The tyzenhaus from madhead

Welcome message should ask users to invoke a /reg command
Reg command should be processed and users should be saved into "members" for this group
If the bot sees new members (admin option) it should ask them to register after they are added

Configure workflow_dispatch for the deployment workflow

Print the transaction after creating

Make a [relatively] good selling video

Implement ChatCurrenciesService

It should read all the transactions for a given chat, group them by currency and sort (desc) by the number of transactions. Then N top currencies should be returned. 3-5 maybe more, need to check that in different clients.

Basic group expenses tracking

As a Tyzenhaus bot user I want to be able to add the bot to the group to start tracking group expenses. Basic expense tracking must include support of:

Single payer
Multiple users being paid for
Currencies
Purpose (text)

I want to be able to ask for my debts stats at any time.

Show a message when new members join a group

Show a welcome message with some info for new members joining a group. Admin rigths may be required

Delete messages on FSM transitions

The bot could probably just delete the messages from previous steps.

Chat ID is changed for some reason. Balance is lost!

Check migrate_from_chat_id

Debt settlement

Open the stats

Something like https://nomadlist.com/open

Character '!' is reserved and must be escaped with the preceding '\\'

Move away from Heroku

https://blog.heroku.com/next-chapter

Update dependencies

Bugs found during α

/lang shouldn't have any state
/expense should check user ids on actions
/expense should not allow zeros or empty list of participants
Non-participants should not be allowed to create transactions
Currencies must be limited to 120-128 chars (current DB limit)
There should be a fallback in case the user leves the chat after tracking some transactions

When a new user is added to the group AFTER everybody else registered it could break the bot:

java.util.NoSuchElementException: Collection contains no element matching the predicate.
    at me.madhead.tyzenhaus.core.telegram.updates.expense.DebtsCommandUpdateProcessor$process$debtsMessage$1.invoke(DebtsCommandUpdateProcessor.kt:114) ~[tyzenhaus-core-0.0.1.jar:?]
    at me.madhead.tyzenhaus.core.telegram.updates.expense.DebtsCommandUpdateProcessor$process$debtsMessage$1.invoke(DebtsCommandUpdateProcessor.kt:88) ~[tyzenhaus-core-0.0.1.jar:?]
    at kotlin.text.StringsKt__AppendableKt.appendElement(Appendable.kt:85) ~[kotlin-stdlib-1.5.10.jar:1.5.10-release-890 (1.5.10)]
    at kotlin.collections.CollectionsKt___CollectionsKt.joinTo(_Collections.kt:3344) ~[kotlin-stdlib-1.5.10.jar:1.5.10-release-890 (1.5.10)]
    at kotlin.collections.CollectionsKt___CollectionsKt.joinToString(_Collections.kt:3361) ~[kotlin-stdlib-1.5.10.jar:1.5.10-release-890 (1.5.10)]
    at kotlin.collections.CollectionsKt___CollectionsKt.joinToString$default(_Collections.kt:3360) ~[kotlin-stdlib-1.5.10.jar:1.5.10-release-890 (1.5.10)]
    at me.madhead.tyzenhaus.core.telegram.updates.expense.DebtsCommandUpdateProcessor.process(DebtsCommandUpdateProcessor.kt:85) ~[tyzenhaus-core-0.0.1.jar:?]
    at me.madhead.tyzenhaus.core.telegram.updates.expense.DebtsCommandUpdateProcessor$process$1.invokeSuspend(DebtsCommandUpdateProcessor.kt) ~[tyzenhaus-core-0.0.1.jar:?]
    at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33) [kotlin-stdlib-1.5.10.jar:1.5.10-release-890 (1.5.10)]