# Source code for pex.variables

    # Copyright 2015 Pants project contributors (see CONTRIBUTORS.md).
    # Licensed under the Apache License, Version 2.0 (see LICENSE).

    # Due to the PEX_ properties, disable checkstyle.
    # checkstyle: noqa

    import os
    import sys
    from contextlib import contextmanager

    from .common import die

    __all__ = ('ENV', 'Variables')

    class Variables(object):
      """Environment variables supported by the PEX runtime."""

      @classmethod
      def process_pydoc(cls, pydoc):
        if pydoc is None:
          return 'Unknown', 'Unknown'
        pydoc = pydoc.splitlines()
        variable_type = pydoc[0]
        variable_text = ' '.join(filter(None, (line.strip() for line in pydoc[2:])))
        return variable_type, variable_text

      @classmethod
      def iter_help(cls):
        for variable_name, value in sorted(cls.__dict__.items()):
          if not variable_name.startswith('PEX_'):
            continue
          variable_type, variable_text = cls.process_pydoc(getattr(value, '__doc__'))
          yield variable_name, variable_type, variable_text

      @classmethod
      def from_rc(cls, rc=None):
        """Read pex runtime configuration variables from a pexrc file.

        :param rc: an absolute path to a pexrc file.
        :return: A dict of key value pairs found in processed pexrc files.
        :rtype: dict
        """
        ret_vars = {}
        rc_locations = ['/etc/pexrc',
                        '~/.pexrc',
                        os.path.join(os.path.dirname(sys.argv[0]), '.pexrc')]
        if rc:
          rc_locations.append(rc)
        for filename in rc_locations:
          try:
            with open(os.path.expanduser(filename)) as fh:
              rc_items = map(cls._get_kv, fh)
              ret_vars.update(dict(filter(None, rc_items)))
          except IOError:
            continue
        return ret_vars

      @classmethod
      def _get_kv(cls, variable):
        kv = variable.strip().split('=')
        if len(list(filter(None, kv))) == 2:
          return kv

      def __init__(self, environ=None, rc=None, use_defaults=True):
        self._use_defaults = use_defaults
        self._environ = environ.copy() if environ else os.environ
        if not self.PEX_IGNORE_RCFILES:
          rc_values = self.from_rc(rc).copy()
          rc_values.update(self._environ)
          self._environ = rc_values

      def copy(self):
        return self._environ.copy()

      def delete(self, variable):
        self._environ.pop(variable, None)

      def set(self, variable, value):
        self._environ[variable] = str(value)

      def _defaulted(self, default):
        return default if self._use_defaults else None

      def _get_bool(self, variable, default=False):
        value = self._environ.get(variable)
        if value is not None:
          if value.lower() in ('0', 'false'):
            return False
          elif value.lower() in ('1', 'true'):
            return True
          else:
            die('Invalid value for %s, must be 0/1/false/true, got %r' % (variable, value))
        else:
          return self._defaulted(default)

      def _get_string(self, variable, default=None):
        return self._environ.get(variable, self._defaulted(default))

      def _get_path(self, variable, default=None):
        value = self._get_string(variable, default=default)
        if value is not None:
          return os.path.realpath(os.path.expanduser(value))

      def _get_int(self, variable, default=None):
        try:
          return int(self._environ[variable])
        except ValueError:
          die('Invalid value for %s, must be an integer, got %r' % (variable, self._environ[variable]))
        except KeyError:
          return self._defaulted(default)

      def strip_defaults(self):
        """Returns a copy of these variables but with defaults stripped.

        Any variables not explicitly set in the environment will have a value of `None`.
        """
        return Variables(environ=self.copy(), use_defaults=False)

      @contextmanager
      def patch(self, **kw):
        """Update the environment for the duration of a context."""
        old_environ = self._environ
        self._environ = self._environ.copy()
        self._environ.update(kw)
        yield
        self._environ = old_environ

      @property
      def PEX_ALWAYS_CACHE(self):
        """Boolean

        Always write PEX dependencies to disk prior to invoking regardless whether or not the
        dependencies are zip-safe.  For certain dependencies that are very large such as numpy, this
        can reduce the RAM necessary to launch the PEX.  The data will be written into $PEX_ROOT,
        which by default is $HOME/.pex.  Default: false.
        """
        return self._get_bool('PEX_ALWAYS_CACHE', default=False)

      @property
      def PEX_COVERAGE(self):
        """Boolean

        Enable coverage reporting for this PEX file.  This requires that the "coverage" module is
        available in the PEX environment.  Default: false.
        """
        return self._get_bool('PEX_COVERAGE', default=False)

      @property
      def PEX_COVERAGE_FILENAME(self):
        """Filename

        Write the coverage data to the specified filename.  If PEX_COVERAGE_FILENAME is not specified
        but PEX_COVERAGE is, coverage information will be printed to stdout and not saved.
        """
        return self._get_path('PEX_COVERAGE_FILENAME', default=None)

      @property
      def PEX_FORCE_LOCAL(self):
        """Boolean

        Force this PEX to be not-zip-safe. This forces all code and dependencies to be written into
        $PEX_ROOT prior to invocation.  This is an option for applications with static assets that
        refer to paths relative to __file__ instead of using pkgutil/pkg_resources.  Default: false.
        """
        return self._get_bool('PEX_FORCE_LOCAL', default=False)

      @property
      def PEX_IGNORE_ERRORS(self):
        """Boolean

        Ignore any errors resolving dependencies when invoking the PEX file. This can be useful if you
        know that a particular failing dependency is not necessary to run the application.  Default:
        false.
        """
        return self._get_bool('PEX_IGNORE_ERRORS', default=False)

      @property
      def PEX_INHERIT_PATH(self):
        """Boolean

        Allow inheriting packages from site-packages.  By default, PEX scrubs any packages and
        namespace packages from sys.path prior to invoking the application.  This is generally not
        advised, but can be used in situations when certain dependencies do not conform to standard
        packaging practices and thus cannot be bundled into PEX files.  Default: false.
        """
        return self._get_string('PEX_INHERIT_PATH', default='false')

      @property
      def PEX_INTERPRETER(self):
        """Boolean

        Drop into a REPL instead of invoking the predefined entry point of this PEX. This can be
        useful for inspecting the PEX environment interactively.  It can also be used to treat the PEX
        file as an interpreter in order to execute other scripts in the context of the PEX file, e.g.
        "PEX_INTERPRETER=1 ./app.pex my_script.py".  Equivalent to setting PEX_MODULE to empty.
        Default: false.
        """
        return self._get_bool('PEX_INTERPRETER', default=False)

      @property
      def PEX_MODULE(self):
        """String

        Override the entry point into the PEX file.  Can either be a module, e.g.  'SimpleHTTPServer',
        or a specific entry point in module:symbol form, e.g.  "myapp.bin:main".
        """
        return self._get_string('PEX_MODULE', default=None)

      @property
      def PEX_PROFILE(self):
        """Boolean

        Enable application profiling.  If specified and PEX_PROFILE_FILENAME is not specified, PEX will
        print profiling information to stdout.
        """
        return self._get_path('PEX_PROFILE', default=None)

      @property
      def PEX_PROFILE_FILENAME(self):
        """Filename

        Profile the application and dump a profile into the specified filename in the standard
        "profile" module format.
        """
        return self._get_path('PEX_PROFILE_FILENAME', default=None)

      @property
      def PEX_PROFILE_SORT(self):
        """String

        Toggle the profile sorting algorithm used to print out profile columns.  Default:
        'cumulative'.
        """
        return self._get_string('PEX_PROFILE_SORT', default='cumulative')

      @property
      def PEX_PYTHON(self):
        """String

        Override the Python interpreter used to invoke this PEX.  Can be either an absolute path to an
        interpreter or a base name e.g.  "python3.3".  If a base name is provided, the $PATH will be
        searched for an appropriate match.
        """
        return self._get_string('PEX_PYTHON', default=None)

      @property
      def PEX_PYTHON_PATH(self):
        """String

        A colon-separated string containing paths of blessed Python interpreters
        for overriding the Python interpreter used to invoke this PEX. Must be absolute paths to the
        interpreter.

        Ex: "/path/to/python27:/path/to/python36"
        """
        return self._get_string('PEX_PYTHON_PATH', default=None)

      @property
      def PEX_ROOT(self):
        """Directory

        The directory location for PEX to cache any dependencies and code.  PEX must write
        not-zip-safe eggs and all wheels to disk in order to activate them.  Default: ~/.pex
        """
        return self._get_path('PEX_ROOT', default=os.path.expanduser('~/.pex'))

      @property
      def PEX_PATH(self):
        """A set of one or more PEX files

        Merge the packages from other PEX files into the current environment.  This allows you to
        do things such as create a PEX file containing the "coverage" module or create PEX files
        containing plugin entry points to be consumed by a main application.  Paths should be
        specified in the same manner as $PATH, e.g. PEX_PATH=/path/to/pex1.pex:/path/to/pex2.pex
        and so forth.
        """
        return self._get_string('PEX_PATH', default='')

      @property
      def PEX_SCRIPT(self):
        """String

        The script name within the PEX environment to execute.  This must either be an entry point as
        defined in a distribution's console_scripts, or a script as defined in a distribution's
        scripts section.  While Python supports any script including shell scripts, PEX only supports
        invocation of Python scripts in this fashion.
        """
        return self._get_string('PEX_SCRIPT', default=None)

      @property
      def PEX_TEARDOWN_VERBOSE(self):
        """Boolean

        Enable verbosity for when the interpreter shuts down.  This is mostly only useful for
        debugging PEX itself.  Default: false.
        """
        return self._get_bool('PEX_TEARDOWN_VERBOSE', default=False)

      @property
      def PEX_VERBOSE(self):
        """Integer

        Set the verbosity level of PEX debug logging.  The higher the number, the more logging, with 0
        being disabled.  This environment variable can be extremely useful in debugging PEX
        environment issues.  Default: 0
        """
        return self._get_int('PEX_VERBOSE', default=0)

      # TODO(wickman) Remove and push into --flags.  #94
      @property
      def PEX_HTTP_RETRIES(self):
        """Integer

        The number of HTTP retries when performing dependency resolution when building a PEX file.
        Default: 5.
        """
        return self._get_int('PEX_HTTP_RETRIES', default=5)

      @property
      def PEX_IGNORE_RCFILES(self):
        """Boolean

        Explicitly disable the reading/parsing of pexrc files (~/.pexrc). Default: false.
        """
        return self._get_bool('PEX_IGNORE_RCFILES', default=False)

    # Global singleton environment
    ENV = Variables()