Merge pull request #24 from dcr-guys/feature/dcr

bot/commands/__init__.py

@@ -1,10 +1,11 @@
 from bot.commands.base import config_handlers as base_handlers
 from bot.commands.subscription import config_handlers as subscription_handlers
 from bot.commands.callback import config_handlers as callback_handlers
-
+from bot.commands.exchange import config_handlers as exchange_handlers
 
 handlers = [
     base_handlers,
     subscription_handlers,
-    callback_handlers
+    callback_handlers,
+    exchange_handlers
 ]

bot/commands/exchange.py

@@ -0,0 +1,64 @@
+import logging
+
+from telegram import Update
+from telegram.ext import CommandHandler, CallbackContext
+
+from bot.core import BotTelegramCore
+from bot.utils import convert_dcr
+from bot.exceptions import DcrDataAPIError, ExchangeAPIError
+
+
+logging.basicConfig(
+    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
+    level=logging.INFO)
+
+logger = logging.getLogger(__name__)
+
+
+def dcr(update: Update, context: CallbackContext):
+    target_currency = None
+    dcr_amount = None
+
+    try:
+        arg_0 = context.args[0]
+        if arg_0.isdigit():
+            dcr_amount = float(arg_0)
+        else:
+            target_currency = arg_0.upper()
+    except IndexError:
+        dcr_amount = 1
+        target_currency = "USD"
+
+    try:
+        arg_1 = context.args[1]
+        if arg_1.isdigit():
+            dcr_amount = float(arg_1)
+        else:
+            target_currency = arg_1.upper()
+    except IndexError:
+        if target_currency is None:
+            target_currency = "USD"
+        if dcr_amount is None:
+            dcr_amount = 1
+
+    try:
+        target_value = convert_dcr(dcr_amount, target_currency)
+    except ExchangeAPIError as e:
+        update.effective_message.reply_text(f"{e}")
+        return
+    except DcrDataAPIError as e:
+        update.effective_message.reply_text("Error requests data from "
+                                            "DCRData API.\n "
+                                            "Please contact my managers!")
+        update.effective_message.reply_text(f"{e}")
+        return
+
+    message = f"{dcr_amount} DCR => {target_value:.2f} {target_currency}"
+
+    update.effective_message.reply_text(message)
+
+
+def config_handlers(instance: BotTelegramCore):
+    logger.info('Setting exchange commands...')
+
+    instance.add_handler(CommandHandler("dcr", dcr))

bot/exceptions.py

@@ -0,0 +1,7 @@
+
+class ExchangeAPIError(Exception):
+    pass
+
+
+class DcrDataAPIError(Exception):
+    pass

bot/utils.py

@@ -1,3 +1,8 @@
+import json
+
+import requests
+
+from bot.exceptions import DcrDataAPIError, ExchangeAPIError
 
 
 def build_menu(buttons,
@@ -10,3 +15,28 @@ def build_menu(buttons,
     if footer_buttons:
         menu.append([footer_buttons])
     return menu
+
+
+def convert_dcr(dcr_amount: float, target_currency: str):
+    dcrdata_response = requests.get("https://dcrdata.decred.org/api/exchanges")
+    if dcrdata_response.status_code != 200:
+        raise DcrDataAPIError(dcrdata_response.content)
+
+    dcr_to_usd_value = json.loads(dcrdata_response.content)
+    dcr_to_usd_value = dcr_to_usd_value.get("price")
+
+    if target_currency == 'USD':
+        return dcr_amount*dcr_to_usd_value
+
+    exchangerate_response = requests.get(f"https://api.exchangeratesapi.io/"
+                                         f"latest?base=USD"
+                                         f"&symbols={target_currency}")
+    if exchangerate_response.status_code != 200:
+        raise ExchangeAPIError(f"Currency {target_currency} is not valid!\n"
+                               f"Choose one from "
+                               f"https://api.exchangeratesapi.io/latest")
+
+    usd_to_target_value = json.loads(exchangerate_response.content)
+    usd_to_target_value = usd_to_target_value.get("rates").get(target_currency)
+
+    return dcr_amount*dcr_to_usd_value*usd_to_target_value

requirements.txt

@@ -2,4 +2,5 @@ python-decouple==3.3
 mongoengine==0.18.2
 python-telegram-bot==12.2.0
 websocket-client==0.56.0
-pendulum==2.0.5
+pendulum==2.0.5
+requests==2.22.0