# The Vision Egg: Configuration
#
# Copyright (C) 2001-2003 Andrew Straw.
# Copyright (C) 2008 California Institute of Technology
#
# URL: <http://www.visionegg.org/>
#
# Distributed under the terms of the GNU Lesser General Public License
# (LGPL). See LICENSE.TXT that came with this file.

"""
Load config values from environment, config file, or defaults.

Applications should not import this module directly.  Instead, 'import
VisionEgg' will result in an attribute 'VisionEgg.config', which has
the configuration options as attributes.

This module searches for configuration options from the following
places: environment variables, configuration file, generic defaults.
Environment variables take precedence over the configuration file,
which takes precedence over the generic defaults.

This module also determines the location of the Vision Egg
directories.  The VISIONEGG_SYSTEM_DIR directory is by default the
'VisionEgg' directory in Python's site-packages.  VISIONEGG_USER_DIR
is by default 'VisionEgg' in the directory specified by the
environment variable HOME, if it exists, and os.curdir otherwise.

You can create a configuration file that contains defaults for your
system.  This should be a text file with key/value pairs.  Blank lines
and anything after the pound symbol ('#') will be treated as a
comment.  Each key/value pairs should be on its own line and in the
format 'KEY=VALUE'.  By default the file 'VisionEgg.cfg' from the
VISIONEGG_USER_DIR or VISIONEGG_SYSTEM_DIR as specified above.
However, You can specify a different filename and directory by setting
the environment variable VISIONEGG_CONFIG_FILE.

"""

# Warning: This code is a bit of a hack

import VisionEgg
import re, os, errno, sys                  # standard python packages
import ConfigParser

####################################################################
#
#        Default configuration variables
#
####################################################################

defaults= {
    'VISIONEGG_ALWAYS_START_LOGGING': 0,
    'VISIONEGG_DOUBLE_BUFFER':        1,
    'VISIONEGG_FRAMELESS_WINDOW':     0,
    'VISIONEGG_FULLSCREEN':           0,
    'VISIONEGG_GUI_INIT':             1,
    'VISIONEGG_GAMMA_INVERT_RED':     2.1, # only used in 'invert' mode
    'VISIONEGG_GAMMA_INVERT_GREEN':   2.1, # only used in 'invert' mode
    'VISIONEGG_GAMMA_INVERT_BLUE':    2.1, # only used in 'invert' mode
    'VISIONEGG_GAMMA_FILE':           'custom.ve_gamma', # only used in 'file' mode
    'VISIONEGG_GAMMA_SOURCE':         'none', #also 'invert' or 'file'
    'VISIONEGG_GUI_ON_ERROR':         1,
    'VISIONEGG_HIDE_MOUSE':           1,
    'VISIONEGG_LOG_FILE':             'VisionEgg.log',
    'VISIONEGG_LOG_TO_STDERR':        1,
    'VISIONEGG_MAXPRIORITY':          0,
    'VISIONEGG_MONITOR_REFRESH_HZ':   60.0,
    'VISIONEGG_MULTISAMPLE_SAMPLES':  0,
    'VISIONEGG_PREFERRED_BPP':        32,
    'VISIONEGG_REQUEST_ALPHA_BITS':   8,
    'VISIONEGG_REQUEST_BLUE_BITS':    8,
    'VISIONEGG_REQUEST_GREEN_BITS':   8,
    'VISIONEGG_REQUEST_RED_BITS':     8,
    'VISIONEGG_REQUEST_STEREO':       0,
    'VISIONEGG_SCREEN_W':             640,
    'VISIONEGG_SCREEN_H':             480,
    'VISIONEGG_SYNC_SWAP':            1,
    'VISIONEGG_TKINTER_OK':           1,
    'SYNCLYNC_PRESENT':               0,
    }
if sys.platform.startswith('linux'):
    defaults['VISIONEGG_PREFERRED_BPP']=24

extra_darwin_defaults = {
    'VISIONEGG_DARWIN_MAXPRIORITY_CONVENTIONAL_NOT_REALTIME'  : 1,
    'VISIONEGG_DARWIN_CONVENTIONAL_PRIORITY'                  : -20, # -20 is best priority
    'VISIONEGG_DARWIN_REALTIME_PERIOD_DENOM'                  : 120,
    'VISIONEGG_DARWIN_REALTIME_COMPUTATION_DENOM'             : 2400,
    'VISIONEGG_DARWIN_REALTIME_CONSTRAINT_DENOM'              : 1200,
    'VISIONEGG_DARWIN_REALTIME_PREEMPTIBLE'                   : 0,
    'VISIONEGG_DARWIN_PTHREAD_PRIORITY'                      : 'max',
}

class Config:
    """Holds global Vision Egg configuration information."""
    def __init__(self):
        """Load global Vision Egg configuration information."""
        cfg = ConfigParser.ConfigParser()

        if sys.executable == sys.argv[0]: # Windows binary
            self.VISIONEGG_SYSTEM_DIR = os.curdir
            self.VISIONEGG_USER_DIR = os.curdir
        else:
            # non-standard VisionEgg installations
            try:
                self.VISIONEGG_SYSTEM_DIR = os.environ['VISIONEGG_SYSTEM_DIR']
            except KeyError:
                self.VISIONEGG_SYSTEM_DIR = os.path.split(__file__)[0]
            user_dir = os.path.expanduser("~")
            self.VISIONEGG_USER_DIR = os.path.join(user_dir,"VisionEgg")

        # See if there's an environment variable for the config file
        if 'VISIONEGG_CONFIG_FILE' in os.environ.keys():
            configFile = os.environ['VISIONEGG_CONFIG_FILE']
        else:
            # Is there one in VISIONEGG_USER_DIR?
            configFile = os.path.join(self.VISIONEGG_USER_DIR,"VisionEgg.cfg")
            if not os.path.isfile(configFile):
                configFile = os.path.join(self.VISIONEGG_SYSTEM_DIR,"VisionEgg.cfg")
                if not os.path.isfile(configFile):
                    configFile = None # No file, use defaults specified in environment variables then here

        if configFile:
            cfg.read(configFile)
        else:
            # pretend we have a config file
            cfg.add_section('General')
            for key in defaults.keys():
                cfg.set('General',key,str(defaults[key]))
            if sys.platform == 'darwin':
                cfg.add_section('darwin')
                for key in extra_darwin_defaults.keys():
                    cfg.set('darwin',key,str(extra_darwin_defaults[key]))

        # Do the general stuff first
        # Set the default values
        for name in defaults.keys():
            if name in os.environ.keys():
                value = os.environ[name]
            else:
                value = defaults[name]
            if isinstance(defaults[name], int):
		if value == 'False':
		    value = 0
		elif value == 'True':
		    value = 1
                setattr(self,name,int(value))
            elif isinstance(defaults[name], float):
                setattr(self,name,float(value))
            else:
                setattr(self,name,value)

        # Get the values from the configFile
        general_options = cfg.options('General')

        self._delayed_configuration_log_warnings = [] # chick and egg problem
        # set defaults from config file
        for option in general_options:
            name = option.upper()
            if name not in defaults.keys():
                self._delayed_configuration_log_warnings.append(
                    "While reading %s: The variable \"%s\" is not (anymore) a Vision Egg variable."%(os.path.abspath(configFile),option))
                continue
            value = cfg.get('General',option)
            if name in os.environ.keys():
                value = os.environ[name]
            if isinstance(defaults[name], int):
		if value == 'False':
		    value = 0
		elif value == 'True':
		    value = 1
                setattr(self,name,int(value))
            elif isinstance(defaults[name], float):
                setattr(self,name,float(value))
            else:
                setattr(self,name,value)

        # Do platform specific stuff
        # Set the default values
        platform_name = sys.platform
        extra_name = "extra_%s_defaults"%(platform_name,)
        if extra_name in globals().keys():
            extra_defaults = globals()[extra_name]
            for name in extra_defaults.keys():
                setattr(self,name,extra_defaults[name])

            # Get the values from the configFile
            platform_options = cfg.options(platform_name)
            for option in platform_options:
                name = option.upper()
                if name not in extra_defaults.keys():
                    raise KeyError("No Vision Egg configuration variable \"%s\""%option)
                value = cfg.get(platform_name,option)
                if name in os.environ.keys():
                    value = os.environ[name]
                if isinstance(extra_defaults[name], int):
		    if value == 'False':
		        value = 0
    		    elif value == 'True':
		        value = 1
                    setattr(self,name,int(value))
                elif isinstance(extra_defaults[name], float):
                    setattr(self,name,float(value))
                else:
                    setattr(self,name,value)

        if(configFile):
            self.VISIONEGG_CONFIG_FILE = os.path.abspath(configFile)
        else:
            self.VISIONEGG_CONFIG_FILE = None

def save_settings():
    """Save the current values to the config file, overwriting what is there."""

    dont_save = ['VISIONEGG_CONFIG_FILE',
                 'VISIONEGG_SYSTEM_DIR',
                 'VISIONEGG_USER_DIR',
                 ]

    if not VisionEgg.config.VISIONEGG_CONFIG_FILE:
        raise RuntimeError("No config file in use.")
    re_setting_finder = re.compile(r"^\s?((?:VISIONEGG_[A-Z_]*)|(?:SYNCLYNC_[A-Z_]*))\s?=\s?(\S*)\s?$",re.IGNORECASE)

    orig_file = open(VisionEgg.config.VISIONEGG_CONFIG_FILE,"r")
    orig_lines = orig_file.readlines()

    line_ending = orig_lines[0][-2:]
    if line_ending[0] not in ['\r','\n','\l']:
        line_ending = line_ending[1]

    out_file_lines = []

    saved_config_vars = []

    for line in orig_lines:
        out_line = line # The output is the same as the input unless there's a match
        match = re_setting_finder.match(line)
        if match:
            name = match.group(1).upper()
            if name in VisionEgg.config.__dict__.keys():
                if name not in dont_save:
                    # Change the output line
                    out_line = ("%s = %s"%(name,getattr(VisionEgg.config,name,))) + line_ending
                    saved_config_vars.append(name)
        out_file_lines.append(out_line)

    # Close and reopen orig_file in write mode
    orig_file.close()
    orig_file = open(VisionEgg.config.VISIONEGG_CONFIG_FILE,"w")
    for line in out_file_lines:
        orig_file.write(line)

