Creating a decorator to explicitly mark bot's commands

bot.py

@@ -0,0 +1,226 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""
+Simple bot to get trains statuses.
+
+Attempt to create a simple decorator that
+explicitly marks commands to serve.
+
+TODO: make the help command able to discover
+others automatically
+"""
+
+import configparser
+import json
+import urllib3
+
+from datetime import datetime
+
+from telegram.ext import CommandHandler, Updater
+
+config = configparser.RawConfigParser()
+config.read('rail.cfg')
+token = config.get('telegram', 'token')
+api_key = config.get('railwayAPI', 'key')
+api = 'https://api.railwayapi.com/v2'
+updater = Updater(token)
+
+
+def request(method, path):
+    """Method to request data from the API"""
+    url = api + path + '/apikey/' + api_key
+    http = urllib3.PoolManager()
+    response = http.request(method.upper(), url)
+    data = json.loads(response.data.decode('utf-8'))
+    http_response_code = data['response_code']
+    if http_response_code == 200:
+        return data
+    else:
+        return False  # TODO: specialise result according to documentation
+
+
+def command_maker(dispatcher):
+    """dispatcher is a telegram.ext.Updater.dispatcher object"""
+    def command(**kwargs):
+        def decorator(func):
+            dispatcher.add_handler(
+                CommandHandler(func.__name__, func, **kwargs)
+                )
+            return func
+        return decorator
+    return command
+
+
+command = command_maker(updater.dispatcher)
+
+
+@command()
+def help(bot, update):
+    message = "This is a not so helpful message"
+    update.message.reply_text(message)
+
+
+@command(pass_args=True)
+def pnr(bot, update, args):
+    pass
+
+
+@command(pass_args=True)
+def trains(bot, update, args):
+    """Get a list of available trains between 2 stations today.
+    Usage example: /trains awy sbc
+    """
+    try:
+        departure, arrival = args
+    except ValueError as exc:
+        message = "Please provide exact departure and arrival stations"
+    else:
+        message = "Trains between {departure} and {arrival} are:\n{trains}"
+        # querying API to get trains
+        current_date = datetime.today().strftime('%d-%m-%Y')
+        path = '/between/source/{departure}/dest/{arrival}/date/{date}'.format(
+            departure=departure,
+            arrival=arrival,
+            date=current_date
+            )
+        data = request('GET', path)
+        if not data:
+            message = (
+                "Unable to find trains. Please verify you entered "
+                "the right code for each station"
+                )
+        else:
+            trains = '\n'.join(
+                [
+                    '{name} (#{number}) D: {departure} A: {arrival}'.format(
+                        name=train_infos['name'],
+                        number=train_infos['number'],
+                        departure=train_infos['src_departure_time'],
+                        arrival=train_infos['dest_arrival_time']
+                        )
+                    for train_infos in data['trains']
+                    ]
+                )
+            message = message.format(
+                departure=departure,
+                arrival=arrival,
+                trains=trains
+                )
+    finally:
+        update.message.reply_text(message)
+
+
+@command(pass_args=True)
+def live(bot, update, args):
+    """Gives the live position of a train.
+    Required args are the train number and the date.
+    Usage example: /live 12046 01-12-2018
+    """
+    try:
+        train_number, date = args
+    except ValueError as exc:
+        message = (
+            "Please provide the train number and the date. "
+            "Date format is dd-mm-yyyy"
+            )
+    else:
+        path = '/live/train/{train}/date/{date}'.format(
+            train=train_number,
+            date=date
+            )
+        data = request('GET', path)
+        if not data:
+            message = "Couldn't retrieve live position"
+        else:
+            train_name = data['train']['name']
+            position = data['position']
+            message = (
+                'Train: {name}\n'
+                'Status: {position}'
+                ).format(
+                    name=train_name,
+                    position=position
+                    )
+    finally:
+        update.message.reply_text(message)
+
+
+@command(pass_args=True)
+def arrivals(bot, update, args):
+    """Returns a list of trains arriving at a given station
+    within a window period (bonus: live position is displayed)
+    Usage example: /arrivals sbc 2
+    """
+    try:
+        station_code, hours_window = args
+    except ValueError as exc:
+        message = "Please provide exact station code and hours window"
+    else:
+        # for now we won't implement a date validator
+        path = '/arrivals/station/{station}/hours/{hours}'.format(
+            station=station_code,
+            hours=hours_window
+            )
+        data = request('GET', path)
+        if not data:
+            message = "Something went horribly wrong :-/"
+        else:
+            arriving_trains = data['trains']
+            total_trains = data['total']
+            window_text = hours_window + ' hours'
+            if hours_window == 1:
+                window_text = 'hour'
+            if arriving_trains:
+                message = (
+                    '{total} trains arriving '
+                    'in the next {window_text}'.format(
+                        total=total_trains,
+                        window_text=window_text
+                        )
+                    )
+                for arriving_train in arriving_trains:
+                    train_name = arriving_train["name"]
+                    train_number = arriving_train["number"]
+
+                    sch_arr = arriving_train["scharr"]
+                    act_arr = arriving_train["actarr"]
+                    delay_arr = arriving_train["delayarr"]
+
+                    sched_dep = arriving_train["schdep"]
+                    act_dep = arriving_train["actdep"]
+                    delay_dep = arriving_train["delaydep"]
+
+                    msg = (
+                        'Train: {name}\n'
+                        'Train Number: {number}\n'
+                        'Scheduled Arrival: {scharr}\n'
+                        'Actual Arrival: {actarr}\n'
+                        'Delay in Arrival: {delayarr}\n'
+                        'Scheduled Departure: {schdep}\n'
+                        'Actual Departure: {actdep}\n'
+                        'Delay in Departure: {delaydep}'
+                        ).format(
+                            name=train_name,
+                            number=train_number,
+                            scharr=sch_arr,
+                            actarr=act_arr,
+                            delayarr=delay_arr,
+                            schdep=sched_dep,
+                            actdep=act_dep,
+                            delaydep=delay_dep
+                            )
+                    message += '\n{}'.format(msg)
+            else:
+                message = "No arriving trains in the next {window_text}".format(
+                    window_text=window_text
+                    )
+    finally:
+        update.message.reply_text(message)
+
+
+if __name__ == '__main__':
+    updater.start_polling()
+    updater.idle()
+
+# EOF