poll: Implement poll notifications in core

[jamescowens]

This PR implements the ability to specify an external command to run via -pollnotify=<cmd> argument that takes two placeholders, %s1 and %s2, which are replaced with the poll txid and the notification status (added, deleted, or expiration_warning).

The notifications are sent on all non-expired polls. Add/delete notifications are executed by the poll contract handlers. The expiration warning is handled by a scheduler function which checks every 5 minutes and does a single shot notification for polls that are within -pollexpirewarningtime=<hours> of expiration.

This should be sufficient to drive an external script for notification via email or other desired approach. The external script can call gridcoinresearchd getpollresults <poll txid> or listpolls to get the details of the poll.

This PR includes an example script, poll_notify.sh, to email the poll notification that can be found in the contrib directory.

Closes #2803 and gridcoin-community/Gridcoin-Tasks#255.

[Copilot]

Pull Request Overview

This PR implements poll notifications by adding new command-line options for external commands, extending the poll registry to support notification types, and scheduling poll notifications to be executed on poll events and expiration warnings.

• Adds -pollnotify and -pollexpirewarningtime arguments in src/init.cpp.
• Introduces a new PollNotificationType enum and associated notification functions in src/gridcoin/voting/registry.
• Schedules poll notifications using a new NotifyPoll function in src/gridcoin/gridcoin.cpp.

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/init.cpp	Added new arguments for poll notifications and expiration warnings.
src/gridcoin/voting/registry.h	Introduced PollNotificationType enum and new notification methods.
src/gridcoin/voting/registry.cpp	Implemented the notification functions and updated poll handling.
src/gridcoin/gridcoin.h	Declared the NotifyPoll function.
src/gridcoin/gridcoin.cpp	Scheduled poll notifications via the scheduler and defined NotifyPoll.

Comments suppressed due to low confidence (1)

src/gridcoin/gridcoin.cpp:634

• [nitpick] Typo in variable name 'poll_registy'; consider renaming it to 'poll_registry' for clarity.

PollRegistry& poll_registy = GetPollRegistry();

[div72]

I mean it's kind of fine now since you implemented it but since the poll notify consumers already need to handle things like 1-block forks, you could've just passed the poll txid and left the extra machinery of type and expire to the consumer.

[jamescowens]

I get where you are coming from; however, not every person using this will have a sophisticated state machine that tracks polls. Some are just enthusiasts running a command line wallet. On the expire warning, it is more efficient to implement an internal scheduler to check this rather than having someone either 1. creating a sophisticated external state machine to track poll expirations, and/or 2. poll the wallet to check.

This allows the external script to be much simpler for most uses.

The extra little bit of functionality wasn't that hard, anyway! :)

[jamescowens]

Tested this. Both the test rpc and the expiration warning works.

[div72]

Tested ACK 5e379a8689b0af90a1fb613e454ee744b7a9f75b.