DoorControl/door_pi_control/door/token_control.py

from ... import util
import datetime
import os
import select
from threading import Thread, RLock

class TokenControl(util.Loggable):
    def __init__(self, token_path, fifo_path, control):
        super().__init__("door")
        self._token_path = token_path
        self._fifo_path = fifo_path
        self._control = control

        self._open_fifo()
        self.refresh_tokens()

        pipes = os.pipe()
        self._mutex = RLock()
        self._stop_pipe_write = pipes[1]
        self._stop_pipe_read = pipes[0]

        self._thread = None

    def _open_fifo(self):
        self._fifo = open(self._fifo_path, "r")

    def refresh_tokens(self):
        """Refreshes all tokens from config.valid_tokens"""
        valid = {}
        try:
            self._logger().info("Loading tokens")
            lines =[ s.strip() for s in open(self._token_path, "r").readlines() ]
            for i, line in enumerate(lines):
                l = line.split('|')
                if len(l) == 5:
                    if not l[0].strip().startswith('#'):
                        token, name, organization, email, valid_thru = l
                        try:
                            if len(valid_thru.strip()) > 0:
                                valid_thru = datetime.date.fromisoformat(valid_thru)
                            else:
                                valid_thru = None
                        except Exception:
                            self._logger().error(f"Could not parse valid thru date for token {token} in line {i}")
                            valid_thru = None
                        self._logger().debug(f"Got token {token} associated with {name} <{email}> of {organization}, valid thru {valid_thru}")
                        if token in valid:
                            self._logger().warning(f"Overwriting token {token}")
                        valid[token] = {
                            'name': name,
                            'organization': organization,
                            'email': email,
                            'valid_thru': valid_thru
                        }
                else:
                    self._logger().warning(f"Skipping line {i} ({line}) since it does not contain exactly 5 data field")
        except Exception as e:
            valid = {}
            self._logger().error(f"Error reading token file. Exception: {e}")
        with self._mutex:
            self._tokens = valid

    def start(self):
        with self._mutex:
            if self._thread != None:
                return

            self._thread = Thread(target = self.run, daemon=True)
            self._thread.start()

    def stop(self):
        with self._mutex:
            if self._thread == None:
                return

            self._stop_pipe_write.write('c')
            self._thread.join()
            self._thread = None

    def run(self):
        while True:
            readable = select.select([self._fifo, self._stop_pipe_read], [], [], 0.5)[0]
            if self._stop_pipe_read in readable:
                self._stop_pipe_read.read(1)
                return
            if self._fifo in readable:
                line = self._fifo.readline()
                if line == None:
                    self._open_fifo()
                    continue