#!/usr/bin/env python3

class ExtensionConfig:
    num = None

    callgroup_members = []
    dect_claim_token = None
    dect_ipei = None
    dialout_allowed = False
    name = None
    outgoing_extension = None
    sip_password = None
    static_target = None
    trunk = False
    type = None

    def __init__(self, **kwargs):
        for name, value in kwargs.items():
            if hasattr(type(self), name):
                self.__setattr__(name, value)
            else:
                raise Exception("Invalid config option {}".format(name))

        if self.type is None:
            raise Exception("Type field for extension {} is required".format(self.num))
        elif self.type == "dect":
            if self.dect_ipei is None and self.dect_claim_token is None:
                raise Exception("dect_ipei can't be used together with dect_claim_token in extension {}".format(self.num))
        elif self.type == "sip":
            if self.sip_password is None:
                raise Exception("sip_password is required for sip extension {}".format(self.num))
        elif self.type == "static":
            if self.static_target is None:
                raise Exception("static_target is required for static extension {}".format(self.num))

    def check_global(self, extensions):
        for e in extensions.extensions:
            if e.num != self.num and e.num.startswith(self.num):
                raise Exception("Extension {} uses {} as prefix, which is already defined as an extension".format(e.num, self.num))

        if self.type == "callgroup":
            for member in self.callgroup_members:
                if member not in extensions.extensions_by_num.keys():
                    raise Exception("Callgroup member {} of callgroup {} does not exist as extension".format(member, self.num))


class Extensions:
    extensions = []
    extensions_by_num = {}

    def __init__(self, c):
        for num, e in c.get("extensions", {}).items():
            extension_config = ExtensionConfig(**{
                "num": num,
            } | e)

            self.extensions.append(extension_config)

            if extension_config.num in self.extensions_by_num.keys():
                raise Exception("Extension num already used {}".format(num))

            self.extensions_by_num[num] = extension_config

        for e in self.extensions:
            e.check_global(self)


    def extensions_by_type(self, t):
        for e in self.extensions:
            if e.type == t:
                yield e