#!/usr/bin/env python
# -*- coding: utf-8 -*-

from datetime import datetime
from pathlib import Path
import logging
import json
import re
from redis import StrictRedis
from uuid import uuid4
from io import BytesIO
import importlib

from typing import List, Union, Tuple
import types

from .libs.helpers import safe_create_dir, set_running, unset_running, get_socket_path


class RawFilesParser():

    def __init__(self, config_file: Path, storage_directory: Path,
                 loglevel: int=logging.DEBUG) -> None:
        with open(config_file, 'r') as f:
            module_parameters = json.load(f)
        self.vendor = module_parameters['vendor']
        self.listname = module_parameters['name']
        if 'parser' in module_parameters:
            self.parse_raw_file = types.MethodType(importlib.import_module(module_parameters['parser'], 'bgpranking').parse_raw_file, self)
        self.source = f'{self.vendor}-{self.listname}'
        self.directory = storage_directory / self.vendor / self.listname
        safe_create_dir(self.directory)
        self.unparsable_dir = self.directory / 'unparsable'
        safe_create_dir(self.unparsable_dir)
        self.__init_logger(loglevel)
        self.redis_intake = StrictRedis(unix_socket_path=get_socket_path('intake'), db=0)
        self.logger.debug(f'Starting intake on {self.source}')

    def __init_logger(self, loglevel) -> None:
        self.logger = logging.getLogger(f'{self.__class__.__name__}-{self.vendor}-{self.listname}')
        self.logger.setLevel(loglevel)

    @property
    def files_to_parse(self) -> List[Path]:
        return sorted([f for f in self.directory.iterdir() if f.is_file()], reverse=True)

    def extract_ipv4(self, bytestream: bytes) -> List[bytes]:
        return re.findall(rb'[0-9]+(?:\.[0-9]+){3}', bytestream)

    def strip_leading_zeros(self, ips: List[bytes]) -> List[bytes]:
        '''Helper to get rid of leading 0s in an IP list.
        Only run it when needed, it is nasty and slow'''
        return ['.'.join(str(int(part)) for part in ip.split(b'.')).encode() for ip in ips]

    def parse_raw_file(self, f: BytesIO) -> List[bytes]:
        # If the list doesn't provide a time, fallback to current day, midnight
        self.datetime = datetime.now().replace(hour=0, minute=0, second=0, microsecond=0)
        return self.extract_ipv4(f.getvalue())

    def parse_raw_files(self) -> None:
        set_running(f'{self.__class__.__name__}-{self.source}')
        nb_unparsable_files = len([f for f in self.unparsable_dir.iterdir() if f.is_file()])
        if nb_unparsable_files:
            self.logger.warning(f'Was unable to parse {nb_unparsable_files} files.')
        try:
            for filepath in self.files_to_parse:
                self.logger.debug('Parsing {}, {} to go.'.format(filepath, len(self.files_to_parse) - 1))
                with open(filepath, 'rb') as f:
                    to_parse = BytesIO(f.read())
                p = self.redis_intake.pipeline()
                for ip in self.parse_raw_file(to_parse):
                    if isinstance(ip, tuple):
                        ip, datetime = ip
                    else:
                        datetime = self.datetime
                    uuid = uuid4()
                    p.hmset(uuid, {'ip': ip, 'source': self.source,
                                   'datetime': datetime.isoformat()})
                    p.sadd('intake', uuid)
                p.execute()
                self._archive(filepath)
        except Exception as e:
            self.logger.exception("That didn't go well")
            self._unparsable(filepath)
        finally:
            unset_running(f'{self.__class__.__name__}-{self.source}')

    def _archive(self, filepath: Path) -> None:
        '''After processing, move file to the archive directory'''
        filepath.rename(self.directory / 'archive' / filepath.name)

    def _unparsable(self, filepath: Path) -> None:
        '''After processing, move file to the archive directory'''
        filepath.rename(self.unparsable_dir / filepath.name)