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""" 
Module for statical analysis. 
""" 
from parso.python import tree

from jedi._compatibility import force_unicode
from jedi import debug 
from jedi.evaluate.compiled import CompiledObject 
from jedi.evaluate.helpers import is_string
 
 
CODES = { 
    'attribute-error': (1, AttributeError, 'Potential AttributeError.'), 
    'name-error': (2, NameError, 'Potential NameError.'), 
    'import-error': (3, ImportError, 'Potential ImportError.'), 
    'type-error-too-many-arguments': (4, TypeError, None),
    'type-error-too-few-arguments': (5, TypeError, None),
    'type-error-keyword-argument': (6, TypeError, None),
    'type-error-multiple-values': (7, TypeError, None),
    'type-error-star-star': (8, TypeError, None),
    'type-error-star': (9, TypeError, None),
    'type-error-operation': (10, TypeError, None),
    'type-error-not-iterable': (11, TypeError, None),
    'type-error-isinstance': (12, TypeError, None),
    'type-error-not-subscriptable': (13, TypeError, None),
    'value-error-too-many-values': (14, ValueError, None),
    'value-error-too-few-values': (15, ValueError, None),
} 
 
 
class Error(object): 
    def __init__(self, name, module_path, start_pos, message=None): 
        self.path = module_path 
        self._start_pos = start_pos 
        self.name = name 
        if message is None: 
            message = CODES[self.name][2] 
        self.message = message 
 
    @property 
    def line(self): 
        return self._start_pos[0] 
 
    @property 
    def column(self): 
        return self._start_pos[1] 
 
    @property 
    def code(self): 
        # The class name start 
        first = self.__class__.__name__[0] 
        return first + str(CODES[self.name][0]) 
 
    def __unicode__(self): 
        return '%s:%s:%s: %s %s' % (self.path, self.line, self.column, 
                                    self.code, self.message) 
 
    def __str__(self): 
        return self.__unicode__() 
 
    def __eq__(self, other): 
        return (self.path == other.path and self.name == other.name and
                self._start_pos == other._start_pos)
 
    def __ne__(self, other): 
        return not self.__eq__(other) 
 
    def __hash__(self): 
        return hash((self.path, self._start_pos, self.name)) 
 
    def __repr__(self): 
        return '<%s %s: %s@%s,%s>' % (self.__class__.__name__, 
                                      self.name, self.path, 
                                      self._start_pos[0], self._start_pos[1]) 
 
 
class Warning(Error): 
    pass 
 
 
def add(node_context, error_name, node, message=None, typ=Error, payload=None):
    exception = CODES[error_name][1]
    if _check_for_exception_catch(node_context, node, exception, payload):
        return 
 
    # TODO this path is probably not right
    module_context = node_context.get_root_context()
    module_path = module_context.py__file__()
    instance = typ(error_name, module_path, node.start_pos, message)
    debug.warning(str(instance), format=False)
    node_context.evaluator.analysis.append(instance)
 
 
def _check_for_setattr(instance): 
    """ 
    Check if there's any setattr method inside an instance. If so, return True. 
    """ 
    from jedi.evaluate.context import ModuleContext
    module = instance.get_root_context()
    if not isinstance(module, ModuleContext):
        return False

    node = module.tree_node
    try: 
        stmts = node.get_used_names()['setattr']
    except KeyError: 
        return False 
 
    return any(node.start_pos < stmt.start_pos < node.end_pos
               for stmt in stmts) 
 
 
def add_attribute_error(name_context, lookup_context, name):
    message = ('AttributeError: %s has no attribute %s.' % (lookup_context, name))
    from jedi.evaluate.context.instance import AbstractInstanceContext, CompiledInstanceName
    # Check for __getattr__/__getattribute__ existance and issue a warning 
    # instead of an error, if that happens. 
    typ = Error
    if isinstance(lookup_context, AbstractInstanceContext):
        slot_names = lookup_context.get_function_slot_names(u'__getattr__') + \
            lookup_context.get_function_slot_names(u'__getattribute__')
        for n in slot_names:
            # TODO do we even get here?
            if isinstance(name, CompiledInstanceName) and \
                    n.parent_context.obj == object:
                typ = Warning
                break
 
        if _check_for_setattr(lookup_context):
            typ = Warning
 
    payload = lookup_context, name
    add(name_context, 'attribute-error', name, message, typ, payload)
 

def _check_for_exception_catch(node_context, jedi_name, exception, payload=None):
    """ 
    Checks if a jedi object (e.g. `Statement`) sits inside a try/catch and 
    doesn't count as an error (if equal to `exception`). 
    Also checks `hasattr` for AttributeErrors and uses the `payload` to compare 
    it. 
    Returns True if the exception was catched. 
    """ 
    def check_match(cls, exception): 
        try: 
            return isinstance(cls, CompiledObject) and cls.is_super_class(exception)
        except TypeError: 
            return False 
 
    def check_try_for_except(obj, exception): 
        # Only nodes in try 
        iterator = iter(obj.children) 
        for branch_type in iterator: 
            colon = next(iterator) 
            suite = next(iterator) 
            if branch_type == 'try' \ 
                    and not (branch_type.start_pos < jedi_name.start_pos <= suite.end_pos):
                return False 
 
        for node in obj.get_except_clause_tests():
            if node is None: 
                return True  # An exception block that catches everything. 
            else: 
                except_classes = node_context.eval_node(node)
                for cls in except_classes: 
                    from jedi.evaluate.context import iterable
                    if isinstance(cls, iterable.Sequence) and \
                            cls.array_type == 'tuple':
                        # multiple exceptions 
                        for lazy_context in cls.py__iter__():
                            for typ in lazy_context.infer():
                                if check_match(typ, exception):
                                    return True
                    else: 
                        if check_match(cls, exception): 
                            return True 
 
    def check_hasattr(node, suite): 
        try: 
            assert suite.start_pos <= jedi_name.start_pos < suite.end_pos
            assert node.type in ('power', 'atom_expr')
            base = node.children[0] 
            assert base.type == 'name' and base.value == 'hasattr' 
            trailer = node.children[1] 
            assert trailer.type == 'trailer' 
            arglist = trailer.children[1] 
            assert arglist.type == 'arglist' 
            from jedi.evaluate.arguments import TreeArguments
            args = list(TreeArguments(node_context.evaluator, node_context, arglist).unpack())
            # Arguments should be very simple 
            assert len(args) == 2 
 
            # Check name 
            key, lazy_context = args[1]
            names = list(lazy_context.infer())
            assert len(names) == 1 and is_string(names[0])
            assert force_unicode(names[0].get_safe_value()) == payload[1].value
 
            # Check objects 
            key, lazy_context = args[0]
            objects = lazy_context.infer()
            return payload[0] in objects 
        except AssertionError: 
            return False 
 
    obj = jedi_name
    while obj is not None and not isinstance(obj, (tree.Function, tree.Class)):
        if isinstance(obj, tree.Flow):
            # try/except catch check 
            if obj.type == 'try_stmt' and check_try_for_except(obj, exception):
                return True 
            # hasattr check 
            if exception == AttributeError and obj.type in ('if_stmt', 'while_stmt'):
                if check_hasattr(obj.children[1], obj.children[3]): 
                    return True 
        obj = obj.parent 
 
    return False