#!/usr/bin/env python3
"""
Generate SVG Favicon

Generates an SVG favicon with a rounded rectangle background and centered text.
Uses Material 3 color palette.

Usage:
    python generate_favicon.py <char> <bg_color> <fg_color> [output_file]

Arguments:
    char        Character(s) to display (typically 1-2 letters)
    bg_color    Background color name (e.g., 'azure', 'blue') or hex value
    fg_color    Foreground/text color name or hex value
    output_file Output file path (default: favicon.svg)

Examples:
    python generate_favicon.py T azure white
    python generate_favicon.py AB blue white /tmp/favicon.svg
    python generate_favicon.py X "#ff5500" "#ffffff"
"""

from __future__ import annotations

import sys
from pathlib import Path

from PIL import Image, ImageDraw, ImageFont

# Material 3 color palette
COLORS = {
    "azure": "#0074e9",
    "blue": "#5a64ff",
    "violet": "#944aff",
    "magenta": "#d200d2",
    "rose": "#e80074",
    "red": "#ef0000",
    "orange": "#bc5d00",
    "yellow": "#7b7b00",
    "chartreuse": "#418700",
    "green": "#038b00",
    "spring-green": "#008942",
    "cyan": "#008585",
    "black": "#000000",
    "white": "#ffffff",
    "gray": "#6b7280",
}


def get_color_hex(color_name: str) -> str:
    """Convert color name to hex value, or return as-is if already hex."""
    if color_name.startswith("#"):
        return color_name
    return COLORS.get(color_name.lower(), COLORS["azure"])


def generate_svg(char: str, bg_color: str, fg_color: str) -> str:
    """Generate SVG favicon content."""
    bg_hex = get_color_hex(bg_color)
    fg_hex = get_color_hex(fg_color)

    # Adjust font size based on character count
    font_size = 320 if len(char) == 1 else 200

    svg = f'''<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512">
  <rect x="0" y="0" width="512" height="512" rx="77" ry="77" fill="{bg_hex}"/>
  <text x="256" y="256" font-family="system-ui, -apple-system, sans-serif" font-size="{font_size}" font-weight="600" fill="{fg_hex}" text-anchor="middle" dominant-baseline="central">{char}</text>
</svg>'''
    return svg


FONT_PATHS = [
    "/usr/share/fonts/dejavu/DejaVuSans-Bold.ttf",
    "/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf",
    "/usr/share/fonts/google-noto/NotoSans-Bold.ttf",
    "/usr/share/fonts/truetype/noto/NotoSans-Bold.ttf",
    "/System/Library/Fonts/Helvetica.ttc",
]


def find_font(size: int) -> ImageFont.FreeTypeFont | ImageFont.ImageFont:
    """Find a system font, falling back to Pillow default."""
    for path in FONT_PATHS:
        if Path(path).exists():
            return ImageFont.truetype(path, size)
    return ImageFont.load_default(size)


def hex_to_rgb(hex_color: str) -> tuple[int, int, int]:
    """Convert hex color string to RGB tuple."""
    hex_color = hex_color.lstrip("#")
    return tuple(int(hex_color[i:i + 2], 16) for i in (0, 2, 4))


def generate_png(char: str, bg_color: str, fg_color: str, output_path: Path):
    """Generate a 512x512 PNG favicon matching the SVG design."""
    bg_rgb = hex_to_rgb(get_color_hex(bg_color))
    fg_rgb = hex_to_rgb(get_color_hex(fg_color))

    img = Image.new("RGBA", (512, 512), (0, 0, 0, 0))
    draw = ImageDraw.Draw(img)
    draw.rounded_rectangle([0, 0, 511, 511], radius=77, fill=bg_rgb)

    font_size = 320 if len(char) == 1 else 200
    font = find_font(font_size)
    bbox = draw.textbbox((0, 0), char, font=font)
    text_w = bbox[2] - bbox[0]
    text_h = bbox[3] - bbox[1]
    x = (512 - text_w) / 2 - bbox[0]
    y = (512 - text_h) / 2 - bbox[1]
    draw.text((x, y), char, fill=fg_rgb, font=font)

    img.save(str(output_path), "PNG")


def main():
    if len(sys.argv) < 4:
        print(__doc__)
        sys.exit(1)

    char = sys.argv[1]
    bg_color = sys.argv[2]
    fg_color = sys.argv[3]
    output_file = sys.argv[4] if len(sys.argv) > 4 else "favicon.svg"

    svg_content = generate_svg(char, bg_color, fg_color)

    output_path = Path(output_file)
    output_path.write_text(svg_content)
    print(f"Generated favicon: {output_path}")

    # Also generate PNG for WordPress Site Icon registration
    png_path = output_path.with_suffix(".png")
    generate_png(char, bg_color, fg_color, png_path)
    print(f"Generated PNG: {png_path}")


if __name__ == "__main__":
    main()