#!/usr/bin/env python3
"""
Report which Unicode code points have vector outlines in ALL of the given font files.

Usage: python3 font-glyphs.py font1.ttf font2.ttf ...
"""

import sys
import unicodedata
from fontTools.ttLib import TTFont
from fontTools.pens.statisticsPen import StatisticsPen


def get_vector_codepoints(path):
    """Return the set of code points that have actual vector outlines in the font."""
    font = TTFont(path)
    cmap = font.getBestCmap()
    if cmap is None:
        print(f"WARNING: {path} has no cmap table", file=sys.stderr)
        return set()

    glyf = font.get("glyf")  # TrueType outlines
    cff = font.get("CFF ")    # CFF outlines

    result = set()
    for codepoint, glyph_name in cmap.items():
        has_outline = False
        if glyf is not None:
            g = glyf.get(glyph_name)
            if g is not None and g.numberOfContours != 0:
                has_outline = True
        if cff is not None:
            # CFF fonts store outlines in charstrings.
            try:
                cs = cff.cff.topDictIndex[0].CharStrings[glyph_name]
                pen = StatisticsPen(glyphset=font.getGlyphSet())
                cs.draw(pen)
                if pen.area != 0:
                    has_outline = True
            except (KeyError, AttributeError):
                pass
        if has_outline:
            result.add(codepoint)

    font.close()
    return result


def main():
    if len(sys.argv) < 2:
        print(f"Usage: {sys.argv[0]} font1.ttf [font2.ttf ...]", file=sys.stderr)
        sys.exit(1)

    paths = sys.argv[1:]

    # Process each font and intersect.
    common = None
    for path in paths:
        cps = get_vector_codepoints(path)
        print(f"{len(cps):6d} glyphs  {path}")
        if common is None:
            common = cps
        else:
            common &= cps

    if len(paths) > 1:
        print(f"{len(common):6d} glyphs  common to all {len(paths)} fonts", file=sys.stderr)

    # Build the character string, excluding quote and backslash.
    chars = []
    for cp in sorted(common):
        if cp == ord('"') or cp == ord('\\'):
            continue
        chars.append(chr(cp))

    # Emit C++ file.
    print("// Auto-generated by tools/font-glyphs.py — do not edit by hand.")
    print(f"// {len(chars)} characters common to all {len(paths)} font(s).")
    print()
    print("const TCHAR *CommonChars = TEXT(")

    # Break into lines of ~70 chars for readability.
    line = ""
    for ch in chars:
        line += ch
        if len(line) >= 70:
            print(f'\t"{line}"')
            line = ""
    if line:
        print(f'\t"{line}"')

    print(");")


if __name__ == "__main__":
    main()