# -*- coding: utf-8 -*-
"option types and option description for the configuration management"
# Copyright (C) 2012 Team tiramisu (see AUTHORS for all contributors)
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# The original `Config` design model is unproudly borrowed from 
# the rough pypy's guys: http://codespeak.net/svn/pypy/dist/pypy/config/
# the whole pypy projet is under MIT licence
# ____________________________________________________________
from tiramisu.basetype import HiddenBaseType, DisabledBaseType
from tiramisu.error import (ConfigError, ConflictConfigError, NotFoundError, 
    RequiresError, RequirementRecursionError, MandatoryError)
requires_actions = [('hide', 'show'), ('enable', 'disable'), ('freeze', 'unfreeze')]

available_actions = []
reverse_actions = {}
for act1, act2 in requires_actions:
    available_actions.extend([act1, act2])
    reverse_actions[act1] = act2
    reverse_actions[act2] = act1

# ____________________________________________________________
# OptionDescription authorized group_type values
group_types = ['default', 'family', 'group', 'master']
# ____________________________________________________________
# multi types 
class Multi(list):
    "container that support items for the values of list (multi) options" 
    def __init__(self, lst, config, child):
        self.config = config
        self.child = child
        super(Multi, self).__init__(lst)
        
    def __setitem__(self, key, value):
        return self.setoption(value, key)

    def append(self, value):
        self.setoption(value)
   
    def setoption(self, value, key=None):
        owners = self.child.getowner(self.config)
        # None is replaced by default_multi
        if value == None:
            defval = self.child.getdefault()
            if key is not None and len(defval) > key:
                value = defval[key]
            else:
                value = self.child.default_multi
            who = 'default'
        else:
            who = self.config._cfgimpl_owner
            if not self.child._validate(value):
                raise ConfigError("invalid value {0} "
                    "for option {1}".format(str(value), self.child._name))
        oldvalue = list(self)
        oldowner = self.child.getowner(self.config)
        if key is None:
            ret = super(Multi, self).append(value)
            oldvalue.append(None)
            oldowner.append(who)
        else:
            ret = super(Multi, self).__setitem__(key, value)
            oldowner[key] = who
        self.config._cfgimpl_previous_values[self.child._name] = oldvalue
        self.child.setowner(self.config, oldowner)
        return ret
        
    def pop(self, key):
        oldowner = self.child.getowner(self.config)
        oldowner.pop(key)
        self.child.setowner(self.config, oldowner)
        super(Multi, self).pop(key)
# ____________________________________________________________
#
class Option(HiddenBaseType, DisabledBaseType):
    #reminder: an Option object is **not** a container for the value
    _frozen = False
    _force_default_on_freeze = False
    def __init__(self, name, doc, default=None, default_multi=None, 
                 requires=None, mandatory=False, multi=False, callback=None, 
                 callback_params=None):
        self._name = name
        self.doc = doc
        self._requires = requires
        self._mandatory = mandatory
        self.multi = multi
        if not self.multi and default_multi is not None:
            raise ConfigError("a default_multi is set whereas multi is False"
                  " in option: {0}".format(name)) 
        if default_multi is not None and not self._validate(default_multi):
            raise ConfigError("invalid default_multi value {0} "
                "for option {1}".format(str(default_multi), name))
        self.default_multi = default_multi
        #if self.multi and default_multi is None:
            # _cfgimpl_warnings[name] = DefaultMultiWarning   
        if callback is not None and (default is not None or default_multi is not None):
            raise ConfigError("defaut values not allowed if option: {0} " 
                "is calculated".format(name))
        self.callback = callback
        if self.callback is None and callback_params is not None:
            raise ConfigError("params defined for a callback function but"
            " no callback defined yet for option {0}".format(name)) 
        self.callback_params = callback_params
        if self.multi == True:
            if default == None:
                default = []
            if not isinstance(default, list) or not self.validate(default):
                raise ConfigError("invalid default value {0} "
                "for option {1} : not list type".format(str(default), name))
        else:
            if default != None and not self.validate(default):
                raise ConfigError("invalid default value {0} " 
                                         "for option {1}".format(str(default), name))
        self.default = default
        self.properties = [] # 'hidden', 'disabled'...
      
    def validate(self, value):
        if self.multi == False:
            # None allows the reset of the value
            if value != None:
                return self._validate(value)
        else:
            if not isinstance(value, list): 
                raise ConfigError("invalid value {0} " 
                        "for option {1} which must be a list".format(value,
                        self._name))
            for val in value:
                if val != None:
                    # None allows the reset of the value
                    if not self._validate(val):
                        return False
        return True

    def getdefault(self):
        return self.default

    def is_empty_by_default(self):
        if ((not self.is_multi() and self.default == None) or
            (self.is_multi() and self.default == []) or None in self.default):
            return True
        return False

    def force_default(self):
        self._force_default_on_freeze = True

    def hascallback_and_isfrozen():
        return self._frozen and self.has_callback()

    def is_forced_on_freeze(self):
        return self._frozen and self._force_default_on_freeze

    def getdoc(self):
        return self.doc

    def getcallback(self):
        return self.callback
    
    def has_callback(self):
        if self.callback == None:
            return False
        else:
            return True

    def getcallback_params(self):
        return self.callback_params

    def setowner(self, config, owner):
        # config *must* be only the **parent** config (not the toplevel config) 
        # owner is a **real* owner, a list is actually allowable here
        name = self._name
        if self.is_multi():
            if not type(owner) == list:
                raise ConfigError("invalid owner for multi "
                    "option: {0}".format(name))
        config._cfgimpl_value_owners[name] = owner

    def getowner(self, config):
        # config *must* be only the **parent** config (not the toplevel config) 
        return config._cfgimpl_value_owners[self._name]

    def setoption(self, config, value, who):
        "who is **not necessarily** a owner because it cannot be a list"
        name = self._name
        if not self.validate(value):
            raise ConfigError('invalid value %s for option %s' % (value, name))
        if self.is_mandatory():
            # value shall not be '' for a mandatory option
            # so '' is considered as being None
            if not self.is_multi() and value == '':
                value = None
            if self.is_multi() and '' in value:
                value = Multi([{'': None}.get(i, i) for i in value], config, self)
            if config.is_mandatory() and ((self.is_multi() and value == []) or \
                (not self.is_multi() and value is None)):
                raise MandatoryError('cannot change the value to %s for '
              'option %s' % (value, name))
        if name not in config._cfgimpl_values:
            raise AttributeError('unknown option %s' % (name))

        if config.is_frozen() and self.is_frozen():
            raise TypeError('cannot change the value to %s for '
               'option %s' % (str(value), name))
        if who == "default":
            # changes the default value (and therefore resets the previous value)
            if self._validate(value):
                self.default = value
            else:
                raise ConfigError("invalid value %s for option %s" % (value, name))
        apply_requires(self, config)
        # FIXME put the validation for the multi somewhere else
#            # it is a multi **and** it has requires
#            if self.multi == True:
#                if type(value) != list:
#                    raise TypeError("value {0} must be a list".format(value))
#                if self._requires is not None:
#                    for reqname in self._requires:
#                        # FIXME : verify that the slaves are all multi
#                        #option = getattr(config._cfgimpl_descr, reqname)
#    #                    if not option.multi == True:
#    #                        raise ConflictConfigError("an option with requires "
#    #                         "has to be a list type : {0}".format(name)) 
#                        if len(config._cfgimpl_values[reqname]) != len(value):
#                            raise ConflictConfigError("an option with requires "
#                             "has not the same length of the others " 
#                             "in the group : {0}".format(reqname)) 
        if type(config._cfgimpl_values[name]) == Multi:
            config._cfgimpl_previous_values[name] = list(config._cfgimpl_values[name])
        else:
            config._cfgimpl_previous_values[name] = config._cfgimpl_values[name] 
        config._cfgimpl_values[name] = value

    def getkey(self, value):
        return value
    # ____________________________________________________________
    def freeze(self):
        self._frozen = True
        return True

    def unfreeze(self):
        self._frozen = False

    def is_frozen(self):
        return self._frozen
    # ____________________________________________________________
    def is_multi(self):
        return self.multi

    def is_mandatory(self):
        return self._mandatory
        
class ChoiceOption(Option):
    opt_type = 'string'
    
    def __init__(self, name, doc, values, default=None,
                 requires=None, callback=None, callback_params=None,
                 multi=False, mandatory=False, open_values=False):
        self.values = values
        if open_values not in [True, False]:
            raise ConfigError('Open_values must be a boolean for '
                              '{0}'.format(name))
        self.open_values = open_values
        super(ChoiceOption, self).__init__(name, doc, default=default,
                           callback=callback, callback_params=callback_params, 
                           requires=requires, multi=multi, mandatory=mandatory)

    def _validate(self, value):
        if not self.open_values:
            return value is None or value in self.values
        else:
            return True

class BoolOption(Option):
    opt_type = 'bool'
    
    def _validate(self, value):
        return isinstance(value, bool)

# config level validator             
#    def setoption(self, config, value, who):
#        name = self._name
#        if value and self._validator is not None:
#            toplevel = config._cfgimpl_get_toplevel()
#            self._validator(toplevel)
#        super(BoolOption, self).setoption(config, value, who)

class IntOption(Option):
    opt_type = 'int'
    
    def _validate(self, value):
        return isinstance(value, int)

class FloatOption(Option):
    opt_type = 'float'

    def _validate(self, value):
        return isinstance(value, float)

class StrOption(Option):
    opt_type = 'string'
    
    def _validate(self, value):
        return isinstance(value, str)
                                     
class SymLinkOption(object):
    opt_type = 'symlink'
    
    def __init__(self, name, path):
        self._name = name
        self.path = path 
    
    def setoption(self, config, value, who):
        setattr(config, self.path, value) # .setoption(self.path, value, who)

class IPOption(Option):
    opt_type = 'ip'
    
    def _validate(self, value):
        # by now the validation is nothing but a string, use IPy instead
        return isinstance(value, str)
                                     
class NetmaskOption(Option):
    opt_type = 'netmask'
    
    def _validate(self, value):
        # by now the validation is nothing but a string, use IPy instead
        return isinstance(value, str)
                                     
class ArbitraryOption(Option):
    def __init__(self, name, doc, default=None, defaultfactory=None, 
                                   requires=None, multi=False, mandatory=False):
        super(ArbitraryOption, self).__init__(name, doc, requires=requires,
                                               multi=multi, mandatory=mandatory)
        self.defaultfactory = defaultfactory
        if defaultfactory is not None:
            assert default is None

    def _validate(self, value):
        return True

    def getdefault(self):
        if self.defaultfactory is not None:
            return self.defaultfactory()
        return self.default

class OptionDescription(HiddenBaseType, DisabledBaseType):
    group_type = 'default'

    def __init__(self, name, doc, children, requires=None):
        self._name = name
        self.doc = doc
        self._children = children
        self._requires = requires
        self._build()
        self.properties = [] # 'hidden', 'disabled'...
        
    def getdoc(self):
        return self.doc

    def _build(self):
        for child in self._children:
            setattr(self, child._name, child)

    def add_child(self, child):
        "dynamically adds a configuration option"
        #Nothing is static. Even the Mona Lisa is falling apart.
        for ch in self._children:
            if isinstance(ch, Option):
                if child._name == ch._name:
                    raise ConflictConfigError("existing option : {0}".format(
                                                                   child._name))
        self._children.append(child)
        setattr(self, child._name, child)
    
    def update_child(self, child):
        "modification of an existing option"
        # XXX : corresponds to the `redefine`, is it usefull 
        pass
        
    def getkey(self, config):
        return tuple([child.getkey(getattr(config, child._name))
                      for child in self._children])

    def getpaths(self, include_groups=False, currpath=None):
        """returns a list of all paths in self, recursively
           currpath should not be provided (helps with recursion)
        """
        if currpath is None:
            currpath = []
        paths = []
        for option in self._children:
            attr = option._name
            if attr.startswith('_cfgimpl'):
                continue
            if isinstance(option, OptionDescription):
                if include_groups:
                    paths.append('.'.join(currpath + [attr]))
                currpath.append(attr)
                paths += option.getpaths(include_groups=include_groups,
                                        currpath=currpath)
                currpath.pop()
            else:
                paths.append('.'.join(currpath + [attr]))
        return paths
    # ____________________________________________________________

    def set_group_type(self, group_type):
        if group_type in group_types:
            self.group_type = group_type
        else:
            raise ConfigError('not allowed value for group_type : {0}'.format(
                              group_type))
    
    def get_group_type(self):
        return self.group_type
    # ____________________________________________________________
    def hide(self):
        super(OptionDescription, self).hide()
        # FIXME : AND THE SUBCHILDREN ? 
        for child in self._children:
            if isinstance(child, OptionDescription):
                child.hide()
    
    def show(self):
        # FIXME : AND THE SUBCHILDREN ?? 
        super(OptionDescription, self).show()
        for child in self._children:
            if isinstance(child, OptionDescription):
                child.show()
    # ____________________________________________________________
    def disable(self):
        super(OptionDescription, self).disable()
        # FIXME : AND THE SUBCHILDREN ? 
        for child in self._children:
            if isinstance(child, OptionDescription):
                child.disable()
    
    def enable(self):
        # FIXME : AND THE SUBCHILDREN ? 
        super(OptionDescription, self).enable()
        for child in self._children:
            if isinstance(child, OptionDescription):
                child.enable()
# ____________________________________________________________

def validate_requires_arg(requires, name):
    # malformed requirements
    config_action = []
    for req in requires:
        if not type(req) == tuple and len(req) != 3:
            raise RequiresError("malformed requirements for option:"
                                           " {0}".format(name))
        action = req[2]
        if action not in available_actions:
            raise RequiresError("malformed requirements for option: {0}"
                                "unknown action: {1}".format(name, action))
        if reverse_actions[action] in config_action:
            raise RequiresError("inconsistency in action types for option: {0}"
                                "action: {1} in contradiction with {2}\n"
                                " ({3})".format(name, action,
                                    reverse_actions[action], requires))
        config_action.append(action)

def build_actions(requires):
    trigger_actions = {}
    for require in requires:
        action = require[2]
        trigger_actions.setdefault(action, []).append(require)
    return trigger_actions

def apply_requires(opt, config):
    if hasattr(opt, '_requires') and opt._requires is not None:
        rootconfig = config._cfgimpl_get_toplevel()
        validate_requires_arg(opt._requires, opt._name)
        # filters the callbacks
        trigger_actions = build_actions(opt._requires)
        for requires in trigger_actions.values():
            matches = False
            for require in requires:
                name, expected, action = require
                path = config._cfgimpl_get_path() + '.' + opt._name
                if name.startswith(path):
                    raise RequirementRecursionError("malformed requirements "
                          "imbrication detected for option: '{0}' "
                          "with requirement on: '{1}'".format(path, name))
                homeconfig, shortname = rootconfig._cfgimpl_get_home_by_path(name)
                if shortname in homeconfig._cfgimpl_values:
                    value = homeconfig._cfgimpl_values[shortname]
                    if value == expected:
                        getattr(opt, action)() #.hide() or show() or...
                        # FIXME generic programming opt.property_launch(action, False)
                        matches = True
                else: # option doesn't exist ! should not happen...
                    raise NotFoundError("required option not found: "
                                                             "{0}".format(name))
            # no callback has been triggered, then just reverse the action
            if not matches:
                getattr(opt, reverse_actions[action])()