#-----------------------------------------------------------------------------
# Copyright (c) 2012 - 2018, Anaconda, Inc. All rights reserved.
#
# Powered by the Bokeh Development Team.
#
# The full license is in the file LICENSE.txt, distributed with this software.
#-----------------------------------------------------------------------------
''' Control global configuration options with environment variables.
A global settings object that other parts of Bokeh can refer to.


``BOKEH_BROWSER`` --- What browser to use when opening plots.

  Valid values are any of the browser names understood by the python
  standard library webbrowser_ module.

``BOKEH_DEV`` --- Whether to use development mode.

  This uses absolute paths to development (non-minified) BokehJS components,
  sets logging to ``debug``, makes generated HTML and JSON human-readable,
  etc.

  This is a meta variable equivalent to the following environment variables:

  - ``BOKEH_BROWSER=none``
  - ``BOKEH_LOG_LEVEL=debug``
  - ``BOKEH_MINIFIED=false``
  - ``BOKEH_PRETTY=true``
  - ``BOKEH_PY_LOG_LEVEL=debug``
  - ``BOKEH_RESOURCES=absolute-dev``
  - ``BOKEH_SIMPLE_IDS=true``

  Accepted values are ``yes``/``no``, ``true``/``false`` or ``0``/``1``.

``BOKEH_DOCS_CDN`` --- What version of BokehJS to use when building sphinx.

  See :ref:`bokeh.resources` module reference for full details.

``BOKEH_DOCS_VERSION`` --- What version of Bokeh to show when building sphinx docs locally.

  Useful for re-deployment purposes.

  Set to ``"local"`` to use a locally built dev version of BokehJS.

  .. note::
      This variable is only used when building documentation from the
      development version.

``BOKEH_DOCS_CSS_SERVER`` --- Where to get the CSS stylesheet from.

  By default use CSS from bokehplots.com

  .. note::
      This variable is only used when building documentation from the
      development version.

  Set to ``"local"`` to use a locally built dev version of BokehJS.

``BOKEH_LOG_LEVEL`` --- The BokehJS console logging level to use.

  Valid values are, in order of increasing severity:

  - ``trace``
  - ``debug``
  - ``info``
  - ``warn``
  - ``error``
  - ``fatal``

  The default logging level is ``info``.

  .. note::
      When running server examples, it is the value of this
      ``BOKEH_LOG_LEVEL`` that is set for the server that matters.

``BOKEH_MINIFIED`` --- Whether to emit minified JavaScript for ``bokeh.js``.

  Accepted values are ``yes``/``no``, ``true``/``false`` or ``0``/``1``.

``BOKEH_PRETTY`` --- Whether to emit "pretty printed" JSON.

  Accepted values are ``yes``/``no``, ``true``/``false`` or ``0``/``1``.

``BOKEH_PY_LOG_LEVEL`` --- The Python logging level to set.

  As in the JS side, valid values are, in order of increasing severity:

  - ``trace``
  - ``debug``
  - ``info``
  - ``warn``
  - ``error``
  - ``fatal``
  - ``none``

  The default logging level is ``none``.

``BOKEH_RESOURCES`` --- What kind of BokehJS resources to configure.

  For example:  ``inline``, ``cdn``, ``server``. See the
  :class:`~bokeh.core.resources.Resources` class reference for full details.

``BOKEH_ROOTDIR`` --- Root directory to use with ``relative`` resources.

  See the :class:`~bokeh.resources.Resources` class reference for full
  details.

``BOKEH_SIMPLE_IDS`` --- Whether to generate human-friendly object IDs.

  Accepted values are ``yes``/``no``, ``true``/``false`` or ``0``/``1``.
  Normally Bokeh generates UUIDs for object identifiers. Setting this variable
  to an affirmative value will result in more friendly simple numeric IDs
  counting up from 1000.

``BOKEH_VERSION`` --- What version of BokehJS to use with ``cdn`` resources.

  See the :class:`~bokeh.resources.Resources` class reference for full details.

.. _webbrowser: https://docs.python.org/2/library/webbrowser.html
'''
#-----------------------------------------------------------------------------
# Boilerplate
#-----------------------------------------------------------------------------
from __future__ import absolute_import, division, print_function, unicode_literals

import logging
log = logging.getLogger(__name__)

#-----------------------------------------------------------------------------
# Imports
#-----------------------------------------------------------------------------

# Standard library imports
import codecs
import os
from os.path import join, abspath, isdir

# External imports

# Bokeh imports
from .util.paths import ROOT_DIR, bokehjsdir

#-----------------------------------------------------------------------------
# Globals and constants
#-----------------------------------------------------------------------------

# __all__ defined at the bottom on the class module

#-----------------------------------------------------------------------------
# General API
#-----------------------------------------------------------------------------

#-----------------------------------------------------------------------------
# Dev API
#-----------------------------------------------------------------------------

#-----------------------------------------------------------------------------
# Private API
#-----------------------------------------------------------------------------

class _Settings(object):
    ''' A class to collect global, overridable Bokeh configuration settings.

    '''

    _prefix = "BOKEH_"
    debugjs = False

    # Properties --------------------------------------------------------------

    @property
    def _environ(self):
        return os.environ

    def _get(self, key, default=None):
        return self._environ.get(self._prefix + key, default)

    @property
    def _is_dev(self):
        return self._get_bool("DEV", False)

    @property
    def dev(self):
        return self._is_dev

    # Public methods ----------------------------------------------------------

    def _dev_or_default(self, default, dev):
        return dev if dev is not None and self._is_dev else default

    def _get_str(self, key, default, dev=None):
        return self._get(key, self._dev_or_default(default, dev))

    def _get_int(self, key, default, dev=None):
        return int(self._get(key, self._dev_or_default(default, dev)))

    def _get_bool(self, key, default, dev=None):
        value = self._get(key)

        if value is None:
            value = self._dev_or_default(default, dev)
        elif value.lower() in ["true", "yes", "on", "1"]:
            value = True
        elif value.lower() in ["false", "no", "off", "0"]:
            value = False
        else:
            raise ValueError("invalid value %r for boolean property %s%s" % (value, self._prefix, key))

        return value

    def browser(self, default=None):
        ''' Set the default browser that Bokeh should use to show documents
        with.

        '''
        return self._get_str("BROWSER", default, "none")

    def resources(self, default=None):
        ''' Set (override) the type of resources that Bokeh should use when
        outputting documents.

        '''
        return self._get_str("RESOURCES", default, "absolute-dev")

    def rootdir(self, default=None):
        ''' Set the root directory for "relative" resources.

        '''
        return self._get_str("ROOTDIR", default)

    def version(self, default=None):
        ''' Set (override) the standard reported Bokeh version.

        '''
        return self._get_str("VERSION", default)

    def docs_cdn(self, default=None):
        ''' Set the version of BokehJS should use for CDN resources when
        building the docs.

        '''
        return self._get_str("DOCS_CDN", default)

    def docs_version(self, default=None):
        ''' Set the version to use for building the docs.

        '''
        return self._get_str("DOCS_VERSION", default)

    def minified(self, default=None):
        ''' Set whether Bokeh should use minified BokehJS resources.

        '''
        return self._get_bool("MINIFIED", default, False)

    def log_level(self, default=None):
        ''' Set the log level for JavaScript BokehJS code.

        '''
        return self._get_str("LOG_LEVEL", default, "debug")

    def py_log_level(self, default='none'):
        ''' Set the log level for python Bokeh code.

        '''
        level = self._get_str("PY_LOG_LEVEL", default, "debug")
        LEVELS = {'trace': logging.TRACE,
                  'debug': logging.DEBUG,
                  'info' : logging.INFO,
                  'warn' : logging.WARNING,
                  'error': logging.ERROR,
                  'fatal': logging.CRITICAL,
                  'none' : None}
        return LEVELS[level]

    def pretty(self, default=None):
        ''' Set whether JSON strings should be pretty-printed.

        '''
        return self._get_bool("PRETTY", default, True)

    def simple_ids(self, default=None):
        ''' Set whether Bokeh should generate simple numeric model IDs.

        '''
        return self._get_bool("SIMPLE_IDS", default, True)

    def strict(self, default=None):
        ''' Set whether validation should be performed strictly.

        '''
        return self._get_bool("STRICT", default, False)

    def secret_key(self, default=None):
        ''' Set the secret key.

        Should be a long, cryptographically-random secret unique the
        Bokeh deployment.
        '''
        return self._get_str("SECRET_KEY", default)

    def secret_key_bytes(self):
        ''' Return the secret_key, converted to bytes and cached.

        '''
        if not hasattr(self, '_secret_key_bytes'):
            key = self.secret_key()
            if key is None:
                self._secret_key_bytes = None
            else:
                self._secret_key_bytes = codecs.encode(key, "utf-8")
        return self._secret_key_bytes

    def sign_sessions(self, default=False):
        ''' Set whether the server should only allow sessions signed with
        our secret key.

        If True, BOKEH_SECRET_KEY must also be set.

        '''
        return self._get_bool("SIGN_SESSIONS", default)

    def perform_document_validation(self, default=True):
        ''' Set whether Bokeh should perform validation checks on documents.

        '''
        return self._get_bool("VALIDATE_DOC", default)

    # Server settings go here:

    def bokehjssrcdir(self):
        ''' The absolute path of the BokehJS source code in the installed
        Bokeh source tree.

        '''
        if self._is_dev or self.debugjs:
            bokehjssrcdir = abspath(join(ROOT_DIR, '..', 'bokehjs', 'src'))

            if isdir(bokehjssrcdir):
                return bokehjssrcdir

        return None

    def bokehjsdir(self):
        '''

        '''
        return bokehjsdir(self._is_dev or self.debugjs)

    def js_files(self):
        ''' The JS files in the BokehJS directory.

        '''
        bokehjsdir = self.bokehjsdir()
        js_files = []
        for root, dirnames, files in os.walk(bokehjsdir):
            for fname in files:
                if fname.endswith(".js"):
                    js_files.append(join(root, fname))
        return js_files

    def css_files(self):
        ''' The CSS files in the BokehJS directory.

        '''
        bokehjsdir = self.bokehjsdir()
        js_files = []
        for root, dirnames, files in os.walk(bokehjsdir):
            for fname in files:
                if fname.endswith(".css"):
                    js_files.append(join(root, fname))
        return js_files

    def nodejs_path(self, default=None):
        return self._get_str("NODEJS_PATH", default)

    def phantomjs_path(self, default=None):
        return self._get_str("PHANTOMJS_PATH", default)

    def ignore_filename(self):
        return self._get_bool("IGNORE_FILENAME", False)

#-----------------------------------------------------------------------------
# Code
#-----------------------------------------------------------------------------

settings = _Settings()

if settings.secret_key() is not None:
    if len(settings.secret_key()) < 32:
        import warnings
        warnings.warn("BOKEH_SECRET_KEY is recommended to have at least 32 bytes of entropy chosen with a cryptographically-random algorithm")

if settings.sign_sessions() and settings.secret_key() is None:
    import warnings
    warnings.warn("BOKEH_SECRET_KEY must be set if BOKEH_SIGN_SESSIONS is set to true")

__all__ = (
  'settings',
)
