#!/usr/bin/python
#
# Copyright 2010-2012, Google Inc.
# Author: Raph Levien (<firstname.lastname>@gmail.com)
# Author: Dave Crossland (dave@understandinglimited.com)
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.
#
# Version 1.01 Released 2012-03-27
#
# A script for subsetting a font, using FontForge. See README for details.

import fontforge
import sys
import getopt
import os
import struct

def log_namelist(nam, unicode):
    if nam and isinstance(unicode, int):
        print >> nam, "0x%0.4X" % unicode, fontforge.nameFromUnicode(unicode)

def select_with_refs(font, unicode, newfont, pe = None, nam = None):
    newfont.selection.select(('more', 'unicode'), unicode)
    log_namelist(nam, unicode)
    if pe:
        print >> pe, "SelectMore(%d)" % unicode
    try:
        for ref in font[unicode].references:
            newfont.selection.select(('more',), ref[0])
            log_namelist(nam, ref[0])
            if pe:
                print >> pe, 'SelectMore("%s")' % ref[0]
    except:
        print 'Resolving references on u+%04x failed' % unicode

def subset_font_raw(font_in, font_out, unicodes, opts):
    if '--namelist' in opts:
        # 2010-12-06 DC To allow setting namelist filenames, 
        # change getopt.gnu_getopt from namelist to namelist= 
        # and invert comments on following 2 lines
        # nam_fn = opts['--namelist']
        nam_fn = font_out + '.nam'
        nam = file(nam_fn, 'w')
    else:
        nam = None
    if '--script' in opts:
        pe_fn = "/tmp/script.pe"
        pe = file(pe_fn, 'w')
    else:
        pe = None
    font = fontforge.open(font_in)
    if pe:
      print >> pe, 'Open("' + font_in + '")'
      extract_vert_to_script(font_in, pe)
    for i in unicodes:
        select_with_refs(font, i, font, pe, nam)

    addl_glyphs = []
    if '--nmr' in opts: addl_glyphs.append('nonmarkingreturn')
    if '--null' in opts: addl_glyphs.append('.null')
    for glyph in addl_glyphs:
        font.selection.select(('more',), glyph)
        if nam:
            print >> nam, "0x%0.4X" % fontforge.unicodeFromName(glyph), glyph
        if pe:
            print >> pe, 'SelectMore("%s")' % glyph

    flags = ()

    if '--simplify' in opts:
        font.simplify()
        font.round()
        flags = ('omit-instructions',)

    if '--strip_names' in opts:
        font.sfnt_names = ()

    if '--new' in opts:
        font.copy()
        new = fontforge.font()
        new.encoding = font.encoding
        new.em = font.em
        new.layers['Fore'].is_quadratic = font.layers['Fore'].is_quadratic
        for i in unicodes:
            select_with_refs(font, i, new, pe, nam)
        new.paste()
        # This is a hack - it should have been taken care of above.
        font.selection.select('space')
        font.copy()
        new.selection.select('space')
        new.paste()
        new.sfnt_names = font.sfnt_names
        font = new
    else:
        font.selection.invert()
        print >> pe, "SelectInvert()"
        font.cut()
        print >> pe, "Clear()"

    if nam: 
        print "Writing NameList", 
        nam.close()

    if pe:
        print >> pe, 'Generate("' + font_out + '")'
        pe.close()
        os.system("fontforge -script " + pe_fn)
    else:
        font.generate(font_out, flags = flags)
    font.close()

    if '--roundtrip' in opts:
        # FontForge apparently contains a bug where it incorrectly calculates
        # the advanceWidthMax in the hhea table, and a workaround is to open
        # and re-generate
        font2 = fontforge.open(font_out)
        font2.generate(font_out, flags = flags)

def subset_font(font_in, font_out, unicodes, opts):
    font_out_raw = font_out
    if not font_out_raw.endswith('.ttf'):
        font_out_raw += '.ttf';
    subset_font_raw(font_in, font_out_raw, unicodes, opts)
    if font_out != font_out_raw:
        os.rename(font_out_raw, font_out)
# 2011-02-14 DC this needs to only happen with --namelist is used
#        os.rename(font_out_raw + '.nam', font_out + '.nam')

def getsubset(subset):
    subsets = subset.split('+')

    punc  = [0x00a2] # cent
    punc += [0x00a3] # sterling
    punc += [0x00a5] # yen
    punc += [0x00a9] # copyright
    punc += [0x00ad] # softhyphen
    punc += [0x00ae] # registered
    punc += [0x00b4] # accuteaccent

    punc += [0x2010] # hyphen
    punc += [0x2011] # nonbreakinghyphen
    punc += [0x2012] # figuredash
    punc += [0x2013] # endash
    punc += [0x2014] # emdash
    punc += [0x2015] # horizontalbar
    punc += [0x2026] # horizontalellipsis
    punc += [0x20ac] # euro
    punc += [0x2122] # trademark
    punc += [0x25a0] # blacksquare

    quotes  = [0x2013] # endash
    quotes += [0x2014] # emdash
    quotes += [0x2018] # quoteleft
    quotes += [0x2019] # quoteright
    quotes += [0x201A] # quotesinglbase
    quotes += [0x201C] # quotedblleft
    quotes += [0x201D] # quotedblright
    quotes += [0x201E] # quotedblbase
    quotes += [0x2022] # bullet
    quotes += [0x2039] # guilsinglleft
    quotes += [0x203A] # guilsinglright

    basic = range(0x20, 0x7f) # Basic Latin (A-Z, a-z, numbers)

    latin = range(0xa0, 0x100) # Western European symbols and diacritics
    latin += [0x20ac] # Euro
    latin += [0x0152] # OE
    latin += [0x0153] # oe
    latin += [0x003b] # semicolon
    latin += [0x00b7] # periodcentered
    latin += [0x0131] # dotlessi
    latin += [0x02c6] # circumflex
    latin += [0x02da] # ring
    latin += [0x02dc] # tilde
    latin += [0x2074] # foursuperior
    latin += [0x2215] # divison slash
    latin += [0x2044] # fraction slash
    latin += [0xe0ff] # PUA: Font logo
    latin += [0xeffd] # PUA: Font version number
    latin += [0xf000] # PUA: font ppem size indicator: run `ftview -f 1255 10 Ubuntu-Regular.ttf` to see it in action!

    dieresis  = [0x00a8] # dieresis *
    dieresis += [0x00c4] # ADieresis *
    dieresis += [0x00cb] # Edieresis *
    dieresis += [0x00cf] # Idieresis *
    dieresis += [0x00d6] # ODieresis *
    dieresis += [0x00dc] # Udieresis *
    dieresis += [0x00e4] # adieresis *
    dieresis += [0x00eb] # edieresis *
    dieresis += [0x00ef] # idieresis *
    dieresis += [0x00f6] # odieresis *
    dieresis += [0x00fc] # udieresis *
    dieresis += [0x00ff] # ydieresis *

    circumflex  = [0x00c2] # Acircumflex *
    circumflex += [0x00ca] # Ecircumflex *
    circumflex += [0x00ce] # Icircumflex *
    circumflex += [0x00d4] # Ocircumflex *
    circumflex += [0x00db] # Ucircumflex *
    circumflex += [0x00e2] # acircumflex *
    circumflex += [0x00ea] # ecircumflex *
    circumflex += [0x00ee] # icircumflex *
    circumflex += [0x00f4] # ocircumflex *
    circumflex += [0x00fb] # ucircumflex *
    circumflex += [0x02c6] # circumflex *

    acute  = [0x00c1] # Aacute *
    acute += [0x00c9] # Eacute *
    acute += [0x00cd] # Iacute *
    acute += [0x00d3] # Oacute *
    acute += [0x00da] # Uacute *
    acute += [0x00e1] # aacute *
    acute += [0x00e9] # eacute *
    acute += [0x00ed] # iacute *
    acute += [0x00f3] # oacute *
    acute += [0x00fa] # uacute *

    result = quotes
    if 'ascii' in subset:
        result += basic
    if 'en' in subset:
        result += basic
        result += punc
    if 'es' in subset:
        result += basic
        result += punc
        result += acute
        result += [0x00a1] # exclamdown *
        result += [0x00a8] # dieresis *
        result += [0x00ab] # guillemotleft *

        result += [0x00b8] # cedilla *
        result += [0x00bb] # guillemotright *
        result += [0x00bf] # questiondown *
        result += [0x00d1] # Ntilde *
        result += [0x00dc] # UDieresis *
        result += [0x00f1] # ntilde *
        result += [0x00fc] # udieresis *
        result += [0x0131] # dotlessi *
        result += [0x02c6] # circumflex *
        result += [0x02da] # ring *
        result += [0x02dc] # tilde *

    # Taken from:
    # http://en.wikipedia.org/wiki/Portuguese_alphabet
    # http://symbolcodes.tlt.psu.edu/bylanguage/portuguese.html
    if 'pt' in subset:
        result += basic
        result += punc
        result += acute

        result += [0x00ab] # guillemotleft *
        result += [0x00bb] # guillemotright *

        result += [0x00aa] # ordfeminine *
        result += [0x00ba] # ordmasculine *

        result += [0x00c2] # Acircumflex *
        result += [0x00ca] # Ecircumflex *
        result += [0x00d4] # Ocircumflex *
        result += [0x00e2] # acircumflex *
        result += [0x00ea] # ecircumflex *
        result += [0x00f4] # ocircumflex *

        result += [0x00c3] # Atilde *
        result += [0x00e3] # atilde *
        result += [0x00d5] # Otilde *
        result += [0x00f5] # otilde *

        result += [0x00dc] # Udiaeresis *
        result += [0x00fc] # udiaeresis *

        result += [0x00c0] # Agrave *
        result += [0x00e0] # agrave *
        result += [0x00d2] # Ograve *
        result += [0x00f2] # ograve *

        result += [0x00b8] # cedilla *
        result += [0x00c7] # Ccedilla *
        result += [0x00e7] # ccedilla *

    if 'de' in subset:
        result += basic
        result += punc
        result += dieresis
        result += [0x00ab] # guillemotleft *

        result += [0x00b8] # cedilla *
        result += [0x00bb] # guillemotright *
        result += [0x00df] # germandbls *
        result += [0x02c6] # circumflex *
        result += [0x02da] # ring *
        result += [0x02dc] # tilde *

    if 'fr' in subset:
        result += basic
        result += punc
        result += dieresis
        result += circumflex
        result += [0x00a0] # uni00A0 *
        result += [0x00ab] # guillemotleft *
        result += [0x00b8] # cedilla *
        result += [0x00bb] # guillemotright *
        result += [0x00c0] # Agrave *
        result += [0x00c6] # AE
        result += [0x00c7] # Ccedillia *
        result += [0x00c8] # Egrave *
        result += [0x00c9] # Eacute *
        result += [0x00d9] # Ugrave *
        result += [0x00e0] # agrave *
        result += [0x00e6] # AE
        result += [0x00e7] # ccedillia *
        result += [0x00e8] # egrave *
        result += [0x00e9] # eacute *
        result += [0x00f9] # ugrave *

        result += [0x0131] # dotlessi *
        result += [0x0152] # OE *
        result += [0x0153] # oe *

        result += [0x02da] # ring *
        result += [0x02dc] # tilde *


    if 'latin' in subset:
        result += basic
        result += latin
    if 'latin-ext' in subset:
        # These ranges include Extended A, B, C, D, and Additional with the
        # exception of Vietnamese, which is a separate range
        result += (range(0x100, 0x370) +
                   range(0x1d00, 0x1ea0) +
                   range(0x1ef2, 0x1f00) +
                   range(0x2070, 0x20d0) +
                   range(0x2c60, 0x2c80) +
                   range(0xa700, 0xa800))
    if 'vietnamese' in subset:
        # 2011-07-16 DC: Charset from http://vietunicode.sourceforge.net/charset/ + U+1ef9 from Fontaine
        result += [0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00C8, 0x00C9, 
               0x00CA, 0x00CC, 0x00CD, 0x00D2, 0x00D3, 0x00D4, 
               0x00D5, 0x00D9, 0x00DA, 0x00DD, 0x00E0, 0x00E1, 
               0x00E2, 0x00E3, 0x00E8, 0x00E9, 0x00EA, 0x00EC, 
               0x00ED, 0x00F2, 0x00F3, 0x00F4, 0x00F5, 0x00F9, 
               0x00FA, 0x00FD, 0x0102, 0x0103, 0x0110, 0x0111, 
               0x0128, 0x0129, 0x0168, 0x0169, 0x01A0, 0x01A1, 
               0x01AF, 0x01B0, 0x20AB] + range(0x1EA0, 0x1EFA)
    if 'greek' in subset:
        # Could probably be more aggressive here and exclude archaic characters,
        # but lack data
        result += range(0x370, 0x400)
    if 'greek-ext' in subset:
        result += range(0x370, 0x400) + range(0x1f00, 0x2000)
    if 'cyrillic' in subset:
        # Based on character frequency analysis
        result += range(0x400, 0x460) + [0x490, 0x491, 0x4b0, 0x4b1]
    if 'cyrillic-ext' in subset:
        result += (range(0x400, 0x530) +
                   [0x20b4] +
                   range(0x2de0, 0x2e00) +
                   range(0xa640, 0xa6a0))
    if 'arabic' in subset:
        # Based on Droid Arabic Kufi 1.0
        result += [0x000D, 0x0020, 0x0621, 0x0627, 0x062D, 
                   0x062F, 0x0631, 0x0633, 0x0635, 0x0637, 0x0639, 
                   0x0643, 0x0644, 0x0645, 0x0647, 0x0648, 0x0649, 
                   0x0640, 0x066E, 0x066F, 0x0660, 0x0661, 0x0662, 
                   0x0663, 0x0664, 0x0665, 0x0666, 0x0667, 0x0668, 
                   0x0669, 0x06F4, 0x06F5, 0x06F6, 0x06BE, 0x06D2, 
                   0x06A9, 0x06AF, 0x06BA, 0x066A, 0x061F, 0x060C, 
                   0x061B, 0x066B, 0x066C, 0x066D, 0x064B, 0x064D, 
                   0x064E, 0x064F, 0x064C, 0x0650, 0x0651, 0x0652, 
                   0x0653, 0x0654, 0x0655, 0x0670, 0x0656, 0x0615, 
                   0x0686, 0x0623, 0x0625, 0x0622, 0x0671, 0x0628, 
                   0x067E, 0x062A, 0x062B, 0x0679, 0x0629, 0x062C, 
                   0x062E, 0x0630, 0x0688, 0x0632, 0x0691, 0x0698, 
                   0x0634, 0x0636, 0x0638, 0x063A, 0x0641, 0x0642, 
                   0x0646, 0x06D5, 0x06C0, 0x0624, 0x064A, 0x06CC, 
                   0x06D3, 0x0626, 0x06C2, 0x06C1, 0x06C3, 0x06F0, 
                   0x06F1, 0x06F2, 0x06F3, 0x06F9, 0x06F7, 0x06F8, 
                   0xFC63, 0x0672, 0x0673, 0x0675, 0x0676, 0x0677, 
                   0x0678, 0x067A, 0x067B, 0x067C, 0x067D, 0x067F, 
                   0x0680, 0x0681, 0x0682, 0x0683, 0x0684, 0x0685, 
                   0x0687, 0x0689, 0x068A, 0x068B, 0x068C, 0x068D, 
                   0x068E, 0x068F, 0x0690, 0x0692, 0x0693, 0x0694, 
                   0x0695, 0x0696, 0x0697, 0x0699, 0x069A, 0x069B, 
                   0x069C, 0x069D, 0x069E, 0x069F, 0x06A0, 0x06A1, 
                   0x06A2, 0x06A3, 0x06A5, 0x06A6, 0x06A7, 0x06A8, 
                   0x06AA, 0x06AB, 0x06AC, 0x06AD, 0x06AE, 0x06B0, 
                   0x06B1, 0x06B2, 0x06B3, 0x06B4, 0x06B5, 0x06B6, 
                   0x06B7, 0x06B8, 0x06B9, 0x06BB, 0x06BC, 0x06BD, 
                   0x06BF, 0x06C4, 0x06C5, 0x06CD, 0x06D6, 0x06D7, 
                   0x06D8, 0x06D9, 0x06DA, 0x06DB, 0x06DC, 0x06DF, 
                   0x06E1, 0x06E2, 0x06E3, 0x06E4, 0x06E5, 0x06E6, 
                   0x06E7, 0x06E8, 0x06EA, 0x06EB, 0x06ED, 0x06FB, 
                   0x06FC, 0x06FD, 0x06FE, 0x0600, 0x0601, 0x0602, 
                   0x0603, 0x060E, 0x060F, 0x0610, 0x0611, 0x0612, 
                   0x0613, 0x0614, 0x0657, 0x0658, 0x06EE, 0x06EF, 
                   0x06FF, 0x060B, 0x061E, 0x0659, 0x065A, 0x065B, 
                   0x065C, 0x065D, 0x065E, 0x0750, 0x0751, 0x0752, 
                   0x0753, 0x0754, 0x0755, 0x0756, 0x0757, 0x0758, 
                   0x0759, 0x075A, 0x075B, 0x075C, 0x075D, 0x075E, 
                   0x075F, 0x0760, 0x0761, 0x0762, 0x0763, 0x0764, 
                   0x0765, 0x0766, 0x0767, 0x0768, 0x0769, 0x076A, 
                   0x076B, 0x076C, 0x076D, 0x06A4, 0x06C6, 0x06C7, 
                   0x06C8, 0x06C9, 0x06CA, 0x06CB, 0x06CF, 0x06CE, 
                   0x06D0, 0x06D1, 0x06D4, 0x06FA, 0x06DD, 0x06DE, 
                   0x06E0, 0x06E9, 0x060D, 0xFD3E, 0xFD3F, 0x25CC,
                   # Added from https://groups.google.com/d/topic/googlefontdirectory-discuss/MwlMWMPNCXs/discussion
                   0x063b, 0x063c, 0x063d, 0x063e, 0x063f, 0x0620,
                   0x0674, 0x0674, 0x06EC]
    return result

# code for extracting vertical metrics from a TrueType font

class Sfnt:
    def __init__(self, data):
        version, numTables, _, _, _ = struct.unpack('>IHHHH', data[:12])
        self.tables = {}
        for i in range(numTables):
            tag, checkSum, offset, length = struct.unpack('>4sIII', data[12 + 16 * i: 28 + 16 * i])
            self.tables[tag] = data[offset: offset + length]

    def hhea(self):
        r = {}
        d = self.tables['hhea']
        r['Ascender'], r['Descender'], r['LineGap'] = struct.unpack('>hhh', d[4:10])
        return r

    def os2(self):
        r = {}
        d = self.tables['OS/2']
        r['fsSelection'], = struct.unpack('>H', d[62:64])
        r['sTypoAscender'], r['sTypoDescender'], r['sTypoLineGap'] = struct.unpack('>hhh', d[68:74])
        r['usWinAscender'], r['usWinDescender'] = struct.unpack('>HH', d[74:78])
        return r

def set_os2(pe, name, val):
    print >> pe, 'SetOS2Value("' + name + '", %d)' % val

def set_os2_vert(pe, name, val):
    set_os2(pe, name + 'IsOffset', 0)
    set_os2(pe, name, val)

# Extract vertical metrics data directly out of font file, and emit
# script code to set the values in the generated font. This is a (rather
# ugly) workaround for the issue described in:
# http://sourceforge.net/mailarchive/forum.php?thread_name=20100906085718.GB1907%40khaled-laptop&forum_name=fontforge-users

def extract_vert_to_script(font_in, pe):
    data = file(font_in, 'rb').read()
    sfnt = Sfnt(data)
    hhea = sfnt.hhea()
    os2 = sfnt.os2()
    set_os2_vert(pe, "WinAscent", os2['usWinAscender'])
    set_os2_vert(pe, "WinDescent", os2['usWinDescender'])
    set_os2_vert(pe, "TypoAscent", os2['sTypoAscender'])
    set_os2_vert(pe, "TypoDescent", os2['sTypoDescender'])
    set_os2_vert(pe, "HHeadAscent", hhea['Ascender'])
    set_os2_vert(pe, "HHeadDescent", hhea['Descender'])

def main(argv):
    optlist, args = getopt.gnu_getopt(argv, '', ['string=', 'strip_names',
                                                 'simplify', 'new', 'script',
                                                 'nmr', 'roundtrip', 'subset=',
                                                 'namelist', 'null'])

    font_in, font_out = args
    opts = dict(optlist)
    if '--string' in opts:
        subset = map(ord, opts['--string'])
    else:
        subset = getsubset(opts.get('--subset', 'latin'))
    subset_font(font_in, font_out, subset, opts)

if __name__ == '__main__':
    main(sys.argv[1:])