#LIBCLANG_FILENAME = '/home/vstinner/llvm-project/_build/lib/libclang.so'
LIBCLANG_FILENAME = "/usr/lib64/llvm6.0/lib/libclang.so"

from ctypes import c_char_p, c_void_p, c_int, Structure, POINTER, c_ulong, cdll
import unittest

c_object_p = POINTER(c_void_p)

def b(x):
    if isinstance(x, bytes):
        return x
    return x.encode('utf8')

class ClangObject(object):
    def __init__(self, obj):
        assert isinstance(obj, c_object_p) and obj
        self.obj = self._as_parameter_ = obj

    def from_param(self):
        return self._as_parameter_

class _CXUnsavedFile(Structure):
    _fields_ = [("name", c_char_p), ("contents", c_char_p), ('length', c_ulong)]

class Cursor(Structure):
    _fields_ = [("_kind_id", c_int), ("xdata", c_int), ("data", c_void_p * 3)]

class Index(ClangObject):
    pass

class TranslationUnit(ClangObject):
    def __init__(self, ptr):
        ClangObject.__init__(self, ptr)

def from_source(lib, index):
    source = """
class test_class {
public:
  void public_member_function();
protected:
  void protected_member_function();
private:
  void private_member_function();
};
    """

    filename = 't.cpp'
    args = ['-std=c++11']
    unsaved_files=[(filename, source)]
    options=0

    args_array = (c_char_p * len(args))(*[b(x) for x in args])

    unsaved_array = None
    if len(unsaved_files) > 0:
        unsaved_array = (_CXUnsavedFile * len(unsaved_files))()
        for i, (name, contents) in enumerate(unsaved_files):
            if hasattr(contents, "read"):
                contents = contents.read()
            contents = b(contents)
            unsaved_array[i].name = b(name)
            unsaved_array[i].contents = contents
            unsaved_array[i].length = len(contents)

    func = lib.clang_parseTranslationUnit
    func.argtypes = [Index, c_char_p, c_void_p, c_int, c_void_p, c_int, c_int]
    func.restype = c_object_p

    ptr = func(index,
               filename.encode('utf8'),
               args_array,
               len(args), unsaved_array,
               len(unsaved_files), options)

    if not ptr:
        raise Exception

    assert isinstance(index, Index)
    return TranslationUnit(ptr)

def test_access_specifiers():
    lib = cdll.LoadLibrary(LIBCLANG_FILENAME)

    # define the class her to get 'lib' variable in __del__
    class _CXString(Structure):
        _fields_ = [("spelling", c_char_p), ("free", c_int)]

        def __del__(self):
            print("_CXString del: obj id=%x" % id(self))
            func = lib.clang_disposeString
            func.argtypes = [_CXString]
            func(self)

    func = lib.clang_getTranslationUnitCursor
    func.argtypes = [TranslationUnit]
    func.restype = Cursor

    func2 = lib.clang_getCursorSpelling
    func2.argtypes = [Cursor]
    func2.restype = _CXString

    func3 = lib.clang_createIndex
    func3.argtypes = [c_int, c_int]
    func3.restype = c_object_p

    index = Index(func3(False, 0))
    tu = from_source(lib, index)
    cursor = func(tu)

    print("spelling")
    spelling = func2(cursor)

    print("spelling = None")
    spelling = None
    print("spelling = None ---")

    cursor = None

    func = lib.clang_disposeIndex
    func.argtypes = [Index]
    func(index)
    index = tu.index = None

    func = lib.clang_disposeTranslationUnit
    func.argtypes = [TranslationUnit]
    func(tu)
    tu = None


if __name__ == "__main__":
    test_access_specifiers()