Implement a Rest-Client

[Highlife1911]

We need a Rest-Client to implement our Watson component. The Client should run inside the server and should simplify Rest Communication. It should take a request url to a http or https resource. This resource should be queried and the result should be made available in some way. The subtasks are:

• [x] Implement a Rest-Client for HTTP and HTTPS
• [x] Add some unit tests, maybe mock a very simple server for this
• [x] Think about error cases like 404 and how this should affect the server
• [x] Implement a very simple rest service to query the Coinhive user balance. See https://coinhive.com/documentation/http-api for an API specification. See the miner prototype in the prototype branch. You can ask ma about the private key.

[Tobias1595]

Basic implementation is done, tested manually. Coinhive balance method is done and should work. Unit tests come next. A few questions remain:

• How far should this implementation parse the reply?
• Who is "ma"? What format is going to get used to save the key?
• Which "server" should be considered in case of an error (point 3 above)? The rest-server sending the error, or Watson?

[Highlife1911]

Please upload your state and create a pull request.

[Highlife1911]

Parsing should be done to the point that we don't test their api: So if we expect that the service returns a number it is sufficient to just cast to int. But in no cases should our implementation crash/hang because of a malformed input or when the service in unavailable.

To store the key it is probably the easiest to use a private.json that contains all private keys we need.

Revised To Do List:

• [ ] Merge The prototype into the prototype branch
• [x] Based on the prototype, create a CoinHive object with the following interface:

The class should query the balance of user using top at a fixed rate (like once every minute). Then it should withdraw the maximum amount possible, but keep it to a multiple of a fixed constant like 1024 (If a user has a balance of 2304, only withdraw 2048). Then the class should emit a signal like addCoin that contains the username and the amount of blocks mined (2 in the above example).

The class should work asynchronous (probably with a QTimer), so it can be instantiated somewhere and notify mining activity to Watson. The implementation of Watson is not your task. In case of error just do something reasonable: When coinhive servers are down or the private key is missing, just print something using qDebug() and not quit the application.