import logging
from logger import getLogger
from pathlib import Path
from lxml import etree
from functools import cached_property, lru_cache
from arguments import ArgumentsParser
from typing import NamedTuple, Optional, Any
from collections import OrderedDict
import xmltodict

class TriggerTuple(NamedTuple):
    name: str
    interval_in_seconds: int
    governor: str
    custom_config: OrderedDict[str, Any]
    
    def __repr__(self) -> str:
        return f"{self.name}, interval: {self.interval_in_seconds}, governor: {self.governor}, custom_config: {self.custom_config}"


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:
        _tree = self.root.xpath('/cpuGovernorAutoAdjust')
        assert isinstance(_tree, list) and len(_tree) == 1, "main config section cpuGovernorAutoAdjust not found"
        ret_val = _tree.pop()
        assert isinstance(ret_val, etree._Element), "Unexpected error has occurred, cpuGovernorAutoAdjust is not of type etree._Element"
    
        return ret_val
    
    @cached_property
    def loglevel(self) -> str:
        _loglevel = self._get_single_text_value_from_xpath('logLevel')
        value = _loglevel.upper()
        _available_loglevels = ", ".join(logging.getLevelNamesMapping().keys())
        if value not in logging.getLevelNamesMapping().keys():
            raise ValueError(
                "logLevel can only contain one of these values: "
                f"{_available_loglevels}"
            )
        return value
    
    @cached_property
    def log(self) -> logging.Logger:
        return getLogger(self.__class__.__name__, loglevel=self.loglevel.upper())
    
    @cached_property
    def testmode(self) -> bool:
        _testmode = self._get_single_text_value_from_xpath('testMode')
        value = _testmode.lower()
        if value is None:
            self.log.warning("testMode not set in config")
        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 = []
        _trigger_elements = self._get_multiple_elements_by_xpath('triggers/trigger')
        for trigger_elem in _trigger_elements:
            name = self._get_single_text_value_from_xpath('name', trigger_elem)
            interval_in_seconds = self._get_single_text_value_from_xpath('intervalInSeconds', trigger_elem)
            governor = self._get_single_text_value_from_xpath('governor', trigger_elem)
            try:
                custom_config_elem = self._get_single_element_by_xpath('customConfig', trigger_elem)
                custom_config = xmltodict.parse(etree.tostring(custom_config_elem))['customConfig']
            except AssertionError:
                self.log.debug("Trigger %s has no custom config", name)
                custom_config = OrderedDict({})
            _new_trigger = TriggerTuple(
                    name=name,
                    interval_in_seconds=int(interval_in_seconds),
                    governor=governor,
                    custom_config=custom_config
            )
            ret_val.append(_new_trigger)
            self.log.info("Loaded trigger: %s", _new_trigger)
            
        return ret_val
    
    @lru_cache(maxsize=99)
    def get_trigger_by_name(self, name: str) -> Optional[TriggerTuple]:
        self.log.debug("getting trigger: %s", name)
        _all_trigger_tuples = self.triggertuples.copy()
        ret_val = next((t for t in _all_trigger_tuples if t.name == name), None)
        if ret_val is None:
            self.log.error("trigger not found: %s", ret_val)
        return ret_val
    
    def _get_single_text_value_from_xpath(self, xpath_str: str, element: Optional[etree._Element] = None) -> str:
        _elem = self._get_single_element_by_xpath(xpath_str, element)
        value = _elem.text
        assert isinstance(value, str)
        return value
    
    def _get_single_element_by_xpath(self, xpath_str: str, element: Optional[etree._Element] = None) -> etree._Element:
        if element is None:
            element = self.app_root
        _list_of_elements = element.xpath(xpath_str)
        assert isinstance(_list_of_elements, list) and len(_list_of_elements) == 1, f"config section {xpath_str} not found"
        _elem = _list_of_elements.pop()
        assert isinstance(_elem, etree._Element)
        return _elem
    
    def _get_multiple_elements_by_xpath(self, xpath_str: str, element: Optional[etree._Element] = None) -> list[etree._Element]:
        if element is None:
            element = self.app_root
        _list_of_elements = element.xpath(xpath_str)
        assert isinstance(_list_of_elements, list) and len(_list_of_elements) >= 1, f"config section {xpath_str} not found"
        assert all(isinstance(_elem, etree._Element) for _elem in _list_of_elements)
        return _list_of_elements  # type: ignore