# pyenchant
#
# Copyright (C) 2004-2008, Ryan Kelly
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.
#
# In addition, as a special exception, you are
# given permission to link the code of this program with
# non-LGPL Spelling Provider libraries (eg: a MSFT Office
# spell checker backend) and distribute linked combinations including
# the two.  You must obey the GNU Lesser General Public License in all
# respects for all of the code used other than said providers.  If you modify
# this file, you may extend this exception to your version of the
# file, but you are not obligated to do so.  If you do not wish to
# do so, delete this exception statement from your version.
#
"""

    enchant._enchant:  ctypes-based wrapper for enchant C library

    This module implements the low-level interface to the underlying
    C library for enchant.  The interface is based on ctypes and tries 
    to do as little as possible while making the higher-level components
    easier to write.

    The following conveniences are provided that differ from the underlying
    C API:

        * the "enchant" prefix has been removed from all functions, since
          python has a proper module system
        * callback functions do not take a user_data argument, since
          python has proper closures that can manage this internally
        * string lengths are not passed into functions such as dict_check,
          since python strings know how long they are

"""

import sys, os, os.path
from ctypes import *
from ctypes.util import find_library

from enchant import utils
from enchant.errors import *
from enchant.utils import unicode

# Locate and load the enchant dll.
# We've got several options based on the host platform.

e = None

def _e_path_possibilities():
    """Generator yielding possible locations of the enchant library."""
    # Allow it to be overridden using an environment variable.
    yield os.environ.get("PYENCHANT_LIBRARY_PATH")
    # For linuxish systems, allow default soname lookup a chance to succeed.
    if sys.platform not in ("win32", "darwin"):
        yield "libenchant.so.1.6.0"
        yield "libenchant.so.1"
        yield "libenchant.so"
    # See if ctypes can find the library for us, under various names.
    yield find_library("enchant")
    yield find_library("libenchant")
    yield find_library("libenchant-1")
    # Special-case handling for enchant installed by macports.
    if sys.platform == 'darwin':
         yield "/opt/local/lib/libenchant.dylib"


# On win32 we ship a bundled version of the enchant DLLs.
# Use them if they're present.
if sys.platform == "win32":
    e_path = None
    try:
        e_path = utils.get_resource_filename("libenchant.dll")
    except (Error,ImportError):
         try:
            e_path = utils.get_resource_filename("libenchant-1.dll")
         except (Error,ImportError):
            pass
    if e_path is not None:
        # We need to use LoadLibraryEx with LOAD_WITH_ALTERED_SEARCH_PATH so
        # that we don't accidentally suck in other versions of e.g. glib.
        if not isinstance(e_path,unicode):
            e_path = unicode(e_path,sys.getfilesystemencoding())
        LoadLibraryEx = windll.kernel32.LoadLibraryExW
        LOAD_WITH_ALTERED_SEARCH_PATH = 0x00000008
        e_handle = LoadLibraryEx(e_path,None,LOAD_WITH_ALTERED_SEARCH_PATH)
        if not e_handle:
            raise WinError()
        e = CDLL(e_path,handle=e_handle)


# On darwin we ship a bundled version of the enchant DLLs.
# Use them if they're present.
if e is None and sys.platform == "darwin":
  try:
      e_path = utils.get_resource_filename("lib/libenchant.1.dylib")
  except (Error,ImportError):
      pass
  else:
      # Enchant doesn't natively support relocatable binaries on OSX.
      # We fake it by patching the enchant source to expose a char**, which
      # we can write the runtime path into ourselves.
      e = CDLL(e_path)
      try:
          e_dir = os.path.dirname(os.path.dirname(e_path))
          if isinstance(e_dir,unicode):
              e_dir = e_dir.encode(sys.getfilesystemencoding())
          prefix_dir = POINTER(c_char_p).in_dll(e,"enchant_prefix_dir_p")
          prefix_dir.contents = c_char_p(e_dir)
      except AttributeError:
          e = None


# Not found yet, search various standard system locations.
if e is None:
    for e_path in _e_path_possibilities():
        if e_path is not None:
            try:
                e = cdll.LoadLibrary(e_path)
            except OSError:
                pass
            else:
                break


# No usable enchant install was found :-(
if e is None:
   msg = "The 'enchant' C library was not found. "\
         "Please install it via your OS package manager, "\
         "or use a pre-built binary wheel from PyPI."
   raise ImportError(msg)


# Define various callback function types

def CALLBACK(restype,*argtypes):
    """Factory for generating callback function prototypes.

    This is factored into a factory so I can easily change the definition
    for experimentation or debugging.
    """
    return CFUNCTYPE(restype,*argtypes)

t_broker_desc_func = CALLBACK(None,c_char_p,c_char_p,c_char_p,c_void_p)
t_dict_desc_func = CALLBACK(None,c_char_p,c_char_p,c_char_p,c_char_p,c_void_p)


# Simple typedefs for readability

t_broker = c_void_p
t_dict = c_void_p


# Now we can define the types of each function we are going to use

broker_init = e.enchant_broker_init
broker_init.argtypes = []
broker_init.restype = t_broker

broker_free = e.enchant_broker_free
broker_free.argtypes = [t_broker]
broker_free.restype = None

broker_request_dict = e.enchant_broker_request_dict
broker_request_dict.argtypes = [t_broker,c_char_p]
broker_request_dict.restype = t_dict

broker_request_pwl_dict = e.enchant_broker_request_pwl_dict
broker_request_pwl_dict.argtypes = [t_broker,c_char_p]
broker_request_pwl_dict.restype = t_dict

broker_free_dict = e.enchant_broker_free_dict
broker_free_dict.argtypes = [t_broker,t_dict]
broker_free_dict.restype = None

broker_dict_exists = e.enchant_broker_dict_exists
broker_dict_exists.argtypes = [t_broker,c_char_p]
broker_free_dict.restype = c_int

broker_set_ordering = e.enchant_broker_set_ordering
broker_set_ordering.argtypes = [t_broker,c_char_p,c_char_p]
broker_set_ordering.restype = None

broker_get_error = e.enchant_broker_get_error
broker_get_error.argtypes = [t_broker]
broker_get_error.restype = c_char_p

broker_describe1 = e.enchant_broker_describe
broker_describe1.argtypes = [t_broker,t_broker_desc_func,c_void_p]
broker_describe1.restype = None
def broker_describe(broker,cbfunc):
    def cbfunc1(*args):
        cbfunc(*args[:-1])
    broker_describe1(broker,t_broker_desc_func(cbfunc1),None)

broker_list_dicts1 = e.enchant_broker_list_dicts
broker_list_dicts1.argtypes = [t_broker,t_dict_desc_func,c_void_p]
broker_list_dicts1.restype = None
def broker_list_dicts(broker,cbfunc):
    def cbfunc1(*args):
        cbfunc(*args[:-1])
    broker_list_dicts1(broker,t_dict_desc_func(cbfunc1),None)

try:
    broker_get_param = e.enchant_broker_get_param
except AttributeError:
    #  Make the lookup error occur at runtime
    def broker_get_param(broker,param_name):
        return e.enchant_broker_get_param(param_name)
else:
    broker_get_param.argtypes = [t_broker,c_char_p]
    broker_get_param.restype = c_char_p

try:
    broker_set_param = e.enchant_broker_set_param
except AttributeError:
    #  Make the lookup error occur at runtime
    def broker_set_param(broker,param_name):
        return e.enchant_broker_set_param(param_name)
else:
    broker_set_param.argtypes = [t_broker,c_char_p,c_char_p]
    broker_set_param.restype = None

try:
    get_version = e.enchant_get_version
except AttributeError:
    #  Make the lookup error occur at runtime
    def get_version():
        return e.enchant_get_version()
else:
    get_version.argtypes = []
    get_version.restype = c_char_p


dict_check1 = e.enchant_dict_check
dict_check1.argtypes = [t_dict,c_char_p,c_size_t]
dict_check1.restype = c_int
def dict_check(dict,word):
    return dict_check1(dict,word,len(word))

dict_suggest1 = e.enchant_dict_suggest
dict_suggest1.argtypes = [t_dict,c_char_p,c_size_t,POINTER(c_size_t)]
dict_suggest1.restype = POINTER(c_char_p)
def dict_suggest(dict,word):
    numSuggsP = pointer(c_size_t(0))
    suggs_c = dict_suggest1(dict,word,len(word),numSuggsP)
    suggs = []
    n = 0
    while n < numSuggsP.contents.value:
        suggs.append(suggs_c[n])
        n = n + 1
    if numSuggsP.contents.value > 0:
        dict_free_string_list(dict,suggs_c)
    return suggs

dict_add1 = e.enchant_dict_add
dict_add1.argtypes = [t_dict,c_char_p,c_size_t]
dict_add1.restype = None
def dict_add(dict,word):
    return dict_add1(dict,word,len(word))

dict_add_to_pwl1 = e.enchant_dict_add
dict_add_to_pwl1.argtypes = [t_dict,c_char_p,c_size_t]
dict_add_to_pwl1.restype = None
def dict_add_to_pwl(dict,word):
    return dict_add_to_pwl1(dict,word,len(word))

dict_add_to_session1 = e.enchant_dict_add_to_session
dict_add_to_session1.argtypes = [t_dict,c_char_p,c_size_t]
dict_add_to_session1.restype = None
def dict_add_to_session(dict,word):
    return dict_add_to_session1(dict,word,len(word))

dict_remove1 = e.enchant_dict_remove
dict_remove1.argtypes = [t_dict,c_char_p,c_size_t]
dict_remove1.restype = None
def dict_remove(dict,word):
    return dict_remove1(dict,word,len(word))

dict_remove_from_session1 = e.enchant_dict_remove_from_session
dict_remove_from_session1.argtypes = [t_dict,c_char_p,c_size_t]
dict_remove_from_session1.restype = c_int
def dict_remove_from_session(dict,word):
    return dict_remove_from_session1(dict,word,len(word))

dict_is_added1 = e.enchant_dict_is_added
dict_is_added1.argtypes = [t_dict,c_char_p,c_size_t]
dict_is_added1.restype = c_int
def dict_is_added(dict,word):
    return dict_is_added1(dict,word,len(word))

dict_is_removed1 = e.enchant_dict_is_removed
dict_is_removed1.argtypes = [t_dict,c_char_p,c_size_t]
dict_is_removed1.restype = c_int
def dict_is_removed(dict,word):
    return dict_is_removed1(dict,word,len(word))

dict_store_replacement1 = e.enchant_dict_store_replacement
dict_store_replacement1.argtypes = [t_dict,c_char_p,c_size_t,c_char_p,c_size_t]
dict_store_replacement1.restype = None
def dict_store_replacement(dict,mis,cor):
    return dict_store_replacement1(dict,mis,len(mis),cor,len(cor))

dict_free_string_list = e.enchant_dict_free_string_list
dict_free_string_list.argtypes = [t_dict,POINTER(c_char_p)]
dict_free_string_list.restype = None

dict_get_error = e.enchant_dict_get_error
dict_get_error.argtypes = [t_dict]
dict_get_error.restype = c_char_p

dict_describe1 = e.enchant_dict_describe
dict_describe1.argtypes = [t_dict,t_dict_desc_func,c_void_p]
dict_describe1.restype = None
def dict_describe(dict,cbfunc):
    def cbfunc1(tag,name,desc,file,data):
        cbfunc(tag,name,desc,file)
    dict_describe1(dict,t_dict_desc_func(cbfunc1),None)

