# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
# For details: https://github.com/PyCQA/pylint/blob/master/COPYING


import optparse
from typing import Any, Dict, Tuple

from pylint.config.option import _validate


class UnsupportedAction(Exception):
    """raised by set_option when it doesn't know what to do for an action"""


class OptionsProviderMixIn:
    """Mixin to provide options to an OptionsManager"""

    # those attributes should be overridden
    priority = -1
    name = "default"
    options = ()  # type: Tuple[Tuple[str, Dict[str, Any]], ...]
    level = 0

    def __init__(self):
        self.config = optparse.Values()
        self.load_defaults()

    def load_defaults(self):
        """initialize the provider using default values"""
        for opt, optdict in self.options:
            action = optdict.get("action")
            if action != "callback":
                # callback action have no default
                if optdict is None:
                    optdict = self.get_option_def(opt)
                default = optdict.get("default")
                self.set_option(opt, default, action, optdict)

    def option_attrname(self, opt, optdict=None):
        """get the config attribute corresponding to opt"""
        if optdict is None:
            optdict = self.get_option_def(opt)
        return optdict.get("dest", opt.replace("-", "_"))

    def option_value(self, opt):
        """get the current value for the given option"""
        return getattr(self.config, self.option_attrname(opt), None)

    def set_option(self, optname, value, action=None, optdict=None):
        """method called to set an option (registered in the options list)"""
        if optdict is None:
            optdict = self.get_option_def(optname)
        if value is not None:
            value = _validate(value, optdict, optname)
        if action is None:
            action = optdict.get("action", "store")
        if action == "store":
            setattr(self.config, self.option_attrname(optname, optdict), value)
        elif action in ("store_true", "count"):
            setattr(self.config, self.option_attrname(optname, optdict), 0)
        elif action == "store_false":
            setattr(self.config, self.option_attrname(optname, optdict), 1)
        elif action == "append":
            optname = self.option_attrname(optname, optdict)
            _list = getattr(self.config, optname, None)
            if _list is None:
                if isinstance(value, (list, tuple)):
                    _list = value
                elif value is not None:
                    _list = []
                    _list.append(value)
                setattr(self.config, optname, _list)
            elif isinstance(_list, tuple):
                setattr(self.config, optname, _list + (value,))
            else:
                _list.append(value)
        elif action == "callback":
            optdict["callback"](None, optname, value, None)
        else:
            raise UnsupportedAction(action)

    def get_option_def(self, opt):
        """return the dictionary defining an option given its name"""
        assert self.options
        for option in self.options:
            if option[0] == opt:
                return option[1]
        raise optparse.OptionError(
            "no such option %s in section %r" % (opt, self.name), opt
        )

    def options_by_section(self):
        """return an iterator on options grouped by section

        (section, [list of (optname, optdict, optvalue)])
        """
        sections = {}
        for optname, optdict in self.options:
            sections.setdefault(optdict.get("group"), []).append(
                (optname, optdict, self.option_value(optname))
            )
        if None in sections:
            yield None, sections.pop(None)
        for section, options in sorted(sections.items()):
            yield section.upper(), options

    def options_and_values(self, options=None):
        if options is None:
            options = self.options
        for optname, optdict in options:
            yield (optname, optdict, self.option_value(optname))
