import os
from bs4 import BeautifulSoup
from fontTools.subset import Subsetter, Options
from fontTools.ttLib import TTFont

# Directories
HTML_DIR = "."    # Directory with .html files
FONT_DIR = "."          # Directory containing fonts to be modified

FONT_EXTENSIONS = (".ttf", ".woff", ".woff2", ".otf")  # Font file types

def extract_text_from_html(file_path):
    """Extract text content from a single HTML file."""
    with open(file_path, "r", encoding="utf-8") as f:
        soup = BeautifulSoup(f.read(), "html.parser")
        return soup.get_text()

def get_used_characters(directory):
    """Collect unique characters from all .html files in the given directory."""
    char_set = set()
    for root, _, files in os.walk(directory):
        for file in files:
            if file.endswith(".html"):
                full_path = os.path.join(root, file)
                text = extract_text_from_html(full_path)
                char_set.update(text)
    return "".join(sorted(char_set))

def find_font_files(directory):
    """Find all font files in the given directory, recursively."""
    font_files = []
    for root, _, files in os.walk(directory):
        for file in files:
            if file.endswith(FONT_EXTENSIONS):
                font_files.append(os.path.join(root, file))
    return font_files

def subset_font_in_place(font_path, characters):
    """Subsets the given font file to include only the specified characters."""
    # Convert characters to their integer code points
    unicode_set = {ord(c) for c in characters}

    font = TTFont(font_path)
    options = Options()
    options.drop_tables += ["DSIG"]
    options.drop_tables += ["LTSH", "VDMX", "hdmx", "gasp"]
    options.unicodes = unicode_set
    options.variations = False
    options.drop_variations = True
    options.layout_features = ["*"]  # keep all OT features
    options.hinting = False

    # Preserve original format if it was WOFF/WOFF2
    if font_path.endswith(".woff2"):
        options.flavor = "woff2"
    elif font_path.endswith(".woff"):
        options.flavor = "woff"

    subsetter = Subsetter(options)
    subsetter.populate(unicodes=unicode_set)
    subsetter.subset(font)

    # Overwrite the original font file
    font.save(font_path)
    print(f"Subsetted font in place: {font_path}")

if __name__ == "__main__":
    used_chars = get_used_characters(HTML_DIR)
    print(f"Extracted {len(used_chars)} unique characters from HTML files.")

    font_files = find_font_files(FONT_DIR)
    print(f"Found {len(font_files)} font files to subset.")

    for font_file in font_files:
        subset_font_in_place(font_file, used_chars)