"""
utility functions for asteval

   Matthew Newville <newville@cars.uchicago.edu>,
   The University of Chicago
"""
import ast
import io
import math
import numbers
import re
from sys import exc_info
from tokenize import ENCODING as tk_ENCODING
from tokenize import NAME as tk_NAME
from tokenize import tokenize as generate_tokens

builtins = __builtins__
if not isinstance(builtins, dict):
    builtins = builtins.__dict__

HAS_NUMPY = False
try:
    import numpy
    numpy_version = numpy.version.version.split('.', 2)
    HAS_NUMPY = True
except ImportError:
    numpy = None

HAS_NUMPY_FINANCIAL = False
try:
    import numpy_financial
    HAS_NUMPY_FINANCIAL = True
except ImportError:
    pass



MAX_EXPONENT = 10000
MAX_STR_LEN = 2 << 17  # 256KiB
MAX_SHIFT = 1000
MAX_OPEN_BUFFER = 2 << 17

RESERVED_WORDS = ('False', 'None', 'True', 'and', 'as', 'assert',
                  'async', 'await', 'break', 'class', 'continue',
                  'def', 'del', 'elif', 'else', 'except', 'finally',
                  'for', 'from', 'global', 'if', 'import', 'in', 'is',
                  'lambda', 'nonlocal', 'not', 'or', 'pass', 'raise',
                  'return', 'try', 'while', 'with', 'yield', 'exec',
                  'eval', 'execfile', '__import__', '__package__')

NAME_MATCH = re.compile(r"[a-zA-Z_][a-zA-Z0-9_]*$").match

UNSAFE_ATTRS = ('__subclasses__', '__bases__', '__globals__', '__code__',
                '__reduce__', '__reduce_ex__',  '__mro__',
                '__closure__', '__func__', '__self__', '__module__',
                '__dict__', '__class__', '__call__', '__get__',
                '__getattribute__', '__subclasshook__', '__new__',
                '__init__', 'func_globals', 'func_code', 'func_closure',
                'im_class', 'im_func', 'im_self', 'gi_code', 'gi_frame',
                'f_locals', '__asteval__')

# inherit these from python's __builtins__
FROM_PY = ('ArithmeticError', 'AssertionError', 'AttributeError',
           'BaseException', 'BufferError', 'BytesWarning',
           'DeprecationWarning', 'EOFError', 'EnvironmentError',
           'Exception', 'False', 'FloatingPointError', 'GeneratorExit',
           'IOError', 'ImportError', 'ImportWarning', 'IndentationError',
           'IndexError', 'KeyError', 'KeyboardInterrupt', 'LookupError',
           'MemoryError', 'NameError', 'None',
           'NotImplementedError', 'OSError', 'OverflowError',
           'ReferenceError', 'RuntimeError', 'RuntimeWarning',
           'StopIteration', 'SyntaxError', 'SyntaxWarning', 'SystemError',
           'SystemExit', 'True', 'TypeError', 'UnboundLocalError',
           'UnicodeDecodeError', 'UnicodeEncodeError', 'UnicodeError',
           'UnicodeTranslateError', 'UnicodeWarning', 'ValueError',
           'Warning', 'ZeroDivisionError', 'abs', 'all', 'any', 'bin',
           'bool', 'bytearray', 'bytes', 'chr', 'complex', 'dict', 'dir',
           'divmod', 'enumerate', 'filter', 'float', 'format', 'frozenset',
           'hash', 'hex', 'id', 'int', 'isinstance', 'len', 'list', 'map',
           'max', 'min', 'oct', 'ord', 'pow', 'range', 'repr',
           'reversed', 'round', 'set', 'slice', 'sorted', 'str', 'sum',
           'tuple', 'zip')

BUILTINS_TABLE = {sym: builtins[sym] for sym in FROM_PY if sym in builtins}

# inherit these from python's math
FROM_MATH = ('acos', 'acosh', 'asin', 'asinh', 'atan', 'atan2', 'atanh',
             'ceil', 'copysign', 'cos', 'cosh', 'degrees', 'e', 'exp',
             'fabs', 'factorial', 'floor', 'fmod', 'frexp', 'fsum',
             'hypot', 'isinf', 'isnan', 'ldexp', 'log', 'log10', 'log1p',
             'modf', 'pi', 'pow', 'radians', 'sin', 'sinh', 'sqrt', 'tan',
             'tanh', 'trunc')

MATH_TABLE = {sym: getattr(math, sym) for sym in FROM_MATH if hasattr(math, sym)}


FROM_NUMPY = ('Inf', 'NAN', 'abs', 'add', 'all', 'amax', 'amin', 'angle',
              'any', 'append', 'arange', 'arccos', 'arccosh', 'arcsin',
              'arcsinh', 'arctan', 'arctan2', 'arctanh', 'argmax', 'argmin',
              'argsort', 'argwhere', 'around', 'array', 'array2string',
              'asanyarray', 'asarray', 'asarray_chkfinite',
              'ascontiguousarray', 'asfarray', 'asfortranarray', 'asmatrix',
              'atleast_1d', 'atleast_2d', 'atleast_3d', 'average', 'bartlett',
              'base_repr', 'bitwise_and', 'bitwise_not', 'bitwise_or',
              'bitwise_xor', 'blackman', 'broadcast', 'broadcast_arrays',
              'byte', 'c_', 'cdouble', 'ceil', 'cfloat', 'chararray', 'choose',
              'clip', 'clongdouble', 'clongfloat', 'column_stack',
              'common_type', 'complex128', 'complex64', 'complex_',
              'complexfloating', 'compress', 'concatenate', 'conjugate',
              'convolve', 'copy', 'copysign', 'corrcoef', 'correlate', 'cos',
              'cosh', 'cov', 'cross', 'csingle', 'cumprod', 'cumsum',
              'datetime_data', 'deg2rad', 'degrees', 'delete', 'diag',
              'diag_indices', 'diag_indices_from', 'diagflat', 'diagonal',
              'diff', 'digitize', 'divide', 'dot', 'double', 'dsplit',
              'dstack', 'dtype', 'e', 'ediff1d', 'empty', 'empty_like',
              'equal', 'exp', 'exp2', 'expand_dims', 'expm1', 'extract', 'eye',
              'fabs', 'fft', 'fill_diagonal', 'finfo', 'fix', 'flatiter',
              'flatnonzero', 'fliplr', 'flipud', 'float32', 'float64',
              'float_', 'floating', 'floor', 'floor_divide', 'fmax', 'fmin',
              'fmod', 'format_parser', 'frexp', 'frombuffer', 'fromfile',
              'fromfunction', 'fromiter', 'frompyfunc', 'fromregex',
              'fromstring', 'genfromtxt', 'getbufsize', 'geterr', 'gradient',
              'greater', 'greater_equal', 'hamming', 'hanning', 'histogram',
              'histogram2d', 'histogramdd', 'hsplit', 'hstack', 'hypot', 'i0',
              'identity', 'iinfo', 'imag', 'in1d', 'index_exp', 'indices',
              'inexact', 'inf', 'info', 'infty', 'inner', 'insert', 'int16',
              'int32', 'int64', 'int8', 'int_', 'intc', 'integer', 'interp',
              'intersect1d', 'intp', 'invert', 'iscomplex', 'iscomplexobj',
              'isfinite', 'isfortran', 'isinf', 'isnan', 'isneginf',
              'isposinf', 'isreal', 'isrealobj', 'isscalar', 'issctype',
              'iterable', 'ix_', 'kaiser', 'kron', 'ldexp', 'left_shift',
              'less', 'less_equal', 'linalg', 'linspace', 'little_endian',
              'load', 'loadtxt', 'log', 'log10', 'log1p', 'log2', 'logaddexp',
              'logaddexp2', 'logical_and', 'logical_not', 'logical_or',
              'logical_xor', 'logspace', 'longcomplex', 'longdouble',
              'longfloat', 'longlong', 'mask_indices', 'mat', 'matrix',
              'maximum', 'maximum_sctype', 'may_share_memory', 'mean',
              'median', 'memmap', 'meshgrid', 'mgrid', 'minimum',
              'mintypecode', 'mod', 'modf', 'msort', 'multiply', 'nan',
              'nan_to_num', 'nanargmax', 'nanargmin', 'nanmax', 'nanmin',
              'nansum', 'ndarray', 'ndenumerate', 'ndim', 'ndindex',
              'negative', 'newaxis', 'nextafter', 'nonzero', 'not_equal',
              'number', 'obj2sctype', 'ogrid', 'ones', 'ones_like', 'outer',
              'packbits', 'percentile', 'pi', 'piecewise', 'place', 'poly',
              'poly1d', 'polyadd', 'polyder', 'polydiv', 'polyfit', 'polyint',
              'polymul', 'polynomial', 'polysub', 'polyval', 'power', 'prod',
              'product', 'ptp', 'put', 'putmask', 'r_', 'rad2deg', 'radians',
              'random', 'ravel', 'real', 'real_if_close', 'reciprocal',
              'record', 'remainder', 'repeat', 'reshape', 'resize',
              'right_shift', 'rint', 'roll', 'rollaxis', 'roots', 'rot90',
              'round', 'round_', 'row_stack', 's_', 'sctype2char',
              'searchsorted', 'select', 'setbufsize', 'setdiff1d', 'seterr',
              'setxor1d', 'shape', 'short', 'sign', 'signbit', 'signedinteger',
              'sin', 'sinc', 'single', 'singlecomplex', 'sinh', 'size',
              'sometrue', 'sort', 'sort_complex', 'spacing', 'split', 'sqrt',
              'square', 'squeeze', 'std', 'str_', 'subtract', 'sum',
              'swapaxes', 'take', 'tan', 'tanh', 'tensordot', 'tile', 'trace',
              'transpose', 'trapz', 'tri', 'tril', 'tril_indices',
              'tril_indices_from', 'trim_zeros', 'triu', 'triu_indices',
              'triu_indices_from', 'true_divide', 'trunc', 'ubyte', 'uint',
              'uint16', 'uint32', 'uint64', 'uint8', 'uintc', 'uintp',
              'ulonglong', 'union1d', 'unique', 'unravel_index',
              'unsignedinteger', 'unwrap', 'ushort', 'vander', 'var', 'vdot',
              'vectorize', 'vsplit', 'vstack', 'where', 'who', 'zeros',
              'zeros_like')

FROM_NUMPY_FINANCIAL = ('fv', 'ipmt', 'irr', 'mirr', 'nper', 'npv',
                        'pmt', 'ppmt', 'pv', 'rate')

NUMPY_RENAMES = {'ln': 'log', 'asin': 'arcsin', 'acos': 'arccos',
                 'atan': 'arctan', 'atan2': 'arctan2', 'atanh':
                 'arctanh', 'acosh': 'arccosh', 'asinh': 'arcsinh'}

if HAS_NUMPY:
    numpy_deprecated = []
    if int(numpy_version[0]) == 1 and int(numpy_version[1]) >= 20:
        # aliases deprecated in NumPy v1.20.0
        numpy_deprecated = ['str', 'bool', 'int', 'float', 'complex', 'pv', 'rate',
                            'pmt', 'ppmt', 'npv', 'nper', 'long', 'mirr', 'fv',
                            'irr', 'ipmt']
    if int(numpy_version[0]) == 1 and int(numpy_version[1]) >= 24:
        # aliases deprecated in NumPy v1.24.0
        numpy_deprecated += ['int0', 'uint0', 'bool8']

    FROM_NUMPY = tuple(set(FROM_NUMPY) - set(numpy_deprecated))

    FROM_NUMPY = tuple(sym for sym in FROM_NUMPY if hasattr(numpy, sym))
    NUMPY_RENAMES = {sym: value for sym, value in NUMPY_RENAMES.items() if hasattr(numpy, value)}

    NUMPY_TABLE = {}
    for sym in FROM_NUMPY:
        NUMPY_TABLE[sym] = getattr(numpy, sym)
    for sname, sym in NUMPY_RENAMES.items():
        NUMPY_TABLE[sname] = getattr(numpy, sym)

    if HAS_NUMPY_FINANCIAL:
        for sym in FROM_NUMPY_FINANCIAL:
            NUMPY_TABLE[sym] = getattr(numpy_financial, sym)

else:
    NUMPY_TABLE = {}


def _open(filename, mode='r', buffering=-1, encoding=None):
    """read only version of open()"""
    if mode not in ('r', 'rb', 'rU'):
        raise RuntimeError("Invalid open file mode, must be 'r', 'rb', or 'rU'")
    if buffering > MAX_OPEN_BUFFER:
        raise RuntimeError(f"Invalid buffering value, max buffer size is {MAX_OPEN_BUFFER}")
    return open(filename, mode, buffering, encoding=encoding)


def _type(obj):
    """type that prevents varargs and varkws"""
    return type(obj).__name__


LOCALFUNCS = {'open': _open, 'type': _type}


# Safe versions of functions to prevent denial of service issues

def safe_pow(base, exp):
    """safe version of pow"""
    if isinstance(exp, numbers.Number):
        if exp > MAX_EXPONENT:
            raise RuntimeError(f"Invalid exponent, max exponent is {MAX_EXPONENT}")
    elif HAS_NUMPY and isinstance(exp, numpy.ndarray):
        if numpy.nanmax(exp) > MAX_EXPONENT:
            raise RuntimeError(f"Invalid exponent, max exponent is {MAX_EXPONENT}")
    return base ** exp


def safe_mult(arg1, arg2):
    """safe version of multiply"""
    if isinstance(arg1, str) and isinstance(arg2, int) and len(arg1) * arg2 > MAX_STR_LEN:
        raise RuntimeError(f"String length exceeded, max string length is {MAX_STR_LEN}")
    return arg1 * arg2


def safe_add(arg1, arg2):
    """safe version of add"""
    if isinstance(arg1, str) and isinstance(arg2, str) and len(arg1) + len(arg2) > MAX_STR_LEN:
        raise RuntimeError(f"String length exceeded, max string length is {MAX_STR_LEN}")
    return arg1 + arg2


def safe_lshift(arg1, arg2):
    """safe version of lshift"""
    if isinstance(arg2, numbers.Number):
        if arg2 > MAX_SHIFT:
            raise RuntimeError(f"Invalid left shift, max left shift is {MAX_SHIFT}")
    elif HAS_NUMPY and isinstance(arg2, numpy.ndarray):
        if numpy.nanmax(arg2) > MAX_SHIFT:
            raise RuntimeError(f"Invalid left shift, max left shift is {MAX_SHIFT}")
    return arg1 << arg2


OPERATORS = {ast.Is: lambda a, b: a is b,
             ast.IsNot: lambda a, b: a is not b,
             ast.In: lambda a, b: a in b,
             ast.NotIn: lambda a, b: a not in b,
             ast.Add: safe_add,
             ast.BitAnd: lambda a, b: a & b,
             ast.BitOr: lambda a, b: a | b,
             ast.BitXor: lambda a, b: a ^ b,
             ast.Div: lambda a, b: a / b,
             ast.FloorDiv: lambda a, b: a // b,
             ast.LShift: safe_lshift,
             ast.RShift: lambda a, b: a >> b,
             ast.Mult: safe_mult,
             ast.Pow: safe_pow,
             ast.MatMult: lambda a, b: a @ b,
             ast.Sub: lambda a, b: a - b,
             ast.Mod: lambda a, b: a % b,
             ast.And: lambda a, b: a and b,
             ast.Or: lambda a, b: a or b,
             ast.Eq: lambda a, b: a == b,
             ast.Gt: lambda a, b: a > b,
             ast.GtE: lambda a, b: a >= b,
             ast.Lt: lambda a, b: a < b,
             ast.LtE: lambda a, b: a <= b,
             ast.NotEq: lambda a, b: a != b,
             ast.Invert: lambda a: ~a,
             ast.Not: lambda a: not a,
             ast.UAdd: lambda a: +a,
             ast.USub: lambda a: -a}


def valid_symbol_name(name):
    """Determine whether the input symbol name is a valid name.

    Arguments
    ---------
      name  : str
         name to check for validity.

    Returns
    --------
      valid :  bool
        whether name is a a valid symbol name

    This checks for Python reserved words and that the name matches
    the regular expression ``[a-zA-Z_][a-zA-Z0-9_]``
    """
    if name in RESERVED_WORDS:
        return False

    gen = generate_tokens(io.BytesIO(name.encode('utf-8')).readline)
    typ, _, start, end, _ = next(gen)
    if typ == tk_ENCODING:
        typ, _, start, end, _ = next(gen)
    return typ == tk_NAME and start == (1, 0) and end == (1, len(name))


def op2func(oper):
    """Return function for operator nodes."""
    return OPERATORS[oper.__class__]


class Empty:
    """Empty class."""
    def __init__(self):
        """TODO: docstring in public method."""
        return

    def __nonzero__(self):
        """Empty is TODO: docstring in magic method."""
        return False

    def __repr__(self):
        """Empty is TODO: docstring in magic method."""
        return "Empty"

ReturnedNone = Empty()

class ExceptionHolder:
    """Basic exception handler."""
    def __init__(self, node, exc=None, msg='', expr=None, lineno=None):
        """TODO: docstring in public method."""
        self.node = node
        self.expr = expr
        self.msg = msg
        self.exc = exc
        self.lineno = lineno
        self.exc_info = exc_info()
        if self.exc is None and self.exc_info[0] is not None:
            self.exc = self.exc_info[0]
        if self.msg == '' and self.exc_info[1] is not None:
            self.msg = self.exc_info[1]

    def get_error(self):
        """Retrieve error data."""
        col_offset = -1
        if self.node is not None:
            try:
                col_offset = self.node.col_offset
            except AttributeError:
                pass
        try:
            exc_name = self.exc.__name__
        except AttributeError:
            exc_name = str(self.exc)
        if exc_name in (None, 'None'):
            exc_name = 'UnknownError'

        out = [f"   {self.expr}"]
        if col_offset > 0:
            out.append(f"    {col_offset*' '}^^^")
        out.append(str(self.msg))
        return (exc_name, '\n'.join(out))


class NameFinder(ast.NodeVisitor):
    """Find all symbol names used by a parsed node."""

    def __init__(self):
        """TODO: docstring in public method."""
        self.names = []
        ast.NodeVisitor.__init__(self)

    def generic_visit(self, node):
        """TODO: docstring in public method."""
        if node.__class__.__name__ == 'Name':
            if node.id not in self.names:
                self.names.append(node.id)
        ast.NodeVisitor.generic_visit(self, node)


def get_ast_names(astnode):
    """Return symbol Names from an AST node."""
    finder = NameFinder()
    finder.generic_visit(astnode)
    return finder.names


def valid_varname(name):
    "is this a valid variable name"
    return name.isidentifier() and name not in RESERVED_WORDS


class Group(dict):
    """
    Group: a container of objects that can be accessed either as an object attributes
    or dictionary  key/value.  Attribute names must follow Python naming conventions.


    """
    def __init__(self, name=None, searchgroups=None, **kws):
        if name is None:
            name = hex(id(self))
        self.__name__ = name
        dict.__init__(self, **kws)
        self._searchgroups = searchgroups

    def __setattr__(self, name, value):
        if not valid_varname(name):
            raise SyntaxError(f"invalid attribute name '{name}'")
        self[name] = value

    def __getattr__(self, name, default=None):
        if name in self:
            return self[name]
        if default is not None:
            return default
        raise KeyError(f"no attribute named '{name}'")

    def __setitem__(self, name, value):
        if not valid_varname(name):
            raise SyntaxError(f"invalid attribute name '{name}'")
        dict.__setitem__(self, name, value)

    def get(self, key, default=None):
        val = self.__getattr__(key, ReturnedNone)
        if not isinstance(val, Empty):
            return val
        searchgroups = self._searchgroups
        if searchgroups is not None:
            for sgroup in searchgroups:
                grp = self.__getattr__(sgroup, None)
                if isinstance(grp, (Group, dict)):
                    val = grp.__getattr__(key, ReturnedNone)
                    if not isinstance(val, Empty):
                        return val
        return default


    def __repr__(self):
        keys = [a for a in self.keys() if a != '__name__']
        return f"Group('{self.__name__}', {len(keys)} symbols)"

    def _repr_html_(self):
        """HTML representation for Jupyter notebook"""
        html = [f"<table><caption>Group('{self.__name__}')</caption>",
  "<tr><th>Attribute</th><th>DataType</th><th><b>Value</b></th></tr>"]
        for key, val in self.items():
            html.append(f"""
<tr><td>{key}</td><td><i>{type(val).__name__}</i></td>
    <td>{repr(val):.75s}</td>
</tr>""")
        html.append("</table>")
        return '\n'.join(html)


def make_symbol_table(use_numpy=True, nested=False, top=True,  **kws):
    """Create a default symboltable, taking dict of user-defined symbols.

    Arguments
    ---------
    numpy : bool, optional
       whether to include symbols from numpy [True]
    nested : bool, optional
       whether to make a "new-style" nested table instead of a plain dict [False]
    top : bool, optional
       whether this is the top-level table in a nested-table [True]
    kws :  optional
       additional symbol name, value pairs to include in symbol table

    Returns
    --------
    symbol_table : dict or nested Group
       a symbol table that can be used in `asteval.Interpereter`

    """
    if nested:
        if top:
            name = '_main'
            if 'name' in kws:
                name = kws.pop('name')
        symtable = Group(name=name)
    else:
        symtable = {}

    symtable.update(BUILTINS_TABLE)
    symtable.update(LOCALFUNCS)
    symtable.update(kws)
    math_functions = dict(MATH_TABLE.items())
    if use_numpy:
        math_functions.update(NUMPY_TABLE)

    if nested:
        symtable['math'] = Group(name='math', **math_functions)
        symtable._searchgroups = ('math',)
    else:
        symtable.update(math_functions)
    symtable.update(**kws)
    return symtable


class Procedure:
    """Procedure: user-defined function for asteval.

    This stores the parsed ast nodes as from the 'functiondef' ast node
    for later evaluation.

    """

    def __init__(self, name, interp, doc=None, lineno=0,
                 body=None, args=None, kwargs=None,
                 vararg=None, varkws=None):
        """TODO: docstring in public method."""
        self.__ininit__ = True
        self.name = name
        self.__name__ = self.name
        self.__asteval__ = interp
        self.raise_exc = self.__asteval__.raise_exception
        self.__doc__ = doc
        self.body = body
        self.argnames = args
        self.kwargs = kwargs
        self.vararg = vararg
        self.varkws = varkws
        self.lineno = lineno
        self.__ininit__ = False

    def __setattr__(self, attr, val):
        if not getattr(self, '__ininit__', True):
            self.raise_exc(None, exc=TypeError,
                           msg="procedure is read-only")
        self.__dict__[attr] = val

    def __dir__(self):
        return ['name']

    def __repr__(self):
        """TODO: docstring in magic method."""
        sig = ""
        if len(self.argnames) > 0:
            sig = sig + ', '.join(self.argnames)
        if self.vararg is not None:
            sig = sig + f"*{self.vararg}"
        if len(self.kwargs) > 0:
            if len(sig) > 0:
                sig = f"{sig}, "
            _kw = [f"{k}={v}" for k, v in self.kwargs]
            sig = f"{sig}{', '.join(_kw)}"

        if self.varkws is not None:
            sig = f"%sig, **{self.varkws}"
        sig = f"<Procedure {self.name}({sig})>"
        if self.__doc__ is not None:
            sig = f"{sig}\n {self.__doc__}"
        return sig

    def __call__(self, *args, **kwargs):
        """TODO: docstring in public method."""
        topsym = self.__asteval__.symtable
        if self.__asteval__.config.get('nested_symtable', False):
            sargs = {'_main': topsym}
            sgroups = topsym.get('_searchgroups', None)
            if sgroups is not None:
                for sxname in sgroups:
                    sargs[sxname] = topsym.get(sxname)


            symlocals = Group(name=f'symtable_{self.name}_', **sargs)
            symlocals._searchgroups = list(sargs.keys())
        else:
            symlocals = {}

        args = list(args)
        nargs = len(args)
        nkws = len(kwargs)
        nargs_expected = len(self.argnames)

        # check for too few arguments, but the correct keyword given
        if (nargs < nargs_expected) and nkws > 0:
            for name in self.argnames[nargs:]:
                if name in kwargs:
                    args.append(kwargs.pop(name))
            nargs = len(args)
            nargs_expected = len(self.argnames)
            nkws = len(kwargs)
        if nargs < nargs_expected:
            msg = f"{self.name}() takes at least"
            msg = f"{msg} {nargs_expected} arguments, got {nargs}"
            self.raise_exc(None, exc=TypeError, msg=msg)
        # check for multiple values for named argument
        if len(self.argnames) > 0 and kwargs is not None:
            msg = "multiple values for keyword argument"
            for targ in self.argnames:
                if targ in kwargs:
                    msg = f"{msg} '{targ}' in Procedure {self.name}"
                    self.raise_exc(None, exc=TypeError, msg=msg, lineno=self.lineno)

        # check more args given than expected, varargs not given
        if nargs != nargs_expected:
            msg = None
            if nargs < nargs_expected:
                msg = f"not enough arguments for Procedure {self.name}()"
                msg = f"{msg} (expected {nargs_expected}, got {nargs}"
                self.raise_exc(None, exc=TypeError, msg=msg)

        if nargs > nargs_expected and self.vararg is None:
            if nargs - nargs_expected > len(self.kwargs):
                msg = f"too many arguments for {self.name}() expected at most"
                msg = f"{msg} {len(self.kwargs)+nargs_expected}, got {nargs}"
                self.raise_exc(None, exc=TypeError, msg=msg)

            for i, xarg in enumerate(args[nargs_expected:]):
                kw_name = self.kwargs[i][0]
                if kw_name not in kwargs:
                    kwargs[kw_name] = xarg

        for argname in self.argnames:
            symlocals[argname] = args.pop(0)

        try:
            if self.vararg is not None:
                symlocals[self.vararg] = tuple(args)

            for key, val in self.kwargs:
                if key in kwargs:
                    val = kwargs.pop(key)
                symlocals[key] = val

            if self.varkws is not None:
                symlocals[self.varkws] = kwargs

            elif len(kwargs) > 0:
                msg = f"extra keyword arguments for Procedure {self.name}: "
                msg = msg + ','.join(list(kwargs.keys()))
                self.raise_exc(None, msg=msg, exc=TypeError,
                               lineno=self.lineno)

        except (ValueError, LookupError, TypeError,
                NameError, AttributeError):
            msg = f"incorrect arguments for Procedure {self.name}"
            self.raise_exc(None, msg=msg, lineno=self.lineno)

        if self.__asteval__.config.get('nested_symtable', False):
            save_symtable = self.__asteval__.symtable
            self.__asteval__.symtable = symlocals
        else:
            save_symtable = self.__asteval__.symtable.copy()
            self.__asteval__.symtable.update(symlocals)

        self.__asteval__.retval = None
        self.__asteval__._calldepth += 1
        retval = None

        # evaluate script of function
        for node in self.body:
            self.__asteval__.run(node, expr='<>', lineno=self.lineno)
            if len(self.__asteval__.error) > 0:
                break
            if self.__asteval__.retval is not None:
                retval = self.__asteval__.retval
                self.__asteval__.retval = None
                if retval is ReturnedNone:
                    retval = None
                break

        self.__asteval__.symtable = save_symtable
        self.__asteval__._calldepth -= 1
        symlocals = None
        return retval
