from core.Constants import Constants
from dataclasses import dataclass, field
from dataclasses_json import config, Exclude, dataclass_json
from json import JSONDecodeError
from pathlib import Path
import json
import os
import psutil
import re
import shutil


@dataclass_json
@dataclass
class SessionState:
    id: int = field(
        metadata=config(exclude=Exclude.ALWAYS)
    )
    network_port_numbers: list[int] = field(default_factory=list)
    process_ids: list[int] = field(default_factory=list)

    def get_state_path(self):
        return SessionState._get_state_path(self.id)

    @staticmethod
    def find_by_id(id: int):

        try:
            session_state_file_contents = open(SessionState._get_state_path(id) + '/state.json', 'r').read()
        except FileNotFoundError:
            return None

        try:
            session_state = json.loads(session_state_file_contents)
        except JSONDecodeError:
            return None

        session_state['id'] = id

        # noinspection PyUnresolvedReferences
        return SessionState.from_dict(session_state)

    @staticmethod
    def exists(id: int):
        return os.path.isdir(SessionState._get_state_path(id)) and re.match(r'^\d+$', str(id))

    @staticmethod
    def save(session_state):

        session_state_file_contents = session_state.to_json(indent=4) + '\n'
        os.makedirs(SessionState._get_state_path(session_state.id), exist_ok=True, mode=0o700)

        session_state_file_path = SessionState._get_state_path(session_state.id) + '/state.json'
        Path(session_state_file_path).touch(exist_ok=True, mode=0o600)

        text_io_wrapper = open(session_state_file_path, 'w')
        text_io_wrapper.write(session_state_file_contents)

    @staticmethod
    def dissolve(id: int):

        session_state = SessionState.find_by_id(id)

        if session_state is not None:

            session_state_path = session_state.get_state_path()

            SessionState._kill_associated_processes(session_state)
            shutil.rmtree(session_state_path, ignore_errors=True)

    @staticmethod
    def _kill_associated_processes(session_state):

        associated_process_ids = list(session_state.process_ids)
        network_connections = psutil.net_connections()

        for network_port_number in session_state.network_port_numbers:

            for network_connection in network_connections:

                if network_connection.laddr != tuple() and network_connection.laddr.port == network_port_number:

                    if network_connection.pid is not None:
                        associated_process_ids.append(network_connection.pid)

                if network_connection.raddr != tuple() and network_connection.raddr.port == network_port_number:

                    if network_connection.pid is not None:
                        associated_process_ids.append(network_connection.pid)

        for process in psutil.process_iter():

            if process.pid in associated_process_ids and process.is_running():

                for child_process in process.children(True):
                    child_process.kill()

                process.kill()

    @staticmethod
    def _get_state_path(id: int):
        return Constants.SP_SESSION_STATE_HOME + '/' + str(id)