marshaller/net/server.py

import io
import select
import socket
import sys

from . import logging
from . import wifi
from . import http


class Server:

    def __init__(self):
        self.wlan = wifi.connect()
        self.socket = socket.socket()
        self.poller = select.poll()
        self.default_path = 'index.html'

    def cleanup(self):
        self.socket.close()
        self.wlan.disconnect()

    def run(self):
        try:
            addr = self.listen()
            self.poller.register(self.socket, select.POLLIN)

            logging.info(f'listening on {addr}')

            while True:
                try:
                    self.serve()
                    self.work()
                except Exception as e:
                    self.log_exception(e)
        finally:
            self.cleanup()

    def log_exception(self, e):
        buf = io.StringIO()
        sys.print_exception(e, buf)
        logging.debug(f'exception:', buf.getvalue())

    def listen(self):
        addr = socket.getaddrinfo('0.0.0.0', 80)[0][-1]
        self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.socket.bind(addr)
        self.socket.listen(1)

        return addr

    def serve(self):
        evts = self.poller.poll(50)

        for sock, _evt in evts:
            try:
                conn, addr = sock.accept()
                logging.info(f'client connected from {addr}')
                request = conn.recv(1024).decode('utf-8').strip()

                self.handle_request(conn, request)
            except:
                conn.write(http.server_error_response)
                raise
            finally:
                conn.close()

    def handle_request(self, conn, request):
        [method, path, _protocol] = request.partition('\n')[0].split()

        logging.info(f'{method} {path}')

        try:
            if method == 'GET':
                response = self.handle_path(path.strip('/'))

                conn.write(self.get_content_type(path, response))
                conn.write(response)
            else:
                conn.write(http.not_found_response)
        except OSError:
            conn.write(http.not_found_response)

    def get_content_type(self, path, response):
        if path.endswith('.txt'):
            return http.ok_text_response
        elif path.endswith('.json'):
            return http.ok_json_response
        elif path.endswith('.ico'):
            return http.ok_icon_response
        elif response == '':
            return http.no_content_response

        return http.ok_response

    def handle_path(self, _path):
        return ''

    def work(self):
        if not self.wlan.isconnected():
            self.wlan = wifi.connect()