#!/usr/bin/env python3
"""Generate WESP favicons: Cyrillic «К» on transparent background."""

from __future__ import annotations

import sys
from pathlib import Path

from fontTools.ttLib import TTFont
from PIL import Image, ImageDraw, ImageFont

ROOT = Path(__file__).resolve().parents[1]
STATIC = ROOT / "static"
CYRILLIC_K = "\u041a"
BRAND = (255, 255, 255, 255)

FONT_CANDIDATES = [
    "/System/Library/Fonts/Supplemental/Arial Bold.ttf",
    "/Library/Fonts/Arial Unicode.ttf",
    "/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf",
    "/usr/share/fonts/truetype/liberation/LiberationSans-Bold.ttf",
]


def _pick_font_path() -> Path:
    for candidate in FONT_CANDIDATES:
        path = Path(candidate)
        if path.is_file():
            return path
    raise FileNotFoundError("No suitable bold font found for Cyrillic «К»")


def _write_svg(dest: Path) -> None:
    svg = """<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32" role="img" aria-label="Комптон">
  <text x="16" y="24.5" text-anchor="middle"
        font-family="Arial, Helvetica, 'DejaVu Sans', sans-serif"
        font-size="22" font-weight="700" fill="#ffffff">К</text>
</svg>
"""
    dest.write_text(svg, encoding="utf-8")


def _draw_png(size: int, font_path: Path, dest: Path) -> None:
    img = Image.new("RGBA", (size, size), (0, 0, 0, 0))
    draw = ImageDraw.Draw(img)
    font = ImageFont.truetype(str(font_path), round(size * 0.72))
    bbox = draw.textbbox((0, 0), CYRILLIC_K, font=font)
    tw = bbox[2] - bbox[0]
    th = bbox[3] - bbox[1]
    x = (size - tw) / 2 - bbox[0]
    y = (size - th) / 2 - bbox[1] - size * 0.02
    draw.text((x, y), CYRILLIC_K, font=font, fill=BRAND)
    img.save(dest, format="PNG")


def main() -> int:
    font_path = _pick_font_path()
    _write_svg(STATIC / "favicon.svg")
    _draw_png(32, font_path, STATIC / "favicon-32.png")
    _draw_png(180, font_path, STATIC / "apple-touch-icon.png")
    print(f"Generated favicons using {font_path}")
    return 0


if __name__ == "__main__":
    sys.exit(main())