""" Adobe character mapping (CMap) support.

CMaps provide the mapping between character codes and Unicode
code-points to character ids (CIDs).

More information is available on the Adobe website:

  http://opensource.adobe.com/wiki/display/cmap/CMap+Resources

"""

import sys
import os
import os.path
import gzip
try:
    import cPickle as pickle
except ImportError:
    import pickle as pickle
import struct
import logging
from .psparser import PSStackParser
from .psparser import PSSyntaxError
from .psparser import PSEOF
from .psparser import PSLiteral
from .psparser import literal_name
from .psparser import KWD
from .encodingdb import name2unicode
from .utils import choplist
from .utils import nunpack

import six  #Python 2+3 compatibility

log = logging.getLogger(__name__)


class CMapError(Exception):
    pass


##  CMapBase
##
class CMapBase(object):

    debug = 0

    def __init__(self, **kwargs):
        self.attrs = kwargs.copy()
        return

    def is_vertical(self):
        return self.attrs.get('WMode', 0) != 0

    def set_attr(self, k, v):
        self.attrs[k] = v
        return

    def add_code2cid(self, code, cid):
        return

    def add_cid2unichr(self, cid, code):
        return

    def use_cmap(self, cmap):
        return


##  CMap
##
class CMap(CMapBase):

    def __init__(self, **kwargs):
        CMapBase.__init__(self, **kwargs)
        self.code2cid = {}
        return

    def __repr__(self):
        return '<CMap: %s>' % self.attrs.get('CMapName')

    def use_cmap(self, cmap):
        assert isinstance(cmap, CMap), str(type(cmap))

        def copy(dst, src):
            for (k, v) in src.iteritems():
                if isinstance(v, dict):
                    d = {}
                    dst[k] = d
                    copy(d, v)
                else:
                    dst[k] = v
        copy(self.code2cid, cmap.code2cid)
        return

    def decode(self, code):
        log.debug('decode: %r, %r', self, code)
        d = self.code2cid
        for i in six.iterbytes(code):
            if i in d:
                d = d[i]
                if isinstance(d, int):
                    yield d
                    d = self.code2cid
            else:
                d = self.code2cid
        return

    def dump(self, out=sys.stdout, code2cid=None, code=None):
        if code2cid is None:
            code2cid = self.code2cid
            code = ()
        for (k, v) in sorted(code2cid.iteritems()):
            c = code+(k,)
            if isinstance(v, int):
                out.write('code %r = cid %d\n' % (c, v))
            else:
                self.dump(out=out, code2cid=v, code=c)
        return


##  IdentityCMap
##
class IdentityCMap(CMapBase):

    def decode(self, code):
        n = len(code)//2
        if n:
            return struct.unpack('>%dH' % n, code)
        else:
            return ()


##  UnicodeMap
##
class UnicodeMap(CMapBase):

    def __init__(self, **kwargs):
        CMapBase.__init__(self, **kwargs)
        self.cid2unichr = {}
        return

    def __repr__(self):
        return '<UnicodeMap: %s>' % self.attrs.get('CMapName')

    def get_unichr(self, cid):
        log.debug('get_unichr: %r, %r', self, cid)
        return self.cid2unichr[cid]

    def dump(self, out=sys.stdout):
        for (k, v) in sorted(self.cid2unichr.iteritems()):
            out.write('cid %d = unicode %r\n' % (k, v))
        return


##  FileCMap
##
class FileCMap(CMap):

    def add_code2cid(self, code, cid):
        assert isinstance(code, str) and isinstance(cid, int), str((type(code), type(cid)))
        d = self.code2cid
        for c in code[:-1]:
            c = ord(c)
            if c in d:
                d = d[c]
            else:
                t = {}
                d[c] = t
                d = t
        c = ord(code[-1])
        d[c] = cid
        return


##  FileUnicodeMap
##
class FileUnicodeMap(UnicodeMap):

    def add_cid2unichr(self, cid, code):
        assert isinstance(cid, int), str(type(cid))
        if isinstance(code, PSLiteral):
            # Interpret as an Adobe glyph name.
            self.cid2unichr[cid] = name2unicode(code.name)
        elif isinstance(code, bytes):
            # Interpret as UTF-16BE.
            self.cid2unichr[cid] = code.decode('UTF-16BE', 'ignore')
        elif isinstance(code, int):
            self.cid2unichr[cid] = six.unichr(code)
        else:
            raise TypeError(code)
        return


##  PyCMap
##
class PyCMap(CMap):

    def __init__(self, name, module):
        CMap.__init__(self, CMapName=name)
        self.code2cid = module.CODE2CID
        if module.IS_VERTICAL:
            self.attrs['WMode'] = 1
        return


##  PyUnicodeMap
##
class PyUnicodeMap(UnicodeMap):

    def __init__(self, name, module, vertical):
        UnicodeMap.__init__(self, CMapName=name)
        if vertical:
            self.cid2unichr = module.CID2UNICHR_V
            self.attrs['WMode'] = 1
        else:
            self.cid2unichr = module.CID2UNICHR_H
        return


##  CMapDB
##
class CMapDB(object):

    _cmap_cache = {}
    _umap_cache = {}

    class CMapNotFound(CMapError):
        pass

    @classmethod
    def _load_data(klass, name):
        name = name.replace("\0", "")
        filename = '%s.pickle.gz' % name
        log.info('loading: %r', name)
        cmap_paths = (os.environ.get('CMAP_PATH', '/usr/share/pdfminer/'),
                      os.path.join(os.path.dirname(__file__), 'cmap'),)
        for directory in cmap_paths:
            path = os.path.join(directory, filename)
            if os.path.exists(path):
                gzfile = gzip.open(path)
                try:
                    return type(str(name), (), pickle.loads(gzfile.read()))
                finally:
                    gzfile.close()
        else:
            raise CMapDB.CMapNotFound(name)

    @classmethod
    def get_cmap(klass, name):
        if name == 'Identity-H':
            return IdentityCMap(WMode=0)
        elif name == 'Identity-V':
            return IdentityCMap(WMode=1)
        try:
            return klass._cmap_cache[name]
        except KeyError:
            pass
        data = klass._load_data(name)
        klass._cmap_cache[name] = cmap = PyCMap(name, data)
        return cmap

    @classmethod
    def get_unicode_map(klass, name, vertical=False):
        try:
            return klass._umap_cache[name][vertical]
        except KeyError:
            pass
        data = klass._load_data('to-unicode-%s' % name)
        klass._umap_cache[name] = umaps = [PyUnicodeMap(name, data, v) for v in (False, True)]
        return umaps[vertical]


##  CMapParser
##
class CMapParser(PSStackParser):

    def __init__(self, cmap, fp):
        PSStackParser.__init__(self, fp)
        self.cmap = cmap
        # some ToUnicode maps don't have "begincmap" keyword.
        self._in_cmap = True
        return

    def run(self):
        try:
            self.nextobject()
        except PSEOF:
            pass
        return

    KEYWORD_BEGINCMAP = KWD(b'begincmap')
    KEYWORD_ENDCMAP = KWD(b'endcmap')
    KEYWORD_USECMAP = KWD(b'usecmap')
    KEYWORD_DEF = KWD(b'def')
    KEYWORD_BEGINCODESPACERANGE = KWD(b'begincodespacerange')
    KEYWORD_ENDCODESPACERANGE = KWD(b'endcodespacerange')
    KEYWORD_BEGINCIDRANGE = KWD(b'begincidrange')
    KEYWORD_ENDCIDRANGE = KWD(b'endcidrange')
    KEYWORD_BEGINCIDCHAR = KWD(b'begincidchar')
    KEYWORD_ENDCIDCHAR = KWD(b'endcidchar')
    KEYWORD_BEGINBFRANGE = KWD(b'beginbfrange')
    KEYWORD_ENDBFRANGE = KWD(b'endbfrange')
    KEYWORD_BEGINBFCHAR = KWD(b'beginbfchar')
    KEYWORD_ENDBFCHAR = KWD(b'endbfchar')
    KEYWORD_BEGINNOTDEFRANGE = KWD(b'beginnotdefrange')
    KEYWORD_ENDNOTDEFRANGE = KWD(b'endnotdefrange')

    def do_keyword(self, pos, token):
        if token is self.KEYWORD_BEGINCMAP:
            self._in_cmap = True
            self.popall()
            return
        elif token is self.KEYWORD_ENDCMAP:
            self._in_cmap = False
            return
        if not self._in_cmap:
            return
        #
        if token is self.KEYWORD_DEF:
            try:
                ((_, k), (_, v)) = self.pop(2)
                self.cmap.set_attr(literal_name(k), v)
            except PSSyntaxError:
                pass
            return

        if token is self.KEYWORD_USECMAP:
            try:
                ((_, cmapname),) = self.pop(1)
                self.cmap.use_cmap(CMapDB.get_cmap(literal_name(cmapname)))
            except PSSyntaxError:
                pass
            except CMapDB.CMapNotFound:
                pass
            return

        if token is self.KEYWORD_BEGINCODESPACERANGE:
            self.popall()
            return
        if token is self.KEYWORD_ENDCODESPACERANGE:
            self.popall()
            return

        if token is self.KEYWORD_BEGINCIDRANGE:
            self.popall()
            return
        if token is self.KEYWORD_ENDCIDRANGE:
            objs = [obj for (__, obj) in self.popall()]
            for (s, e, cid) in choplist(3, objs):
                if (not isinstance(s, str) or not isinstance(e, str) or
                   not isinstance(cid, int) or len(s) != len(e)):
                    continue
                sprefix = s[:-4]
                eprefix = e[:-4]
                if sprefix != eprefix:
                    continue
                svar = s[-4:]
                evar = e[-4:]
                s1 = nunpack(svar)
                e1 = nunpack(evar)
                vlen = len(svar)
                #assert s1 <= e1, str((s1, e1))
                for i in range(e1-s1+1):
                    x = sprefix+struct.pack('>L', s1+i)[-vlen:]
                    self.cmap.add_code2cid(x, cid+i)
            return

        if token is self.KEYWORD_BEGINCIDCHAR:
            self.popall()
            return
        if token is self.KEYWORD_ENDCIDCHAR:
            objs = [obj for (__, obj) in self.popall()]
            for (cid, code) in choplist(2, objs):
                if isinstance(code, str) and isinstance(cid, str):
                    self.cmap.add_code2cid(code, nunpack(cid))
            return

        if token is self.KEYWORD_BEGINBFRANGE:
            self.popall()
            return
        if token is self.KEYWORD_ENDBFRANGE:
            objs = [obj for (__, obj) in self.popall()]
            for (s, e, code) in choplist(3, objs):
                if (not isinstance(s, bytes) or not isinstance(e, bytes) or
                   len(s) != len(e)):
                        continue
                s1 = nunpack(s)
                e1 = nunpack(e)
                #assert s1 <= e1, str((s1, e1))
                if isinstance(code, list):
                    for i in range(e1-s1+1):
                        self.cmap.add_cid2unichr(s1+i, code[i])
                else:
                    var = code[-4:]
                    base = nunpack(var)
                    prefix = code[:-4]
                    vlen = len(var)
                    for i in range(e1-s1+1):
                        x = prefix+struct.pack('>L', base+i)[-vlen:]
                        self.cmap.add_cid2unichr(s1+i, x)
            return

        if token is self.KEYWORD_BEGINBFCHAR:
            self.popall()
            return
        if token is self.KEYWORD_ENDBFCHAR:
            objs = [obj for (__, obj) in self.popall()]
            for (cid, code) in choplist(2, objs):
                if isinstance(cid, bytes) and isinstance(code, bytes):
                    self.cmap.add_cid2unichr(nunpack(cid), code)
            return

        if token is self.KEYWORD_BEGINNOTDEFRANGE:
            self.popall()
            return
        if token is self.KEYWORD_ENDNOTDEFRANGE:
            self.popall()
            return

        self.push((pos, token))
        return


# test
def main(argv):
    args = argv[1:]
    for fname in args:
        fp = open(fname, 'rb')
        cmap = FileUnicodeMap()
        #cmap = FileCMap()
        CMapParser(cmap, fp).run()
        fp.close()
        cmap.dump()
    return

if __name__ == '__main__':
    sys.exit(main(sys.argv))