[Reporting - API] Add method to count messages sent/received by date

[reichert621]

Problem
Users should be able to see a breakdown of messages sent vs received in the reporting dashboard.

Solution
Let's create two methods in the Reporting context (https://github.com/papercups-io/papercups/blob/master/lib/chat_api/reporting.ex)

• One should retrieve daily counts of "sent" messages
  • "Sent" messages are messages where user_id is not null (i.e. it was sent by a signed-in user)
• The other should retrieve daily counts of "received" messages
  • "Received" messages are messages where customer_id is not null (i.e. it was sent by a customer through the chat widget)

The responses should look something like this:

[
  %{date: "2020-09-01", count: 7},
  %{date: "2020-09-02", count: 12}, 
  %{date: "2020-09-03", count: 4}
]

Testing
Please add tests to test/chat_api/reporting_test.exs and make sure they pass with mix test :)

Context
See #252

Questions, or need help getting started?
Feel free to ask below, or ping us on Slack :)

(You can also check out our CONTRIBUTING.md)

[eikooc]

As mentioned in #254 I'd like to pick this up 👍

[reichert621]

sure @eikooc! once #254 is completed i'll assign this one to you :)

[WLSF]

I'd like to help with this one, is it available? I saw that there was nos activity over the past 4 days.

[reichert621]

sure! i'll reassign it to you since i think @eikooc still hasn't finished #254 👍

(cc @eikooc let me know if you have any updates!)

[WLSF]

Wow ok, thanks!

[eikooc]

Totally fine. It is taking me some time to set up the Elixir development environment for some reason, so I am still working on #254 :-)

[WLSF]

@eikooc If you need some help, you can call me and we can pair or something to set the environment and discuss about the task... 😸

[reichert621]

btw we also have a shared slack channel if you guys want to chat there :) https://github.com/papercups-io/papercups#get-in-touch

[eikooc]

@WLSF that would be fun! join the slack channel and let's coordinate! 🐈

[reichert621]

done in #272