""" Unicode Mapping Parser and Codec Generator.

This script parses Unicode mapping files as available from the Unicode

site (ftp://ftp.unicode.org/Public/MAPPINGS/) and creates Python codec

modules from them. The codecs use the standard character mapping codec

to actually apply the mapping.

Synopsis: gencodec.py dir codec_prefix

All files in dir are scanned and those producing non-empty mappings

will be written to <codec_prefix><mapname>.py with <mapname> being the

first part of the map's filename ('a' in a.b.c.txt) converted to

lowercase with hyphens replaced by underscores.

The tool also writes marshalled versions of the mapping tables to the

same location (with .mapping extension).

Written by Marc-Andre Lemburg (mal@lemburg.com).

(c) Copyright CNRI, All Rights Reserved. NO WARRANTY.

(c) Copyright Guido van Rossum, 2000.

Table generation:

(c) Copyright Marc-Andre Lemburg, 2005.

    Licensed to PSF under a Contributor Agreement.

"""#"

import re, os, marshal, codecs

# Maximum allowed size of charmap tables

MAX_TABLE_SIZE = 8192

# Standard undefined Unicode code point

UNI_UNDEFINED = unichr(0xFFFE)

mapRE = re.compile('((?:0x[0-9a-fA-F]+\+?)+)'

                   '\s+'

                   '((?:(?:0x[0-9a-fA-Z]+|<[A-Za-z]+>)\+?)*)'

                   '\s*'

                   '(#.+)?')

def parsecodes(codes,

               len=len, filter=filter,range=range):

    """ Converts code combinations to either a single code integer

        or a tuple of integers.

        meta-codes (in angular brackets, e.g. <LR> and <RL>) are

        ignored.

        Empty codes or illegal ones are returned as None.

    """

    if not codes:

        return None

    l = codes.split('+')

    if len(l) == 1:

        return int(l[0],16)

    for i in range(len(l)):

        try:

            l[i] = int(l[i],16)

        except ValueError:

            l[i] = None

    l = filter(lambda x: x is not None, l)

    if len(l) == 1:

        return l[0]

    else:

        return tuple(l)

def readmap(filename):

    f = open(filename,'r')

    lines = f.readlines()

    f.close()

    enc2uni = {}

    identity = []

    unmapped = range(256)

    # UTC mapping tables per convention don't include the identity

    # mappings for code points 0x00 - 0x1F and 0x7F, unless these are

    # explicitly mapped to different characters or undefined

    for i in range(32) + [127]:

        identity.append(i)

        unmapped.remove(i)

        enc2uni[i] = (i, 'CONTROL CHARACTER')

    for line in lines:

        line = line.strip()

        if not line or line[0] == '#':

            continue

        m = mapRE.match(line)

        if not m:

            #print '* not matched: %s' % repr(line)

            continue

        enc,uni,comment = m.groups()

        enc = parsecodes(enc)

        uni = parsecodes(uni)

        if comment is None:

            comment = ''

        else:

            comment = comment[1:].strip()

        if enc < 256:

            if enc in unmapped:

                unmapped.remove(enc)

            if enc == uni:

                identity.append(enc)

            enc2uni[enc] = (uni,comment)

        else:

            enc2uni[enc] = (uni,comment)

    # If there are more identity-mapped entries than unmapped entries,

    # it pays to generate an identity dictionary first, and add explicit

    # mappings to None for the rest

    if len(identity) >= len(unmapped):

        for enc in unmapped:

            enc2uni[enc] = (None, "")

        enc2uni['IDENTITY'] = 256

    return enc2uni

def hexrepr(t, precision=4):

    if t is None:

        return 'None'

    try:

        len(t)

    except:

        return '0x%0*X' % (precision, t)

    try:

        return '(' + ', '.join(['0x%0*X' % (precision, item)

                                for item in t]) + ')'

    except TypeError, why:

        print '* failed to convert %r: %s' % (t, why)

        raise

def python_mapdef_code(varname, map, comments=1, precisions=(2, 4)):

    l = []

    append = l.append

    if map.has_key("IDENTITY"):

        append("%s = codecs.make_identity_dict(range(%d))" %

               (varname, map["IDENTITY"]))

        append("%s.update({" % varname)

        splits = 1

        del map["IDENTITY"]

        identity = 1

    else:

        append("%s = {" % varname)

        splits = 0

        identity = 0

    mappings = map.items()

    mappings.sort()

    i = 0

    key_precision, value_precision = precisions

    for mapkey, mapvalue in mappings:

        mapcomment = ''

        if isinstance(mapkey, tuple):

            (mapkey, mapcomment) = mapkey

        if isinstance(mapvalue, tuple):

            (mapvalue, mapcomment) = mapvalue

        if mapkey is None:

            continue

        if (identity and

            mapkey == mapvalue and

            mapkey < 256):

            # No need to include identity mappings, since these

            # are already set for the first 256 code points.

            continue

        key = hexrepr(mapkey, key_precision)

        value = hexrepr(mapvalue, value_precision)

        if mapcomment and comments:

            append('    %s: %s,\t#  %s' % (key, value, mapcomment))

        else:

            append('    %s: %s,' % (key, value))

        i += 1

        if i == 4096:

            # Split the definition into parts to that the Python

            # parser doesn't dump core

            if splits == 0:

                append('}')

            else:

                append('})')

            append('%s.update({' % varname)

            i = 0

            splits = splits + 1

    if splits == 0:

        append('}')

    else:

        append('})')

    return l

def python_tabledef_code(varname, map, comments=1, key_precision=2):

    l = []

    append = l.append

    append('%s = (' % varname)

    # Analyze map and create table dict

    mappings = map.items()

    mappings.sort()

    table = {}

    maxkey = 0

    if map.has_key('IDENTITY'):

        for key in range(256):

            table[key] = (key, '')

        maxkey = 255

        del map['IDENTITY']

    for mapkey, mapvalue in mappings:

        mapcomment = ''

        if isinstance(mapkey, tuple):

            (mapkey, mapcomment) = mapkey

        if isinstance(mapvalue, tuple):

            (mapvalue, mapcomment) = mapvalue

        if mapkey is None:

            continue

        table[mapkey] = (mapvalue, mapcomment)

        if mapkey > maxkey:

            maxkey = mapkey

    if maxkey > MAX_TABLE_SIZE:

        # Table too large

        return None

    # Create table code

    for key in range(maxkey + 1):

        if key not in table:

            mapvalue = None

            mapcomment = 'UNDEFINED'

        else:

            mapvalue, mapcomment = table[key]

        if mapvalue is None:

            mapchar = UNI_UNDEFINED

        else:

            if isinstance(mapvalue, tuple):

                # 1-n mappings not supported

                return None

            else:

                mapchar = unichr(mapvalue)

        if mapcomment and comments:

            append('    %r\t#  %s -> %s' % (mapchar,

                                            hexrepr(key, key_precision),

                                            mapcomment))

        else:

            append('    %r' % mapchar)

    append(')')

    return l

def codegen(name, map, encodingname, comments=1):

    """ Returns Python source for the given map.

        Comments are included in the source, if comments is true (default).

    """

    # Generate code

    decoding_map_code = python_mapdef_code(

        'decoding_map',

        map,

        comments=comments)

    decoding_table_code = python_tabledef_code(

        'decoding_table',

        map,

        comments=comments)

    encoding_map_code = python_mapdef_code(

        'encoding_map',

        codecs.make_encoding_map(map),

        comments=comments,

        precisions=(4, 2))

    if decoding_table_code:

        suffix = 'table'

    else:

        suffix = 'map'

    l = [

        '''\

""" Python Character Mapping Codec %s generated from '%s' with gencodec.py.

"""#"

import codecs

### Codec APIs

class Codec(codecs.Codec):

    def encode(self,input,errors='strict'):

        return codecs.charmap_encode(input,errors,encoding_%s)

    def decode(self,input,errors='strict'):

        return codecs.charmap_decode(input,errors,decoding_%s)

''' % (encodingname, name, suffix, suffix)]

    l.append('''\

class IncrementalEncoder(codecs.IncrementalEncoder):

    def encode(self, input, final=False):

        return codecs.charmap_encode(input,self.errors,encoding_%s)[0]

class IncrementalDecoder(codecs.IncrementalDecoder):

    def decode(self, input, final=False):

        return codecs.charmap_decode(input,self.errors,decoding_%s)[0]''' %

        (suffix, suffix))

    l.append('''

class StreamWriter(Codec,codecs.StreamWriter):

    pass

class StreamReader(Codec,codecs.StreamReader):

    pass

### encodings module API

def getregentry():

    return codecs.CodecInfo(

        name=%r,

        encode=Codec().encode,

        decode=Codec().decode,

        incrementalencoder=IncrementalEncoder,

        incrementaldecoder=IncrementalDecoder,

        streamreader=StreamReader,

        streamwriter=StreamWriter,

    )

''' % encodingname.replace('_', '-'))

    # Add decoding table or map (with preference to the table)

    if not decoding_table_code:

        l.append('''

### Decoding Map

''')

        l.extend(decoding_map_code)

    else:

        l.append('''

### Decoding Table

''')

        l.extend(decoding_table_code)

    # Add encoding map

    if decoding_table_code:

        l.append('''

### Encoding table

encoding_table=codecs.charmap_build(decoding_table)

''')

    else:

        l.append('''

### Encoding Map

''')

        l.extend(encoding_map_code)

    # Final new-line

    l.append('')

    return '\n'.join(l).expandtabs()

def pymap(name,map,pyfile,encodingname,comments=1):

    code = codegen(name,map,encodingname,comments)

    f = open(pyfile,'w')

    f.write(code)

    f.close()

def marshalmap(name,map,marshalfile):

    d = {}

    for e,(u,c) in map.items():

        d[e] = (u,c)

    f = open(marshalfile,'wb')

    marshal.dump(d,f)

    f.close()

def convertdir(dir, dirprefix='', nameprefix='', comments=1):

    mapnames = os.listdir(dir)

    for mapname in mapnames:

        mappathname = os.path.join(dir, mapname)

        if not os.path.isfile(mappathname):

            continue

        name = os.path.split(mapname)[1]

        name = name.replace('-','_')

        name = name.split('.')[0]

        name = name.lower()

        name = nameprefix + name

        codefile = name + '.py'

        marshalfile = name + '.mapping'

        print 'converting %s to %s and %s' % (mapname,

                                              dirprefix + codefile,

                                              dirprefix + marshalfile)

        try:

            map = readmap(os.path.join(dir,mapname))

            if not map:

                print '* map is empty; skipping'

            else:

                pymap(mappathname, map, dirprefix + codefile,name,comments)

                marshalmap(mappathname, map, dirprefix + marshalfile)

        except ValueError, why:

            print '* conversion failed: %s' % why

            raise

def rewritepythondir(dir, dirprefix='', comments=1):

    mapnames = os.listdir(dir)

    for mapname in mapnames:

        if not mapname.endswith('.mapping'):

            continue

        name = mapname[:-len('.mapping')]

        codefile = name + '.py'

        print 'converting %s to %s' % (mapname,

                                       dirprefix + codefile)

        try:

            map = marshal.load(open(os.path.join(dir,mapname),

                               'rb'))

            if not map:

                print '* map is empty; skipping'

            else:

                pymap(mapname, map, dirprefix + codefile,name,comments)

        except ValueError, why:

            print '* conversion failed: %s' % why

if __name__ == '__main__':

    import sys

    if 1:

        apply(convertdir,tuple(sys.argv[1:]))

    else:

        apply(rewritepythondir,tuple(sys.argv[1:]))