import logging
from pathlib import Path
from lxml import etree
from functools import cached_property
from arguments import ArgumentsParser
from typing import NamedTuple, Optional


class TriggerTuple(NamedTuple):
    name: str
    interval_in_seconds: int
    
    
class MissingConfig(Exception):
    pass


class Config:
    def __init__(self, basepath: Path) -> None:
        self.basepath = basepath
        self.config = ArgumentsParser().parser.config
    
    @cached_property
    def root(self) -> etree.ElementTree:
        return etree.parse(self.basepath / self.config)
    
    @cached_property
    def app_root(self) -> etree.Element:
        return self.root.xpath('/cpuGovernorAutoAdjust').pop()
    
    @cached_property
    def loglevel(self) -> str:
        value = self.app_root.xpath('logLevel').pop().text.upper()
        _loglevels = ", ".join(logging.getLevelNamesMapping().keys())
        if value not in logging.getLevelNamesMapping().keys():
            raise ValueError(
                "logLevel can only contain one of these values: "
                f"{_loglevels}"
            )
        return value
    
    @cached_property
    def testmode(self) -> bool:
        value = self.app_root.xpath('testMode').pop().text.lower()
        if value not in ['true', 'false']:
            raise ValueError("testMode can only be 'true' or 'false")
        return True if value == 'true' else False
    
    @cached_property
    def triggertuples(self) -> list[TriggerTuple]:
        ret_val = []
        _triggers = self.app_root.xpath('triggers/trigger')
        for trigger in _triggers:
            name = trigger.xpath('name').pop().text
            interval_in_seconds = trigger.xpath('intervalInSeconds').pop().text
            ret_val.append(
                TriggerTuple(
                    name=name,
                    interval_in_seconds=interval_in_seconds
                )
            )
            
        return ret_val
    
    def get_trigger_by_name(self, name: str) -> Optional[TriggerTuple]:
        _all_trigger_tuples = self.triggertuples.copy()
        return next((t for t in _all_trigger_tuples if t.name == name), None)