#!/usr/bin/python3
#
# An HTTP server to provide a "talk to Alexa" service.
#
# Inspired by several items:
#   https://github.com/sammachin/alexaweb
#   https://developers.google.com/web/fundamentals/media/recording-audio
#

import sys
import os
import os.path
import configparser
import http.client
import http.server
import ssl

CONFIG_FNAME = '/etc/homesvr/talky.conf'
SECTION_NAME = 'listener'

THIS_DIR = os.path.dirname(__file__)
STATIC_CONTENT = {
    # PATH: FILENAME
    '/': 'index.html',
    '/capture.js': 'capture.js',
    }


class TalkyServer(http.server.HTTPServer):
    def __init__(self, cfg):
        port = cfg.getint(SECTION_NAME, 'port')
        super().__init__(('', port), TalkyHandler)
        #self.path = cfg.get('listener', 'path')  # URL path that we serve
        #self.hub = cfg.get('listener', 'hub')  # backend hub to control devices

        _log_message('Listening on port: %d', port)


# similar to BaseHTTPRequestHandler.log_message()
def _log_message(format, *args):
    "Log a message without an instance."
    sys.stderr.write("- - - [%s] %s\n" % (_log_date_time_string(), format % args))


def _log_date_time_string():
    "Format a date/time string without an instance."
    return _BHRH.log_date_time_string(_BHRH)
_BHRH = http.server.BaseHTTPRequestHandler


class TalkyHandler(http.server.BaseHTTPRequestHandler):
    def do_POST(self):
        if self.path == '/talk':
            self.handle_talk()
        else:
            self.send_error(404)

    def do_GET(self):
        if self.path in STATIC_CONTENT:
            self.handle_static()
        else:
            # likely: '/favicon.ico'
            self.send_error(404)

    def handle_static(self):
        fname = STATIC_CONTENT[self.path]
        # Read the content on each request, to follow changes.
        content = open(os.path.join(THIS_DIR, fname), 'rb').read()
        self.send_response(200)
        self.send_header('Content-Type', 'text/html')
        self.send_header('Content-Length', str(len(content)))
        self.send_header('Cache-Control', 'no-store')  # helps with JS
        self.end_headers()
        self.wfile.write(content)

    def handle_talk(self):
        pass


def main():
    cfg = configparser.ConfigParser()
    cfg.read(CONFIG_FNAME)

    with TalkyServer(cfg) as server:
        # Interpose SSL processing.
        server.socket = ssl.wrap_socket(
            server.socket,
            keyfile=cfg.get(SECTION_NAME, 'keyfile'),
            certfile=cfg.get(SECTION_NAME, 'certfile'),
            server_side=True)

        # Assume that a HUP or something will end this loop.
        server.serve_forever()


if __name__ == '__main__':
    main()