180), BACKGROUND)
    apple.alpha_composite(enlarge(base, 9), (18, 18))
    apple = apple.convert("RGB")
    apple.save(OUTPUT / "apple-touch-icon.png", optimize=True)
    icons.append(("apple-touch-icon.png", apple.convert("RGBA")))

    for size in (192, 512):
        icon = enlarge(base, size // 16)
        name = f"icon-{size}.png"
        icon.save(OUTPUT / name, optimize=True)
        icons.append((name, icon))

    # Fornire tutti i frame evita il ridimensionamento implicito di Pillow.
    icons[2][1].save(
        OUTPUT / "favicon.ico",
        format="ICO",
        sizes=[(16, 16), (32, 32), (48, 48)],
        append_images=[icons[0][1], icons[1][1]],
    )
    preview(icons)
    for name, _ in icons:
        print(OUTPUT / name)
    print(OUTPUT / "favicon.ico")
    print(PREVIEW)


if __name__ == "__main__":
    main()