-#!/usr/bin/env python3
-
-from flask import Flask, request, make_response
-
-from slackeventsapi import SlackEventAdapter
-from slack import WebClient
-from slack.errors import SlackApiError
-from slack.signature import SignatureVerifier
-import os
-import requests
-import re
-
-app = Flask(__name__)
-
-slack_signing_secret = os.environ['SLACK_SIGNING_SECRET']
-slack_bot_token = os.environ['SLACK_BOT_TOKEN']
-
-slack_events = SlackEventAdapter(slack_signing_secret, "/slack/events", app)
-signature_verifier = SignatureVerifier(slack_signing_secret)
-slack_client = WebClient(slack_bot_token)
-
-def slack_is_valid_request(request):
- """Returns true if request actually came from Slack.
-
- By means of checking the requests signature together with the slack
- signing key.
-
- Note: If flask is in debug mode, this function will always return true."""
-
- if app.debug:
- return True
-
- data = request.get_data()
- headers = request.headers
-
- return signature_verifier.is_valid_request(data, headers)
-
-def slack_send_reply(request, text):
- """Send a Slack message as a reply to a specified request.
-
- If the request is associated with a direct message, the reply is
- made by using the "response_url" from the request. Otherwise, the
- reply will be sent to the channel associated with the request.
-
- Note: If flask is in debug mode, this function will just print the
- text to stdout."""
-
- channel_name = request.form.get('channel_name')
- response_url = request.form.get('response_url')
- channel = request.form.get('channel_id')
-
- if (app.debug):
- print("Sending message to channel '{}': {}".format(channel, text))
- return
-
- if (channel_name == "directmessage"):
- resp = requests.post(response_url,
- json = {"text": text},
- headers = {"Content-type": "application/json"})
- if (resp.status_code != 200):
- app.logger.error("Error posting request to Slack: " + resp.text)
- else:
- try:
- slack_client.chat_postMessage(channel=channel, text=text)
- except SlackApiError as e:
- app.logger.error("Slack API error: " + e.response["error"])
-
-def rot_string(str, n=13):
- """Return a rotated version of a string
-
- Specifically, this functions returns a version of the input string
- where each uppercase letter has been advanced 'n' positions in the
- alphabet (wrapping around). Lowercase letters and any non-alphabetic
- characters will be unchanged."""
-
- result = ''
- for letter in str:
- if letter.isupper():
- result += chr(ord("A") + (ord(letter) - ord("A") + n) % 26)
- else:
- result += letter
- return result
-
-@app.route('/rot', methods = ['POST'])
-def rot():
- """Implements the /rot route for the /rot slash command in Slack
-
- This implements the /rot command of our Slack bot. The format of this
- command is as follows:
-
- /rot [count|*] String to be rotated
-
- The optional count indicates an amount to rotate each character in the
- string. If the count is '*' or is not present, then the string will
- be rotated through all possible 25 values.
-
- The result of the rotation is provided as a message in Slack. If the
- slash command was issued in a direct message, the response is made by
- using the "response_url" from the request. This allows the bot to reply
- in a direct message that it is not a member of. Otherwise, if the slash
- command was issued in a channel, the bot will reply in that channel."""
-
- if not slack_is_valid_request(request):
- return make_response("invalid request", 403)
-
- query = request.form.get('text')
- match = re.match(r'^([0-9]+|\*) (.*)$', query)
- if (match):
- try:
- count = int(match.group(1))
- except ValueError:
- count = None
- text = match.group(2)
- else:
- count = None
- text = query
-
- text = text.upper()
-
- reply = "```/rot {} {}\n".format(count if count else '*', text)
-
- if count:
- reply += rot_string(text, count)
- else:
- reply += "\n".join(["{:02d} ".format(count) + rot_string(text, count)
- for count in range(1, 26)])
-
- reply += "```"
-
- slack_send_reply(request, reply)
-
- return ""
-
-@slack_events.on("error")
-def handle_error(error):
- app.logger.error("Error from Slack: " + str(error))