TT-001

Test Task 001 - Telegram change bot

Implement a small exchange rate telegram bot which does the following: Uses exchange rate data from this web service: exchangeratesapi.io or similar. Returns the latest exchange rates in a listview. USD should be used as base currency and converts currency from the list.

Requirements.

1. Add the following commands: /list or /lst - returns list of all available rates from: https://api.exchangeratesapi.io/latest?base=USD. Item of the listview should have 2 rows: the currency name in the first row and the latest exchange rate (with two decimal precision) in the second row: Ex.

   DKK: 6.74
   HUF: 299.56
   

   Once the currency data is loaded from the service, save it in a local database too. Also, save the timestamp of the last request somewhere. Next time user requests anything the app you should check whether 10 minutes elapsed since the last request:

   • If yes, you should load new data from web service.
   • If no, you should load previously saved data from the local database.

2. /exchange $10 to CAD or /exchange 10 USD to CAD - converts to the second currency with two decimal precision and return. Ex.:

   $15.55
   

3. /history USD/CAD for 7 days - return an image graph chart which shows the exchange rate graph/chart of the selected currency for the last 7 days. Here it is not necessary to save anything in the local database, you should request every time the currency data for the last 7 days. Example request for getting currency history in a given period between USD and CAD: https://api.exchangeratesapi.io/history?start_at=2019-11-27&end_at=2019-12-03&base=USD&symbols=CAD

4. Results must be given as sources and short instruction how to run it.

You can use any third party library for drawing currency graph/chart. If web service doesnt return data for the last 7 days, please show a warning popup with the following message: No exchange rate data is available for the selected currency.

How to run

1. Run using polling (TESTED)

For testing purposes use local ttl cache instead redis

export IS_LOCAL=1
export TELEGRAM_TOKEN=*********
./run_polling.py

2 Run using webhooks

export TELEGRAM_TOKEN=*********
export WEBHOOK_URL=https://bot.****.****/
export PORT=1234
./run_webhook.py

2.1 Ngrok (TESTED)

First run ngrok

ngrok http 4480

Run bot

export TELEGRAM_TOKEN=*********
export WEBHOOK_URL=https://$(curl --silent --show-error http://127.0.0.1:4040/api/tunnels | sed -nE 's/.*public_url":"https:..([^"]*).*/\1/p')
export PORT=4480
./run_webhook.py