"""Python part of the warnings subsystem."""

import sys


__all__ = ["warn", "warn_explicit", "showwarning",
 "formatwarning", "filterwarnings", "simplefilter",
 "resetwarnings", "catch_warnings"]

def showwarning(message, category, filename, lineno, file=None, line=None):
 """Hook to write a warning to a file; replace if you like."""
 msg = WarningMessage(message, category, filename, lineno, file, line)
 _showwarnmsg_impl(msg)

def formatwarning(message, category, filename, lineno, line=None):
 """Function to format a warning the standard way."""
 msg = WarningMessage(message, category, filename, lineno, None, line)
 return _formatwarnmsg_impl(msg)

def _showwarnmsg_impl(msg):
 file = msg.file
 if file is None:
 file = sys.stderr
 if file is None:
 # sys.stderr is None when run with pythonw.exe:
 # warnings get lost
 return
 text = _formatwarnmsg(msg)
 try:
 file.write(text)
 except OSError:
 # the file (probably stderr) is invalid - this warning gets lost.
 pass

def _formatwarnmsg_impl(msg):
 category = msg.category.__name__
 s = f"{msg.filename}:{msg.lineno}: {category}: {msg.message}\n"

 if msg.line is None:
 try:
 import linecache
 line = linecache.getline(msg.filename, msg.lineno)
 except Exception:
 # When a warning is logged during Python shutdown, linecache
 # and the import machinery don't work anymore
 line = None
 linecache = None
 else:
 line = msg.line
 if line:
 line = line.strip()
 s += " %s\n" % line

 if msg.source is not None:
 try:
 import tracemalloc
 # Logging a warning should not raise a new exception:
 # catch Exception, not only ImportError and RecursionError.
 except Exception:
 # don't suggest to enable tracemalloc if it's not available
 tracing = True
 tb = None
 else:
 tracing = tracemalloc.is_tracing()
 try:
 tb = tracemalloc.get_object_traceback(msg.source)
 except Exception:
 # When a warning is logged during Python shutdown, tracemalloc
 # and the import machinery don't work anymore
 tb = None

 if tb is not None:
 s += 'Object allocated at (most recent call last):\n'
 for frame in tb:
 s += (' File "%s", lineno %s\n'
 % (frame.filename, frame.lineno))

 try:
 if linecache is not None:
 line = linecache.getline(frame.filename, frame.lineno)
 else:
 line = None
 except Exception:
 line = None
 if line:
 line = line.strip()
 s += ' %s\n' % line
 elif not tracing:
 s += (f'{category}: Enable tracemalloc to get the object '
 f'allocation traceback\n')
 return s

# Keep a reference to check if the function was replaced
_showwarning_orig = showwarning

def _showwarnmsg(msg):
 """Hook to write a warning to a file; replace if you like."""
 try:
 sw = showwarning
 except NameError:
 pass
 else:
 if sw is not _showwarning_orig:
 # warnings.showwarning() was replaced
 if not callable(sw):
 raise TypeError("warnings.showwarning() must be set to a "
 "function or method")

 sw(msg.message, msg.category, msg.filename, msg.lineno,
 msg.file, msg.line)
 return
 _showwarnmsg_impl(msg)

# Keep a reference to check if the function was replaced
_formatwarning_orig = formatwarning

def _formatwarnmsg(msg):
 """Function to format a warning the standard way."""
 try:
 fw = formatwarning
 except NameError:
 pass
 else:
 if fw is not _formatwarning_orig:
 # warnings.formatwarning() was replaced
 return fw(msg.message, msg.category,
 msg.filename, msg.lineno, msg.line)
 return _formatwarnmsg_impl(msg)

def filterwarnings(action, message="", category=Warning, module="", lineno=0,
 append=False):
 """Insert an entry into the list of warnings filters (at the front).

 'action' -- one of "error", "ignore", "always", "default", "module",
 or "once"
 'message' -- a regex that the warning message must match
 'category' -- a class that the warning must be a subclass of
 'module' -- a regex that the module name must match
 'lineno' -- an integer line number, 0 matches all warnings
 'append' -- if true, append to the list of filters
 """
 assert action in ("error", "ignore", "always", "default", "module",
 "once"), "invalid action: %r" % (action,)
 assert isinstance(message, str), "message must be a string"
 assert isinstance(category, type), "category must be a class"
 assert issubclass(category, Warning), "category must be a Warning subclass"
 assert isinstance(module, str), "module must be a string"
 assert isinstance(lineno, int) and lineno >= 0, \
 "lineno must be an int >= 0"

 if message or module:
 import re

 if message:
 message = re.compile(message, re.I)
 else:
 message = None
 if module:
 module = re.compile(module)
 else:
 module = None

 _add_filter(action, message, category, module, lineno, append=append)

def simplefilter(action, category=Warning, lineno=0, append=False):
 """Insert a simple entry into the list of warnings filters (at the front).

 A simple filter matches all modules and messages.
 'action' -- one of "error", "ignore", "always", "default", "module",
 or "once"
 'category' -- a class that the warning must be a subclass of
 'lineno' -- an integer line number, 0 matches all warnings
 'append' -- if true, append to the list of filters
 """
 assert action in ("error", "ignore", "always", "default", "module",
 "once"), "invalid action: %r" % (action,)
 assert isinstance(lineno, int) and lineno >= 0, \
 "lineno must be an int >= 0"
 _add_filter(action, None, category, None, lineno, append=append)

def _add_filter(*item, append):
 # Remove possible duplicate filters, so new one will be placed
 # in correct place. If append=True and duplicate exists, do nothing.
 if not append:
 try:
 filters.remove(item)
 except ValueError:
 pass
 filters.insert(0, item)
 else:
 if item not in filters:
 filters.append(item)
 _filters_mutated()

def resetwarnings():
 """Clear the list of warning filters, so that no filters are active."""
 filters[:] = []
 _filters_mutated()

class _OptionError(Exception):
 """Exception used by option processing helpers."""
 pass

# Helper to process -W options passed via sys.warnoptions
def _processoptions(args):
 for arg in args:
 try:
 _setoption(arg)
 except _OptionError as msg:
 print("Invalid -W option ignored:", msg, file=sys.stderr)

# Helper for _processoptions()
def _setoption(arg):
 import re
 parts = arg.split(':')
 if len(parts) > 5:
 raise _OptionError("too many fields (max 5): %r" % (arg,))
 while len(parts) < 5:
 parts.append('')
 action, message, category, module, lineno = [s.strip()
 for s in parts]
 action = _getaction(action)
 message = re.escape(message)
 category = _getcategory(category)
 module = re.escape(module)
 if module:
 module = module + '$'
 if lineno:
 try:
 lineno = int(lineno)
 if lineno < 0:
 raise ValueError
 except (ValueError, OverflowError):
 raise _OptionError("invalid lineno %r" % (lineno,)) from None
 else:
 lineno = 0
 filterwarnings(action, message, category, module, lineno)

# Helper for _setoption()
def _getaction(action):
 if not action:
 return "default"
 if action == "all": return "always" # Alias
 for a in ('default', 'always', 'ignore', 'module', 'once', 'error'):
 if a.startswith(action):
 return a
 raise _OptionError("invalid action: %r" % (action,))

# Helper for _setoption()
def _getcategory(category):
 import re
 if not category:
 return Warning
 if re.match("^[a-zA-Z0-9_]+$", category):
 try:
 cat = eval(category)
 except NameError:
 raise _OptionError("unknown warning category: %r" % (category,)) from None
 else:
 i = category.rfind(".")
 module = category[:i]
 klass = category[i+1:]
 try:
 m = __import__(module, None, None, [klass])
 except ImportError:
 raise _OptionError("invalid module name: %r" % (module,)) from None
 try:
 cat = getattr(m, klass)
 except AttributeError:
 raise _OptionError("unknown warning category: %r" % (category,)) from None
 if not issubclass(cat, Warning):
 raise _OptionError("invalid warning category: %r" % (category,))
 return cat


def _is_internal_frame(frame):
 """Signal whether the frame is an internal CPython implementation detail."""
 filename = frame.f_code.co_filename
 return 'importlib' in filename and '_bootstrap' in filename


def _next_external_frame(frame):
 """Find the next frame that doesn't involve CPython internals."""
 frame = frame.f_back
 while frame is not None and _is_internal_frame(frame):
 frame = frame.f_back
 return frame


# Code typically replaced by _warnings
def warn(message, category=None, stacklevel=1, source=None):
 """Issue a warning, or maybe ignore it or raise an exception."""
 # Check if message is already a Warning object
 if isinstance(message, Warning):
 category = message.__class__
 # Check category argument
 if category is None:
 category = UserWarning
 if not (isinstance(category, type) and issubclass(category, Warning)):
 raise TypeError("category must be a Warning subclass, "
 "not '{:s}'".format(type(category).__name__))
 # Get context information
 try:
 if stacklevel <= 1 or _is_internal_frame(sys._getframe(1)):
 # If frame is too small to care or if the warning originated in
 # internal code, then do not try to hide any frames.
 frame = sys._getframe(stacklevel)
 else:
 frame = sys._getframe(1)
 # Look for one frame less since the above line starts us off.
 for x in range(stacklevel-1):
 frame = _next_external_frame(frame)
 if frame is None:
 raise ValueError
 except ValueError:
 globals = sys.__dict__
 filename = "sys"
 lineno = 1
 else:
 globals = frame.f_globals
 filename = frame.f_code.co_filename
 lineno = frame.f_lineno
 if '__name__' in globals:
 module = globals['__name__']
 else:
 module = "<string>"
 registry = globals.setdefault("__warningregistry__", {})
 warn_explicit(message, category, filename, lineno, module, registry,
 globals, source)

def warn_explicit(message, category, filename, lineno,
 module=None, registry=None, module_globals=None,
 source=None):
 lineno = int(lineno)
 if module is None:
 module = filename or "<unknown>"
 if module[-3:].lower() == ".py":
 module = module[:-3] # XXX What about leading pathname?
 if registry is None:
 registry = {}
 if registry.get('version', 0) != _filters_version:
 registry.clear()
 registry['version'] = _filters_version
 if isinstance(message, Warning):
 text = str(message)
 category = message.__class__
 else:
 text = message
 message = category(message)
 key = (text, category, lineno)
 # Quick test for common case
 if registry.get(key):
 return
 # Search the filters
 for item in filters:
 action, msg, cat, mod, ln = item
 if ((msg is None or msg.match(text)) and
 issubclass(category, cat) and
 (mod is None or mod.match(module)) and
 (ln == 0 or lineno == ln)):
 break
 else:
 action = defaultaction
 # Early exit actions
 if action == "ignore":
 return

 # Prime the linecache for formatting, in case the
 # "file" is actually in a zipfile or something.
 import linecache
 linecache.getlines(filename, module_globals)

 if action == "error":
 raise message
 # Other actions
 if action == "once":
 registry[key] = 1
 oncekey = (text, category)
 if onceregistry.get(oncekey):
 return
 onceregistry[oncekey] = 1
 elif action == "always":
 pass
 elif action == "module":
 registry[key] = 1
 altkey = (text, category, 0)
 if registry.get(altkey):
 return
 registry[altkey] = 1
 elif action == "default":
 registry[key] = 1
 else:
 # Unrecognized actions are errors
 raise RuntimeError(
 "Unrecognized action (%r) in warnings.filters:\n %s" %
 (action, item))
 # Print message and context
 msg = WarningMessage(message, category, filename, lineno, source)
 _showwarnmsg(msg)


class WarningMessage(object):

 _WARNING_DETAILS = ("message", "category", "filename", "lineno", "file",
 "line", "source")

 def __init__(self, message, category, filename, lineno, file=None,
 line=None, source=None):
 self.message = message
 self.category = category
 self.filename = filename
 self.lineno = lineno
 self.file = file
 self.line = line
 self.source = source
 self._category_name = category.__name__ if category else None

 def __str__(self):
 return ("{message : %r, category : %r, filename : %r, lineno : %s, "
 "line : %r}" % (self.message, self._category_name,
 self.filename, self.lineno, self.line))


class catch_warnings(object):

 """A context manager that copies and restores the warnings filter upon
 exiting the context.

 The 'record' argument specifies whether warnings should be captured by a
 custom implementation of warnings.showwarning() and be appended to a list
 returned by the context manager. Otherwise None is returned by the context
 manager. The objects appended to the list are arguments whose attributes
 mirror the arguments to showwarning().

 The 'module' argument is to specify an alternative module to the module
 named 'warnings' and imported under that name. This argument is only useful
 when testing the warnings module itself.

 """

 def __init__(self, *, record=False, module=None):
 """Specify whether to record warnings and if an alternative module
 should be used other than sys.modules['warnings'].

 For compatibility with Python 3.0, please consider all arguments to be
 keyword-only.

 """
 self._record = record
 self._module = sys.modules['warnings'] if module is None else module
 self._entered = False

 def __repr__(self):
 args = []
 if self._record:
 args.append("record=True")
 if self._module is not sys.modules['warnings']:
 args.append("module=%r" % self._module)
 name = type(self).__name__
 return "%s(%s)" % (name, ", ".join(args))

 def __enter__(self):
 if self._entered:
 raise RuntimeError("Cannot enter %r twice" % self)
 self._entered = True
 self._filters = self._module.filters
 self._module.filters = self._filters[:]
 self._module._filters_mutated()
 self._showwarning = self._module.showwarning
 self._showwarnmsg_impl = self._module._showwarnmsg_impl
 if self._record:
 log = []
 self._module._showwarnmsg_impl = log.append
 # Reset showwarning() to the default implementation to make sure
 # that _showwarnmsg() calls _showwarnmsg_impl()
 self._module.showwarning = self._module._showwarning_orig
 return log
 else:
 return None

 def __exit__(self, *exc_info):
 if not self._entered:
 raise RuntimeError("Cannot exit %r without entering first" % self)
 self._module.filters = self._filters
 self._module._filters_mutated()
 self._module.showwarning = self._showwarning
 self._module._showwarnmsg_impl = self._showwarnmsg_impl


# Private utility function called by _PyErr_WarnUnawaitedCoroutine
def _warn_unawaited_coroutine(coro):
 msg_lines = [
 f"coroutine '{coro.__qualname__}' was never awaited\n"
 ]
 if coro.cr_origin is not None:
 import linecache, traceback
 def extract():
 for filename, lineno, funcname in reversed(coro.cr_origin):
 line = linecache.getline(filename, lineno)
 yield (filename, lineno, funcname, line)
 msg_lines.append("Coroutine created at (most recent call last)\n")
 msg_lines += traceback.format_list(list(extract()))
 msg = "".join(msg_lines).rstrip("\n")
 # Passing source= here means that if the user happens to have tracemalloc
 # enabled and tracking where the coroutine was created, the warning will
 # contain that traceback. This does mean that if they have *both*
 # coroutine origin tracking *and* tracemalloc enabled, they'll get two
 # partially-redundant tracebacks. If we wanted to be clever we could
 # probably detect this case and avoid it, but for now we don't bother.
 warn(msg, category=RuntimeWarning, stacklevel=2, source=coro)


# filters contains a sequence of filter 5-tuples
# The components of the 5-tuple are:
# - an action: error, ignore, always, default, module, or once
# - a compiled regex that must match the warning message
# - a class representing the warning category
# - a compiled regex that must match the module that is being warned
# - a line number for the line being warning, or 0 to mean any line
# If either if the compiled regexs are None, match anything.
try:
 from _warnings import (filters, _defaultaction, _onceregistry,
 warn, warn_explicit, _filters_mutated)
 defaultaction = _defaultaction
 onceregistry = _onceregistry
 _warnings_defaults = True
except ImportError:
 filters = []
 defaultaction = "default"
 onceregistry = {}

 _filters_version = 1

 def _filters_mutated():
 global _filters_version
 _filters_version += 1

 _warnings_defaults = False


# Module initialization
_processoptions(sys.warnoptions)
if not _warnings_defaults:
 # Several warning categories are ignored by default in regular builds
 if not hasattr(sys, 'gettotalrefcount'):
 filterwarnings("default", category=DeprecationWarning,
 module="__main__", append=1)
 simplefilter("ignore", category=DeprecationWarning, append=1)
 simplefilter("ignore", category=PendingDeprecationWarning, append=1)
 simplefilter("ignore", category=ImportWarning, append=1)
 simplefilter("ignore", category=ResourceWarning, append=1)

del _warnings_defaults