import json
import os
import sys
from typing import Any, Dict, Optional

from bot import app_vars, utils
from bot.config.models import ConfigModel
from bot.migrators import config_migrator

import portalocker

config_data_type = Dict[str, Any]


def save_default_file() -> None:
    with open(utils.get_abs_path("config_default.json"), "w") as f:
        json.dump(ConfigModel().dict(), f, indent=4, ensure_ascii=False)


class ConfigManager:
    version = 1

    def __init__(self, file_name: Optional[str]) -> None:
        if file_name:
            if os.path.isfile(file_name):
                self.file_name = os.path.abspath(file_name)
                config_dict = config_migrator.migrate(self, self._load())
                self.config_dir = os.path.dirname(self.file_name)
                self._lock()
            else:
                sys.exit("Incorrect configuration file path")
        else:
            self.config_dir = app_vars.directory
            config_dict = {}
        self.config: ConfigModel = ConfigModel(**config_dict)

    def _dump(self, data: config_data_type):
        with open(self.file_name, "w", encoding="UTF-8") as f:
            json.dump(data, f, indent=4, ensure_ascii=False)

    def _load(self):
        with open(self.file_name, "r", encoding="UTF-8") as f:
            try:
                return json.load(f)
            except json.decoder.JSONDecodeError as e:
                sys.exit("Syntax error in configuration file: " + str(e))

    def _lock(self):
        self.file_locker = portalocker.Lock(
            self.file_name,
            timeout=0,
            flags=portalocker.LOCK_EX | portalocker.LOCK_NB,
        )
        try:
            self.file_locker.acquire()
        except portalocker.exceptions.LockException:
            raise PermissionError()

    def close(self):
        self.file_locker.release()

    def save(self):
        self.file_locker.release()
        self._dump(self.config.dict())
        self.file_locker.acquire()